Commit a2b107db authored by Vitaly Kuznetsov's avatar Vitaly Kuznetsov Committed by Eduardo Habkost
Browse files

i386/kvm: expose HV_CPUID_ENLIGHTMENT_INFO.EAX and HV_CPUID_NESTED_FEATURES.EAX as feature words 



It was found that QMP users of QEMU (e.g. libvirt) may need
HV_CPUID_ENLIGHTMENT_INFO.EAX/HV_CPUID_NESTED_FEATURES.EAX information. In
particular, 'hv_tlbflush' and 'hv_evmcs' enlightenments are only exposed in
HV_CPUID_ENLIGHTMENT_INFO.EAX.

HV_CPUID_NESTED_FEATURES.EAX is exposed for two reasons: convenience
(we don't need to export it from hyperv_handle_properties() and as
future-proof for Enlightened MSR-Bitmap, PV EPT invalidation and
direct virtual flush features.

Signed-off-by: default avatarVitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20181126135958.20956-1-vkuznets@redhat.com>
Reviewed-by: default avatarRoman Kagan <rkagan@virtuozzo.com>
Signed-off-by: default avatarEduardo Habkost <ehabkost@redhat.com>
parent 7260438b

target/i386/cpu.c

+30 −0
Original line number Diff line number Diff line
@@ -980,6 +980,36 @@ static FeatureWordInfo feature_word_info[FEATURE_WORDS] = { 
        },

        .cpuid = { .eax = 0x40000003, .reg = R_EDX, },

    },

    [FEAT_HV_RECOMM_EAX] = {

        .type = CPUID_FEATURE_WORD,

        .feat_names = {

            NULL /* hv_recommend_pv_as_switch */,

            NULL /* hv_recommend_pv_tlbflush_local */,

            NULL /* hv_recommend_pv_tlbflush_remote */,

            NULL /* hv_recommend_msr_apic_access */,

            NULL /* hv_recommend_msr_reset */,

            NULL /* hv_recommend_relaxed_timing */,

            NULL /* hv_recommend_dma_remapping */,

            NULL /* hv_recommend_int_remapping */,

            NULL /* hv_recommend_x2apic_msrs */,

            NULL /* hv_recommend_autoeoi_deprecation */,

            NULL /* hv_recommend_pv_ipi */,

            NULL /* hv_recommend_ex_hypercalls */,

            NULL /* hv_hypervisor_is_nested */,

            NULL /* hv_recommend_int_mbec */,

            NULL /* hv_recommend_evmcs */,

            NULL,

            NULL, NULL, NULL, NULL,

            NULL, NULL, NULL, NULL,

            NULL, NULL, NULL, NULL,

            NULL, NULL, NULL, NULL,

        },

        .cpuid = { .eax = 0x40000004, .reg = R_EAX, },

    },

    [FEAT_HV_NESTED_EAX] = {

        .type = CPUID_FEATURE_WORD,

        .cpuid = { .eax = 0x4000000A, .reg = R_EAX, },

    },

    [FEAT_SVM] = {

        .type = CPUID_FEATURE_WORD,

        .feat_names = {

target/i386/cpu.h

+2 −0
Original line number Diff line number Diff line
@@ -497,6 +497,8 @@ typedef enum FeatureWord { 
    FEAT_HYPERV_EAX,    /* CPUID[4000_0003].EAX */

    FEAT_HYPERV_EBX,    /* CPUID[4000_0003].EBX */

    FEAT_HYPERV_EDX,    /* CPUID[4000_0003].EDX */

    FEAT_HV_RECOMM_EAX, /* CPUID[4000_0004].EAX */

    FEAT_HV_NESTED_EAX, /* CPUID[4000_000A].EAX */

    FEAT_SVM,           /* CPUID[8000_000A].EDX */

    FEAT_XSAVE,         /* CPUID[EAX=0xd,ECX=1].EAX */

    FEAT_6_EAX,         /* CPUID[6].EAX */

target/i386/kvm.c

+45 −40
Original line number Diff line number Diff line
@@ -798,6 +798,48 @@ static int hyperv_handle_properties(CPUState *cs) 
        }

        env->features[FEAT_HYPERV_EAX] |= HV_SYNTIMERS_AVAILABLE;

    }

    if (cpu->hyperv_relaxed_timing) {

        env->features[FEAT_HV_RECOMM_EAX] |= HV_RELAXED_TIMING_RECOMMENDED;

    }

    if (cpu->hyperv_vapic) {

        env->features[FEAT_HV_RECOMM_EAX] |= HV_APIC_ACCESS_RECOMMENDED;

    }

    if (cpu->hyperv_tlbflush) {

        if (kvm_check_extension(cs->kvm_state,

                                KVM_CAP_HYPERV_TLBFLUSH) <= 0) {

            fprintf(stderr, "Hyper-V TLB flush support "

                    "(requested by 'hv-tlbflush' cpu flag) "

                    " is not supported by kernel\n");

            return -ENOSYS;

        }

        env->features[FEAT_HV_RECOMM_EAX] |= HV_REMOTE_TLB_FLUSH_RECOMMENDED;

        env->features[FEAT_HV_RECOMM_EAX] |= HV_EX_PROCESSOR_MASKS_RECOMMENDED;

    }

    if (cpu->hyperv_ipi) {

        if (kvm_check_extension(cs->kvm_state,

                                KVM_CAP_HYPERV_SEND_IPI) <= 0) {

            fprintf(stderr, "Hyper-V IPI send support "

                    "(requested by 'hv-ipi' cpu flag) "

                    " is not supported by kernel\n");

            return -ENOSYS;

        }

        env->features[FEAT_HV_RECOMM_EAX] |= HV_CLUSTER_IPI_RECOMMENDED;

        env->features[FEAT_HV_RECOMM_EAX] |= HV_EX_PROCESSOR_MASKS_RECOMMENDED;

    }

    if (cpu->hyperv_evmcs) {

        uint16_t evmcs_version;



        if (kvm_vcpu_enable_cap(cs, KVM_CAP_HYPERV_ENLIGHTENED_VMCS, 0,

                                (uintptr_t)&evmcs_version)) {

            fprintf(stderr, "Hyper-V Enlightened VMCS "

                    "(requested by 'hv-evmcs' cpu flag) "

                    "is not supported by kernel\n");

            return -ENOSYS;

        }

        env->features[FEAT_HV_RECOMM_EAX] |= HV_ENLIGHTENED_VMCS_RECOMMENDED;

        env->features[FEAT_HV_NESTED_EAX] = evmcs_version;

    }



    return 0;

}
@@ -879,7 +921,6 @@ int kvm_arch_init_vcpu(CPUState *cs) 
    uint32_t unused;

    struct kvm_cpuid_entry2 *c;

    uint32_t signature[3];

    uint16_t evmcs_version;

    int kvm_base = KVM_CPUID_SIGNATURE;

    int r;

    Error *local_err = NULL;
@@ -954,44 +995,8 @@ int kvm_arch_init_vcpu(CPUState *cs) 


        c = &cpuid_data.entries[cpuid_i++];

        c->function = HV_CPUID_ENLIGHTMENT_INFO;

        if (cpu->hyperv_relaxed_timing) {

            c->eax |= HV_RELAXED_TIMING_RECOMMENDED;

        }

        if (cpu->hyperv_vapic) {

            c->eax |= HV_APIC_ACCESS_RECOMMENDED;

        }

        if (cpu->hyperv_tlbflush) {

            if (kvm_check_extension(cs->kvm_state,

                                    KVM_CAP_HYPERV_TLBFLUSH) <= 0) {

                fprintf(stderr, "Hyper-V TLB flush support "

                        "(requested by 'hv-tlbflush' cpu flag) "

                        " is not supported by kernel\n");

                return -ENOSYS;

            }

            c->eax |= HV_REMOTE_TLB_FLUSH_RECOMMENDED;

            c->eax |= HV_EX_PROCESSOR_MASKS_RECOMMENDED;

        }

        if (cpu->hyperv_ipi) {

            if (kvm_check_extension(cs->kvm_state,

                                    KVM_CAP_HYPERV_SEND_IPI) <= 0) {

                fprintf(stderr, "Hyper-V IPI send support "

                        "(requested by 'hv-ipi' cpu flag) "

                        " is not supported by kernel\n");

                return -ENOSYS;

            }

            c->eax |= HV_CLUSTER_IPI_RECOMMENDED;

            c->eax |= HV_EX_PROCESSOR_MASKS_RECOMMENDED;

        }

        if (cpu->hyperv_evmcs) {

            if (kvm_vcpu_enable_cap(cs, KVM_CAP_HYPERV_ENLIGHTENED_VMCS, 0,

                                    (uintptr_t)&evmcs_version)) {

                fprintf(stderr, "Hyper-V Enlightened VMCS "

                        "(requested by 'hv-evmcs' cpu flag) "

                        "is not supported by kernel\n");

                return -ENOSYS;

            }

            c->eax |= HV_ENLIGHTENED_VMCS_RECOMMENDED;

        }



        c->eax = env->features[FEAT_HV_RECOMM_EAX];

        c->ebx = cpu->hyperv_spinlock_attempts;



        c = &cpuid_data.entries[cpuid_i++];
@@ -1015,7 +1020,7 @@ int kvm_arch_init_vcpu(CPUState *cs) 


            c = &cpuid_data.entries[cpuid_i++];

            c->function = HV_CPUID_NESTED_FEATURES;

            c->eax = evmcs_version;

            c->eax = env->features[FEAT_HV_NESTED_EAX];

        }

    }