Re: [PATCH] kvm: fix wrong exception emulation in check_rdtsc

[Paolo Bonzini]

On 18/08/21 05:36, Hou Wenlong wrote:
> According to Intel's SDM Vol2 and AMD's APM Vol3, when
> CR4.TSD is set, use rdtsc/rdtscp instruction above privilege
> level 0 should trigger a #GP.
>
> Fixes: d7eb82030699e ("KVM: SVM: Add intercept checks for remaining group7 instructions")
> Signed-off-by: Hou Wenlong <houwenlong93@xxxxxxxxxxxxxxxxx>
> ---
>   arch/x86/kvm/emulate.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
> index 2837110e66ed..c589ac832265 100644
> --- a/arch/x86/kvm/emulate.c
> +++ b/arch/x86/kvm/emulate.c
> @@ -4206,7 +4206,7 @@ static int check_rdtsc(struct x86_emulate_ctxt *ctxt)
>   	u64 cr4 = ctxt->ops->get_cr(ctxt, 4);
>   
>   	if (cr4 & X86_CR4_TSD && ctxt->ops->cpl(ctxt))
> -		return emulate_ud(ctxt);
> +		return emulate_gp(ctxt, 0);
>   
>   	return X86EMUL_CONTINUE;
>   }

Queued, thanks.

Paolo