From: "Jan Beulich" <JBeulich@novell.com>
To: Christoph Egger <Christoph.Egger@amd.com>
Cc: xen-devel@lists.xensource.com
Subject: Re: [PATCH] xen svm: fix PAUSE instruction intercept
Date: Thu, 12 Aug 2010 11:07:54 +0100 [thread overview]
Message-ID: <4C63E41A020000780000F773@vpn.id2.novell.com> (raw)
In-Reply-To: <201008121122.36706.Christoph.Egger@amd.com>
>>> On 12.08.10 at 11:22, Christoph Egger <Christoph.Egger@amd.com> wrote:
> In svm_vmexit_do_pause() update the instruction pointer.
> This fixes strange PAUSE intercepts on UP guests.
This won't work when the instruction needs to actually be decoded:
__get_instruction_length_from_list() strips all prefix bytes from
the byte stream being decoded, and since 'pause' uses a prefix the
actual opcode comparison will never produce a match.
Even in the case that CPUs supporting the pause filter would always
support nextrip I think that the special case minimally deserves a
code comment to that effect, but perhaps even warrants an
ASSERT() or BUG_ON().
Jan
next prev parent reply other threads:[~2010-08-12 10:07 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-08-12 9:22 [PATCH] xen svm: fix PAUSE instruction intercept Christoph Egger
2010-08-12 10:07 ` Jan Beulich [this message]
2010-08-12 12:50 ` Christoph Egger
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