qemu

xics_kvm.c (14395B)

---

 /*
  * QEMU PowerPC pSeries Logical Partition (aka sPAPR) hardware System Emulator
  *
  * PAPR Virtualized Interrupt System, aka ICS/ICP aka xics, in-kernel emulation
  *
  * Copyright (c) 2013 David Gibson, IBM Corporation.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
  * in the Software without restriction, including without limitation the rights
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
  *
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  *
  */
 
 #include "qemu/osdep.h"
 #include "qapi/error.h"
 #include "trace.h"
 #include "sysemu/kvm.h"
 #include "hw/ppc/spapr.h"
 #include "hw/ppc/spapr_cpu_core.h"
 #include "hw/ppc/xics.h"
 #include "hw/ppc/xics_spapr.h"
 #include "kvm_ppc.h"
 #include "qemu/config-file.h"
 #include "qemu/error-report.h"
 
 #include <sys/ioctl.h>
 
 static int kernel_xics_fd = -1;
 
 typedef struct KVMEnabledICP {
     unsigned long vcpu_id;
     QLIST_ENTRY(KVMEnabledICP) node;
 } KVMEnabledICP;
 
 static QLIST_HEAD(, KVMEnabledICP)
     kvm_enabled_icps = QLIST_HEAD_INITIALIZER(&kvm_enabled_icps);
 
 static void kvm_disable_icps(void)
 {
     KVMEnabledICP *enabled_icp, *next;
 
     QLIST_FOREACH_SAFE(enabled_icp, &kvm_enabled_icps, node, next) {
         QLIST_REMOVE(enabled_icp, node);
         g_free(enabled_icp);
     }
 }
 
 /*
  * ICP-KVM
  */
 void icp_get_kvm_state(ICPState *icp)
 {
     uint64_t state;
     int ret;
 
     /* The KVM XICS device is not in use */
     if (kernel_xics_fd == -1) {
         return;
     }
 
     /* ICP for this CPU thread is not in use, exiting */
     if (!icp->cs) {
         return;
     }
 
     ret = kvm_get_one_reg(icp->cs, KVM_REG_PPC_ICP_STATE, &state);
     if (ret != 0) {
         error_report("Unable to retrieve KVM interrupt controller state"
                 " for CPU %ld: %s", kvm_arch_vcpu_id(icp->cs), strerror(errno));
         exit(1);
     }
 
     icp->xirr = state >> KVM_REG_PPC_ICP_XISR_SHIFT;
     icp->mfrr = (state >> KVM_REG_PPC_ICP_MFRR_SHIFT)
         & KVM_REG_PPC_ICP_MFRR_MASK;
     icp->pending_priority = (state >> KVM_REG_PPC_ICP_PPRI_SHIFT)
         & KVM_REG_PPC_ICP_PPRI_MASK;
 }
 
 static void do_icp_synchronize_state(CPUState *cpu, run_on_cpu_data arg)
 {
     icp_get_kvm_state(arg.host_ptr);
 }
 
 void icp_synchronize_state(ICPState *icp)
 {
     if (icp->cs) {
         run_on_cpu(icp->cs, do_icp_synchronize_state, RUN_ON_CPU_HOST_PTR(icp));
     }
 }
 
 int icp_set_kvm_state(ICPState *icp, Error **errp)
 {
     uint64_t state;
     int ret;
 
     /* The KVM XICS device is not in use */
     if (kernel_xics_fd == -1) {
         return 0;
     }
 
     /* ICP for this CPU thread is not in use, exiting */
     if (!icp->cs) {
         return 0;
     }
 
     state = ((uint64_t)icp->xirr << KVM_REG_PPC_ICP_XISR_SHIFT)
         | ((uint64_t)icp->mfrr << KVM_REG_PPC_ICP_MFRR_SHIFT)
         | ((uint64_t)icp->pending_priority << KVM_REG_PPC_ICP_PPRI_SHIFT);
 
     ret = kvm_set_one_reg(icp->cs, KVM_REG_PPC_ICP_STATE, &state);
     if (ret < 0) {
         error_setg_errno(errp, -ret,
                          "Unable to restore KVM interrupt controller state (0x%"
                          PRIx64 ") for CPU %ld", state,
                          kvm_arch_vcpu_id(icp->cs));
         return ret;
     }
 
     return 0;
 }
 
 void icp_kvm_realize(DeviceState *dev, Error **errp)
 {
     ICPState *icp = ICP(dev);
     CPUState *cs;
     KVMEnabledICP *enabled_icp;
     unsigned long vcpu_id;
     int ret;
 
     /* The KVM XICS device is not in use */
     if (kernel_xics_fd == -1) {
         return;
     }
 
     cs = icp->cs;
     vcpu_id = kvm_arch_vcpu_id(cs);
 
     /*
      * If we are reusing a parked vCPU fd corresponding to the CPU
      * which was hot-removed earlier we don't have to renable
      * KVM_CAP_IRQ_XICS capability again.
      */
     QLIST_FOREACH(enabled_icp, &kvm_enabled_icps, node) {
         if (enabled_icp->vcpu_id == vcpu_id) {
             return;
         }
     }
 
     ret = kvm_vcpu_enable_cap(cs, KVM_CAP_IRQ_XICS, 0, kernel_xics_fd, vcpu_id);
     if (ret < 0) {
         Error *local_err = NULL;
 
         error_setg(&local_err, "Unable to connect CPU%ld to kernel XICS: %s",
                    vcpu_id, strerror(errno));
         if (errno == ENOSPC) {
             error_append_hint(&local_err, "Try -smp maxcpus=N with N < %u\n",
                               MACHINE(qdev_get_machine())->smp.max_cpus);
         }
         error_propagate(errp, local_err);
         return;
     }
     enabled_icp = g_malloc(sizeof(*enabled_icp));
     enabled_icp->vcpu_id = vcpu_id;
     QLIST_INSERT_HEAD(&kvm_enabled_icps, enabled_icp, node);
 }
 
 /*
  * ICS-KVM
  */
 void ics_get_kvm_state(ICSState *ics)
 {
     uint64_t state;
     int i;
 
     /* The KVM XICS device is not in use */
     if (kernel_xics_fd == -1) {
         return;
     }
 
     for (i = 0; i < ics->nr_irqs; i++) {
         ICSIRQState *irq = &ics->irqs[i];
 
         if (ics_irq_free(ics, i)) {
             continue;
         }
 
         kvm_device_access(kernel_xics_fd, KVM_DEV_XICS_GRP_SOURCES,
                           i + ics->offset, &state, false, &error_fatal);
 
         irq->server = state & KVM_XICS_DESTINATION_MASK;
         irq->saved_priority = (state >> KVM_XICS_PRIORITY_SHIFT)
             & KVM_XICS_PRIORITY_MASK;
         /*
          * To be consistent with the software emulation in xics.c, we
          * split out the masked state + priority that we get from the
          * kernel into 'current priority' (0xff if masked) and
          * 'saved priority' (if masked, this is the priority the
          * interrupt had before it was masked).  Masking and unmasking
          * are done with the ibm,int-off and ibm,int-on RTAS calls.
          */
         if (state & KVM_XICS_MASKED) {
             irq->priority = 0xff;
         } else {
             irq->priority = irq->saved_priority;
         }
 
         irq->status = 0;
         if (state & KVM_XICS_PENDING) {
             if (state & KVM_XICS_LEVEL_SENSITIVE) {
                 irq->status |= XICS_STATUS_ASSERTED;
             } else {
                 /*
                  * A pending edge-triggered interrupt (or MSI)
                  * must have been rejected previously when we
                  * first detected it and tried to deliver it,
                  * so mark it as pending and previously rejected
                  * for consistency with how xics.c works.
                  */
                 irq->status |= XICS_STATUS_MASKED_PENDING
                     | XICS_STATUS_REJECTED;
             }
         }
         if (state & KVM_XICS_PRESENTED) {
                 irq->status |= XICS_STATUS_PRESENTED;
         }
         if (state & KVM_XICS_QUEUED) {
                 irq->status |= XICS_STATUS_QUEUED;
         }
     }
 }
 
 void ics_synchronize_state(ICSState *ics)
 {
     ics_get_kvm_state(ics);
 }
 
 int ics_set_kvm_state_one(ICSState *ics, int srcno, Error **errp)
 {
     uint64_t state;
     ICSIRQState *irq = &ics->irqs[srcno];
     int ret;
 
     /* The KVM XICS device is not in use */
     if (kernel_xics_fd == -1) {
         return 0;
     }
 
     state = irq->server;
     state |= (uint64_t)(irq->saved_priority & KVM_XICS_PRIORITY_MASK)
         << KVM_XICS_PRIORITY_SHIFT;
     if (irq->priority != irq->saved_priority) {
         assert(irq->priority == 0xff);
     }
 
     if (irq->priority == 0xff) {
         state |= KVM_XICS_MASKED;
     }
 
     if (irq->flags & XICS_FLAGS_IRQ_LSI) {
         state |= KVM_XICS_LEVEL_SENSITIVE;
         if (irq->status & XICS_STATUS_ASSERTED) {
             state |= KVM_XICS_PENDING;
         }
     } else {
         if (irq->status & XICS_STATUS_MASKED_PENDING) {
             state |= KVM_XICS_PENDING;
         }
     }
     if (irq->status & XICS_STATUS_PRESENTED) {
         state |= KVM_XICS_PRESENTED;
     }
     if (irq->status & XICS_STATUS_QUEUED) {
         state |= KVM_XICS_QUEUED;
     }
 
     ret = kvm_device_access(kernel_xics_fd, KVM_DEV_XICS_GRP_SOURCES,
                             srcno + ics->offset, &state, true, errp);
     if (ret < 0) {
         return ret;
     }
 
     return 0;
 }
 
 int ics_set_kvm_state(ICSState *ics, Error **errp)
 {
     int i;
 
     /* The KVM XICS device is not in use */
     if (kernel_xics_fd == -1) {
         return 0;
     }
 
     for (i = 0; i < ics->nr_irqs; i++) {
         int ret;
 
         if (ics_irq_free(ics, i)) {
             continue;
         }
 
         ret = ics_set_kvm_state_one(ics, i, errp);
         if (ret < 0) {
             return ret;
         }
     }
 
     return 0;
 }
 
 void ics_kvm_set_irq(ICSState *ics, int srcno, int val)
 {
     struct kvm_irq_level args;
     int rc;
 
     /* The KVM XICS device should be in use */
     assert(kernel_xics_fd != -1);
 
     args.irq = srcno + ics->offset;
     if (ics->irqs[srcno].flags & XICS_FLAGS_IRQ_MSI) {
         if (!val) {
             return;
         }
         args.level = KVM_INTERRUPT_SET;
     } else {
         args.level = val ? KVM_INTERRUPT_SET_LEVEL : KVM_INTERRUPT_UNSET;
     }
     rc = kvm_vm_ioctl(kvm_state, KVM_IRQ_LINE, &args);
     if (rc < 0) {
         perror("kvm_irq_line");
     }
 }
 
 int xics_kvm_connect(SpaprInterruptController *intc, uint32_t nr_servers,
                      Error **errp)
 {
     ICSState *ics = ICS_SPAPR(intc);
     int rc;
     CPUState *cs;
     Error *local_err = NULL;
 
     /*
      * The KVM XICS device already in use. This is the case when
      * rebooting under the XICS-only interrupt mode.
      */
     if (kernel_xics_fd != -1) {
         return 0;
     }
 
     if (!kvm_enabled() || !kvm_check_extension(kvm_state, KVM_CAP_IRQ_XICS)) {
         error_setg(errp,
                    "KVM and IRQ_XICS capability must be present for in-kernel XICS");
         return -1;
     }
 
     rc = kvmppc_define_rtas_kernel_token(RTAS_IBM_SET_XIVE, "ibm,set-xive");
     if (rc < 0) {
         error_setg_errno(&local_err, -rc,
                          "kvmppc_define_rtas_kernel_token: ibm,set-xive");
         goto fail;
     }
 
     rc = kvmppc_define_rtas_kernel_token(RTAS_IBM_GET_XIVE, "ibm,get-xive");
     if (rc < 0) {
         error_setg_errno(&local_err, -rc,
                          "kvmppc_define_rtas_kernel_token: ibm,get-xive");
         goto fail;
     }
 
     rc = kvmppc_define_rtas_kernel_token(RTAS_IBM_INT_ON, "ibm,int-on");
     if (rc < 0) {
         error_setg_errno(&local_err, -rc,
                          "kvmppc_define_rtas_kernel_token: ibm,int-on");
         goto fail;
     }
 
     rc = kvmppc_define_rtas_kernel_token(RTAS_IBM_INT_OFF, "ibm,int-off");
     if (rc < 0) {
         error_setg_errno(&local_err, -rc,
                          "kvmppc_define_rtas_kernel_token: ibm,int-off");
         goto fail;
     }
 
     /* Create the KVM XICS device */
     rc = kvm_create_device(kvm_state, KVM_DEV_TYPE_XICS, false);
     if (rc < 0) {
         error_setg_errno(&local_err, -rc, "Error on KVM_CREATE_DEVICE for XICS");
         goto fail;
     }
 
     /* Tell KVM about the # of VCPUs we may have (POWER9 and newer only) */
     if (kvm_device_check_attr(rc, KVM_DEV_XICS_GRP_CTRL,
                               KVM_DEV_XICS_NR_SERVERS)) {
         if (kvm_device_access(rc, KVM_DEV_XICS_GRP_CTRL,
                               KVM_DEV_XICS_NR_SERVERS, &nr_servers, true,
                               &local_err)) {
             goto fail;
         }
     }
 
     kernel_xics_fd = rc;
     kvm_kernel_irqchip = true;
     kvm_msi_via_irqfd_allowed = true;
     kvm_gsi_direct_mapping = true;
 
     /* Create the presenters */
     CPU_FOREACH(cs) {
         PowerPCCPU *cpu = POWERPC_CPU(cs);
 
         icp_kvm_realize(DEVICE(spapr_cpu_state(cpu)->icp), &local_err);
         if (local_err) {
             goto fail;
         }
     }
 
     /* Update the KVM sources */
     ics_set_kvm_state(ics, &local_err);
     if (local_err) {
         goto fail;
     }
 
     /* Connect the presenters to the initial VCPUs of the machine */
     CPU_FOREACH(cs) {
         PowerPCCPU *cpu = POWERPC_CPU(cs);
         icp_set_kvm_state(spapr_cpu_state(cpu)->icp, &local_err);
         if (local_err) {
             goto fail;
         }
     }
 
     return 0;
 
 fail:
     error_propagate(errp, local_err);
     xics_kvm_disconnect(intc);
     return -1;
 }
 
 void xics_kvm_disconnect(SpaprInterruptController *intc)
 {
     /*
      * Only on P9 using the XICS-on XIVE KVM device:
      *
      * When the KVM device fd is closed, the device is destroyed and
      * removed from the list of devices of the VM. The VCPU presenters
      * are also detached from the device.
      */
     if (kernel_xics_fd != -1) {
         close(kernel_xics_fd);
         kernel_xics_fd = -1;
     }
 
     kvmppc_define_rtas_kernel_token(0, "ibm,set-xive");
     kvmppc_define_rtas_kernel_token(0, "ibm,get-xive");
     kvmppc_define_rtas_kernel_token(0, "ibm,int-on");
     kvmppc_define_rtas_kernel_token(0, "ibm,int-off");
 
     kvm_kernel_irqchip = false;
     kvm_msi_via_irqfd_allowed = false;
     kvm_gsi_direct_mapping = false;
 
     /* Clear the presenter from the VCPUs */
     kvm_disable_icps();
 }
 
 /*
  * This is a heuristic to detect older KVMs on POWER9 hosts that don't
  * support destruction of a KVM XICS device while the VM is running.
  * Required to start a spapr machine with ic-mode=dual,kernel-irqchip=on.
  */
 bool xics_kvm_has_broken_disconnect(void)
 {
     int rc;
 
     rc = kvm_create_device(kvm_state, KVM_DEV_TYPE_XICS, false);
     if (rc < 0) {
         /*
          * The error is ignored on purpose. The KVM XICS setup code
          * will catch it again anyway. The goal here is to see if
          * close() actually destroys the device or not.
          */
         return false;
     }
 
     close(rc);
 
     rc = kvm_create_device(kvm_state, KVM_DEV_TYPE_XICS, false);
     if (rc >= 0) {
         close(rc);
         return false;
     }
 
     return errno == EEXIST;
 }