Tracing facility for nested virtualization Signed-off-by: Christoph Egger <Christoph.Egger@amd.com> -- ---to satisfy European Law for business letters: Advanced Micro Devices GmbH Einsteinring 24, 85689 Dornach b. Muenchen Geschaeftsfuehrer: Alberto Bozzo, Andrew Bowd Sitz: Dornach, Gemeinde Aschheim, Landkreis Muenchen Registergericht Muenchen, HRB Nr. 43632 _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
On 13/04/2011 16:34, "Christoph Egger" <Christoph.Egger@amd.com> wrote:> > Tracing facility for nested virtualization > > Signed-off-by: Christoph Egger <Christoph.Egger@amd.com>I fixed this, by adding an extra argument to HVMTRACE_ND() -- it wasn''t really valid to make the first argument be an arbitarry C expression, due to argument concatenation that then went on in the macro body. I also discarded the change to the VMENTRY record to add the guest EIP. Firstly, it was incomplete, because it did not handle 64-bit RIP. Secondly, it does not logically belong in this patch. Finally, George may have a reason for not including RIP in VMENTRY records (e.g., not that useful compared with the extra space taken up in trace records). So you''d need to submit a new patch and get an Ack from George (who is currently on holiday). -- Keir _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
On 04/14/11 16:00, Keir Fraser wrote:> On 13/04/2011 16:34, "Christoph Egger"<Christoph.Egger@amd.com> wrote: > >> >> Tracing facility for nested virtualization >> >> Signed-off-by: Christoph Egger<Christoph.Egger@amd.com> > > I fixed this, by adding an extra argument to HVMTRACE_ND() -- it wasn''t > really valid to make the first argument be an arbitarry C expression, due to > argument concatenation that then went on in the macro body.Thanks for your effort.> I also discarded the change to the VMENTRY record to add the guest EIP. > Firstly, it was incomplete, because it did not handle 64-bit RIP. Secondly, > it does not logically belong in this patch. Finally, George may have a > reason for not including RIP in VMENTRY records (e.g., not that useful > compared with the extra space taken up in trace records). So you''d need to > submit a new patch and get an Ack from George (who is currently on holiday).Ok. If he has one I would like to know it. For nested virtualization it is at least good debugging information to see if the l2 guest loops somewhere or not. Christoph -- ---to satisfy European Law for business letters: Advanced Micro Devices GmbH Einsteinring 24, 85689 Dornach b. Muenchen Geschaeftsfuehrer: Alberto Bozzo, Andrew Bowd Sitz: Dornach, Gemeinde Aschheim, Landkreis Muenchen Registergericht Muenchen, HRB Nr. 43632 _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
On 14/04/2011 15:36, "Christoph Egger" <Christoph.Egger@amd.com> wrote:>> I also discarded the change to the VMENTRY record to add the guest EIP. >> Firstly, it was incomplete, because it did not handle 64-bit RIP. Secondly, >> it does not logically belong in this patch. Finally, George may have a >> reason for not including RIP in VMENTRY records (e.g., not that useful >> compared with the extra space taken up in trace records). So you''d need to >> submit a new patch and get an Ack from George (who is currently on holiday). > > Ok. If he has one I would like to know it. > For nested virtualization it is at least good debugging information to > see if the l2 guest loops somewhere or not.He might at least agree to it in the L2 case only. Anyhow, that''s his call not mine. -- Keir _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
On Thu, Apr 14, 2011 at 3:36 PM, Christoph Egger <Christoph.Egger@amd.com> wrote:>> Finally, George may have a >> reason for not including RIP in VMENTRY records (e.g., not that useful >> compared with the extra space taken up in trace records). So you''d need to >> submit a new patch and get an Ack from George (who is currently on >> holiday).Yeah, the general principle is just to not log duplicate information, or information which can be inferred. VMENTRY logs happen a *lot*, and so a small change has a non-negligible impact on trace size. To this point, I haven''t needed the RIP on VMENTRY, since having it on VMEXIT is generally sufficient.> Ok. If he has one I would like to know it. > For nested virtualization it is at least good debugging information to see > if the l2 guest loops somewhere or not.Can''t you get this information from looking at the RIP on the corresponding VMEXIT? -George _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel