[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH] xen svm: fix PAUSE instruction intercept
On Thursday 12 August 2010 12:07:54 Jan Beulich wrote: > >>> On 12.08.10 at 11:22, Christoph Egger <Christoph.Egger@xxxxxxx> 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. Thank you for pointing this out. New attached version fixes this. Signed-off-by: Christoph Egger <Christoph.Egger@xxxxxxx> > 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(). This is true for real hardware but not necessarily when it comes to nested virtualization, because you emulate SVM features in software. Christoph -- ---to satisfy European Law for business letters: Advanced Micro Devices GmbH Einsteinring 24, 85609 Dornach b. Muenchen Geschaeftsfuehrer: Alberto Bozzo, Andrew Bowd Sitz: Dornach, Gemeinde Aschheim, Landkreis Muenchen Registergericht Muenchen, HRB Nr. 43632 Attachment:
xen_pausefilter.diff _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxxxxxxxx http://lists.xensource.com/xen-devel
|
![]() |
Lists.xenproject.org is hosted with RackSpace, monitoring our |