On Wed, Jun 26, 2019 at 08:02:12PM +0100, Andrew Cooper wrote: > From: Sergey Dyasli <[email protected]> > > Otherwise hvm_set_cr0() will check the wrong CR4 bits (L1 instead of L2 > and vice-versa). > > Signed-off-by: Sergey Dyasli <[email protected]> > Reviewed-by: Andrew Cooper <[email protected]>
Reviewed-by: Roger Pau Monné <[email protected]> > --- > CC: Jan Beulich <[email protected]> > CC: Wei Liu <[email protected]> > CC: Roger Pau Monné <[email protected]> > CC: Jun Nakajima <[email protected]> > CC: Kevin Tian <[email protected]> > > I found this patch languishing in the XenServer patchqueue, and Sergey is OoO > so I'm submitting it on his behalf. > > Without this change, nested virt is broken when L1 and L2 differ in their use > of PCID. > > This is only a stopgap solution - it resolves the PCID issue without > introducing other issues, but the proper fix needs to consider all control > bits at once, rather than considering a vmentry/exit as a sequence of changes > of discrete registers. The current approach seems prone to such ordering issues, and I don't see a way to make it more robust while keeping the current approach, so I guess setting all the registers state and then evaluating them would make more sense and prevent this kind of mistakes. Thanks. _______________________________________________ Xen-devel mailing list [email protected] https://lists.xenproject.org/mailman/listinfo/xen-devel
