Re: [Qemu-devel] [PATCH 2/4] target/i386: kvm: Init nested-state for vCPU exposed with SVM

[Paolo Bonzini <pbonzini@redhat.com>]

On 05/07/19 23:06, Liran Alon wrote:
> Reviewed-by: Joao Martins <joao.m.martins@oracle.com>
> Signed-off-by: Liran Alon <liran.alon@oracle.com>
> ---
>  target/i386/cpu.h | 5 +++++
>  target/i386/kvm.c | 2 ++
>  2 files changed, 7 insertions(+)
> 
> diff --git a/target/i386/cpu.h b/target/i386/cpu.h
> index 93345792f4cb..cdb0e43676a9 100644
> --- a/target/i386/cpu.h
> +++ b/target/i386/cpu.h
> @@ -1867,6 +1867,11 @@ static inline bool cpu_has_vmx(CPUX86State *env)
>      return env->features[FEAT_1_ECX] & CPUID_EXT_VMX;
>  }
>  
> +static inline bool cpu_has_svm(CPUX86State *env)
> +{
> +    return env->features[FEAT_8000_0001_ECX] & CPUID_EXT3_SVM;
> +}
> +
>  /* fpu_helper.c */
>  void update_fp_status(CPUX86State *env);
>  void update_mxcsr_status(CPUX86State *env);
> diff --git a/target/i386/kvm.c b/target/i386/kvm.c
> index b57f873ec9e8..4e2c8652168f 100644
> --- a/target/i386/kvm.c
> +++ b/target/i386/kvm.c
> @@ -1721,6 +1721,8 @@ int kvm_arch_init_vcpu(CPUState *cs)
>              env->nested_state->format = KVM_STATE_NESTED_FORMAT_VMX;
>              vmx_hdr->vmxon_pa = -1ull;
>              vmx_hdr->vmcs12_pa = -1ull;
> +        } else if (cpu_has_svm(env)) {
> +            env->nested_state->format = KVM_STATE_NESTED_FORMAT_SVM;
>          }
>      }
>  
> 

I'm not sure about it.  We have no idea what the format will be, so we
shouldn't set the format carelessly.

Paolo