From: Avi Kivity <avi@redhat.com>
To: Marcelo Tosatti <mtosatti@redhat.com>
Cc: kvm@vger.kernel.org, "Stephan Bärwolf" <stephan.baerwolf@tu-ilmenau.de>
Subject: Re: [PATCH] KVM: x86 emulator: reject SYSENTER in compatibility mode on AMD guests
Date: Wed, 01 Feb 2012 15:25:55 +0200 [thread overview]
Message-ID: <4F293D63.1080704@redhat.com> (raw)
In-Reply-To: <20120201110044.GA26183@amt.cnet>
On 02/01/2012 01:00 PM, Marcelo Tosatti wrote:
> On Wed, Feb 01, 2012 at 12:27:00PM +0200, Avi Kivity wrote:
> > If the guest thinks it's an AMD, it will not have prepared the SYSENTER MSRs,
> > and if the guest executes SYSENTER in compatibility mode, it will fails.
> >
> > Detect this condition and #UD instead, like the spec says.
>
> Note the SYSENTER_CS & 0xfffc == 0 check protects against a fatal error (unlike
> the SYSCALL bug), in case of zeroed MSRs.
That's a relief. It's still possible for this to fail (say kexec from
32-bit guest to 64-bit guest) but it's incredibly unlikely.
--
error compiling committee.c: too many arguments to function
prev parent reply other threads:[~2012-02-01 13:26 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-02-01 10:27 [PATCH] KVM: x86 emulator: reject SYSENTER in compatibility mode on AMD guests Avi Kivity
2012-02-01 10:45 ` Stephan Bärwolf
2012-02-01 10:50 ` Avi Kivity
2012-02-01 10:59 ` Stephan Bärwolf
2012-02-01 11:03 ` Avi Kivity
2012-02-01 11:00 ` Marcelo Tosatti
2012-02-01 13:25 ` Avi Kivity [this message]
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=4F293D63.1080704@redhat.com \
--to=avi@redhat.com \
--cc=kvm@vger.kernel.org \
--cc=mtosatti@redhat.com \
--cc=stephan.baerwolf@tu-ilmenau.de \
/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
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox