[Qemu-devel] [PATCH v3 1/1] cpu: report hyperv feature words through qom

["Denis V. Lunev" <den@openvz.org>]

From: Evgeny Yakovlev <eyakovlev@virtuozzo.com>

This change adds hyperv feature words report through qom rpc.

When VM is configured with hyperv features enabled
libvirt will check that required feature words are set
in cpuid leaf 40000003 through qom request.

Currently qemu does not report hyperv feature words
which prevents windows guests from starting with libvirt.

To avoid conflicting with current hyperv properties all added feature
words cannot be set directly with -cpu +feature yet.

Signed-off-by: Evgeny Yakovlev <eyakovlev@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Richard Henderson <rth@twiddle.net>
CC: Eduardo Habkost <ehabkost@redhat.com>
CC: Marcelo Tosatti <mtosatti@redhat.com>
---
Changes from v2:
- removed all hyperv feature_names so that we don't have two ways of
  setting CPUID bits

Changes from v1:
- renamed hyperv features so they don't conflict with hyperv properties
- refactored kvm_arch_init_vcpu to process hyperv props into feature words

target-i386/cpu.c |  53 +++++++++++++++++++++++++
 target-i386/cpu.h |   3 ++
 target-i386/kvm.c | 114 +++++++++++++++++++++++++++++++-----------------------
 3 files changed, 122 insertions(+), 48 deletions(-)

diff --git a/target-i386/cpu.c b/target-i386/cpu.c
index 3bd3cfc..d07da78 100644
--- a/target-i386/cpu.c
+++ b/target-i386/cpu.c
@@ -245,6 +245,47 @@ static const char *kvm_feature_name[] = {
     NULL, NULL, NULL, NULL,
 };
 
+static const char *hyperv_priv_feature_name[] = {
+    NULL /* hv_msr_vp_runtime_access */, NULL /* hv_msr_time_refcount_access */,
+    NULL /* hv_msr_synic_access */, NULL /* hv_msr_stimer_access */,
+    NULL /* hv_msr_apic_access */, NULL /* hv_msr_hypercall_access */,
+    NULL /* hv_vpindex_access */, NULL /* hv_msr_reset_access */,
+    NULL /* hv_msr_stats_access */, NULL /* hv_reftsc_access */,
+    NULL /* hv_msr_idle_access */, NULL /* hv_msr_frequency_access */,
+    NULL, NULL, NULL, NULL,
+    NULL, NULL, NULL, NULL,
+    NULL, NULL, NULL, NULL,
+    NULL, NULL, NULL, NULL,
+    NULL, NULL, NULL, NULL,
+};
+
+static const char *hyperv_ident_feature_name[] = {
+    NULL /* hv_create_partitions */, NULL /* hv_access_partition_id */,
+    NULL /* hv_access_memory_pool */, NULL /* hv_adjust_message_buffers */,
+    NULL /* hv_post_messages */, NULL /* hv_signal_events */,
+    NULL /* hv_create_port */, NULL /* hv_connect_port */,
+    NULL /* hv_access_stats */, NULL, NULL, NULL /* hv_debugging */,
+    NULL /* hv_cpu_power_management */, NULL /* hv_configure_profiler */,
+    NULL, NULL,
+    NULL, NULL, NULL, NULL,
+    NULL, NULL, NULL, NULL,
+    NULL, NULL, NULL, NULL,
+    NULL, NULL, NULL, NULL,
+};
+
+static const char *hyperv_misc_feature_name[] = {
+    NULL /* hv_mwait */, NULL /* hv_guest_debugging */,
+    NULL /* hv_perf_monitor */, NULL /* hv_cpu_dynamic_part */,
+    NULL /* hv_hypercall_params_xmm */, NULL /* hv_guest_idle_state */,
+    NULL, NULL,
+    NULL, NULL, NULL /* hv_guest_crash_msr */, NULL,
+    NULL, NULL, NULL, NULL,
+    NULL, NULL, NULL, NULL,
+    NULL, NULL, NULL, NULL,
+    NULL, NULL, NULL, NULL,
+    NULL, NULL, NULL, NULL,
+};
+
 static const char *svm_feature_name[] = {
     "npt", "lbrv", "svm_lock", "nrip_save",
     "tsc_scale", "vmcb_clean",  "flushbyasid", "decodeassists",
@@ -411,6 +452,18 @@ static FeatureWordInfo feature_word_info[FEATURE_WORDS] = {
         .cpuid_eax = KVM_CPUID_FEATURES, .cpuid_reg = R_EAX,
         .tcg_features = TCG_KVM_FEATURES,
     },
+    [FEAT_HYPERV_EAX] = {
+        .feat_names = hyperv_priv_feature_name,
+        .cpuid_eax = 0x40000003, .cpuid_reg = R_EAX,
+    },
+    [FEAT_HYPERV_EBX] = {
+        .feat_names = hyperv_ident_feature_name,
+        .cpuid_eax = 0x40000003, .cpuid_reg = R_EBX,
+    },
+    [FEAT_HYPERV_EDX] = {
+        .feat_names = hyperv_misc_feature_name,
+        .cpuid_eax = 0x40000003, .cpuid_reg = R_EDX,
+    },
     [FEAT_SVM] = {
         .feat_names = svm_feature_name,
         .cpuid_eax = 0x8000000A, .cpuid_reg = R_EDX,
diff --git a/target-i386/cpu.h b/target-i386/cpu.h
index d9ab884..4496c8b 100644
--- a/target-i386/cpu.h
+++ b/target-i386/cpu.h
@@ -440,6 +440,9 @@ typedef enum FeatureWord {
     FEAT_8000_0007_EDX, /* CPUID[8000_0007].EDX */
     FEAT_C000_0001_EDX, /* CPUID[C000_0001].EDX */
     FEAT_KVM,           /* CPUID[4000_0001].EAX (KVM_CPUID_FEATURES) */
+    FEAT_HYPERV_EAX,    /* CPUID[4000_0003].EAX */
+    FEAT_HYPERV_EBX,    /* CPUID[4000_0003].EBX */
+    FEAT_HYPERV_EDX,    /* CPUID[4000_0003].EDX */
     FEAT_SVM,           /* CPUID[8000_000A].EDX */
     FEAT_XSAVE,         /* CPUID[EAX=0xd,ECX=1].EAX */
     FEAT_6_EAX,         /* CPUID[6].EAX */
diff --git a/target-i386/kvm.c b/target-i386/kvm.c
index f3698f1..f44e3c7 100644
--- a/target-i386/kvm.c
+++ b/target-i386/kvm.c
@@ -574,6 +574,66 @@ static int kvm_arch_set_tsc_khz(CPUState *cs)
     return 0;
 }
 
+static int hyperv_handle_properties(CPUState *cs)
+{
+    X86CPU *cpu = X86_CPU(cs);
+    CPUX86State *env = &cpu->env;
+
+    if (cpu->hyperv_relaxed_timing) {
+        env->features[FEAT_HYPERV_EAX] |= HV_X64_MSR_HYPERCALL_AVAILABLE;
+    }
+    if (cpu->hyperv_vapic) {
+        env->features[FEAT_HYPERV_EAX] |= HV_X64_MSR_HYPERCALL_AVAILABLE;
+        env->features[FEAT_HYPERV_EAX] |= HV_X64_MSR_APIC_ACCESS_AVAILABLE;
+        has_msr_hv_vapic = true;
+    }
+    if (cpu->hyperv_time &&
+            kvm_check_extension(cs->kvm_state, KVM_CAP_HYPERV_TIME) > 0) {
+        env->features[FEAT_HYPERV_EAX] |= HV_X64_MSR_HYPERCALL_AVAILABLE;
+        env->features[FEAT_HYPERV_EAX] |= HV_X64_MSR_TIME_REF_COUNT_AVAILABLE;
+        env->features[FEAT_HYPERV_EAX] |= 0x200;
+        has_msr_hv_tsc = true;
+    }
+    if (cpu->hyperv_crash && has_msr_hv_crash) {
+        env->features[FEAT_HYPERV_EDX] |= HV_X64_GUEST_CRASH_MSR_AVAILABLE;
+    }
+    if (cpu->hyperv_reset && has_msr_hv_reset) {
+        env->features[FEAT_HYPERV_EAX] |= HV_X64_MSR_RESET_AVAILABLE;
+    }
+    if (cpu->hyperv_vpindex && has_msr_hv_vpindex) {
+        env->features[FEAT_HYPERV_EAX] |= HV_X64_MSR_VP_INDEX_AVAILABLE;
+    }
+    if (cpu->hyperv_runtime && has_msr_hv_runtime) {
+        env->features[FEAT_HYPERV_EAX] |= HV_X64_MSR_VP_RUNTIME_AVAILABLE;
+    }
+    if (cpu->hyperv_synic) {
+        int sint;
+
+        if (!has_msr_hv_synic ||
+            kvm_vcpu_enable_cap(cs, KVM_CAP_HYPERV_SYNIC, 0)) {
+            fprintf(stderr, "Hyper-V SynIC is not supported by kernel\n");
+            return -ENOSYS;
+        }
+
+        env->features[FEAT_HYPERV_EAX] |= HV_X64_MSR_SYNIC_AVAILABLE;
+        env->msr_hv_synic_version = HV_SYNIC_VERSION_1;
+        for (sint = 0; sint < ARRAY_SIZE(env->msr_hv_synic_sint); sint++) {
+            env->msr_hv_synic_sint[sint] = HV_SYNIC_SINT_MASKED;
+        }
+    }
+    if (cpu->hyperv_stimer) {
+        if (!has_msr_hv_stimer) {
+            fprintf(stderr, "Hyper-V timers aren't supported by kernel\n");
+            return -ENOSYS;
+        }
+        env->features[FEAT_HYPERV_EAX] |= HV_X64_MSR_SYNTIMER_AVAILABLE;
+    }
+    if (MACHINE_GET_CLASS(current_machine)->hot_add_cpu != NULL) {
+        env->features[FEAT_HYPERV_EDX] |= HV_X64_CPU_DYNAMIC_PARTITIONING_AVAILABLE;
+    }
+    return 0;
+}
+
 static Error *invtsc_mig_blocker;
 
 #define KVM_MAX_CPUID_ENTRIES  100
@@ -633,56 +693,14 @@ int kvm_arch_init_vcpu(CPUState *cs)
 
         c = &cpuid_data.entries[cpuid_i++];
         c->function = HYPERV_CPUID_FEATURES;
-        if (cpu->hyperv_relaxed_timing) {
-            c->eax |= HV_X64_MSR_HYPERCALL_AVAILABLE;
-        }
-        if (cpu->hyperv_vapic) {
-            c->eax |= HV_X64_MSR_HYPERCALL_AVAILABLE;
-            c->eax |= HV_X64_MSR_APIC_ACCESS_AVAILABLE;
-            has_msr_hv_vapic = true;
-        }
-        if (cpu->hyperv_time &&
-            kvm_check_extension(cs->kvm_state, KVM_CAP_HYPERV_TIME) > 0) {
-            c->eax |= HV_X64_MSR_HYPERCALL_AVAILABLE;
-            c->eax |= HV_X64_MSR_TIME_REF_COUNT_AVAILABLE;
-            c->eax |= 0x200;
-            has_msr_hv_tsc = true;
-        }
-        if (cpu->hyperv_crash && has_msr_hv_crash) {
-            c->edx |= HV_X64_GUEST_CRASH_MSR_AVAILABLE;
-        }
-        c->edx |= HV_X64_CPU_DYNAMIC_PARTITIONING_AVAILABLE;
-        if (cpu->hyperv_reset && has_msr_hv_reset) {
-            c->eax |= HV_X64_MSR_RESET_AVAILABLE;
-        }
-        if (cpu->hyperv_vpindex && has_msr_hv_vpindex) {
-            c->eax |= HV_X64_MSR_VP_INDEX_AVAILABLE;
-        }
-        if (cpu->hyperv_runtime && has_msr_hv_runtime) {
-            c->eax |= HV_X64_MSR_VP_RUNTIME_AVAILABLE;
+        r = hyperv_handle_properties(cs);
+        if (r) {
+            return r;
         }
-        if (cpu->hyperv_synic) {
-            int sint;
-
-            if (!has_msr_hv_synic ||
-                kvm_vcpu_enable_cap(cs, KVM_CAP_HYPERV_SYNIC, 0)) {
-                fprintf(stderr, "Hyper-V SynIC is not supported by kernel\n");
-                return -ENOSYS;
-            }
+        c->eax = env->features[FEAT_HYPERV_EAX];
+        c->ebx = env->features[FEAT_HYPERV_EBX];
+        c->edx = env->features[FEAT_HYPERV_EDX];
 
-            c->eax |= HV_X64_MSR_SYNIC_AVAILABLE;
-            env->msr_hv_synic_version = HV_SYNIC_VERSION_1;
-            for (sint = 0; sint < ARRAY_SIZE(env->msr_hv_synic_sint); sint++) {
-                env->msr_hv_synic_sint[sint] = HV_SYNIC_SINT_MASKED;
-            }
-        }
-        if (cpu->hyperv_stimer) {
-            if (!has_msr_hv_stimer) {
-                fprintf(stderr, "Hyper-V timers aren't supported by kernel\n");
-                return -ENOSYS;
-            }
-            c->eax |= HV_X64_MSR_SYNTIMER_AVAILABLE;
-        }
         c = &cpuid_data.entries[cpuid_i++];
         c->function = HYPERV_CPUID_ENLIGHTMENT_INFO;
         if (cpu->hyperv_relaxed_timing) {
-- 
2.1.4