Commit e204ac61 authored by Vitaly Kuznetsov's avatar Vitaly Kuznetsov Committed by Paolo Bonzini
Browse files

x86: hv_evmcs CPU flag support 



Adds a new CPU flag to enable the Enlightened VMCS KVM feature.
QEMU enables KVM_CAP_HYPERV_ENLIGHTENED_VMCS and gets back the
version to be advertised in lower 16 bits of CPUID.0x4000000A:EAX.

Suggested-by: default avatarLadi Prosek <lprosek@redhat.com>
Signed-off-by: default avatarVitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20181022165506.30332-3-vkuznets@redhat.com>
Reviewed-by: default avatarRoman Kagan <rkagan@virtuozzo.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 013aabdc

target/i386/cpu.c

+1 −0
Original line number Diff line number Diff line
@@ -5732,6 +5732,7 @@ static Property x86_cpu_properties[] = { 
    DEFINE_PROP_BOOL("hv-frequencies", X86CPU, hyperv_frequencies, false),

    DEFINE_PROP_BOOL("hv-reenlightenment", X86CPU, hyperv_reenlightenment, false),

    DEFINE_PROP_BOOL("hv-tlbflush", X86CPU, hyperv_tlbflush, false),

    DEFINE_PROP_BOOL("hv-evmcs", X86CPU, hyperv_evmcs, false),

    DEFINE_PROP_BOOL("hv-ipi", X86CPU, hyperv_ipi, false),

    DEFINE_PROP_BOOL("check", X86CPU, check_cpuid, true),

    DEFINE_PROP_BOOL("enforce", X86CPU, enforce_cpuid, false),

target/i386/cpu.h

+1 −0
Original line number Diff line number Diff line
@@ -1391,6 +1391,7 @@ struct X86CPU { 
    bool hyperv_frequencies;

    bool hyperv_reenlightenment;

    bool hyperv_tlbflush;

    bool hyperv_evmcs;

    bool hyperv_ipi;

    bool check_cpuid;

    bool enforce_cpuid;

target/i386/hyperv-proto.h

+2 −0
Original line number Diff line number Diff line
@@ -18,6 +18,7 @@ 
#define HV_CPUID_FEATURES                     0x40000003

#define HV_CPUID_ENLIGHTMENT_INFO             0x40000004

#define HV_CPUID_IMPLEMENT_LIMITS             0x40000005

#define HV_CPUID_NESTED_FEATURES              0x4000000A

#define HV_CPUID_MIN                          0x40000005

#define HV_CPUID_MAX                          0x4000ffff

#define HV_HYPERVISOR_PRESENT_BIT             0x80000000
@@ -60,6 +61,7 @@ 
#define HV_RELAXED_TIMING_RECOMMENDED       (1u << 5)

#define HV_CLUSTER_IPI_RECOMMENDED          (1u << 10)

#define HV_EX_PROCESSOR_MASKS_RECOMMENDED   (1u << 11)

#define HV_ENLIGHTENED_VMCS_RECOMMENDED     (1u << 14)



/*

 * Basic virtualized MSRs

target/i386/kvm.c

+28 −2
Original line number Diff line number Diff line
@@ -869,6 +869,7 @@ 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;
@@ -912,7 +913,8 @@ int kvm_arch_init_vcpu(CPUState *cs) 
            memset(signature, 0, 12);

            memcpy(signature, cpu->hyperv_vendor_id, len);

        }

        c->eax = HV_CPUID_MIN;

        c->eax = cpu->hyperv_evmcs ?

            HV_CPUID_NESTED_FEATURES : HV_CPUID_IMPLEMENT_LIMITS;

        c->ebx = signature[0];

        c->ecx = signature[1];

        c->edx = signature[2];
@@ -970,7 +972,16 @@ int kvm_arch_init_vcpu(CPUState *cs) 
            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->ebx = cpu->hyperv_spinlock_attempts;



        c = &cpuid_data.entries[cpuid_i++];
@@ -981,6 +992,21 @@ int kvm_arch_init_vcpu(CPUState *cs) 


        kvm_base = KVM_CPUID_SIGNATURE_NEXT;

        has_msr_hv_hypercall = true;



        if (cpu->hyperv_evmcs) {

            __u32 function;



            /* Create zeroed 0x40000006..0x40000009 leaves */

            for (function = HV_CPUID_IMPLEMENT_LIMITS + 1;

                 function < HV_CPUID_NESTED_FEATURES; function++) {

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

                c->function = function;

            }



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

            c->function = HV_CPUID_NESTED_FEATURES;

            c->eax = evmcs_version;

        }

    }



    if (cpu->expose_kvm) {