Re: [Qemu-devel] [ [PATCH]] nVMX: Initialize IA32_FEATURE_CONTROL MSR in reset and migration

[Arthur Chunqi Li]

Hi Gleb and Paolo,
What is the status of this patch since the relevant patch for KVM is
accepted? These two patches must cooperate to fix the bug.

Arthur

On Sun, Jul 7, 2013 at 11:13 PM, Arthur Chunqi Li <address@hidden> wrote:
> The recent KVM patch adds IA32_FEATURE_CONTROL support. QEMU needs
> to clear this MSR when reset vCPU and keep the value of it when
> migration. This patch add this feature.
>
> Signed-off-by: Arthur Chunqi Li <address@hidden>
> ---
>  target-i386/cpu.h     |    2 ++
>  target-i386/kvm.c     |    4 ++++
>  target-i386/machine.c |   22 ++++++++++++++++++++++
>  3 files changed, 28 insertions(+)
>
> diff --git a/target-i386/cpu.h b/target-i386/cpu.h
> index 62e3547..a418e17 100644
> --- a/target-i386/cpu.h
> +++ b/target-i386/cpu.h
> @@ -301,6 +301,7 @@
>  #define MSR_IA32_APICBASE_BSP           (1<<8)
>  #define MSR_IA32_APICBASE_ENABLE        (1<<11)
>  #define MSR_IA32_APICBASE_BASE          (0xfffff<<12)
> +#define MSR_IA32_FEATURE_CONTROL        0x0000003a
>  #define MSR_TSC_ADJUST                  0x0000003b
>  #define MSR_IA32_TSCDEADLINE            0x6e0
>
> @@ -813,6 +814,7 @@ typedef struct CPUX86State {
>
>      uint64_t mcg_status;
>      uint64_t msr_ia32_misc_enable;
> +    uint64_t msr_ia32_feature_control;
>
>      /* exception/interrupt handling */
>      int error_code;
> diff --git a/target-i386/kvm.c b/target-i386/kvm.c
> index 39f4fbb..3cb2161 100644
> --- a/target-i386/kvm.c
> +++ b/target-i386/kvm.c
> @@ -1122,6 +1122,7 @@ static int kvm_put_msrs(X86CPU *cpu, int level)
>          if (hyperv_vapic_recommended()) {
>              kvm_msr_entry_set(&msrs[n++], HV_X64_MSR_APIC_ASSIST_PAGE, 0);
>          }
> +        kvm_msr_entry_set(&msrs[n++], MSR_IA32_FEATURE_CONTROL, 
> env->msr_ia32_feature_control);
>      }
>      if (env->mcg_cap) {
>          int i;
> @@ -1346,6 +1347,7 @@ static int kvm_get_msrs(X86CPU *cpu)
>      if (has_msr_misc_enable) {
>          msrs[n++].index = MSR_IA32_MISC_ENABLE;
>      }
> +    msrs[n++].index = MSR_IA32_FEATURE_CONTROL;
>
>      if (!env->tsc_valid) {
>          msrs[n++].index = MSR_IA32_TSC;
> @@ -1444,6 +1446,8 @@ static int kvm_get_msrs(X86CPU *cpu)
>          case MSR_IA32_MISC_ENABLE:
>              env->msr_ia32_misc_enable = msrs[i].data;
>              break;
> +        case MSR_IA32_FEATURE_CONTROL:
> +            env->msr_ia32_feature_control = msrs[i].data;
>          default:
>              if (msrs[i].index >= MSR_MC0_CTL &&
>                  msrs[i].index < MSR_MC0_CTL + (env->mcg_cap & 0xff) * 4) {
> diff --git a/target-i386/machine.c b/target-i386/machine.c
> index 3659db9..94ca914 100644
> --- a/target-i386/machine.c
> +++ b/target-i386/machine.c
> @@ -399,6 +399,14 @@ static bool misc_enable_needed(void *opaque)
>      return env->msr_ia32_misc_enable != MSR_IA32_MISC_ENABLE_DEFAULT;
>  }
>
> +static bool feature_control_needed(void *opaque)
> +{
> +    X86CPU *cpu = opaque;
> +    CPUX86State *env = &cpu->env;
> +
> +    return env->msr_ia32_feature_control != 0;
> +}
> +
>  static const VMStateDescription vmstate_msr_ia32_misc_enable = {
>      .name = "cpu/msr_ia32_misc_enable",
>      .version_id = 1,
> @@ -410,6 +418,17 @@ static const VMStateDescription 
> vmstate_msr_ia32_misc_enable = {
>      }
>  };
>
> +static const VMStateDescription vmstate_msr_ia32_feature_control = {
> +    .name = "cpu/msr_ia32_feature_control",
> +    .version_id = 1,
> +    .minimum_version_id = 1,
> +    .minimum_version_id_old = 1,
> +    .fields      = (VMStateField []) {
> +        VMSTATE_UINT64(env.msr_ia32_feature_control, X86CPU),
> +        VMSTATE_END_OF_LIST()
> +    }
> +};
> +
>  const VMStateDescription vmstate_x86_cpu = {
>      .name = "cpu",
>      .version_id = 12,
> @@ -535,6 +554,9 @@ const VMStateDescription vmstate_x86_cpu = {
>          }, {
>              .vmsd = &vmstate_msr_ia32_misc_enable,
>              .needed = misc_enable_needed,
> +        }, {
> +            .vmsd = &vmstate_msr_ia32_feature_control,
> +            .needed = feature_control_needed,
>          } , {
>              /* empty */
>          }
> --
> 1.7.9.5
>