qemu

commands-posix.c (98311B)

---

 /*
  * QEMU Guest Agent POSIX-specific command implementations
  *
  * Copyright IBM Corp. 2011
  *
  * Authors:
  *  Michael Roth      <mdroth@linux.vnet.ibm.com>
  *  Michal Privoznik  <mprivozn@redhat.com>
  *
  * This work is licensed under the terms of the GNU GPL, version 2 or later.
  * See the COPYING file in the top-level directory.
  */
 
 #include "qemu/osdep.h"
 #include <sys/ioctl.h>
 #include <sys/utsname.h>
 #include <sys/wait.h>
 #include <dirent.h>
 #include "qga-qapi-commands.h"
 #include "qapi/error.h"
 #include "qapi/qmp/qerror.h"
 #include "qemu/host-utils.h"
 #include "qemu/sockets.h"
 #include "qemu/base64.h"
 #include "qemu/cutils.h"
 #include "commands-common.h"
 #include "block/nvme.h"
 #include "cutils.h"
 
 #ifdef HAVE_UTMPX
 #include <utmpx.h>
 #endif
 
 #if defined(__linux__)
 #include <mntent.h>
 #include <sys/statvfs.h>
 #include <linux/nvme_ioctl.h>
 
 #ifdef CONFIG_LIBUDEV
 #include <libudev.h>
 #endif
 #endif
 
 #ifdef HAVE_GETIFADDRS
 #include <arpa/inet.h>
 #include <sys/socket.h>
 #include <net/if.h>
 #include <net/ethernet.h>
 #include <sys/types.h>
 #ifdef CONFIG_SOLARIS
 #include <sys/sockio.h>
 #endif
 #endif
 
 static void ga_wait_child(pid_t pid, int *status, Error **errp)
 {
     pid_t rpid;
 
     *status = 0;
 
     do {
         rpid = waitpid(pid, status, 0);
     } while (rpid == -1 && errno == EINTR);
 
     if (rpid == -1) {
         error_setg_errno(errp, errno, "failed to wait for child (pid: %d)",
                          pid);
         return;
     }
 
     g_assert(rpid == pid);
 }
 
 void qmp_guest_shutdown(bool has_mode, const char *mode, Error **errp)
 {
     const char *shutdown_flag;
     Error *local_err = NULL;
     pid_t pid;
     int status;
 
 #ifdef CONFIG_SOLARIS
     const char *powerdown_flag = "-i5";
     const char *halt_flag = "-i0";
     const char *reboot_flag = "-i6";
 #elif defined(CONFIG_BSD)
     const char *powerdown_flag = "-p";
     const char *halt_flag = "-h";
     const char *reboot_flag = "-r";
 #else
     const char *powerdown_flag = "-P";
     const char *halt_flag = "-H";
     const char *reboot_flag = "-r";
 #endif
 
     slog("guest-shutdown called, mode: %s", mode);
     if (!has_mode || strcmp(mode, "powerdown") == 0) {
         shutdown_flag = powerdown_flag;
     } else if (strcmp(mode, "halt") == 0) {
         shutdown_flag = halt_flag;
     } else if (strcmp(mode, "reboot") == 0) {
         shutdown_flag = reboot_flag;
     } else {
         error_setg(errp,
                    "mode is invalid (valid values are: halt|powerdown|reboot");
         return;
     }
 
     pid = fork();
     if (pid == 0) {
         /* child, start the shutdown */
         setsid();
         reopen_fd_to_null(0);
         reopen_fd_to_null(1);
         reopen_fd_to_null(2);
 
 #ifdef CONFIG_SOLARIS
         execl("/sbin/shutdown", "shutdown", shutdown_flag, "-g0", "-y",
               "hypervisor initiated shutdown", (char *)NULL);
 #elif defined(CONFIG_BSD)
         execl("/sbin/shutdown", "shutdown", shutdown_flag, "+0",
                "hypervisor initiated shutdown", (char *)NULL);
 #else
         execl("/sbin/shutdown", "shutdown", "-h", shutdown_flag, "+0",
                "hypervisor initiated shutdown", (char *)NULL);
 #endif
         _exit(EXIT_FAILURE);
     } else if (pid < 0) {
         error_setg_errno(errp, errno, "failed to create child process");
         return;
     }
 
     ga_wait_child(pid, &status, &local_err);
     if (local_err) {
         error_propagate(errp, local_err);
         return;
     }
 
     if (!WIFEXITED(status)) {
         error_setg(errp, "child process has terminated abnormally");
         return;
     }
 
     if (WEXITSTATUS(status)) {
         error_setg(errp, "child process has failed to shutdown");
         return;
     }
 
     /* succeeded */
 }
 
 void qmp_guest_set_time(bool has_time, int64_t time_ns, Error **errp)
 {
     int ret;
     int status;
     pid_t pid;
     Error *local_err = NULL;
     struct timeval tv;
     static const char hwclock_path[] = "/sbin/hwclock";
     static int hwclock_available = -1;
 
     if (hwclock_available < 0) {
         hwclock_available = (access(hwclock_path, X_OK) == 0);
     }
 
     if (!hwclock_available) {
         error_setg(errp, QERR_UNSUPPORTED);
         return;
     }
 
     /* If user has passed a time, validate and set it. */
     if (has_time) {
         GDate date = { 0, };
 
         /* year-2038 will overflow in case time_t is 32bit */
         if (time_ns / 1000000000 != (time_t)(time_ns / 1000000000)) {
             error_setg(errp, "Time %" PRId64 " is too large", time_ns);
             return;
         }
 
         tv.tv_sec = time_ns / 1000000000;
         tv.tv_usec = (time_ns % 1000000000) / 1000;
         g_date_set_time_t(&date, tv.tv_sec);
         if (date.year < 1970 || date.year >= 2070) {
             error_setg_errno(errp, errno, "Invalid time");
             return;
         }
 
         ret = settimeofday(&tv, NULL);
         if (ret < 0) {
             error_setg_errno(errp, errno, "Failed to set time to guest");
             return;
         }
     }
 
     /* Now, if user has passed a time to set and the system time is set, we
      * just need to synchronize the hardware clock. However, if no time was
      * passed, user is requesting the opposite: set the system time from the
      * hardware clock (RTC). */
     pid = fork();
     if (pid == 0) {
         setsid();
         reopen_fd_to_null(0);
         reopen_fd_to_null(1);
         reopen_fd_to_null(2);
 
         /* Use '/sbin/hwclock -w' to set RTC from the system time,
          * or '/sbin/hwclock -s' to set the system time from RTC. */
         execl(hwclock_path, "hwclock", has_time ? "-w" : "-s", NULL);
         _exit(EXIT_FAILURE);
     } else if (pid < 0) {
         error_setg_errno(errp, errno, "failed to create child process");
         return;
     }
 
     ga_wait_child(pid, &status, &local_err);
     if (local_err) {
         error_propagate(errp, local_err);
         return;
     }
 
     if (!WIFEXITED(status)) {
         error_setg(errp, "child process has terminated abnormally");
         return;
     }
 
     if (WEXITSTATUS(status)) {
         error_setg(errp, "hwclock failed to set hardware clock to system time");
         return;
     }
 }
 
 typedef enum {
     RW_STATE_NEW,
     RW_STATE_READING,
     RW_STATE_WRITING,
 } RwState;
 
 struct GuestFileHandle {
     uint64_t id;
     FILE *fh;
     RwState state;
     QTAILQ_ENTRY(GuestFileHandle) next;
 };
 
 static struct {
     QTAILQ_HEAD(, GuestFileHandle) filehandles;
 } guest_file_state = {
     .filehandles = QTAILQ_HEAD_INITIALIZER(guest_file_state.filehandles),
 };
 
 static int64_t guest_file_handle_add(FILE *fh, Error **errp)
 {
     GuestFileHandle *gfh;
     int64_t handle;
 
     handle = ga_get_fd_handle(ga_state, errp);
     if (handle < 0) {
         return -1;
     }
 
     gfh = g_new0(GuestFileHandle, 1);
     gfh->id = handle;
     gfh->fh = fh;
     QTAILQ_INSERT_TAIL(&guest_file_state.filehandles, gfh, next);
 
     return handle;
 }
 
 GuestFileHandle *guest_file_handle_find(int64_t id, Error **errp)
 {
     GuestFileHandle *gfh;
 
     QTAILQ_FOREACH(gfh, &guest_file_state.filehandles, next)
     {
         if (gfh->id == id) {
             return gfh;
         }
     }
 
     error_setg(errp, "handle '%" PRId64 "' has not been found", id);
     return NULL;
 }
 
 typedef const char * const ccpc;
 
 #ifndef O_BINARY
 #define O_BINARY 0
 #endif
 
 /* http://pubs.opengroup.org/onlinepubs/9699919799/functions/fopen.html */
 static const struct {
     ccpc *forms;
     int oflag_base;
 } guest_file_open_modes[] = {
     { (ccpc[]){ "r",          NULL }, O_RDONLY                                 },
     { (ccpc[]){ "rb",         NULL }, O_RDONLY                      | O_BINARY },
     { (ccpc[]){ "w",          NULL }, O_WRONLY | O_CREAT | O_TRUNC             },
     { (ccpc[]){ "wb",         NULL }, O_WRONLY | O_CREAT | O_TRUNC  | O_BINARY },
     { (ccpc[]){ "a",          NULL }, O_WRONLY | O_CREAT | O_APPEND            },
     { (ccpc[]){ "ab",         NULL }, O_WRONLY | O_CREAT | O_APPEND | O_BINARY },
     { (ccpc[]){ "r+",         NULL }, O_RDWR                                   },
     { (ccpc[]){ "rb+", "r+b", NULL }, O_RDWR                        | O_BINARY },
     { (ccpc[]){ "w+",         NULL }, O_RDWR   | O_CREAT | O_TRUNC             },
     { (ccpc[]){ "wb+", "w+b", NULL }, O_RDWR   | O_CREAT | O_TRUNC  | O_BINARY },
     { (ccpc[]){ "a+",         NULL }, O_RDWR   | O_CREAT | O_APPEND            },
     { (ccpc[]){ "ab+", "a+b", NULL }, O_RDWR   | O_CREAT | O_APPEND | O_BINARY }
 };
 
 static int
 find_open_flag(const char *mode_str, Error **errp)
 {
     unsigned mode;
 
     for (mode = 0; mode < ARRAY_SIZE(guest_file_open_modes); ++mode) {
         ccpc *form;
 
         form = guest_file_open_modes[mode].forms;
         while (*form != NULL && strcmp(*form, mode_str) != 0) {
             ++form;
         }
         if (*form != NULL) {
             break;
         }
     }
 
     if (mode == ARRAY_SIZE(guest_file_open_modes)) {
         error_setg(errp, "invalid file open mode '%s'", mode_str);
         return -1;
     }
     return guest_file_open_modes[mode].oflag_base | O_NOCTTY | O_NONBLOCK;
 }
 
 #define DEFAULT_NEW_FILE_MODE (S_IRUSR | S_IWUSR | \
                                S_IRGRP | S_IWGRP | \
                                S_IROTH | S_IWOTH)
 
 static FILE *
 safe_open_or_create(const char *path, const char *mode, Error **errp)
 {
     int oflag;
     int fd = -1;
     FILE *f = NULL;
 
     oflag = find_open_flag(mode, errp);
     if (oflag < 0) {
         goto end;
     }
 
     /* If the caller wants / allows creation of a new file, we implement it
      * with a two step process: open() + (open() / fchmod()).
      *
      * First we insist on creating the file exclusively as a new file. If
      * that succeeds, we're free to set any file-mode bits on it. (The
      * motivation is that we want to set those file-mode bits independently
      * of the current umask.)
      *
      * If the exclusive creation fails because the file already exists
      * (EEXIST is not possible for any other reason), we just attempt to
      * open the file, but in this case we won't be allowed to change the
      * file-mode bits on the preexistent file.
      *
      * The pathname should never disappear between the two open()s in
      * practice. If it happens, then someone very likely tried to race us.
      * In this case just go ahead and report the ENOENT from the second
      * open() to the caller.
      *
      * If the caller wants to open a preexistent file, then the first
      * open() is decisive and its third argument is ignored, and the second
      * open() and the fchmod() are never called.
      */
     fd = qga_open_cloexec(path, oflag | ((oflag & O_CREAT) ? O_EXCL : 0), 0);
     if (fd == -1 && errno == EEXIST) {
         oflag &= ~(unsigned)O_CREAT;
         fd = qga_open_cloexec(path, oflag, 0);
     }
     if (fd == -1) {
         error_setg_errno(errp, errno,
                          "failed to open file '%s' (mode: '%s')",
                          path, mode);
         goto end;
     }
 
     if ((oflag & O_CREAT) && fchmod(fd, DEFAULT_NEW_FILE_MODE) == -1) {
         error_setg_errno(errp, errno, "failed to set permission "
                          "0%03o on new file '%s' (mode: '%s')",
                          (unsigned)DEFAULT_NEW_FILE_MODE, path, mode);
         goto end;
     }
 
     f = fdopen(fd, mode);
     if (f == NULL) {
         error_setg_errno(errp, errno, "failed to associate stdio stream with "
                          "file descriptor %d, file '%s' (mode: '%s')",
                          fd, path, mode);
     }
 
 end:
     if (f == NULL && fd != -1) {
         close(fd);
         if (oflag & O_CREAT) {
             unlink(path);
         }
     }
     return f;
 }
 
 int64_t qmp_guest_file_open(const char *path, bool has_mode, const char *mode,
                             Error **errp)
 {
     FILE *fh;
     Error *local_err = NULL;
     int64_t handle;
 
     if (!has_mode) {
         mode = "r";
     }
     slog("guest-file-open called, filepath: %s, mode: %s", path, mode);
     fh = safe_open_or_create(path, mode, &local_err);
     if (local_err != NULL) {
         error_propagate(errp, local_err);
         return -1;
     }
 
     /* set fd non-blocking to avoid common use cases (like reading from a
      * named pipe) from hanging the agent
      */
     if (!g_unix_set_fd_nonblocking(fileno(fh), true, NULL)) {
         fclose(fh);
         error_setg_errno(errp, errno, "Failed to set FD nonblocking");
         return -1;
     }
 
     handle = guest_file_handle_add(fh, errp);
     if (handle < 0) {
         fclose(fh);
         return -1;
     }
 
     slog("guest-file-open, handle: %" PRId64, handle);
     return handle;
 }
 
 void qmp_guest_file_close(int64_t handle, Error **errp)
 {
     GuestFileHandle *gfh = guest_file_handle_find(handle, errp);
     int ret;
 
     slog("guest-file-close called, handle: %" PRId64, handle);
     if (!gfh) {
         return;
     }
 
     ret = fclose(gfh->fh);
     if (ret == EOF) {
         error_setg_errno(errp, errno, "failed to close handle");
         return;
     }
 
     QTAILQ_REMOVE(&guest_file_state.filehandles, gfh, next);
     g_free(gfh);
 }
 
 GuestFileRead *guest_file_read_unsafe(GuestFileHandle *gfh,
                                       int64_t count, Error **errp)
 {
     GuestFileRead *read_data = NULL;
     guchar *buf;
     FILE *fh = gfh->fh;
     size_t read_count;
 
     /* explicitly flush when switching from writing to reading */
     if (gfh->state == RW_STATE_WRITING) {
         int ret = fflush(fh);
         if (ret == EOF) {
             error_setg_errno(errp, errno, "failed to flush file");
             return NULL;
         }
         gfh->state = RW_STATE_NEW;
     }
 
     buf = g_malloc0(count + 1);
     read_count = fread(buf, 1, count, fh);
     if (ferror(fh)) {
         error_setg_errno(errp, errno, "failed to read file");
     } else {
         buf[read_count] = 0;
         read_data = g_new0(GuestFileRead, 1);
         read_data->count = read_count;
         read_data->eof = feof(fh);
         if (read_count) {
             read_data->buf_b64 = g_base64_encode(buf, read_count);
         }
         gfh->state = RW_STATE_READING;
     }
     g_free(buf);
     clearerr(fh);
 
     return read_data;
 }
 
 GuestFileWrite *qmp_guest_file_write(int64_t handle, const char *buf_b64,
                                      bool has_count, int64_t count,
                                      Error **errp)
 {
     GuestFileWrite *write_data = NULL;
     guchar *buf;
     gsize buf_len;
     int write_count;
     GuestFileHandle *gfh = guest_file_handle_find(handle, errp);
     FILE *fh;
 
     if (!gfh) {
         return NULL;
     }
 
     fh = gfh->fh;
 
     if (gfh->state == RW_STATE_READING) {
         int ret = fseek(fh, 0, SEEK_CUR);
         if (ret == -1) {
             error_setg_errno(errp, errno, "failed to seek file");
             return NULL;
         }
         gfh->state = RW_STATE_NEW;
     }
 
     buf = qbase64_decode(buf_b64, -1, &buf_len, errp);
     if (!buf) {
         return NULL;
     }
 
     if (!has_count) {
         count = buf_len;
     } else if (count < 0 || count > buf_len) {
         error_setg(errp, "value '%" PRId64 "' is invalid for argument count",
                    count);
         g_free(buf);
         return NULL;
     }
 
     write_count = fwrite(buf, 1, count, fh);
     if (ferror(fh)) {
         error_setg_errno(errp, errno, "failed to write to file");
         slog("guest-file-write failed, handle: %" PRId64, handle);
     } else {
         write_data = g_new0(GuestFileWrite, 1);
         write_data->count = write_count;
         write_data->eof = feof(fh);
         gfh->state = RW_STATE_WRITING;
     }
     g_free(buf);
     clearerr(fh);
 
     return write_data;
 }
 
 struct GuestFileSeek *qmp_guest_file_seek(int64_t handle, int64_t offset,
                                           GuestFileWhence *whence_code,
                                           Error **errp)
 {
     GuestFileHandle *gfh = guest_file_handle_find(handle, errp);
     GuestFileSeek *seek_data = NULL;
     FILE *fh;
     int ret;
     int whence;
     Error *err = NULL;
 
     if (!gfh) {
         return NULL;
     }
 
     /* We stupidly exposed 'whence':'int' in our qapi */
     whence = ga_parse_whence(whence_code, &err);
     if (err) {
         error_propagate(errp, err);
         return NULL;
     }
 
     fh = gfh->fh;
     ret = fseek(fh, offset, whence);
     if (ret == -1) {
         error_setg_errno(errp, errno, "failed to seek file");
         if (errno == ESPIPE) {
             /* file is non-seekable, stdio shouldn't be buffering anyways */
             gfh->state = RW_STATE_NEW;
         }
     } else {
         seek_data = g_new0(GuestFileSeek, 1);
         seek_data->position = ftell(fh);
         seek_data->eof = feof(fh);
         gfh->state = RW_STATE_NEW;
     }
     clearerr(fh);
 
     return seek_data;
 }
 
 void qmp_guest_file_flush(int64_t handle, Error **errp)
 {
     GuestFileHandle *gfh = guest_file_handle_find(handle, errp);
     FILE *fh;
     int ret;
 
     if (!gfh) {
         return;
     }
 
     fh = gfh->fh;
     ret = fflush(fh);
     if (ret == EOF) {
         error_setg_errno(errp, errno, "failed to flush file");
     } else {
         gfh->state = RW_STATE_NEW;
     }
 }
 
 #if defined(CONFIG_FSFREEZE) || defined(CONFIG_FSTRIM)
 void free_fs_mount_list(FsMountList *mounts)
 {
      FsMount *mount, *temp;
 
      if (!mounts) {
          return;
      }
 
      QTAILQ_FOREACH_SAFE(mount, mounts, next, temp) {
          QTAILQ_REMOVE(mounts, mount, next);
          g_free(mount->dirname);
          g_free(mount->devtype);
          g_free(mount);
      }
 }
 #endif
 
 #if defined(CONFIG_FSFREEZE)
 typedef enum {
     FSFREEZE_HOOK_THAW = 0,
     FSFREEZE_HOOK_FREEZE,
 } FsfreezeHookArg;
 
 static const char *fsfreeze_hook_arg_string[] = {
     "thaw",
     "freeze",
 };
 
 static void execute_fsfreeze_hook(FsfreezeHookArg arg, Error **errp)
 {
     int status;
     pid_t pid;
     const char *hook;
     const char *arg_str = fsfreeze_hook_arg_string[arg];
     Error *local_err = NULL;
 
     hook = ga_fsfreeze_hook(ga_state);
     if (!hook) {
         return;
     }
     if (access(hook, X_OK) != 0) {
         error_setg_errno(errp, errno, "can't access fsfreeze hook '%s'", hook);
         return;
     }
 
     slog("executing fsfreeze hook with arg '%s'", arg_str);
     pid = fork();
     if (pid == 0) {
         setsid();
         reopen_fd_to_null(0);
         reopen_fd_to_null(1);
         reopen_fd_to_null(2);
 
         execl(hook, hook, arg_str, NULL);
         _exit(EXIT_FAILURE);
     } else if (pid < 0) {
         error_setg_errno(errp, errno, "failed to create child process");
         return;
     }
 
     ga_wait_child(pid, &status, &local_err);
     if (local_err) {
         error_propagate(errp, local_err);
         return;
     }
 
     if (!WIFEXITED(status)) {
         error_setg(errp, "fsfreeze hook has terminated abnormally");
         return;
     }
 
     status = WEXITSTATUS(status);
     if (status) {
         error_setg(errp, "fsfreeze hook has failed with status %d", status);
         return;
     }
 }
 
 /*
  * Return status of freeze/thaw
  */
 GuestFsfreezeStatus qmp_guest_fsfreeze_status(Error **errp)
 {
     if (ga_is_frozen(ga_state)) {
         return GUEST_FSFREEZE_STATUS_FROZEN;
     }
 
     return GUEST_FSFREEZE_STATUS_THAWED;
 }
 
 int64_t qmp_guest_fsfreeze_freeze(Error **errp)
 {
     return qmp_guest_fsfreeze_freeze_list(false, NULL, errp);
 }
 
 int64_t qmp_guest_fsfreeze_freeze_list(bool has_mountpoints,
                                        strList *mountpoints,
                                        Error **errp)
 {
     int ret;
     FsMountList mounts;
     Error *local_err = NULL;
 
     slog("guest-fsfreeze called");
 
     execute_fsfreeze_hook(FSFREEZE_HOOK_FREEZE, &local_err);
     if (local_err) {
         error_propagate(errp, local_err);
         return -1;
     }
 
     QTAILQ_INIT(&mounts);
     if (!build_fs_mount_list(&mounts, &local_err)) {
         error_propagate(errp, local_err);
         return -1;
     }
 
     /* cannot risk guest agent blocking itself on a write in this state */
     ga_set_frozen(ga_state);
 
     ret = qmp_guest_fsfreeze_do_freeze_list(has_mountpoints, mountpoints,
                                             mounts, errp);
 
     free_fs_mount_list(&mounts);
     /* We may not issue any FIFREEZE here.
      * Just unset ga_state here and ready for the next call.
      */
     if (ret == 0) {
         ga_unset_frozen(ga_state);
     } else if (ret < 0) {
         qmp_guest_fsfreeze_thaw(NULL);
     }
     return ret;
 }
 
 int64_t qmp_guest_fsfreeze_thaw(Error **errp)
 {
     int ret;
 
     ret = qmp_guest_fsfreeze_do_thaw(errp);
     if (ret >= 0) {
         ga_unset_frozen(ga_state);
         execute_fsfreeze_hook(FSFREEZE_HOOK_THAW, errp);
     } else {
         ret = 0;
     }
 
     return ret;
 }
 
 static void guest_fsfreeze_cleanup(void)
 {
     Error *err = NULL;
 
     if (ga_is_frozen(ga_state) == GUEST_FSFREEZE_STATUS_FROZEN) {
         qmp_guest_fsfreeze_thaw(&err);
         if (err) {
             slog("failed to clean up frozen filesystems: %s",
                  error_get_pretty(err));
             error_free(err);
         }
     }
 }
 #endif
 
 /* linux-specific implementations. avoid this if at all possible. */
 #if defined(__linux__)
 #if defined(CONFIG_FSFREEZE)
 
 static char *get_pci_driver(char const *syspath, int pathlen, Error **errp)
 {
     char *path;
     char *dpath;
     char *driver = NULL;
     char buf[PATH_MAX];
     ssize_t len;
 
     path = g_strndup(syspath, pathlen);
     dpath = g_strdup_printf("%s/driver", path);
     len = readlink(dpath, buf, sizeof(buf) - 1);
     if (len != -1) {
         buf[len] = 0;
         driver = g_path_get_basename(buf);
     }
     g_free(dpath);
     g_free(path);
     return driver;
 }
 
 static int compare_uint(const void *_a, const void *_b)
 {
     unsigned int a = *(unsigned int *)_a;
     unsigned int b = *(unsigned int *)_b;
 
     return a < b ? -1 : a > b ? 1 : 0;
 }
 
 /* Walk the specified sysfs and build a sorted list of host or ata numbers */
 static int build_hosts(char const *syspath, char const *host, bool ata,
                        unsigned int *hosts, int hosts_max, Error **errp)
 {
     char *path;
     DIR *dir;
     struct dirent *entry;
     int i = 0;
 
     path = g_strndup(syspath, host - syspath);
     dir = opendir(path);
     if (!dir) {
         error_setg_errno(errp, errno, "opendir(\"%s\")", path);
         g_free(path);
         return -1;
     }
 
     while (i < hosts_max) {
         entry = readdir(dir);
         if (!entry) {
             break;
         }
         if (ata && sscanf(entry->d_name, "ata%d", hosts + i) == 1) {
             ++i;
         } else if (!ata && sscanf(entry->d_name, "host%d", hosts + i) == 1) {
             ++i;
         }
     }
 
     qsort(hosts, i, sizeof(hosts[0]), compare_uint);
 
     g_free(path);
     closedir(dir);
     return i;
 }
 
 /*
  * Store disk device info for devices on the PCI bus.
  * Returns true if information has been stored, or false for failure.
  */
 static bool build_guest_fsinfo_for_pci_dev(char const *syspath,
                                            GuestDiskAddress *disk,
                                            Error **errp)
 {
     unsigned int pci[4], host, hosts[8], tgt[3];
     int i, nhosts = 0, pcilen;
     GuestPCIAddress *pciaddr = disk->pci_controller;
     bool has_ata = false, has_host = false, has_tgt = false;
     char *p, *q, *driver = NULL;
     bool ret = false;
 
     p = strstr(syspath, "/devices/pci");
     if (!p || sscanf(p + 12, "%*x:%*x/%x:%x:%x.%x%n",
                      pci, pci + 1, pci + 2, pci + 3, &pcilen) < 4) {
         g_debug("only pci device is supported: sysfs path '%s'", syspath);
         return false;
     }
 
     p += 12 + pcilen;
     while (true) {
         driver = get_pci_driver(syspath, p - syspath, errp);
         if (driver && (g_str_equal(driver, "ata_piix") ||
                        g_str_equal(driver, "sym53c8xx") ||
                        g_str_equal(driver, "virtio-pci") ||
                        g_str_equal(driver, "ahci") ||
                        g_str_equal(driver, "nvme"))) {
             break;
         }
 
         g_free(driver);
         if (sscanf(p, "/%x:%x:%x.%x%n",
                           pci, pci + 1, pci + 2, pci + 3, &pcilen) == 4) {
             p += pcilen;
             continue;
         }
 
         g_debug("unsupported driver or sysfs path '%s'", syspath);
         return false;
     }
 
     p = strstr(syspath, "/target");
     if (p && sscanf(p + 7, "%*u:%*u:%*u/%*u:%u:%u:%u",
                     tgt, tgt + 1, tgt + 2) == 3) {
         has_tgt = true;
     }
 
     p = strstr(syspath, "/ata");
     if (p) {
         q = p + 4;
         has_ata = true;
     } else {
         p = strstr(syspath, "/host");
         q = p + 5;
     }
     if (p && sscanf(q, "%u", &host) == 1) {
         has_host = true;
         nhosts = build_hosts(syspath, p, has_ata, hosts,
                              ARRAY_SIZE(hosts), errp);
         if (nhosts < 0) {
             goto cleanup;
         }
     }
 
     pciaddr->domain = pci[0];
     pciaddr->bus = pci[1];
     pciaddr->slot = pci[2];
     pciaddr->function = pci[3];
 
     if (strcmp(driver, "ata_piix") == 0) {
         /* a host per ide bus, target*:0:<unit>:0 */
         if (!has_host || !has_tgt) {
             g_debug("invalid sysfs path '%s' (driver '%s')", syspath, driver);
             goto cleanup;
         }
         for (i = 0; i < nhosts; i++) {
             if (host == hosts[i]) {
                 disk->bus_type = GUEST_DISK_BUS_TYPE_IDE;
                 disk->bus = i;
                 disk->unit = tgt[1];
                 break;
             }
         }
         if (i >= nhosts) {
             g_debug("no host for '%s' (driver '%s')", syspath, driver);
             goto cleanup;
         }
     } else if (strcmp(driver, "sym53c8xx") == 0) {
         /* scsi(LSI Logic): target*:0:<unit>:0 */
         if (!has_tgt) {
             g_debug("invalid sysfs path '%s' (driver '%s')", syspath, driver);
             goto cleanup;
         }
         disk->bus_type = GUEST_DISK_BUS_TYPE_SCSI;
         disk->unit = tgt[1];
     } else if (strcmp(driver, "virtio-pci") == 0) {
         if (has_tgt) {
             /* virtio-scsi: target*:0:0:<unit> */
             disk->bus_type = GUEST_DISK_BUS_TYPE_SCSI;
             disk->unit = tgt[2];
         } else {
             /* virtio-blk: 1 disk per 1 device */
             disk->bus_type = GUEST_DISK_BUS_TYPE_VIRTIO;
         }
     } else if (strcmp(driver, "ahci") == 0) {
         /* ahci: 1 host per 1 unit */
         if (!has_host || !has_tgt) {
             g_debug("invalid sysfs path '%s' (driver '%s')", syspath, driver);
             goto cleanup;
         }
         for (i = 0; i < nhosts; i++) {
             if (host == hosts[i]) {
                 disk->unit = i;
                 disk->bus_type = GUEST_DISK_BUS_TYPE_SATA;
                 break;
             }
         }
         if (i >= nhosts) {
             g_debug("no host for '%s' (driver '%s')", syspath, driver);
             goto cleanup;
         }
     } else if (strcmp(driver, "nvme") == 0) {
         disk->bus_type = GUEST_DISK_BUS_TYPE_NVME;
     } else {
         g_debug("unknown driver '%s' (sysfs path '%s')", driver, syspath);
         goto cleanup;
     }
 
     ret = true;
 
 cleanup:
     g_free(driver);
     return ret;
 }
 
 /*
  * Store disk device info for non-PCI virtio devices (for example s390x
  * channel I/O devices). Returns true if information has been stored, or
  * false for failure.
  */
 static bool build_guest_fsinfo_for_nonpci_virtio(char const *syspath,
                                                  GuestDiskAddress *disk,
                                                  Error **errp)
 {
     unsigned int tgt[3];
     char *p;
 
     if (!strstr(syspath, "/virtio") || !strstr(syspath, "/block")) {
         g_debug("Unsupported virtio device '%s'", syspath);
         return false;
     }
 
     p = strstr(syspath, "/target");
     if (p && sscanf(p + 7, "%*u:%*u:%*u/%*u:%u:%u:%u",
                     &tgt[0], &tgt[1], &tgt[2]) == 3) {
         /* virtio-scsi: target*:0:<target>:<unit> */
         disk->bus_type = GUEST_DISK_BUS_TYPE_SCSI;
         disk->bus = tgt[0];
         disk->target = tgt[1];
         disk->unit = tgt[2];
     } else {
         /* virtio-blk: 1 disk per 1 device */
         disk->bus_type = GUEST_DISK_BUS_TYPE_VIRTIO;
     }
 
     return true;
 }
 
 /*
  * Store disk device info for CCW devices (s390x channel I/O devices).
  * Returns true if information has been stored, or false for failure.
  */
 static bool build_guest_fsinfo_for_ccw_dev(char const *syspath,
                                            GuestDiskAddress *disk,
                                            Error **errp)
 {
     unsigned int cssid, ssid, subchno, devno;
     char *p;
 
     p = strstr(syspath, "/devices/css");
     if (!p || sscanf(p + 12, "%*x/%x.%x.%x/%*x.%*x.%x/",
                      &cssid, &ssid, &subchno, &devno) < 4) {
         g_debug("could not parse ccw device sysfs path: %s", syspath);
         return false;
     }
 
     disk->has_ccw_address = true;
     disk->ccw_address = g_new0(GuestCCWAddress, 1);
     disk->ccw_address->cssid = cssid;
     disk->ccw_address->ssid = ssid;
     disk->ccw_address->subchno = subchno;
     disk->ccw_address->devno = devno;
 
     if (strstr(p, "/virtio")) {
         build_guest_fsinfo_for_nonpci_virtio(syspath, disk, errp);
     }
 
     return true;
 }
 
 /* Store disk device info specified by @sysfs into @fs */
 static void build_guest_fsinfo_for_real_device(char const *syspath,
                                                GuestFilesystemInfo *fs,
                                                Error **errp)
 {
     GuestDiskAddress *disk;
     GuestPCIAddress *pciaddr;
     bool has_hwinf;
 #ifdef CONFIG_LIBUDEV
     struct udev *udev = NULL;
     struct udev_device *udevice = NULL;
 #endif
 
     pciaddr = g_new0(GuestPCIAddress, 1);
     pciaddr->domain = -1;                       /* -1 means field is invalid */
     pciaddr->bus = -1;
     pciaddr->slot = -1;
     pciaddr->function = -1;
 
     disk = g_new0(GuestDiskAddress, 1);
     disk->pci_controller = pciaddr;
     disk->bus_type = GUEST_DISK_BUS_TYPE_UNKNOWN;
 
 #ifdef CONFIG_LIBUDEV
     udev = udev_new();
     udevice = udev_device_new_from_syspath(udev, syspath);
     if (udev == NULL || udevice == NULL) {
         g_debug("failed to query udev");
     } else {
         const char *devnode, *serial;
         devnode = udev_device_get_devnode(udevice);
         if (devnode != NULL) {
             disk->dev = g_strdup(devnode);
             disk->has_dev = true;
         }
         serial = udev_device_get_property_value(udevice, "ID_SERIAL");
         if (serial != NULL && *serial != 0) {
             disk->serial = g_strdup(serial);
             disk->has_serial = true;
         }
     }
 
     udev_unref(udev);
     udev_device_unref(udevice);
 #endif
 
     if (strstr(syspath, "/devices/pci")) {
         has_hwinf = build_guest_fsinfo_for_pci_dev(syspath, disk, errp);
     } else if (strstr(syspath, "/devices/css")) {
         has_hwinf = build_guest_fsinfo_for_ccw_dev(syspath, disk, errp);
     } else if (strstr(syspath, "/virtio")) {
         has_hwinf = build_guest_fsinfo_for_nonpci_virtio(syspath, disk, errp);
     } else {
         g_debug("Unsupported device type for '%s'", syspath);
         has_hwinf = false;
     }
 
     if (has_hwinf || disk->has_dev || disk->has_serial) {
         QAPI_LIST_PREPEND(fs->disk, disk);
     } else {
         qapi_free_GuestDiskAddress(disk);
     }
 }
 
 static void build_guest_fsinfo_for_device(char const *devpath,
                                           GuestFilesystemInfo *fs,
                                           Error **errp);
 
 /* Store a list of slave devices of virtual volume specified by @syspath into
  * @fs */
 static void build_guest_fsinfo_for_virtual_device(char const *syspath,
                                                   GuestFilesystemInfo *fs,
                                                   Error **errp)
 {
     Error *err = NULL;
     DIR *dir;
     char *dirpath;
     struct dirent *entry;
 
     dirpath = g_strdup_printf("%s/slaves", syspath);
     dir = opendir(dirpath);
     if (!dir) {
         if (errno != ENOENT) {
             error_setg_errno(errp, errno, "opendir(\"%s\")", dirpath);
         }
         g_free(dirpath);
         return;
     }
 
     for (;;) {
         errno = 0;
         entry = readdir(dir);
         if (entry == NULL) {
             if (errno) {
                 error_setg_errno(errp, errno, "readdir(\"%s\")", dirpath);
             }
             break;
         }
 
         if (entry->d_type == DT_LNK) {
             char *path;
 
             g_debug(" slave device '%s'", entry->d_name);
             path = g_strdup_printf("%s/slaves/%s", syspath, entry->d_name);
             build_guest_fsinfo_for_device(path, fs, &err);
             g_free(path);
 
             if (err) {
                 error_propagate(errp, err);
                 break;
             }
         }
     }
 
     g_free(dirpath);
     closedir(dir);
 }
 
 static bool is_disk_virtual(const char *devpath, Error **errp)
 {
     g_autofree char *syspath = realpath(devpath, NULL);
 
     if (!syspath) {
         error_setg_errno(errp, errno, "realpath(\"%s\")", devpath);
         return false;
     }
     return strstr(syspath, "/devices/virtual/block/") != NULL;
 }
 
 /* Dispatch to functions for virtual/real device */
 static void build_guest_fsinfo_for_device(char const *devpath,
                                           GuestFilesystemInfo *fs,
                                           Error **errp)
 {
     ERRP_GUARD();
     g_autofree char *syspath = NULL;
     bool is_virtual = false;
 
     syspath = realpath(devpath, NULL);
     if (!syspath) {
         if (errno != ENOENT) {
             error_setg_errno(errp, errno, "realpath(\"%s\")", devpath);
             return;
         }
 
         /* ENOENT: This devpath may not exist because of container config */
         if (!fs->name) {
             fs->name = g_path_get_basename(devpath);
         }
         return;
     }
 
     if (!fs->name) {
         fs->name = g_path_get_basename(syspath);
     }
 
     g_debug("  parse sysfs path '%s'", syspath);
     is_virtual = is_disk_virtual(syspath, errp);
     if (*errp != NULL) {
         return;
     }
     if (is_virtual) {
         build_guest_fsinfo_for_virtual_device(syspath, fs, errp);
     } else {
         build_guest_fsinfo_for_real_device(syspath, fs, errp);
     }
 }
 
 #ifdef CONFIG_LIBUDEV
 
 /*
  * Wrapper around build_guest_fsinfo_for_device() for getting just
  * the disk address.
  */
 static GuestDiskAddress *get_disk_address(const char *syspath, Error **errp)
 {
     g_autoptr(GuestFilesystemInfo) fs = NULL;
 
     fs = g_new0(GuestFilesystemInfo, 1);
     build_guest_fsinfo_for_device(syspath, fs, errp);
     if (fs->disk != NULL) {
         return g_steal_pointer(&fs->disk->value);
     }
     return NULL;
 }
 
 static char *get_alias_for_syspath(const char *syspath)
 {
     struct udev *udev = NULL;
     struct udev_device *udevice = NULL;
     char *ret = NULL;
 
     udev = udev_new();
     if (udev == NULL) {
         g_debug("failed to query udev");
         goto out;
     }
     udevice = udev_device_new_from_syspath(udev, syspath);
     if (udevice == NULL) {
         g_debug("failed to query udev for path: %s", syspath);
         goto out;
     } else {
         const char *alias = udev_device_get_property_value(
             udevice, "DM_NAME");
         /*
          * NULL means there was an error and empty string means there is no
          * alias. In case of no alias we return NULL instead of empty string.
          */
         if (alias == NULL) {
             g_debug("failed to query udev for device alias for: %s",
                 syspath);
         } else if (*alias != 0) {
             ret = g_strdup(alias);
         }
     }
 
 out:
     udev_unref(udev);
     udev_device_unref(udevice);
     return ret;
 }
 
 static char *get_device_for_syspath(const char *syspath)
 {
     struct udev *udev = NULL;
     struct udev_device *udevice = NULL;
     char *ret = NULL;
 
     udev = udev_new();
     if (udev == NULL) {
         g_debug("failed to query udev");
         goto out;
     }
     udevice = udev_device_new_from_syspath(udev, syspath);
     if (udevice == NULL) {
         g_debug("failed to query udev for path: %s", syspath);
         goto out;
     } else {
         ret = g_strdup(udev_device_get_devnode(udevice));
     }
 
 out:
     udev_unref(udev);
     udev_device_unref(udevice);
     return ret;
 }
 
 static void get_disk_deps(const char *disk_dir, GuestDiskInfo *disk)
 {
     g_autofree char *deps_dir = NULL;
     const gchar *dep;
     GDir *dp_deps = NULL;
 
     /* List dependent disks */
     deps_dir = g_strdup_printf("%s/slaves", disk_dir);
     g_debug("  listing entries in: %s", deps_dir);
     dp_deps = g_dir_open(deps_dir, 0, NULL);
     if (dp_deps == NULL) {
         g_debug("failed to list entries in %s", deps_dir);
         return;
     }
     disk->has_dependencies = true;
     while ((dep = g_dir_read_name(dp_deps)) != NULL) {
         g_autofree char *dep_dir = NULL;
         char *dev_name;
 
         /* Add dependent disks */
         dep_dir = g_strdup_printf("%s/%s", deps_dir, dep);
         dev_name = get_device_for_syspath(dep_dir);
         if (dev_name != NULL) {
             g_debug("  adding dependent device: %s", dev_name);
             QAPI_LIST_PREPEND(disk->dependencies, dev_name);
         }
     }
     g_dir_close(dp_deps);
 }
 
 /*
  * Detect partitions subdirectory, name is "<disk_name><number>" or
  * "<disk_name>p<number>"
  *
  * @disk_name -- last component of /sys path (e.g. sda)
  * @disk_dir -- sys path of the disk (e.g. /sys/block/sda)
  * @disk_dev -- device node of the disk (e.g. /dev/sda)
  */
 static GuestDiskInfoList *get_disk_partitions(
     GuestDiskInfoList *list,
     const char *disk_name, const char *disk_dir,
     const char *disk_dev)
 {
     GuestDiskInfoList *ret = list;
     struct dirent *de_disk;
     DIR *dp_disk = NULL;
     size_t len = strlen(disk_name);
 
     dp_disk = opendir(disk_dir);
     while ((de_disk = readdir(dp_disk)) != NULL) {
         g_autofree char *partition_dir = NULL;
         char *dev_name;
         GuestDiskInfo *partition;
 
         if (!(de_disk->d_type & DT_DIR)) {
             continue;
         }
 
         if (!(strncmp(disk_name, de_disk->d_name, len) == 0 &&
             ((*(de_disk->d_name + len) == 'p' &&
             isdigit(*(de_disk->d_name + len + 1))) ||
                 isdigit(*(de_disk->d_name + len))))) {
             continue;
         }
 
         partition_dir = g_strdup_printf("%s/%s",
             disk_dir, de_disk->d_name);
         dev_name = get_device_for_syspath(partition_dir);
         if (dev_name == NULL) {
             g_debug("Failed to get device name for syspath: %s",
                 disk_dir);
             continue;
         }
         partition = g_new0(GuestDiskInfo, 1);
         partition->name = dev_name;
         partition->partition = true;
         partition->has_dependencies = true;
         /* Add parent disk as dependent for easier tracking of hierarchy */
         QAPI_LIST_PREPEND(partition->dependencies, g_strdup(disk_dev));
 
         QAPI_LIST_PREPEND(ret, partition);
     }
     closedir(dp_disk);
 
     return ret;
 }
 
 static void get_nvme_smart(GuestDiskInfo *disk)
 {
     int fd;
     GuestNVMeSmart *smart;
     NvmeSmartLog log = {0};
     struct nvme_admin_cmd cmd = {
         .opcode = NVME_ADM_CMD_GET_LOG_PAGE,
         .nsid = NVME_NSID_BROADCAST,
         .addr = (uintptr_t)&log,
         .data_len = sizeof(log),
         .cdw10 = NVME_LOG_SMART_INFO | (1 << 15) /* RAE bit */
                  | (((sizeof(log) >> 2) - 1) << 16)
     };
 
     fd = qga_open_cloexec(disk->name, O_RDONLY, 0);
     if (fd == -1) {
         g_debug("Failed to open device: %s: %s", disk->name, g_strerror(errno));
         return;
     }
 
     if (ioctl(fd, NVME_IOCTL_ADMIN_CMD, &cmd)) {
         g_debug("Failed to get smart: %s: %s", disk->name, g_strerror(errno));
         close(fd);
         return;
     }
 
     disk->has_smart = true;
     disk->smart = g_new0(GuestDiskSmart, 1);
     disk->smart->type = GUEST_DISK_BUS_TYPE_NVME;
 
     smart = &disk->smart->u.nvme;
     smart->critical_warning = log.critical_warning;
     smart->temperature = lduw_le_p(&log.temperature); /* unaligned field */
     smart->available_spare = log.available_spare;
     smart->available_spare_threshold = log.available_spare_threshold;
     smart->percentage_used = log.percentage_used;
     smart->data_units_read_lo = le64_to_cpu(log.data_units_read[0]);
     smart->data_units_read_hi = le64_to_cpu(log.data_units_read[1]);
     smart->data_units_written_lo = le64_to_cpu(log.data_units_written[0]);
     smart->data_units_written_hi = le64_to_cpu(log.data_units_written[1]);
     smart->host_read_commands_lo = le64_to_cpu(log.host_read_commands[0]);
     smart->host_read_commands_hi = le64_to_cpu(log.host_read_commands[1]);
     smart->host_write_commands_lo = le64_to_cpu(log.host_write_commands[0]);
     smart->host_write_commands_hi = le64_to_cpu(log.host_write_commands[1]);
     smart->controller_busy_time_lo = le64_to_cpu(log.controller_busy_time[0]);
     smart->controller_busy_time_hi = le64_to_cpu(log.controller_busy_time[1]);
     smart->power_cycles_lo = le64_to_cpu(log.power_cycles[0]);
     smart->power_cycles_hi = le64_to_cpu(log.power_cycles[1]);
     smart->power_on_hours_lo = le64_to_cpu(log.power_on_hours[0]);
     smart->power_on_hours_hi = le64_to_cpu(log.power_on_hours[1]);
     smart->unsafe_shutdowns_lo = le64_to_cpu(log.unsafe_shutdowns[0]);
     smart->unsafe_shutdowns_hi = le64_to_cpu(log.unsafe_shutdowns[1]);
     smart->media_errors_lo = le64_to_cpu(log.media_errors[0]);
     smart->media_errors_hi = le64_to_cpu(log.media_errors[1]);
     smart->number_of_error_log_entries_lo =
         le64_to_cpu(log.number_of_error_log_entries[0]);
     smart->number_of_error_log_entries_hi =
         le64_to_cpu(log.number_of_error_log_entries[1]);
 
     close(fd);
 }
 
 static void get_disk_smart(GuestDiskInfo *disk)
 {
     if (disk->has_address
         && (disk->address->bus_type == GUEST_DISK_BUS_TYPE_NVME)) {
         get_nvme_smart(disk);
     }
 }
 
 GuestDiskInfoList *qmp_guest_get_disks(Error **errp)
 {
     GuestDiskInfoList *ret = NULL;
     GuestDiskInfo *disk;
     DIR *dp = NULL;
     struct dirent *de = NULL;
 
     g_debug("listing /sys/block directory");
     dp = opendir("/sys/block");
     if (dp == NULL) {
         error_setg_errno(errp, errno, "Can't open directory \"/sys/block\"");
         return NULL;
     }
     while ((de = readdir(dp)) != NULL) {
         g_autofree char *disk_dir = NULL, *line = NULL,
             *size_path = NULL;
         char *dev_name;
         Error *local_err = NULL;
         if (de->d_type != DT_LNK) {
             g_debug("  skipping entry: %s", de->d_name);
             continue;
         }
 
         /* Check size and skip zero-sized disks */
         g_debug("  checking disk size");
         size_path = g_strdup_printf("/sys/block/%s/size", de->d_name);
         if (!g_file_get_contents(size_path, &line, NULL, NULL)) {
             g_debug("  failed to read disk size");
             continue;
         }
         if (g_strcmp0(line, "0\n") == 0) {
             g_debug("  skipping zero-sized disk");
             continue;
         }
 
         g_debug("  adding %s", de->d_name);
         disk_dir = g_strdup_printf("/sys/block/%s", de->d_name);
         dev_name = get_device_for_syspath(disk_dir);
         if (dev_name == NULL) {
             g_debug("Failed to get device name for syspath: %s",
                 disk_dir);
             continue;
         }
         disk = g_new0(GuestDiskInfo, 1);
         disk->name = dev_name;
         disk->partition = false;
         disk->alias = get_alias_for_syspath(disk_dir);
         disk->has_alias = (disk->alias != NULL);
         QAPI_LIST_PREPEND(ret, disk);
 
         /* Get address for non-virtual devices */
         bool is_virtual = is_disk_virtual(disk_dir, &local_err);
         if (local_err != NULL) {
             g_debug("  failed to check disk path, ignoring error: %s",
                 error_get_pretty(local_err));
             error_free(local_err);
             local_err = NULL;
             /* Don't try to get the address */
             is_virtual = true;
         }
         if (!is_virtual) {
             disk->address = get_disk_address(disk_dir, &local_err);
             if (local_err != NULL) {
                 g_debug("  failed to get device info, ignoring error: %s",
                     error_get_pretty(local_err));
                 error_free(local_err);
                 local_err = NULL;
             } else if (disk->address != NULL) {
                 disk->has_address = true;
             }
         }
 
         get_disk_deps(disk_dir, disk);
         get_disk_smart(disk);
         ret = get_disk_partitions(ret, de->d_name, disk_dir, dev_name);
     }
 
     closedir(dp);
 
     return ret;
 }
 
 #else
 
 GuestDiskInfoList *qmp_guest_get_disks(Error **errp)
 {
     error_setg(errp, QERR_UNSUPPORTED);
     return NULL;
 }
 
 #endif
 
 /* Return a list of the disk device(s)' info which @mount lies on */
 static GuestFilesystemInfo *build_guest_fsinfo(struct FsMount *mount,
                                                Error **errp)
 {
     GuestFilesystemInfo *fs = g_malloc0(sizeof(*fs));
     struct statvfs buf;
     unsigned long used, nonroot_total, fr_size;
     char *devpath = g_strdup_printf("/sys/dev/block/%u:%u",
                                     mount->devmajor, mount->devminor);
 
     fs->mountpoint = g_strdup(mount->dirname);
     fs->type = g_strdup(mount->devtype);
     build_guest_fsinfo_for_device(devpath, fs, errp);
 
     if (statvfs(fs->mountpoint, &buf) == 0) {
         fr_size = buf.f_frsize;
         used = buf.f_blocks - buf.f_bfree;
         nonroot_total = used + buf.f_bavail;
         fs->used_bytes = used * fr_size;
         fs->total_bytes = nonroot_total * fr_size;
 
         fs->has_total_bytes = true;
         fs->has_used_bytes = true;
     }
 
     g_free(devpath);
 
     return fs;
 }
 
 GuestFilesystemInfoList *qmp_guest_get_fsinfo(Error **errp)
 {
     FsMountList mounts;
     struct FsMount *mount;
     GuestFilesystemInfoList *ret = NULL;
     Error *local_err = NULL;
 
     QTAILQ_INIT(&mounts);
     if (!build_fs_mount_list(&mounts, &local_err)) {
         error_propagate(errp, local_err);
         return NULL;
     }
 
     QTAILQ_FOREACH(mount, &mounts, next) {
         g_debug("Building guest fsinfo for '%s'", mount->dirname);
 
         QAPI_LIST_PREPEND(ret, build_guest_fsinfo(mount, &local_err));
         if (local_err) {
             error_propagate(errp, local_err);
             qapi_free_GuestFilesystemInfoList(ret);
             ret = NULL;
             break;
         }
     }
 
     free_fs_mount_list(&mounts);
     return ret;
 }
 #endif /* CONFIG_FSFREEZE */
 
 #if defined(CONFIG_FSTRIM)
 /*
  * Walk list of mounted file systems in the guest, and trim them.
  */
 GuestFilesystemTrimResponse *
 qmp_guest_fstrim(bool has_minimum, int64_t minimum, Error **errp)
 {
     GuestFilesystemTrimResponse *response;
     GuestFilesystemTrimResult *result;
     int ret = 0;
     FsMountList mounts;
     struct FsMount *mount;
     int fd;
     struct fstrim_range r;
 
     slog("guest-fstrim called");
 
     QTAILQ_INIT(&mounts);
     if (!build_fs_mount_list(&mounts, errp)) {
         return NULL;
     }
 
     response = g_malloc0(sizeof(*response));
 
     QTAILQ_FOREACH(mount, &mounts, next) {
         result = g_malloc0(sizeof(*result));
         result->path = g_strdup(mount->dirname);
 
         QAPI_LIST_PREPEND(response->paths, result);
 
         fd = qga_open_cloexec(mount->dirname, O_RDONLY, 0);
         if (fd == -1) {
             result->error = g_strdup_printf("failed to open: %s",
                                             strerror(errno));
             result->has_error = true;
             continue;
         }
 
         /* We try to cull filesystems we know won't work in advance, but other
          * filesystems may not implement fstrim for less obvious reasons.
          * These will report EOPNOTSUPP; while in some other cases ENOTTY
          * will be reported (e.g. CD-ROMs).
          * Any other error means an unexpected error.
          */
         r.start = 0;
         r.len = -1;
         r.minlen = has_minimum ? minimum : 0;
         ret = ioctl(fd, FITRIM, &r);
         if (ret == -1) {
             result->has_error = true;
             if (errno == ENOTTY || errno == EOPNOTSUPP) {
                 result->error = g_strdup("trim not supported");
             } else {
                 result->error = g_strdup_printf("failed to trim: %s",
                                                 strerror(errno));
             }
             close(fd);
             continue;
         }
 
         result->has_minimum = true;
         result->minimum = r.minlen;
         result->has_trimmed = true;
         result->trimmed = r.len;
         close(fd);
     }
 
     free_fs_mount_list(&mounts);
     return response;
 }
 #endif /* CONFIG_FSTRIM */
 
 
 #define LINUX_SYS_STATE_FILE "/sys/power/state"
 #define SUSPEND_SUPPORTED 0
 #define SUSPEND_NOT_SUPPORTED 1
 
 typedef enum {
     SUSPEND_MODE_DISK = 0,
     SUSPEND_MODE_RAM = 1,
     SUSPEND_MODE_HYBRID = 2,
 } SuspendMode;
 
 /*
  * Executes a command in a child process using g_spawn_sync,
  * returning an int >= 0 representing the exit status of the
  * process.
  *
  * If the program wasn't found in path, returns -1.
  *
  * If a problem happened when creating the child process,
  * returns -1 and errp is set.
  */
 static int run_process_child(const char *command[], Error **errp)
 {
     int exit_status, spawn_flag;
     GError *g_err = NULL;
     bool success;
 
     spawn_flag = G_SPAWN_SEARCH_PATH | G_SPAWN_STDOUT_TO_DEV_NULL |
                  G_SPAWN_STDERR_TO_DEV_NULL;
 
     success =  g_spawn_sync(NULL, (char **)command, NULL, spawn_flag,
                             NULL, NULL, NULL, NULL,
                             &exit_status, &g_err);
 
     if (success) {
         return WEXITSTATUS(exit_status);
     }
 
     if (g_err && (g_err->code != G_SPAWN_ERROR_NOENT)) {
         error_setg(errp, "failed to create child process, error '%s'",
                    g_err->message);
     }
 
     g_error_free(g_err);
     return -1;
 }
 
 static bool systemd_supports_mode(SuspendMode mode, Error **errp)
 {
     const char *systemctl_args[3] = {"systemd-hibernate", "systemd-suspend",
                                      "systemd-hybrid-sleep"};
     const char *cmd[4] = {"systemctl", "status", systemctl_args[mode], NULL};
     int status;
 
     status = run_process_child(cmd, errp);
 
     /*
      * systemctl status uses LSB return codes so we can expect
      * status > 0 and be ok. To assert if the guest has support
      * for the selected suspend mode, status should be < 4. 4 is
      * the code for unknown service status, the return value when
      * the service does not exist. A common value is status = 3
      * (program is not running).
      */
     if (status > 0 && status < 4) {
         return true;
     }
 
     return false;
 }
 
 static void systemd_suspend(SuspendMode mode, Error **errp)
 {
     Error *local_err = NULL;
     const char *systemctl_args[3] = {"hibernate", "suspend", "hybrid-sleep"};
     const char *cmd[3] = {"systemctl", systemctl_args[mode], NULL};
     int status;
 
     status = run_process_child(cmd, &local_err);
 
     if (status == 0) {
         return;
     }
 
     if ((status == -1) && !local_err) {
         error_setg(errp, "the helper program 'systemctl %s' was not found",
                    systemctl_args[mode]);
         return;
     }
 
     if (local_err) {
         error_propagate(errp, local_err);
     } else {
         error_setg(errp, "the helper program 'systemctl %s' returned an "
                    "unexpected exit status code (%d)",
                    systemctl_args[mode], status);
     }
 }
 
 static bool pmutils_supports_mode(SuspendMode mode, Error **errp)
 {
     Error *local_err = NULL;
     const char *pmutils_args[3] = {"--hibernate", "--suspend",
                                    "--suspend-hybrid"};
     const char *cmd[3] = {"pm-is-supported", pmutils_args[mode], NULL};
     int status;
 
     status = run_process_child(cmd, &local_err);
 
     if (status == SUSPEND_SUPPORTED) {
         return true;
     }
 
     if ((status == -1) && !local_err) {
         return false;
     }
 
     if (local_err) {
         error_propagate(errp, local_err);
     } else {
         error_setg(errp,
                    "the helper program '%s' returned an unexpected exit"
                    " status code (%d)", "pm-is-supported", status);
     }
 
     return false;
 }
 
 static void pmutils_suspend(SuspendMode mode, Error **errp)
 {
     Error *local_err = NULL;
     const char *pmutils_binaries[3] = {"pm-hibernate", "pm-suspend",
                                        "pm-suspend-hybrid"};
     const char *cmd[2] = {pmutils_binaries[mode], NULL};
     int status;
 
     status = run_process_child(cmd, &local_err);
 
     if (status == 0) {
         return;
     }
 
     if ((status == -1) && !local_err) {
         error_setg(errp, "the helper program '%s' was not found",
                    pmutils_binaries[mode]);
         return;
     }
 
     if (local_err) {
         error_propagate(errp, local_err);
     } else {
         error_setg(errp,
                    "the helper program '%s' returned an unexpected exit"
                    " status code (%d)", pmutils_binaries[mode], status);
     }
 }
 
 static bool linux_sys_state_supports_mode(SuspendMode mode, Error **errp)
 {
     const char *sysfile_strs[3] = {"disk", "mem", NULL};
     const char *sysfile_str = sysfile_strs[mode];
     char buf[32]; /* hopefully big enough */
     int fd;
     ssize_t ret;
 
     if (!sysfile_str) {
         error_setg(errp, "unknown guest suspend mode");
         return false;
     }
 
     fd = open(LINUX_SYS_STATE_FILE, O_RDONLY);
     if (fd < 0) {
         return false;
     }
 
     ret = read(fd, buf, sizeof(buf) - 1);
     close(fd);
     if (ret <= 0) {
         return false;
     }
     buf[ret] = '\0';
 
     if (strstr(buf, sysfile_str)) {
         return true;
     }
     return false;
 }
 
 static void linux_sys_state_suspend(SuspendMode mode, Error **errp)
 {
     Error *local_err = NULL;
     const char *sysfile_strs[3] = {"disk", "mem", NULL};
     const char *sysfile_str = sysfile_strs[mode];
     pid_t pid;
     int status;
 
     if (!sysfile_str) {
         error_setg(errp, "unknown guest suspend mode");
         return;
     }
 
     pid = fork();
     if (!pid) {
         /* child */
         int fd;
 
         setsid();
         reopen_fd_to_null(0);
         reopen_fd_to_null(1);
         reopen_fd_to_null(2);
 
         fd = open(LINUX_SYS_STATE_FILE, O_WRONLY);
         if (fd < 0) {
             _exit(EXIT_FAILURE);
         }
 
         if (write(fd, sysfile_str, strlen(sysfile_str)) < 0) {
             _exit(EXIT_FAILURE);
         }
 
         _exit(EXIT_SUCCESS);
     } else if (pid < 0) {
         error_setg_errno(errp, errno, "failed to create child process");
         return;
     }
 
     ga_wait_child(pid, &status, &local_err);
     if (local_err) {
         error_propagate(errp, local_err);
         return;
     }
 
     if (WEXITSTATUS(status)) {
         error_setg(errp, "child process has failed to suspend");
     }
 
 }
 
 static void guest_suspend(SuspendMode mode, Error **errp)
 {
     Error *local_err = NULL;
     bool mode_supported = false;
 
     if (systemd_supports_mode(mode, &local_err)) {
         mode_supported = true;
         systemd_suspend(mode, &local_err);
     }
 
     if (!local_err) {
         return;
     }
 
     error_free(local_err);
     local_err = NULL;
 
     if (pmutils_supports_mode(mode, &local_err)) {
         mode_supported = true;
         pmutils_suspend(mode, &local_err);
     }
 
     if (!local_err) {
         return;
     }
 
     error_free(local_err);
     local_err = NULL;
 
     if (linux_sys_state_supports_mode(mode, &local_err)) {
         mode_supported = true;
         linux_sys_state_suspend(mode, &local_err);
     }
 
     if (!mode_supported) {
         error_free(local_err);
         error_setg(errp,
                    "the requested suspend mode is not supported by the guest");
     } else {
         error_propagate(errp, local_err);
     }
 }
 
 void qmp_guest_suspend_disk(Error **errp)
 {
     guest_suspend(SUSPEND_MODE_DISK, errp);
 }
 
 void qmp_guest_suspend_ram(Error **errp)
 {
     guest_suspend(SUSPEND_MODE_RAM, errp);
 }
 
 void qmp_guest_suspend_hybrid(Error **errp)
 {
     guest_suspend(SUSPEND_MODE_HYBRID, errp);
 }
 
 /* Transfer online/offline status between @vcpu and the guest system.
  *
  * On input either @errp or *@errp must be NULL.
  *
  * In system-to-@vcpu direction, the following @vcpu fields are accessed:
  * - R: vcpu->logical_id
  * - W: vcpu->online
  * - W: vcpu->can_offline
  *
  * In @vcpu-to-system direction, the following @vcpu fields are accessed:
  * - R: vcpu->logical_id
  * - R: vcpu->online
  *
  * Written members remain unmodified on error.
  */
 static void transfer_vcpu(GuestLogicalProcessor *vcpu, bool sys2vcpu,
                           char *dirpath, Error **errp)
 {
     int fd;
     int res;
     int dirfd;
     static const char fn[] = "online";
 
     dirfd = open(dirpath, O_RDONLY | O_DIRECTORY);
     if (dirfd == -1) {
         error_setg_errno(errp, errno, "open(\"%s\")", dirpath);
         return;
     }
 
     fd = openat(dirfd, fn, sys2vcpu ? O_RDONLY : O_RDWR);
     if (fd == -1) {
         if (errno != ENOENT) {
             error_setg_errno(errp, errno, "open(\"%s/%s\")", dirpath, fn);
         } else if (sys2vcpu) {
             vcpu->online = true;
             vcpu->can_offline = false;
         } else if (!vcpu->online) {
             error_setg(errp, "logical processor #%" PRId64 " can't be "
                        "offlined", vcpu->logical_id);
         } /* otherwise pretend successful re-onlining */
     } else {
         unsigned char status;
 
         res = pread(fd, &status, 1, 0);
         if (res == -1) {
             error_setg_errno(errp, errno, "pread(\"%s/%s\")", dirpath, fn);
         } else if (res == 0) {
             error_setg(errp, "pread(\"%s/%s\"): unexpected EOF", dirpath,
                        fn);
         } else if (sys2vcpu) {
             vcpu->online = (status != '0');
             vcpu->can_offline = true;
         } else if (vcpu->online != (status != '0')) {
             status = '0' + vcpu->online;
             if (pwrite(fd, &status, 1, 0) == -1) {
                 error_setg_errno(errp, errno, "pwrite(\"%s/%s\")", dirpath,
                                  fn);
             }
         } /* otherwise pretend successful re-(on|off)-lining */
 
         res = close(fd);
         g_assert(res == 0);
     }
 
     res = close(dirfd);
     g_assert(res == 0);
 }
 
 GuestLogicalProcessorList *qmp_guest_get_vcpus(Error **errp)
 {
     GuestLogicalProcessorList *head, **tail;
     const char *cpu_dir = "/sys/devices/system/cpu";
     const gchar *line;
     g_autoptr(GDir) cpu_gdir = NULL;
     Error *local_err = NULL;
 
     head = NULL;
     tail = &head;
     cpu_gdir = g_dir_open(cpu_dir, 0, NULL);
 
     if (cpu_gdir == NULL) {
         error_setg_errno(errp, errno, "failed to list entries: %s", cpu_dir);
         return NULL;
     }
 
     while (local_err == NULL && (line = g_dir_read_name(cpu_gdir)) != NULL) {
         GuestLogicalProcessor *vcpu;
         int64_t id;
         if (sscanf(line, "cpu%" PRId64, &id)) {
             g_autofree char *path = g_strdup_printf("/sys/devices/system/cpu/"
                                                     "cpu%" PRId64 "/", id);
             vcpu = g_malloc0(sizeof *vcpu);
             vcpu->logical_id = id;
             vcpu->has_can_offline = true; /* lolspeak ftw */
             transfer_vcpu(vcpu, true, path, &local_err);
             QAPI_LIST_APPEND(tail, vcpu);
         }
     }
 
     if (local_err == NULL) {
         /* there's no guest with zero VCPUs */
         g_assert(head != NULL);
         return head;
     }
 
     qapi_free_GuestLogicalProcessorList(head);
     error_propagate(errp, local_err);
     return NULL;
 }
 
 int64_t qmp_guest_set_vcpus(GuestLogicalProcessorList *vcpus, Error **errp)
 {
     int64_t processed;
     Error *local_err = NULL;
 
     processed = 0;
     while (vcpus != NULL) {
         char *path = g_strdup_printf("/sys/devices/system/cpu/cpu%" PRId64 "/",
                                      vcpus->value->logical_id);
 
         transfer_vcpu(vcpus->value, false, path, &local_err);
         g_free(path);
         if (local_err != NULL) {
             break;
         }
         ++processed;
         vcpus = vcpus->next;
     }
 
     if (local_err != NULL) {
         if (processed == 0) {
             error_propagate(errp, local_err);
         } else {
             error_free(local_err);
         }
     }
 
     return processed;
 }
 #endif /* __linux__ */
 
 #if defined(__linux__) || defined(__FreeBSD__)
 void qmp_guest_set_user_password(const char *username,
                                  const char *password,
                                  bool crypted,
                                  Error **errp)
 {
     Error *local_err = NULL;
     char *passwd_path = NULL;
     pid_t pid;
     int status;
     int datafd[2] = { -1, -1 };
     char *rawpasswddata = NULL;
     size_t rawpasswdlen;
     char *chpasswddata = NULL;
     size_t chpasswdlen;
 
     rawpasswddata = (char *)qbase64_decode(password, -1, &rawpasswdlen, errp);
     if (!rawpasswddata) {
         return;
     }
     rawpasswddata = g_renew(char, rawpasswddata, rawpasswdlen + 1);
     rawpasswddata[rawpasswdlen] = '\0';
 
     if (strchr(rawpasswddata, '\n')) {
         error_setg(errp, "forbidden characters in raw password");
         goto out;
     }
 
     if (strchr(username, '\n') ||
         strchr(username, ':')) {
         error_setg(errp, "forbidden characters in username");
         goto out;
     }
 
 #ifdef __FreeBSD__
     chpasswddata = g_strdup(rawpasswddata);
     passwd_path = g_find_program_in_path("pw");
 #else
     chpasswddata = g_strdup_printf("%s:%s\n", username, rawpasswddata);
     passwd_path = g_find_program_in_path("chpasswd");
 #endif
 
     chpasswdlen = strlen(chpasswddata);
 
     if (!passwd_path) {
         error_setg(errp, "cannot find 'passwd' program in PATH");
         goto out;
     }
 
     if (!g_unix_open_pipe(datafd, FD_CLOEXEC, NULL)) {
         error_setg(errp, "cannot create pipe FDs");
         goto out;
     }
 
     pid = fork();
     if (pid == 0) {
         close(datafd[1]);
         /* child */
         setsid();
         dup2(datafd[0], 0);
         reopen_fd_to_null(1);
         reopen_fd_to_null(2);
 
 #ifdef __FreeBSD__
         const char *h_arg;
         h_arg = (crypted) ? "-H" : "-h";
         execl(passwd_path, "pw", "usermod", "-n", username, h_arg, "0", NULL);
 #else
         if (crypted) {
             execl(passwd_path, "chpasswd", "-e", NULL);
         } else {
             execl(passwd_path, "chpasswd", NULL);
         }
 #endif
         _exit(EXIT_FAILURE);
     } else if (pid < 0) {
         error_setg_errno(errp, errno, "failed to create child process");
         goto out;
     }
     close(datafd[0]);
     datafd[0] = -1;
 
     if (qemu_write_full(datafd[1], chpasswddata, chpasswdlen) != chpasswdlen) {
         error_setg_errno(errp, errno, "cannot write new account password");
         goto out;
     }
     close(datafd[1]);
     datafd[1] = -1;
 
     ga_wait_child(pid, &status, &local_err);
     if (local_err) {
         error_propagate(errp, local_err);
         goto out;
     }
 
     if (!WIFEXITED(status)) {
         error_setg(errp, "child process has terminated abnormally");
         goto out;
     }
 
     if (WEXITSTATUS(status)) {
         error_setg(errp, "child process has failed to set user password");
         goto out;
     }
 
 out:
     g_free(chpasswddata);
     g_free(rawpasswddata);
     g_free(passwd_path);
     if (datafd[0] != -1) {
         close(datafd[0]);
     }
     if (datafd[1] != -1) {
         close(datafd[1]);
     }
 }
 #else /* __linux__ || __FreeBSD__ */
 void qmp_guest_set_user_password(const char *username,
                                  const char *password,
                                  bool crypted,
                                  Error **errp)
 {
     error_setg(errp, QERR_UNSUPPORTED);
 }
 #endif /* __linux__ || __FreeBSD__ */
 
 #ifdef __linux__
 static void ga_read_sysfs_file(int dirfd, const char *pathname, char *buf,
                                int size, Error **errp)
 {
     int fd;
     int res;
 
     errno = 0;
     fd = openat(dirfd, pathname, O_RDONLY);
     if (fd == -1) {
         error_setg_errno(errp, errno, "open sysfs file \"%s\"", pathname);
         return;
     }
 
     res = pread(fd, buf, size, 0);
     if (res == -1) {
         error_setg_errno(errp, errno, "pread sysfs file \"%s\"", pathname);
     } else if (res == 0) {
         error_setg(errp, "pread sysfs file \"%s\": unexpected EOF", pathname);
     }
     close(fd);
 }
 
 static void ga_write_sysfs_file(int dirfd, const char *pathname,
                                 const char *buf, int size, Error **errp)
 {
     int fd;
 
     errno = 0;
     fd = openat(dirfd, pathname, O_WRONLY);
     if (fd == -1) {
         error_setg_errno(errp, errno, "open sysfs file \"%s\"", pathname);
         return;
     }
 
     if (pwrite(fd, buf, size, 0) == -1) {
         error_setg_errno(errp, errno, "pwrite sysfs file \"%s\"", pathname);
     }
 
     close(fd);
 }
 
 /* Transfer online/offline status between @mem_blk and the guest system.
  *
  * On input either @errp or *@errp must be NULL.
  *
  * In system-to-@mem_blk direction, the following @mem_blk fields are accessed:
  * - R: mem_blk->phys_index
  * - W: mem_blk->online
  * - W: mem_blk->can_offline
  *
  * In @mem_blk-to-system direction, the following @mem_blk fields are accessed:
  * - R: mem_blk->phys_index
  * - R: mem_blk->online
  *-  R: mem_blk->can_offline
  * Written members remain unmodified on error.
  */
 static void transfer_memory_block(GuestMemoryBlock *mem_blk, bool sys2memblk,
                                   GuestMemoryBlockResponse *result,
                                   Error **errp)
 {
     char *dirpath;
     int dirfd;
     char *status;
     Error *local_err = NULL;
 
     if (!sys2memblk) {
         DIR *dp;
 
         if (!result) {
             error_setg(errp, "Internal error, 'result' should not be NULL");
             return;
         }
         errno = 0;
         dp = opendir("/sys/devices/system/memory/");
          /* if there is no 'memory' directory in sysfs,
          * we think this VM does not support online/offline memory block,
          * any other solution?
          */
         if (!dp) {
             if (errno == ENOENT) {
                 result->response =
                     GUEST_MEMORY_BLOCK_RESPONSE_TYPE_OPERATION_NOT_SUPPORTED;
             }
             goto out1;
         }
         closedir(dp);
     }
 
     dirpath = g_strdup_printf("/sys/devices/system/memory/memory%" PRId64 "/",
                               mem_blk->phys_index);
     dirfd = open(dirpath, O_RDONLY | O_DIRECTORY);
     if (dirfd == -1) {
         if (sys2memblk) {
             error_setg_errno(errp, errno, "open(\"%s\")", dirpath);
         } else {
             if (errno == ENOENT) {
                 result->response = GUEST_MEMORY_BLOCK_RESPONSE_TYPE_NOT_FOUND;
             } else {
                 result->response =
                     GUEST_MEMORY_BLOCK_RESPONSE_TYPE_OPERATION_FAILED;
             }
         }
         g_free(dirpath);
         goto out1;
     }
     g_free(dirpath);
 
     status = g_malloc0(10);
     ga_read_sysfs_file(dirfd, "state", status, 10, &local_err);
     if (local_err) {
         /* treat with sysfs file that not exist in old kernel */
         if (errno == ENOENT) {
             error_free(local_err);
             if (sys2memblk) {
                 mem_blk->online = true;
                 mem_blk->can_offline = false;
             } else if (!mem_blk->online) {
                 result->response =
                     GUEST_MEMORY_BLOCK_RESPONSE_TYPE_OPERATION_NOT_SUPPORTED;
             }
         } else {
             if (sys2memblk) {
                 error_propagate(errp, local_err);
             } else {
                 error_free(local_err);
                 result->response =
                     GUEST_MEMORY_BLOCK_RESPONSE_TYPE_OPERATION_FAILED;
             }
         }
         goto out2;
     }
 
     if (sys2memblk) {
         char removable = '0';
 
         mem_blk->online = (strncmp(status, "online", 6) == 0);
 
         ga_read_sysfs_file(dirfd, "removable", &removable, 1, &local_err);
         if (local_err) {
             /* if no 'removable' file, it doesn't support offline mem blk */
             if (errno == ENOENT) {
                 error_free(local_err);
                 mem_blk->can_offline = false;
             } else {
                 error_propagate(errp, local_err);
             }
         } else {
             mem_blk->can_offline = (removable != '0');
         }
     } else {
         if (mem_blk->online != (strncmp(status, "online", 6) == 0)) {
             const char *new_state = mem_blk->online ? "online" : "offline";
 
             ga_write_sysfs_file(dirfd, "state", new_state, strlen(new_state),
                                 &local_err);
             if (local_err) {
                 error_free(local_err);
                 result->response =
                     GUEST_MEMORY_BLOCK_RESPONSE_TYPE_OPERATION_FAILED;
                 goto out2;
             }
 
             result->response = GUEST_MEMORY_BLOCK_RESPONSE_TYPE_SUCCESS;
             result->has_error_code = false;
         } /* otherwise pretend successful re-(on|off)-lining */
     }
     g_free(status);
     close(dirfd);
     return;
 
 out2:
     g_free(status);
     close(dirfd);
 out1:
     if (!sys2memblk) {
         result->has_error_code = true;
         result->error_code = errno;
     }
 }
 
 GuestMemoryBlockList *qmp_guest_get_memory_blocks(Error **errp)
 {
     GuestMemoryBlockList *head, **tail;
     Error *local_err = NULL;
     struct dirent *de;
     DIR *dp;
 
     head = NULL;
     tail = &head;
 
     dp = opendir("/sys/devices/system/memory/");
     if (!dp) {
         /* it's ok if this happens to be a system that doesn't expose
          * memory blocks via sysfs, but otherwise we should report
          * an error
          */
         if (errno != ENOENT) {
             error_setg_errno(errp, errno, "Can't open directory"
                              "\"/sys/devices/system/memory/\"");
         }
         return NULL;
     }
 
     /* Note: the phys_index of memory block may be discontinuous,
      * this is because a memblk is the unit of the Sparse Memory design, which
      * allows discontinuous memory ranges (ex. NUMA), so here we should
      * traverse the memory block directory.
      */
     while ((de = readdir(dp)) != NULL) {
         GuestMemoryBlock *mem_blk;
 
         if ((strncmp(de->d_name, "memory", 6) != 0) ||
             !(de->d_type & DT_DIR)) {
             continue;
         }
 
         mem_blk = g_malloc0(sizeof *mem_blk);
         /* The d_name is "memoryXXX",  phys_index is block id, same as XXX */
         mem_blk->phys_index = strtoul(&de->d_name[6], NULL, 10);
         mem_blk->has_can_offline = true; /* lolspeak ftw */
         transfer_memory_block(mem_blk, true, NULL, &local_err);
         if (local_err) {
             break;
         }
 
         QAPI_LIST_APPEND(tail, mem_blk);
     }
 
     closedir(dp);
     if (local_err == NULL) {
         /* there's no guest with zero memory blocks */
         if (head == NULL) {
             error_setg(errp, "guest reported zero memory blocks!");
         }
         return head;
     }
 
     qapi_free_GuestMemoryBlockList(head);
     error_propagate(errp, local_err);
     return NULL;
 }
 
 GuestMemoryBlockResponseList *
 qmp_guest_set_memory_blocks(GuestMemoryBlockList *mem_blks, Error **errp)
 {
     GuestMemoryBlockResponseList *head, **tail;
     Error *local_err = NULL;
 
     head = NULL;
     tail = &head;
 
     while (mem_blks != NULL) {
         GuestMemoryBlockResponse *result;
         GuestMemoryBlock *current_mem_blk = mem_blks->value;
 
         result = g_malloc0(sizeof(*result));
         result->phys_index = current_mem_blk->phys_index;
         transfer_memory_block(current_mem_blk, false, result, &local_err);
         if (local_err) { /* should never happen */
             goto err;
         }
 
         QAPI_LIST_APPEND(tail, result);
         mem_blks = mem_blks->next;
     }
 
     return head;
 err:
     qapi_free_GuestMemoryBlockResponseList(head);
     error_propagate(errp, local_err);
     return NULL;
 }
 
 GuestMemoryBlockInfo *qmp_guest_get_memory_block_info(Error **errp)
 {
     Error *local_err = NULL;
     char *dirpath;
     int dirfd;
     char *buf;
     GuestMemoryBlockInfo *info;
 
     dirpath = g_strdup_printf("/sys/devices/system/memory/");
     dirfd = open(dirpath, O_RDONLY | O_DIRECTORY);
     if (dirfd == -1) {
         error_setg_errno(errp, errno, "open(\"%s\")", dirpath);
         g_free(dirpath);
         return NULL;
     }
     g_free(dirpath);
 
     buf = g_malloc0(20);
     ga_read_sysfs_file(dirfd, "block_size_bytes", buf, 20, &local_err);
     close(dirfd);
     if (local_err) {
         g_free(buf);
         error_propagate(errp, local_err);
         return NULL;
     }
 
     info = g_new0(GuestMemoryBlockInfo, 1);
     info->size = strtol(buf, NULL, 16); /* the unit is bytes */
 
     g_free(buf);
 
     return info;
 }
 
 #define MAX_NAME_LEN 128
 static GuestDiskStatsInfoList *guest_get_diskstats(Error **errp)
 {
 #ifdef CONFIG_LINUX
     GuestDiskStatsInfoList *head = NULL, **tail = &head;
     const char *diskstats = "/proc/diskstats";
     FILE *fp;
     size_t n;
     char *line = NULL;
 
     fp = fopen(diskstats, "r");
     if (fp  == NULL) {
         error_setg_errno(errp, errno, "open(\"%s\")", diskstats);
         return NULL;
     }
 
     while (getline(&line, &n, fp) != -1) {
         g_autofree GuestDiskStatsInfo *diskstatinfo = NULL;
         g_autofree GuestDiskStats *diskstat = NULL;
         char dev_name[MAX_NAME_LEN];
         unsigned int ios_pgr, tot_ticks, rq_ticks, wr_ticks, dc_ticks, fl_ticks;
         unsigned long rd_ios, rd_merges_or_rd_sec, rd_ticks_or_wr_sec, wr_ios;
         unsigned long wr_merges, rd_sec_or_wr_ios, wr_sec;
         unsigned long dc_ios, dc_merges, dc_sec, fl_ios;
         unsigned int major, minor;
         int i;
 
         i = sscanf(line, "%u %u %s %lu %lu %lu"
                    "%lu %lu %lu %lu %u %u %u %u"
                    "%lu %lu %lu %u %lu %u",
                    &major, &minor, dev_name,
                    &rd_ios, &rd_merges_or_rd_sec, &rd_sec_or_wr_ios,
                    &rd_ticks_or_wr_sec, &wr_ios, &wr_merges, &wr_sec,
                    &wr_ticks, &ios_pgr, &tot_ticks, &rq_ticks,
                    &dc_ios, &dc_merges, &dc_sec, &dc_ticks,
                    &fl_ios, &fl_ticks);
 
         if (i < 7) {
             continue;
         }
 
         diskstatinfo = g_new0(GuestDiskStatsInfo, 1);
         diskstatinfo->name = g_strdup(dev_name);
         diskstatinfo->major = major;
         diskstatinfo->minor = minor;
 
         diskstat = g_new0(GuestDiskStats, 1);
         if (i == 7) {
             diskstat->has_read_ios = true;
             diskstat->read_ios = rd_ios;
             diskstat->has_read_sectors = true;
             diskstat->read_sectors = rd_merges_or_rd_sec;
             diskstat->has_write_ios = true;
             diskstat->write_ios = rd_sec_or_wr_ios;
             diskstat->has_write_sectors = true;
             diskstat->write_sectors = rd_ticks_or_wr_sec;
         }
         if (i >= 14) {
             diskstat->has_read_ios = true;
             diskstat->read_ios = rd_ios;
             diskstat->has_read_sectors = true;
             diskstat->read_sectors = rd_sec_or_wr_ios;
             diskstat->has_read_merges = true;
             diskstat->read_merges = rd_merges_or_rd_sec;
             diskstat->has_read_ticks = true;
             diskstat->read_ticks = rd_ticks_or_wr_sec;
             diskstat->has_write_ios = true;
             diskstat->write_ios = wr_ios;
             diskstat->has_write_sectors = true;
             diskstat->write_sectors = wr_sec;
             diskstat->has_write_merges = true;
             diskstat->write_merges = wr_merges;
             diskstat->has_write_ticks = true;
             diskstat->write_ticks = wr_ticks;
             diskstat->has_ios_pgr = true;
             diskstat->ios_pgr = ios_pgr;
             diskstat->has_total_ticks = true;
             diskstat->total_ticks = tot_ticks;
             diskstat->has_weight_ticks = true;
             diskstat->weight_ticks = rq_ticks;
         }
         if (i >= 18) {
             diskstat->has_discard_ios = true;
             diskstat->discard_ios = dc_ios;
             diskstat->has_discard_merges = true;
             diskstat->discard_merges = dc_merges;
             diskstat->has_discard_sectors = true;
             diskstat->discard_sectors = dc_sec;
             diskstat->has_discard_ticks = true;
             diskstat->discard_ticks = dc_ticks;
         }
         if (i >= 20) {
             diskstat->has_flush_ios = true;
             diskstat->flush_ios = fl_ios;
             diskstat->has_flush_ticks = true;
             diskstat->flush_ticks = fl_ticks;
         }
 
         diskstatinfo->stats = g_steal_pointer(&diskstat);
         QAPI_LIST_APPEND(tail, diskstatinfo);
         diskstatinfo = NULL;
     }
     free(line);
     fclose(fp);
     return head;
 #else
     g_debug("disk stats reporting available only for Linux");
     return NULL;
 #endif
 }
 
 GuestDiskStatsInfoList *qmp_guest_get_diskstats(Error **errp)
 {
     return guest_get_diskstats(errp);
 }
 
 GuestCpuStatsList *qmp_guest_get_cpustats(Error **errp)
 {
     GuestCpuStatsList *head = NULL, **tail = &head;
     const char *cpustats = "/proc/stat";
     int clk_tck = sysconf(_SC_CLK_TCK);
     FILE *fp;
     size_t n;
     char *line = NULL;
 
     fp = fopen(cpustats, "r");
     if (fp  == NULL) {
         error_setg_errno(errp, errno, "open(\"%s\")", cpustats);
         return NULL;
     }
 
     while (getline(&line, &n, fp) != -1) {
         GuestCpuStats *cpustat = NULL;
         GuestLinuxCpuStats *linuxcpustat;
         int i;
         unsigned long user, system, idle, iowait, irq, softirq, steal, guest;
         unsigned long nice, guest_nice;
         char name[64];
 
         i = sscanf(line, "%s %lu %lu %lu %lu %lu %lu %lu %lu %lu %lu",
                    name, &user, &nice, &system, &idle, &iowait, &irq, &softirq,
                    &steal, &guest, &guest_nice);
 
         /* drop "cpu 1 2 3 ...", get "cpuX 1 2 3 ..." only */
         if ((i == EOF) || strncmp(name, "cpu", 3) || (name[3] == '\0')) {
             continue;
         }
 
         if (i < 5) {
             slog("Parsing cpu stat from %s failed, see \"man proc\"", cpustats);
             break;
         }
 
         cpustat = g_new0(GuestCpuStats, 1);
         cpustat->type = GUEST_CPU_STATS_TYPE_LINUX;
 
         linuxcpustat = &cpustat->u.q_linux;
         linuxcpustat->cpu = atoi(&name[3]);
         linuxcpustat->user = user * 1000 / clk_tck;
         linuxcpustat->nice = nice * 1000 / clk_tck;
         linuxcpustat->system = system * 1000 / clk_tck;
         linuxcpustat->idle = idle * 1000 / clk_tck;
 
         if (i > 5) {
             linuxcpustat->has_iowait = true;
             linuxcpustat->iowait = iowait * 1000 / clk_tck;
         }
 
         if (i > 6) {
             linuxcpustat->has_irq = true;
             linuxcpustat->irq = irq * 1000 / clk_tck;
             linuxcpustat->has_softirq = true;
             linuxcpustat->softirq = softirq * 1000 / clk_tck;
         }
 
         if (i > 8) {
             linuxcpustat->has_steal = true;
             linuxcpustat->steal = steal * 1000 / clk_tck;
         }
 
         if (i > 9) {
             linuxcpustat->has_guest = true;
             linuxcpustat->guest = guest * 1000 / clk_tck;
         }
 
         if (i > 10) {
             linuxcpustat->has_guest = true;
             linuxcpustat->guest = guest * 1000 / clk_tck;
             linuxcpustat->has_guestnice = true;
             linuxcpustat->guestnice = guest_nice * 1000 / clk_tck;
         }
 
         QAPI_LIST_APPEND(tail, cpustat);
     }
 
     free(line);
     fclose(fp);
     return head;
 }
 
 #else /* defined(__linux__) */
 
 void qmp_guest_suspend_disk(Error **errp)
 {
     error_setg(errp, QERR_UNSUPPORTED);
 }
 
 void qmp_guest_suspend_ram(Error **errp)
 {
     error_setg(errp, QERR_UNSUPPORTED);
 }
 
 void qmp_guest_suspend_hybrid(Error **errp)
 {
     error_setg(errp, QERR_UNSUPPORTED);
 }
 
 GuestLogicalProcessorList *qmp_guest_get_vcpus(Error **errp)
 {
     error_setg(errp, QERR_UNSUPPORTED);
     return NULL;
 }
 
 int64_t qmp_guest_set_vcpus(GuestLogicalProcessorList *vcpus, Error **errp)
 {
     error_setg(errp, QERR_UNSUPPORTED);
     return -1;
 }
 
 GuestMemoryBlockList *qmp_guest_get_memory_blocks(Error **errp)
 {
     error_setg(errp, QERR_UNSUPPORTED);
     return NULL;
 }
 
 GuestMemoryBlockResponseList *
 qmp_guest_set_memory_blocks(GuestMemoryBlockList *mem_blks, Error **errp)
 {
     error_setg(errp, QERR_UNSUPPORTED);
     return NULL;
 }
 
 GuestMemoryBlockInfo *qmp_guest_get_memory_block_info(Error **errp)
 {
     error_setg(errp, QERR_UNSUPPORTED);
     return NULL;
 }
 
 #endif
 
 #ifdef HAVE_GETIFADDRS
 static GuestNetworkInterface *
 guest_find_interface(GuestNetworkInterfaceList *head,
                      const char *name)
 {
     for (; head; head = head->next) {
         if (strcmp(head->value->name, name) == 0) {
             return head->value;
         }
     }
 
     return NULL;
 }
 
 static int guest_get_network_stats(const char *name,
                        GuestNetworkInterfaceStat *stats)
 {
 #ifdef CONFIG_LINUX
     int name_len;
     char const *devinfo = "/proc/net/dev";
     FILE *fp;
     char *line = NULL, *colon;
     size_t n = 0;
     fp = fopen(devinfo, "r");
     if (!fp) {
         g_debug("failed to open network stats %s: %s", devinfo,
                 g_strerror(errno));
         return -1;
     }
     name_len = strlen(name);
     while (getline(&line, &n, fp) != -1) {
         long long dummy;
         long long rx_bytes;
         long long rx_packets;
         long long rx_errs;
         long long rx_dropped;
         long long tx_bytes;
         long long tx_packets;
         long long tx_errs;
         long long tx_dropped;
         char *trim_line;
         trim_line = g_strchug(line);
         if (trim_line[0] == '\0') {
             continue;
         }
         colon = strchr(trim_line, ':');
         if (!colon) {
             continue;
         }
         if (colon - name_len  == trim_line &&
            strncmp(trim_line, name, name_len) == 0) {
             if (sscanf(colon + 1,
                 "%lld %lld %lld %lld %lld %lld %lld %lld %lld %lld %lld %lld %lld %lld %lld %lld",
                   &rx_bytes, &rx_packets, &rx_errs, &rx_dropped,
                   &dummy, &dummy, &dummy, &dummy,
                   &tx_bytes, &tx_packets, &tx_errs, &tx_dropped,
                   &dummy, &dummy, &dummy, &dummy) != 16) {
                 continue;
             }
             stats->rx_bytes = rx_bytes;
             stats->rx_packets = rx_packets;
             stats->rx_errs = rx_errs;
             stats->rx_dropped = rx_dropped;
             stats->tx_bytes = tx_bytes;
             stats->tx_packets = tx_packets;
             stats->tx_errs = tx_errs;
             stats->tx_dropped = tx_dropped;
             fclose(fp);
             g_free(line);
             return 0;
         }
     }
     fclose(fp);
     g_free(line);
     g_debug("/proc/net/dev: Interface '%s' not found", name);
 #else /* !CONFIG_LINUX */
     g_debug("Network stats reporting available only for Linux");
 #endif /* !CONFIG_LINUX */
     return -1;
 }
 
 #ifndef __FreeBSD__
 /*
  * Fill "buf" with MAC address by ifaddrs. Pointer buf must point to a
  * buffer with ETHER_ADDR_LEN length at least.
  *
  * Returns false in case of an error, otherwise true. "obtained" argument
  * is true if a MAC address was obtained successful, otherwise false.
  */
 bool guest_get_hw_addr(struct ifaddrs *ifa, unsigned char *buf,
                        bool *obtained, Error **errp)
 {
     struct ifreq ifr;
     int sock;
 
     *obtained = false;
 
     /* we haven't obtained HW address yet */
     sock = socket(PF_INET, SOCK_STREAM, 0);
     if (sock == -1) {
         error_setg_errno(errp, errno, "failed to create socket");
         return false;
     }
 
     memset(&ifr, 0, sizeof(ifr));
     pstrcpy(ifr.ifr_name, IF_NAMESIZE, ifa->ifa_name);
     if (ioctl(sock, SIOCGIFHWADDR, &ifr) == -1) {
         /*
          * We can't get the hw addr of this interface, but that's not a
          * fatal error.
          */
         if (errno == EADDRNOTAVAIL) {
             /* The interface doesn't have a hw addr (e.g. loopback). */
             g_debug("failed to get MAC address of %s: %s",
                     ifa->ifa_name, strerror(errno));
         } else{
             g_warning("failed to get MAC address of %s: %s",
                       ifa->ifa_name, strerror(errno));
         }
     } else {
 #ifdef CONFIG_SOLARIS
         memcpy(buf, &ifr.ifr_addr.sa_data, ETHER_ADDR_LEN);
 #else
         memcpy(buf, &ifr.ifr_hwaddr.sa_data, ETHER_ADDR_LEN);
 #endif
         *obtained = true;
     }
     close(sock);
     return true;
 }
 #endif /* __FreeBSD__ */
 
 /*
  * Build information about guest interfaces
  */
 GuestNetworkInterfaceList *qmp_guest_network_get_interfaces(Error **errp)
 {
     GuestNetworkInterfaceList *head = NULL, **tail = &head;
     struct ifaddrs *ifap, *ifa;
 
     if (getifaddrs(&ifap) < 0) {
         error_setg_errno(errp, errno, "getifaddrs failed");
         goto error;
     }
 
     for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
         GuestNetworkInterface *info;
         GuestIpAddressList **address_tail;
         GuestIpAddress *address_item = NULL;
         GuestNetworkInterfaceStat *interface_stat = NULL;
         char addr4[INET_ADDRSTRLEN];
         char addr6[INET6_ADDRSTRLEN];
         unsigned char mac_addr[ETHER_ADDR_LEN];
         bool obtained;
         void *p;
 
         g_debug("Processing %s interface", ifa->ifa_name);
 
         info = guest_find_interface(head, ifa->ifa_name);
 
         if (!info) {
             info = g_malloc0(sizeof(*info));
             info->name = g_strdup(ifa->ifa_name);
 
             QAPI_LIST_APPEND(tail, info);
         }
 
         if (!info->has_hardware_address) {
             if (!guest_get_hw_addr(ifa, mac_addr, &obtained, errp)) {
                 goto error;
             }
             if (obtained) {
                 info->hardware_address =
                     g_strdup_printf("%02x:%02x:%02x:%02x:%02x:%02x",
                                     (int) mac_addr[0], (int) mac_addr[1],
                                     (int) mac_addr[2], (int) mac_addr[3],
                                     (int) mac_addr[4], (int) mac_addr[5]);
                 info->has_hardware_address = true;
             }
         }
 
         if (ifa->ifa_addr &&
             ifa->ifa_addr->sa_family == AF_INET) {
             /* interface with IPv4 address */
             p = &((struct sockaddr_in *)ifa->ifa_addr)->sin_addr;
             if (!inet_ntop(AF_INET, p, addr4, sizeof(addr4))) {
                 error_setg_errno(errp, errno, "inet_ntop failed");
                 goto error;
             }
 
             address_item = g_malloc0(sizeof(*address_item));
             address_item->ip_address = g_strdup(addr4);
             address_item->ip_address_type = GUEST_IP_ADDRESS_TYPE_IPV4;
 
             if (ifa->ifa_netmask) {
                 /* Count the number of set bits in netmask.
                  * This is safe as '1' and '0' cannot be shuffled in netmask. */
                 p = &((struct sockaddr_in *)ifa->ifa_netmask)->sin_addr;
                 address_item->prefix = ctpop32(((uint32_t *) p)[0]);
             }
         } else if (ifa->ifa_addr &&
                    ifa->ifa_addr->sa_family == AF_INET6) {
             /* interface with IPv6 address */
             p = &((struct sockaddr_in6 *)ifa->ifa_addr)->sin6_addr;
             if (!inet_ntop(AF_INET6, p, addr6, sizeof(addr6))) {
                 error_setg_errno(errp, errno, "inet_ntop failed");
                 goto error;
             }
 
             address_item = g_malloc0(sizeof(*address_item));
             address_item->ip_address = g_strdup(addr6);
             address_item->ip_address_type = GUEST_IP_ADDRESS_TYPE_IPV6;
 
             if (ifa->ifa_netmask) {
                 /* Count the number of set bits in netmask.
                  * This is safe as '1' and '0' cannot be shuffled in netmask. */
                 p = &((struct sockaddr_in6 *)ifa->ifa_netmask)->sin6_addr;
                 address_item->prefix =
                     ctpop32(((uint32_t *) p)[0]) +
                     ctpop32(((uint32_t *) p)[1]) +
                     ctpop32(((uint32_t *) p)[2]) +
                     ctpop32(((uint32_t *) p)[3]);
             }
         }
 
         if (!address_item) {
             continue;
         }
 
         address_tail = &info->ip_addresses;
         while (*address_tail) {
             address_tail = &(*address_tail)->next;
         }
         QAPI_LIST_APPEND(address_tail, address_item);
 
         info->has_ip_addresses = true;
 
         if (!info->has_statistics) {
             interface_stat = g_malloc0(sizeof(*interface_stat));
             if (guest_get_network_stats(info->name, interface_stat) == -1) {
                 info->has_statistics = false;
                 g_free(interface_stat);
             } else {
                 info->statistics = interface_stat;
                 info->has_statistics = true;
             }
         }
     }
 
     freeifaddrs(ifap);
     return head;
 
 error:
     freeifaddrs(ifap);
     qapi_free_GuestNetworkInterfaceList(head);
     return NULL;
 }
 
 #else
 
 GuestNetworkInterfaceList *qmp_guest_network_get_interfaces(Error **errp)
 {
     error_setg(errp, QERR_UNSUPPORTED);
     return NULL;
 }
 
 #endif /* HAVE_GETIFADDRS */
 
 #if !defined(CONFIG_FSFREEZE)
 
 GuestFilesystemInfoList *qmp_guest_get_fsinfo(Error **errp)
 {
     error_setg(errp, QERR_UNSUPPORTED);
     return NULL;
 }
 
 GuestFsfreezeStatus qmp_guest_fsfreeze_status(Error **errp)
 {
     error_setg(errp, QERR_UNSUPPORTED);
 
     return 0;
 }
 
 int64_t qmp_guest_fsfreeze_freeze(Error **errp)
 {
     error_setg(errp, QERR_UNSUPPORTED);
 
     return 0;
 }
 
 int64_t qmp_guest_fsfreeze_freeze_list(bool has_mountpoints,
                                        strList *mountpoints,
                                        Error **errp)
 {
     error_setg(errp, QERR_UNSUPPORTED);
 
     return 0;
 }
 
 int64_t qmp_guest_fsfreeze_thaw(Error **errp)
 {
     error_setg(errp, QERR_UNSUPPORTED);
 
     return 0;
 }
 
 GuestDiskInfoList *qmp_guest_get_disks(Error **errp)
 {
     error_setg(errp, QERR_UNSUPPORTED);
     return NULL;
 }
 
 GuestDiskStatsInfoList *qmp_guest_get_diskstats(Error **errp)
 {
     error_setg(errp, QERR_UNSUPPORTED);
     return NULL;
 }
 
 GuestCpuStatsList *qmp_guest_get_cpustats(Error **errp)
 {
     error_setg(errp, QERR_UNSUPPORTED);
     return NULL;
 }
 
 #endif /* CONFIG_FSFREEZE */
 
 #if !defined(CONFIG_FSTRIM)
 GuestFilesystemTrimResponse *
 qmp_guest_fstrim(bool has_minimum, int64_t minimum, Error **errp)
 {
     error_setg(errp, QERR_UNSUPPORTED);
     return NULL;
 }
 #endif
 
 /* add unsupported commands to the list of blocked RPCs */
 GList *ga_command_init_blockedrpcs(GList *blockedrpcs)
 {
 #if !defined(__linux__)
     {
         const char *list[] = {
             "guest-suspend-disk", "guest-suspend-ram",
             "guest-suspend-hybrid", "guest-get-vcpus", "guest-set-vcpus",
             "guest-get-memory-blocks", "guest-set-memory-blocks",
             "guest-get-memory-block-size", "guest-get-memory-block-info",
             NULL};
         char **p = (char **)list;
 
         while (*p) {
             blockedrpcs = g_list_append(blockedrpcs, g_strdup(*p++));
         }
     }
 #endif
 
 #if !defined(HAVE_GETIFADDRS)
     blockedrpcs = g_list_append(blockedrpcs,
                               g_strdup("guest-network-get-interfaces"));
 #endif
 
 #if !defined(CONFIG_FSFREEZE)
     {
         const char *list[] = {
             "guest-get-fsinfo", "guest-fsfreeze-status",
             "guest-fsfreeze-freeze", "guest-fsfreeze-freeze-list",
             "guest-fsfreeze-thaw", "guest-get-fsinfo",
             "guest-get-disks", NULL};
         char **p = (char **)list;
 
         while (*p) {
             blockedrpcs = g_list_append(blockedrpcs, g_strdup(*p++));
         }
     }
 #endif
 
 #if !defined(CONFIG_FSTRIM)
     blockedrpcs = g_list_append(blockedrpcs, g_strdup("guest-fstrim"));
 #endif
 
     blockedrpcs = g_list_append(blockedrpcs, g_strdup("guest-get-devices"));
 
     return blockedrpcs;
 }
 
 /* register init/cleanup routines for stateful command groups */
 void ga_command_state_init(GAState *s, GACommandState *cs)
 {
 #if defined(CONFIG_FSFREEZE)
     ga_command_state_add(cs, NULL, guest_fsfreeze_cleanup);
 #endif
 }
 
 #ifdef HAVE_UTMPX
 
 #define QGA_MICRO_SECOND_TO_SECOND 1000000
 
 static double ga_get_login_time(struct utmpx *user_info)
 {
     double seconds = (double)user_info->ut_tv.tv_sec;
     double useconds = (double)user_info->ut_tv.tv_usec;
     useconds /= QGA_MICRO_SECOND_TO_SECOND;
     return seconds + useconds;
 }
 
 GuestUserList *qmp_guest_get_users(Error **errp)
 {
     GHashTable *cache = NULL;
     GuestUserList *head = NULL, **tail = &head;
     struct utmpx *user_info = NULL;
     gpointer value = NULL;
     GuestUser *user = NULL;
     double login_time = 0;
 
     cache = g_hash_table_new(g_str_hash, g_str_equal);
     setutxent();
 
     for (;;) {
         user_info = getutxent();
         if (user_info == NULL) {
             break;
         } else if (user_info->ut_type != USER_PROCESS) {
             continue;
         } else if (g_hash_table_contains(cache, user_info->ut_user)) {
             value = g_hash_table_lookup(cache, user_info->ut_user);
             user = (GuestUser *)value;
             login_time = ga_get_login_time(user_info);
             /* We're ensuring the earliest login time to be sent */
             if (login_time < user->login_time) {
                 user->login_time = login_time;
             }
             continue;
         }
 
         user = g_new0(GuestUser, 1);
         user->user = g_strdup(user_info->ut_user);
         user->login_time = ga_get_login_time(user_info);
 
         g_hash_table_insert(cache, user->user, user);
 
         QAPI_LIST_APPEND(tail, user);
     }
     endutxent();
     g_hash_table_destroy(cache);
     return head;
 }
 
 #else
 
 GuestUserList *qmp_guest_get_users(Error **errp)
 {
     error_setg(errp, QERR_UNSUPPORTED);
     return NULL;
 }
 
 #endif
 
 /* Replace escaped special characters with theire real values. The replacement
  * is done in place -- returned value is in the original string.
  */
 static void ga_osrelease_replace_special(gchar *value)
 {
     gchar *p, *p2, quote;
 
     /* Trim the string at first space or semicolon if it is not enclosed in
      * single or double quotes. */
     if ((value[0] != '"') || (value[0] == '\'')) {
         p = strchr(value, ' ');
         if (p != NULL) {
             *p = 0;
         }
         p = strchr(value, ';');
         if (p != NULL) {
             *p = 0;
         }
         return;
     }
 
     quote = value[0];
     p2 = value;
     p = value + 1;
     while (*p != 0) {
         if (*p == '\\') {
             p++;
             switch (*p) {
             case '$':
             case '\'':
             case '"':
             case '\\':
             case '`':
                 break;
             default:
                 /* Keep literal backslash followed by whatever is there */
                 p--;
                 break;
             }
         } else if (*p == quote) {
             *p2 = 0;
             break;
         }
         *(p2++) = *(p++);
     }
 }
 
 static GKeyFile *ga_parse_osrelease(const char *fname)
 {
     gchar *content = NULL;
     gchar *content2 = NULL;
     GError *err = NULL;
     GKeyFile *keys = g_key_file_new();
     const char *group = "[os-release]\n";
 
     if (!g_file_get_contents(fname, &content, NULL, &err)) {
         slog("failed to read '%s', error: %s", fname, err->message);
         goto fail;
     }
 
     if (!g_utf8_validate(content, -1, NULL)) {
         slog("file is not utf-8 encoded: %s", fname);
         goto fail;
     }
     content2 = g_strdup_printf("%s%s", group, content);
 
     if (!g_key_file_load_from_data(keys, content2, -1, G_KEY_FILE_NONE,
                                    &err)) {
         slog("failed to parse file '%s', error: %s", fname, err->message);
         goto fail;
     }
 
     g_free(content);
     g_free(content2);
     return keys;
 
 fail:
     g_error_free(err);
     g_free(content);
     g_free(content2);
     g_key_file_free(keys);
     return NULL;
 }
 
 GuestOSInfo *qmp_guest_get_osinfo(Error **errp)
 {
     GuestOSInfo *info = NULL;
     struct utsname kinfo;
     GKeyFile *osrelease = NULL;
     const char *qga_os_release = g_getenv("QGA_OS_RELEASE");
 
     info = g_new0(GuestOSInfo, 1);
 
     if (uname(&kinfo) != 0) {
         error_setg_errno(errp, errno, "uname failed");
     } else {
         info->has_kernel_version = true;
         info->kernel_version = g_strdup(kinfo.version);
         info->has_kernel_release = true;
         info->kernel_release = g_strdup(kinfo.release);
         info->has_machine = true;
         info->machine = g_strdup(kinfo.machine);
     }
 
     if (qga_os_release != NULL) {
         osrelease = ga_parse_osrelease(qga_os_release);
     } else {
         osrelease = ga_parse_osrelease("/etc/os-release");
         if (osrelease == NULL) {
             osrelease = ga_parse_osrelease("/usr/lib/os-release");
         }
     }
 
     if (osrelease != NULL) {
         char *value;
 
 #define GET_FIELD(field, osfield) do { \
     value = g_key_file_get_value(osrelease, "os-release", osfield, NULL); \
     if (value != NULL) { \
         ga_osrelease_replace_special(value); \
         info->has_ ## field = true; \
         info->field = value; \
     } \
 } while (0)
         GET_FIELD(id, "ID");
         GET_FIELD(name, "NAME");
         GET_FIELD(pretty_name, "PRETTY_NAME");
         GET_FIELD(version, "VERSION");
         GET_FIELD(version_id, "VERSION_ID");
         GET_FIELD(variant, "VARIANT");
         GET_FIELD(variant_id, "VARIANT_ID");
 #undef GET_FIELD
 
         g_key_file_free(osrelease);
     }
 
     return info;
 }
 
 GuestDeviceInfoList *qmp_guest_get_devices(Error **errp)
 {
     error_setg(errp, QERR_UNSUPPORTED);
 
     return NULL;
 }
 
 #ifndef HOST_NAME_MAX
 # ifdef _POSIX_HOST_NAME_MAX
 #  define HOST_NAME_MAX _POSIX_HOST_NAME_MAX
 # else
 #  define HOST_NAME_MAX 255
 # endif
 #endif
 
 char *qga_get_host_name(Error **errp)
 {
     long len = -1;
     g_autofree char *hostname = NULL;
 
 #ifdef _SC_HOST_NAME_MAX
     len = sysconf(_SC_HOST_NAME_MAX);
 #endif /* _SC_HOST_NAME_MAX */
 
     if (len < 0) {
         len = HOST_NAME_MAX;
     }
 
     /* Unfortunately, gethostname() below does not guarantee a
      * NULL terminated string. Therefore, allocate one byte more
      * to be sure. */
     hostname = g_new0(char, len + 1);
 
     if (gethostname(hostname, len) < 0) {
         error_setg_errno(errp, errno,
                          "cannot get hostname");
         return NULL;
     }
 
     return g_steal_pointer(&hostname);
 }