Re: [Qemu-devel] [PATCH 3/3] add support for hyperv time parameter

[Paolo Bonzini <pbonzini@redhat.com>]

Il 21/01/2014 09:02, Vadim Rozenfeld ha scritto:
> From: Vadim Rozenfeld <vrozenfeld@gamil.com>
> 
> Signed-off-by: Vadim Rozenfeld <vrozenfe@redhat.com>
> ---
>  linux-headers/asm-x86/hyperv.h |  3 +++
>  linux-headers/linux/kvm.h      |  1 +
>  target-i386/cpu-qom.h          |  1 +
>  target-i386/cpu.c              |  1 +
>  target-i386/cpu.h              |  1 +
>  target-i386/kvm.c              | 19 +++++++++++++++++++
>  target-i386/machine.c          |  1 +
>  7 files changed, 27 insertions(+)
> 
> diff --git a/linux-headers/asm-x86/hyperv.h b/linux-headers/asm-x86/hyperv.h
> index b8f1c01..3b400ee 100644
> --- a/linux-headers/asm-x86/hyperv.h
> +++ b/linux-headers/asm-x86/hyperv.h
> @@ -149,6 +149,9 @@
>  /* MSR used to read the per-partition time reference counter */
>  #define HV_X64_MSR_TIME_REF_COUNT		0x40000020
>  
> +/* A partition's reference time stamp counter (TSC) page */
> +#define HV_X64_MSR_REFERENCE_TSC		0x40000021
> +
>  /* MSR used to retrieve the TSC frequency */
>  #define HV_X64_MSR_TSC_FREQUENCY		0x40000022
>  
> diff --git a/linux-headers/linux/kvm.h b/linux-headers/linux/kvm.h
> index 5a49671..999fb13 100644
> --- a/linux-headers/linux/kvm.h
> +++ b/linux-headers/linux/kvm.h
> @@ -674,6 +674,7 @@ struct kvm_ppc_smmu_info {
>  #define KVM_CAP_ARM_EL1_32BIT 93
>  #define KVM_CAP_SPAPR_MULTITCE 94
>  #define KVM_CAP_EXT_EMUL_CPUID 95
> +#define KVM_CAP_HYPERV_TIME 96
>  
>  #ifdef KVM_CAP_IRQ_ROUTING
>  
> diff --git a/target-i386/cpu-qom.h b/target-i386/cpu-qom.h
> index d1751a4..722f11a 100644
> --- a/target-i386/cpu-qom.h
> +++ b/target-i386/cpu-qom.h
> @@ -69,6 +69,7 @@ typedef struct X86CPU {
>      bool hyperv_vapic;
>      bool hyperv_relaxed_timing;
>      int hyperv_spinlock_attempts;
> +    bool hyperv_time;
>      bool check_cpuid;
>      bool enforce_cpuid;
>  
> diff --git a/target-i386/cpu.c b/target-i386/cpu.c
> index 0eea8c7..ff3290c 100644
> --- a/target-i386/cpu.c
> +++ b/target-i386/cpu.c
> @@ -2744,6 +2744,7 @@ static Property x86_cpu_properties[] = {
>      { .name  = "hv-spinlocks", .info  = &qdev_prop_spinlocks },
>      DEFINE_PROP_BOOL("hv-relaxed", X86CPU, hyperv_relaxed_timing, false),
>      DEFINE_PROP_BOOL("hv-vapic", X86CPU, hyperv_vapic, false),
> +    DEFINE_PROP_BOOL("hv-time", X86CPU, hyperv_time, false),
>      DEFINE_PROP_BOOL("check", X86CPU, check_cpuid, false),
>      DEFINE_PROP_BOOL("enforce", X86CPU, enforce_cpuid, false),
>      DEFINE_PROP_END_OF_LIST()
> diff --git a/target-i386/cpu.h b/target-i386/cpu.h
> index 6eeafdc..f7d7689 100644
> --- a/target-i386/cpu.h
> +++ b/target-i386/cpu.h
> @@ -850,6 +850,7 @@ typedef struct CPUX86State {
>      uint64_t msr_hv_hypercall;
>      uint64_t msr_hv_guest_os_id;
>      uint64_t msr_hv_vapic;
> +    uint64_t msr_hv_tsc;
>  
>      /* exception/interrupt handling */
>      int error_code;
> diff --git a/target-i386/kvm.c b/target-i386/kvm.c
> index 5152e64..75ebc5d 100644
> --- a/target-i386/kvm.c
> +++ b/target-i386/kvm.c
> @@ -73,6 +73,7 @@ static bool has_msr_kvm_steal_time;
>  static int lm_capable_kernel;
>  static bool has_msr_hv_hypercall;
>  static bool has_msr_hv_vapic;
> +static bool has_msr_hv_tsc;
>  
>  static bool has_msr_architectural_pmu;
>  static uint32_t num_architectural_pmu_counters;
> @@ -433,6 +434,7 @@ unsigned long kvm_arch_vcpu_id(CPUState *cs)
>  static bool hyperv_hypercall_available(X86CPU *cpu)
>  {
>      return cpu->hyperv_vapic ||
> +           cpu->hyperv_time  ||
>             (cpu->hyperv_spinlock_attempts != HYPERV_SPINLOCK_NEVER_RETRY);
>  }
>  
> @@ -492,6 +494,13 @@ int kvm_arch_init_vcpu(CPUState *cs)
>              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;
> +        }
>  
>          c = &cpuid_data.entries[cpuid_i++];
>          c->function = HYPERV_CPUID_ENLIGHTMENT_INFO;
> @@ -1195,6 +1204,10 @@ static int kvm_put_msrs(X86CPU *cpu, int level)
>              kvm_msr_entry_set(&msrs[n++], HV_X64_MSR_APIC_ASSIST_PAGE,
>                                env->msr_hv_vapic);
>          }
> +        if (has_msr_hv_tsc) {
> +            kvm_msr_entry_set(&msrs[n++], HV_X64_MSR_REFERENCE_TSC,
> +                              env->msr_hv_tsc);
> +        }
>          if (has_msr_feature_control) {
>              kvm_msr_entry_set(&msrs[n++], MSR_IA32_FEATURE_CONTROL,
>                                env->msr_ia32_feature_control);
> @@ -1480,6 +1493,9 @@ static int kvm_get_msrs(X86CPU *cpu)
>      if (has_msr_hv_vapic) {
>          msrs[n++].index = HV_X64_MSR_APIC_ASSIST_PAGE;
>      }
> +    if (has_msr_hv_tsc) {
> +        msrs[n++].index = HV_X64_MSR_REFERENCE_TSC;
> +    }
>  
>      msr_data.info.nmsrs = n;
>      ret = kvm_vcpu_ioctl(CPU(cpu), KVM_GET_MSRS, &msr_data);
> @@ -1594,6 +1610,9 @@ static int kvm_get_msrs(X86CPU *cpu)
>          case HV_X64_MSR_APIC_ASSIST_PAGE:
>              env->msr_hv_vapic = msrs[i].data;
>              break;
> +        case HV_X64_MSR_REFERENCE_TSC:
> +            env->msr_hv_tsc = msrs[i].data;
> +            break;
>          }
>      }
>  
> diff --git a/target-i386/machine.c b/target-i386/machine.c
> index 58c5b45..9e9a001 100644
> --- a/target-i386/machine.c
> +++ b/target-i386/machine.c
> @@ -523,6 +523,7 @@ static const VMStateDescription vmstate_msr_hyperv = {
>          VMSTATE_UINT64(env.msr_hv_hypercall, X86CPU),
>          VMSTATE_UINT64(env.msr_hv_guest_os_id, X86CPU),
>          VMSTATE_UINT64(env.msr_hv_vapic, X86CPU),
> +        VMSTATE_UINT64(env.msr_hv_tsc, X86CPU),
>          VMSTATE_END_OF_LIST()
>      }
>  };
> 

If you are planning some level of backwards compatibility with RHEL6, it
may make sense to use separate subsections.

Paolo