qemu

s390_flic_kvm.c (18800B)

---

 /*
  * QEMU S390x KVM floating interrupt controller (flic)
  *
  * Copyright 2014 IBM Corp.
  * Author(s): Jens Freimann <jfrei@linux.vnet.ibm.com>
  *            Cornelia Huck <cornelia.huck@de.ibm.com>
  *
  * This work is licensed under the terms of the GNU GPL, version 2 or (at
  * your option) any later version. See the COPYING file in the top-level
  * directory.
  */
 
 #include "qemu/osdep.h"
 #include "kvm/kvm_s390x.h"
 #include <sys/ioctl.h>
 #include "qemu/error-report.h"
 #include "qemu/module.h"
 #include "qapi/error.h"
 #include "sysemu/kvm.h"
 #include "hw/s390x/s390_flic.h"
 #include "hw/s390x/adapter.h"
 #include "hw/s390x/css.h"
 #include "migration/qemu-file-types.h"
 #include "trace.h"
 #include "qom/object.h"
 
 #define FLIC_SAVE_INITIAL_SIZE qemu_real_host_page_size()
 #define FLIC_FAILED (-1UL)
 #define FLIC_SAVEVM_VERSION 1
 
 struct KVMS390FLICState{
     S390FLICState parent_obj;
 
     uint32_t fd;
     bool clear_io_supported;
 };
 
 static KVMS390FLICState *s390_get_kvm_flic(S390FLICState *fs)
 {
     static KVMS390FLICState *flic;
 
     if (!flic) {
         /* we only have one flic device, so this is fine to cache */
         flic = KVM_S390_FLIC(fs);
     }
     return flic;
 }
 
 /**
  * flic_get_all_irqs - store all pending irqs in buffer
  * @buf: pointer to buffer which is passed to kernel
  * @len: length of buffer
  * @flic: pointer to flic device state
  *
  * Returns: -ENOMEM if buffer is too small,
  * -EINVAL if attr.group is invalid,
  * -EFAULT if copying to userspace failed,
  * on success return number of stored interrupts
  */
 static int flic_get_all_irqs(KVMS390FLICState *flic,
                              void *buf, int len)
 {
     struct kvm_device_attr attr = {
         .group = KVM_DEV_FLIC_GET_ALL_IRQS,
         .addr = (uint64_t) buf,
         .attr = len,
     };
     int rc;
 
     rc = ioctl(flic->fd, KVM_GET_DEVICE_ATTR, &attr);
 
     return rc == -1 ? -errno : rc;
 }
 
 static void flic_enable_pfault(KVMS390FLICState *flic)
 {
     struct kvm_device_attr attr = {
         .group = KVM_DEV_FLIC_APF_ENABLE,
     };
     int rc;
 
     rc = ioctl(flic->fd, KVM_SET_DEVICE_ATTR, &attr);
 
     if (rc) {
         fprintf(stderr, "flic: couldn't enable pfault\n");
     }
 }
 
 static void flic_disable_wait_pfault(KVMS390FLICState *flic)
 {
     struct kvm_device_attr attr = {
         .group = KVM_DEV_FLIC_APF_DISABLE_WAIT,
     };
     int rc;
 
     rc = ioctl(flic->fd, KVM_SET_DEVICE_ATTR, &attr);
 
     if (rc) {
         fprintf(stderr, "flic: couldn't disable pfault\n");
     }
 }
 
 /** flic_enqueue_irqs - returns 0 on success
  * @buf: pointer to buffer which is passed to kernel
  * @len: length of buffer
  * @flic: pointer to flic device state
  *
  * Returns: -EINVAL if attr.group is unknown
  */
 static int flic_enqueue_irqs(void *buf, uint64_t len,
                             KVMS390FLICState *flic)
 {
     int rc;
     struct kvm_device_attr attr = {
         .group = KVM_DEV_FLIC_ENQUEUE,
         .addr = (uint64_t) buf,
         .attr = len,
     };
 
     rc = ioctl(flic->fd, KVM_SET_DEVICE_ATTR, &attr);
 
     return rc ? -errno : 0;
 }
 
 static void kvm_s390_inject_flic(S390FLICState *fs, struct kvm_s390_irq *irq)
 {
     static bool use_flic = true;
     int r;
 
     if (use_flic) {
         r = flic_enqueue_irqs(irq, sizeof(*irq), s390_get_kvm_flic(fs));
         if (r == -ENOSYS) {
             use_flic = false;
         }
         if (!r) {
             return;
         }
     }
     /* fallback to legacy KVM IOCTL in case FLIC fails */
     kvm_s390_floating_interrupt_legacy(irq);
 }
 
 static void kvm_s390_inject_service(S390FLICState *fs, uint32_t parm)
 {
         struct kvm_s390_irq irq = {
         .type = KVM_S390_INT_SERVICE,
         .u.ext.ext_params = parm,
     };
 
     kvm_s390_inject_flic(fs, &irq);
 }
 
 static void kvm_s390_inject_io(S390FLICState *fs, uint16_t subchannel_id,
                                uint16_t subchannel_nr, uint32_t io_int_parm,
                                uint32_t io_int_word)
 {
     struct kvm_s390_irq irq = {
         .u.io.subchannel_id = subchannel_id,
         .u.io.subchannel_nr = subchannel_nr,
         .u.io.io_int_parm = io_int_parm,
         .u.io.io_int_word = io_int_word,
     };
 
     if (io_int_word & IO_INT_WORD_AI) {
         irq.type = KVM_S390_INT_IO(1, 0, 0, 0);
     } else {
         irq.type = KVM_S390_INT_IO(0, (subchannel_id & 0xff00) >> 8,
                                       (subchannel_id & 0x0006),
                                       subchannel_nr);
     }
     kvm_s390_inject_flic(fs, &irq);
 }
 
 static void kvm_s390_inject_crw_mchk(S390FLICState *fs)
 {
     struct kvm_s390_irq irq = {
         .type = KVM_S390_MCHK,
         .u.mchk.cr14 = CR14_CHANNEL_REPORT_SC,
         .u.mchk.mcic = s390_build_validity_mcic() | MCIC_SC_CP,
     };
 
     kvm_s390_inject_flic(fs, &irq);
 }
 
 static int kvm_s390_clear_io_flic(S390FLICState *fs, uint16_t subchannel_id,
                            uint16_t subchannel_nr)
 {
     KVMS390FLICState *flic = s390_get_kvm_flic(fs);
     int rc;
     uint32_t sid = subchannel_id << 16 | subchannel_nr;
     struct kvm_device_attr attr = {
         .group = KVM_DEV_FLIC_CLEAR_IO_IRQ,
         .addr = (uint64_t) &sid,
         .attr = sizeof(sid),
     };
     if (unlikely(!flic->clear_io_supported)) {
         return -ENOSYS;
     }
     rc = ioctl(flic->fd, KVM_SET_DEVICE_ATTR, &attr);
     return rc ? -errno : 0;
 }
 
 static int kvm_s390_modify_ais_mode(S390FLICState *fs, uint8_t isc,
                                     uint16_t mode)
 {
     KVMS390FLICState *flic = s390_get_kvm_flic(fs);
     struct kvm_s390_ais_req req = {
         .isc = isc,
         .mode = mode,
     };
     struct kvm_device_attr attr = {
         .group = KVM_DEV_FLIC_AISM,
         .addr = (uint64_t)&req,
     };
 
     if (!fs->ais_supported) {
         return -ENOSYS;
     }
 
     return ioctl(flic->fd, KVM_SET_DEVICE_ATTR, &attr) ? -errno : 0;
 }
 
 static int kvm_s390_inject_airq(S390FLICState *fs, uint8_t type,
                                 uint8_t isc, uint8_t flags)
 {
     KVMS390FLICState *flic = s390_get_kvm_flic(fs);
     uint32_t id = css_get_adapter_id(type, isc);
     struct kvm_device_attr attr = {
         .group = KVM_DEV_FLIC_AIRQ_INJECT,
         .attr = id,
     };
 
     if (!fs->ais_supported) {
         return -ENOSYS;
     }
 
     return ioctl(flic->fd, KVM_SET_DEVICE_ATTR, &attr) ? -errno : 0;
 }
 
 /**
  * __get_all_irqs - store all pending irqs in buffer
  * @flic: pointer to flic device state
  * @buf: pointer to pointer to a buffer
  * @len: length of buffer
  *
  * Returns: return value of flic_get_all_irqs
  * Note: Retry and increase buffer size until flic_get_all_irqs
  * either returns a value >= 0 or a negative error code.
  * -ENOMEM is an exception, which means the buffer is too small
  * and we should try again. Other negative error codes can be
  * -EFAULT and -EINVAL which we ignore at this point
  */
 static int __get_all_irqs(KVMS390FLICState *flic,
                           void **buf, int len)
 {
     int r;
 
     do {
         /* returns -ENOMEM if buffer is too small and number
          * of queued interrupts on success */
         r = flic_get_all_irqs(flic, *buf, len);
         if (r >= 0) {
             break;
         }
         len *= 2;
         *buf = g_try_realloc(*buf, len);
         if (!buf) {
             return -ENOMEM;
         }
     } while (r == -ENOMEM && len <= KVM_S390_FLIC_MAX_BUFFER);
 
     return r;
 }
 
 static int kvm_s390_register_io_adapter(S390FLICState *fs, uint32_t id,
                                         uint8_t isc, bool swap,
                                         bool is_maskable, uint8_t flags)
 {
     struct kvm_s390_io_adapter adapter = {
         .id = id,
         .isc = isc,
         .maskable = is_maskable,
         .swap = swap,
         .flags = flags,
     };
     KVMS390FLICState *flic = KVM_S390_FLIC(fs);
     int r;
     struct kvm_device_attr attr = {
         .group = KVM_DEV_FLIC_ADAPTER_REGISTER,
         .addr = (uint64_t)&adapter,
     };
 
     if (!kvm_gsi_routing_enabled()) {
         /* nothing to do */
         return 0;
     }
 
     r = ioctl(flic->fd, KVM_SET_DEVICE_ATTR, &attr);
 
     return r ? -errno : 0;
 }
 
 static int kvm_s390_io_adapter_map(S390FLICState *fs, uint32_t id,
                                    uint64_t map_addr, bool do_map)
 {
     struct kvm_s390_io_adapter_req req = {
         .id = id,
         .type = do_map ? KVM_S390_IO_ADAPTER_MAP : KVM_S390_IO_ADAPTER_UNMAP,
         .addr = map_addr,
     };
     struct kvm_device_attr attr = {
         .group = KVM_DEV_FLIC_ADAPTER_MODIFY,
         .addr = (uint64_t)&req,
     };
     KVMS390FLICState *flic = s390_get_kvm_flic(fs);
     int r;
 
     if (!kvm_gsi_routing_enabled()) {
         /* nothing to do */
         return 0;
     }
 
     r = ioctl(flic->fd, KVM_SET_DEVICE_ATTR, &attr);
     return r ? -errno : 0;
 }
 
 static int kvm_s390_add_adapter_routes(S390FLICState *fs,
                                        AdapterRoutes *routes)
 {
     int ret, i;
     uint64_t ind_offset = routes->adapter.ind_offset;
 
     if (!kvm_gsi_routing_enabled()) {
         return -ENOSYS;
     }
 
     for (i = 0; i < routes->num_routes; i++) {
         ret = kvm_irqchip_add_adapter_route(kvm_state, &routes->adapter);
         if (ret < 0) {
             goto out_undo;
         }
         routes->gsi[i] = ret;
         routes->adapter.ind_offset++;
     }
     kvm_irqchip_commit_routes(kvm_state);
 
     /* Restore passed-in structure to original state. */
     routes->adapter.ind_offset = ind_offset;
     return 0;
 out_undo:
     while (--i >= 0) {
         kvm_irqchip_release_virq(kvm_state, routes->gsi[i]);
         routes->gsi[i] = -1;
     }
     routes->adapter.ind_offset = ind_offset;
     return ret;
 }
 
 static void kvm_s390_release_adapter_routes(S390FLICState *fs,
                                             AdapterRoutes *routes)
 {
     int i;
 
     if (!kvm_gsi_routing_enabled()) {
         return;
     }
 
     for (i = 0; i < routes->num_routes; i++) {
         if (routes->gsi[i] >= 0) {
             kvm_irqchip_release_virq(kvm_state, routes->gsi[i]);
             routes->gsi[i] = -1;
         }
     }
 }
 
 /**
  * kvm_flic_save - Save pending floating interrupts
  * @f: QEMUFile containing migration state
  * @opaque: pointer to flic device state
  * @size: ignored
  *
  * Note: Pass buf and len to kernel. Start with one page and
  * increase until buffer is sufficient or maxium size is
  * reached
  */
 static int kvm_flic_save(QEMUFile *f, void *opaque, size_t size,
                          const VMStateField *field, JSONWriter *vmdesc)
 {
     KVMS390FLICState *flic = opaque;
     int len = FLIC_SAVE_INITIAL_SIZE;
     void *buf;
     int count;
     int r = 0;
 
     flic_disable_wait_pfault((struct KVMS390FLICState *) opaque);
 
     buf = g_try_malloc0(len);
     if (!buf) {
         /* Storing FLIC_FAILED into the count field here will cause the
          * target system to fail when attempting to load irqs from the
          * migration state */
         error_report("flic: couldn't allocate memory");
         qemu_put_be64(f, FLIC_FAILED);
         return -ENOMEM;
     }
 
     count = __get_all_irqs(flic, &buf, len);
     if (count < 0) {
         error_report("flic: couldn't retrieve irqs from kernel, rc %d",
                      count);
         /* Storing FLIC_FAILED into the count field here will cause the
          * target system to fail when attempting to load irqs from the
          * migration state */
         qemu_put_be64(f, FLIC_FAILED);
         r = count;
     } else {
         qemu_put_be64(f, count);
         qemu_put_buffer(f, (uint8_t *) buf,
                         count * sizeof(struct kvm_s390_irq));
     }
     g_free(buf);
 
     return r;
 }
 
 /**
  * kvm_flic_load - Load pending floating interrupts
  * @f: QEMUFile containing migration state
  * @opaque: pointer to flic device state
  * @size: ignored
  *
  * Returns: value of flic_enqueue_irqs, -EINVAL on error
  * Note: Do nothing when no interrupts where stored
  * in QEMUFile
  */
 static int kvm_flic_load(QEMUFile *f, void *opaque, size_t size,
                          const VMStateField *field)
 {
     uint64_t len = 0;
     uint64_t count = 0;
     void *buf = NULL;
     int r = 0;
 
     flic_enable_pfault((struct KVMS390FLICState *) opaque);
 
     count = qemu_get_be64(f);
     len = count * sizeof(struct kvm_s390_irq);
     if (count == FLIC_FAILED) {
         return -EINVAL;
     }
     if (count == 0) {
         return 0;
     }
     buf = g_try_malloc0(len);
     if (!buf) {
         return -ENOMEM;
     }
 
     if (qemu_get_buffer(f, (uint8_t *) buf, len) != len) {
         r = -EINVAL;
         goto out_free;
     }
     r = flic_enqueue_irqs(buf, len, (struct KVMS390FLICState *) opaque);
 
 out_free:
     g_free(buf);
     return r;
 }
 
 typedef struct KVMS390FLICStateMigTmp {
     KVMS390FLICState *parent;
     uint8_t simm;
     uint8_t nimm;
 } KVMS390FLICStateMigTmp;
 
 static int kvm_flic_ais_pre_save(void *opaque)
 {
     KVMS390FLICStateMigTmp *tmp = opaque;
     KVMS390FLICState *flic = tmp->parent;
     struct kvm_s390_ais_all ais;
     struct kvm_device_attr attr = {
         .group = KVM_DEV_FLIC_AISM_ALL,
         .addr = (uint64_t)&ais,
         .attr = sizeof(ais),
     };
 
     if (ioctl(flic->fd, KVM_GET_DEVICE_ATTR, &attr)) {
         error_report("Failed to retrieve kvm flic ais states");
         return -EINVAL;
     }
 
     tmp->simm = ais.simm;
     tmp->nimm = ais.nimm;
 
     return 0;
 }
 
 static int kvm_flic_ais_post_load(void *opaque, int version_id)
 {
     KVMS390FLICStateMigTmp *tmp = opaque;
     KVMS390FLICState *flic = tmp->parent;
     struct kvm_s390_ais_all ais = {
         .simm = tmp->simm,
         .nimm = tmp->nimm,
     };
     struct kvm_device_attr attr = {
         .group = KVM_DEV_FLIC_AISM_ALL,
         .addr = (uint64_t)&ais,
     };
 
     /* This can happen when the user mis-configures its guests in an
      * incompatible fashion or without a CPU model. For example using
      * qemu with -cpu host (which is not migration safe) and do a
      * migration from a host that has AIS to a host that has no AIS.
      * In that case the target system will reject the migration here.
      */
     if (!ais_needed(flic)) {
         return -ENOSYS;
     }
 
     return ioctl(flic->fd, KVM_SET_DEVICE_ATTR, &attr) ? -errno : 0;
 }
 
 static const VMStateDescription kvm_s390_flic_ais_tmp = {
     .name = "s390-flic-ais-tmp",
     .pre_save = kvm_flic_ais_pre_save,
     .post_load = kvm_flic_ais_post_load,
     .fields = (VMStateField[]) {
         VMSTATE_UINT8(simm, KVMS390FLICStateMigTmp),
         VMSTATE_UINT8(nimm, KVMS390FLICStateMigTmp),
         VMSTATE_END_OF_LIST()
     }
 };
 
 static const VMStateDescription kvm_s390_flic_vmstate_ais = {
     .name = "s390-flic/ais",
     .version_id = 1,
     .minimum_version_id = 1,
     .needed = ais_needed,
     .fields = (VMStateField[]) {
         VMSTATE_WITH_TMP(KVMS390FLICState, KVMS390FLICStateMigTmp,
                          kvm_s390_flic_ais_tmp),
         VMSTATE_END_OF_LIST()
     }
 };
 
 static const VMStateDescription kvm_s390_flic_vmstate = {
     /* should have been like kvm-s390-flic,
      * can't change without breaking compat */
     .name = "s390-flic",
     .version_id = FLIC_SAVEVM_VERSION,
     .minimum_version_id = FLIC_SAVEVM_VERSION,
     .fields = (VMStateField[]) {
         {
             .name = "irqs",
             .info = &(const VMStateInfo) {
                 .name = "irqs",
                 .get = kvm_flic_load,
                 .put = kvm_flic_save,
             },
             .flags = VMS_SINGLE,
         },
         VMSTATE_END_OF_LIST()
     },
     .subsections = (const VMStateDescription * []) {
         &kvm_s390_flic_vmstate_ais,
         NULL
     }
 };
 
 struct KVMS390FLICStateClass {
     S390FLICStateClass parent_class;
     DeviceRealize parent_realize;
 };
 typedef struct KVMS390FLICStateClass KVMS390FLICStateClass;
 
 DECLARE_CLASS_CHECKERS(KVMS390FLICStateClass, KVM_S390_FLIC,
                        TYPE_KVM_S390_FLIC)
 
 
 static void kvm_s390_flic_realize(DeviceState *dev, Error **errp)
 {
     KVMS390FLICState *flic_state = KVM_S390_FLIC(dev);
     struct kvm_create_device cd = {0};
     struct kvm_device_attr test_attr = {0};
     int ret;
     Error *err = NULL;
 
     KVM_S390_FLIC_GET_CLASS(dev)->parent_realize(dev, &err);
     if (err) {
         error_propagate(errp, err);
         return;
     }
     flic_state->fd = -1;
 
     cd.type = KVM_DEV_TYPE_FLIC;
     ret = kvm_vm_ioctl(kvm_state, KVM_CREATE_DEVICE, &cd);
     if (ret < 0) {
         error_setg_errno(errp, errno, "Creating the KVM device failed");
         trace_flic_create_device(errno);
         return;
     }
     flic_state->fd = cd.fd;
 
     /* Check clear_io_irq support */
     test_attr.group = KVM_DEV_FLIC_CLEAR_IO_IRQ;
     flic_state->clear_io_supported = !ioctl(flic_state->fd,
                                             KVM_HAS_DEVICE_ATTR, test_attr);
 }
 
 static void kvm_s390_flic_reset(DeviceState *dev)
 {
     KVMS390FLICState *flic = KVM_S390_FLIC(dev);
     S390FLICState *fs = S390_FLIC_COMMON(dev);
     struct kvm_device_attr attr = {
         .group = KVM_DEV_FLIC_CLEAR_IRQS,
     };
     int rc = 0;
     uint8_t isc;
 
     if (flic->fd == -1) {
         return;
     }
 
     flic_disable_wait_pfault(flic);
 
     if (fs->ais_supported) {
         for (isc = 0; isc <= MAX_ISC; isc++) {
             rc = kvm_s390_modify_ais_mode(fs, isc, SIC_IRQ_MODE_ALL);
             if (rc) {
                 error_report("Failed to reset ais mode for isc %d: %s",
                              isc, strerror(-rc));
             }
         }
     }
 
     rc = ioctl(flic->fd, KVM_SET_DEVICE_ATTR, &attr);
     if (rc) {
         trace_flic_reset_failed(errno);
     }
 
     flic_enable_pfault(flic);
 }
 
 static void kvm_s390_flic_class_init(ObjectClass *oc, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(oc);
     S390FLICStateClass *fsc = S390_FLIC_COMMON_CLASS(oc);
 
     KVM_S390_FLIC_CLASS(oc)->parent_realize = dc->realize;
     dc->realize = kvm_s390_flic_realize;
     dc->vmsd = &kvm_s390_flic_vmstate;
     dc->reset = kvm_s390_flic_reset;
     fsc->register_io_adapter = kvm_s390_register_io_adapter;
     fsc->io_adapter_map = kvm_s390_io_adapter_map;
     fsc->add_adapter_routes = kvm_s390_add_adapter_routes;
     fsc->release_adapter_routes = kvm_s390_release_adapter_routes;
     fsc->clear_io_irq = kvm_s390_clear_io_flic;
     fsc->modify_ais_mode = kvm_s390_modify_ais_mode;
     fsc->inject_airq = kvm_s390_inject_airq;
     fsc->inject_service = kvm_s390_inject_service;
     fsc->inject_io = kvm_s390_inject_io;
     fsc->inject_crw_mchk = kvm_s390_inject_crw_mchk;
 }
 
 static const TypeInfo kvm_s390_flic_info = {
     .name          = TYPE_KVM_S390_FLIC,
     .parent        = TYPE_S390_FLIC_COMMON,
     .instance_size = sizeof(KVMS390FLICState),
     .class_size    = sizeof(KVMS390FLICStateClass),
     .class_init    = kvm_s390_flic_class_init,
 };
 
 static void kvm_s390_flic_register_types(void)
 {
     type_register_static(&kvm_s390_flic_info);
 }
 
 type_init(kvm_s390_flic_register_types)