> From: Andrew Cooper [mailto:am...@hermes.cam.ac.uk] On Behalf Of Andrew Cooper > Sent: Tuesday, February 14, 2017 3:59 PM > > On 14/02/2017 02:52, Tian, Kevin wrote: > >> From: Andrew Cooper [mailto:andrew.coop...@citrix.com] > >> Sent: Monday, February 13, 2017 10:32 PM > >> > >> hvm_hw_cpu->msr_flags is in fact the VMX dirty bitmap of MSRs needing to be > >> restored when switching into guest context. It should never have been > >> part of > >> the migration state to start with, and Xen must not make any decisions > >> based > >> on the value seen during restore. > >> > >> Identify it as obsolete in the header files, consistently save it as zero > >> and > >> ignore it on restore. > >> > >> The MSRs must be considered dirty during VMCS creation to cause the proper > >> defaults of 0 to be visible to the guest. > >> > >> Signed-off-by: Andrew Cooper <andrew.coop...@citrix.com> > > Reviewed-by: Kevin Tian <kevin.t...@intel.com>, with one small comment. > > > > the effect of this patch should be more than not leaking syscall MSR. > > what about making the subject clearer when check-in? > > What other effects do you think are going on here? Yes, we now context > switch the MSRs right from the start of the domain, but that is > necessary to avoid leaking them. >
If just looking at this patch, it's for general MSR save/restore policy, nothing specific to syscall MSR. Thanks Kevin _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org https://lists.xen.org/xen-devel
