On 04/03/2021 23:09, Boris Ostrovsky wrote: > On 3/4/21 9:47 AM, Roger Pau Monne wrote: >> Introduce an option to allow selecting a less strict behaviour for >> rdmsr accesses targeting a MSR not explicitly handled by Xen. Since >> commit 84e848fd7a162f669 accesses to MSRs not explicitly handled by >> Xen result in the injection of a #GP to the guest. This is a behavior >> change since previously a #GP was only injected if accessing the MSR >> on the real hardware will also trigger a #GP. >> >> This commit attempts to offer a fallback option similar to the >> previous behavior. Note however that the value of the underlying MSR >> is never leaked to the guest, as the newly introduced option only >> changes whether a #GP is injected or not. >> >> Long term the plan is to properly handle all the MSRs, so the option >> introduced here should be considered a temporary resort for OSes that >> don't work properly with the new MSR policy. Any OS that requires this >> option to be enabled should be reported to >> xen-devel@lists.xenproject.org. >> >> Signed-off-by: Roger Pau Monné <roger....@citrix.com> >> --- >> Changes since v1: >> - Only apply the option to HVM guests. >> - Only apply the special handling to MSR reads. >> - Sanitize the newly introduced flags field. >> - Print a warning message when the option is used. >> --- >> Cc: Boris Ostrovsky <boris.ostrov...@oracle.com> >> --- >> Boris, could you please test with Solaris to see if this fixes the >> issue? > > Yes, still works. (It worked especially well after I noticed new option name > ;-))
I'm afraid I want to break and rework how this bugfix happens. Solaris is still broken on all older branches and this isn't a suitable fix to backport. ~Andrew
