qemu_process: add check for hyperv features

Commit 7068b56c introduced several hyperv features.  Not all hyperv
features are supported by old enough kernels and we shouldn't allow to
start a guest if kernel doesn't support any of the hyperv feature.

There is one exception, for backward compatibility we cannot error out
if one of the RELAXED, VAPIC or SPINLOCKS isn't supported, for the same
reason we ignore invtsc, to not break restoring saved domains with older
libvirt.
Signed-off-by: NPavel Hrdina <phrdina@redhat.com>

src/cpu/cpu_x86.c

@@ -75,6 +75,14 @@ static const struct x86_kvm_feature x86_kvm_features[] =
     {VIR_CPU_x86_KVM_PV_UNHALT,    { .function = 0x40000001, .eax = 0x00000080 }},
     {VIR_CPU_x86_KVM_CLOCKSOURCE_STABLE_BIT,
                                    { .function = 0x40000001, .eax = 0x01000000 }},
+    {VIR_CPU_x86_KVM_HV_RUNTIME,   { .function = 0x40000003, .eax = 0x00000001 }},
+    {VIR_CPU_x86_KVM_HV_SYNIC,     { .function = 0x40000003, .eax = 0x00000004 }},
+    {VIR_CPU_x86_KVM_HV_STIMER,    { .function = 0x40000003, .eax = 0x00000008 }},
+    {VIR_CPU_x86_KVM_HV_RELAXED,   { .function = 0x40000003, .eax = 0x00000020 }},
+    {VIR_CPU_x86_KVM_HV_SPINLOCK,  { .function = 0x40000003, .eax = 0x00000022 }},
+    {VIR_CPU_x86_KVM_HV_VAPIC,     { .function = 0x40000003, .eax = 0x00000030 }},
+    {VIR_CPU_x86_KVM_HV_VPINDEX,   { .function = 0x40000003, .eax = 0x00000040 }},
+    {VIR_CPU_x86_KVM_HV_RESET,     { .function = 0x40000003, .eax = 0x00000080 }},
 };
 
 struct x86_model {

src/cpu/cpu_x86_data.h

@@ -48,6 +48,14 @@ struct _virCPUx86CPUID {
 # define VIR_CPU_x86_KVM_PV_EOI       "__kvm_pv_eoi"
 # define VIR_CPU_x86_KVM_PV_UNHALT    "__kvm_pv_unhalt"
 # define VIR_CPU_x86_KVM_CLOCKSOURCE_STABLE_BIT "__kvm_clocksource_stable"
+# define VIR_CPU_x86_KVM_HV_RUNTIME   "__kvm_hv_runtime"
+# define VIR_CPU_x86_KVM_HV_SYNIC     "__kvm_hv_synic"
+# define VIR_CPU_x86_KVM_HV_STIMER    "__kvm_hv_stimer"
+# define VIR_CPU_x86_KVM_HV_RELAXED   "__kvm_hv_relaxed"
+# define VIR_CPU_x86_KVM_HV_SPINLOCK  "__kvm_hv_spinlock"
+# define VIR_CPU_x86_KVM_HV_VAPIC     "__kvm_hv_vapic"
+# define VIR_CPU_x86_KVM_HV_VPINDEX   "__kvm_hv_vpindex"
+# define VIR_CPU_x86_KVM_HV_RESET     "__kvm_hv_reset"
 
 
 typedef struct _virCPUx86Data virCPUx86Data;

src/qemu/qemu_process.c

@@ -3928,6 +3928,37 @@ qemuProcessVerifyGuestCPU(virQEMUDriverPtr driver,
             }
         }
 
+        for (i = 0; i < VIR_DOMAIN_HYPERV_LAST; i++) {
+            if (def->hyperv_features[i] == VIR_TRISTATE_SWITCH_ON) {
+                char *cpuFeature;
+                if (virAsprintf(&cpuFeature, "__kvm_hv_%s",
+                                virDomainHypervTypeToString(i)) < 0)
+                    goto cleanup;
+                if (!cpuHasFeature(guestcpu, cpuFeature)) {
+                    switch ((virDomainHyperv) i) {
+                    case VIR_DOMAIN_HYPERV_RELAXED:
+                    case VIR_DOMAIN_HYPERV_VAPIC:
+                    case VIR_DOMAIN_HYPERV_SPINLOCKS:
+                        VIR_WARN("host doesn't support hyperv '%s' feature",
+                                 virDomainHypervTypeToString(i));
+                        break;
+                    case VIR_DOMAIN_HYPERV_VPINDEX:
+                    case VIR_DOMAIN_HYPERV_RUNTIME:
+                    case VIR_DOMAIN_HYPERV_SYNIC:
+                    case VIR_DOMAIN_HYPERV_STIMER:
+                    case VIR_DOMAIN_HYPERV_RESET:
+                    case VIR_DOMAIN_HYPERV_VENDOR_ID:
+                        virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+                                       _("host doesn't support hyperv '%s' feature"),
+                                       virDomainHypervTypeToString(i));
+                        goto cleanup;
+                        break;
+                    case VIR_DOMAIN_HYPERV_LAST:
+                        break;
+                    }
+                }
+            }
+        }
 
         if (def->cpu && def->cpu->mode != VIR_CPU_MODE_HOST_PASSTHROUGH) {
             for (i = 0; i < def->cpu->nfeatures; i++) {