LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Sean Christopherson <seanjc@google.com>
To: Hou Wenlong <houwenlong93@linux.alibaba.com>
Cc: kvm@vger.kernel.org, Paolo Bonzini <pbonzini@redhat.com>,
	Vitaly Kuznetsov <vkuznets@redhat.com>,
	Wanpeng Li <wanpengli@tencent.com>,
	Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
	Avi Kivity <avi@redhat.com>,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] kvm: fix wrong exception emulation in check_rdtsc
Date: Wed, 18 Aug 2021 21:43:09 +0000	[thread overview]
Message-ID: <YR1+7awNToPmkitb@google.com> (raw)
In-Reply-To: <1297c0dd3f1bb47a6d089f850b629c7aa0247040.1629257115.git.houwenlong93@linux.alibaba.com>

On Wed, Aug 18, 2021, 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@linux.alibaba.com>
> ---
>  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);

Heh, I was having some serious deja vu, but the fix I was thinking of was
for em_rdpid, and that was changing #GP -> #UD (commit a9e2e0ae6860).

Reviewed-by: Sean Christopherson <seanjc@google.com>

>  	return X86EMUL_CONTINUE;
>  }
> -- 
> 2.31.1
> 

  parent reply	other threads:[~2021-08-18 21:43 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-18  3:36 Hou Wenlong
2021-08-18 21:07 ` Jim Mattson
2021-08-18 21:43 ` Sean Christopherson [this message]
2021-09-21 18:00 ` Paolo Bonzini

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=YR1+7awNToPmkitb@google.com \
    --to=seanjc@google.com \
    --cc=avi@redhat.com \
    --cc=bp@alien8.de \
    --cc=houwenlong93@linux.alibaba.com \
    --cc=hpa@zytor.com \
    --cc=jmattson@google.com \
    --cc=joro@8bytes.org \
    --cc=kvm@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@redhat.com \
    --cc=pbonzini@redhat.com \
    --cc=tglx@linutronix.de \
    --cc=vkuznets@redhat.com \
    --cc=wanpengli@tencent.com \
    --cc=x86@kernel.org \
    --subject='Re: [PATCH] kvm: fix wrong exception emulation in check_rdtsc' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).