Re: [PATCH 2/4] x86: Introduce MSR_UNHANDLED

2021-01-10 Thread Jan Beulich
On 08.01.2021 21:31, boris.ostrov...@oracle.com wrote: > On 1/8/21 9:55 AM, Jan Beulich wrote: >> On 07.01.2021 21:34, Boris Ostrovsky wrote: >>> + * 0 = return #GP, warning emitted >>> + * 1 = read as 0, writes are dropped, no warning >>> + * 2 = read as 0, writes are dropped, warning emitted

Re: [PATCH 2/4] x86: Introduce MSR_UNHANDLED

2021-01-08 Thread boris . ostrovsky
On 1/8/21 9:55 AM, Jan Beulich wrote: > On 07.01.2021 21:34, Boris Ostrovsky wrote: >> --- a/xen/include/xen/lib/x86/msr.h >> +++ b/xen/include/xen/lib/x86/msr.h >> @@ -2,8 +2,21 @@ >> #ifndef XEN_LIB_X86_MSR_H >> #define XEN_LIB_X86_MSR_H >> >> +/* >> + * Behavior on accesses to MSRs that

Re: [PATCH 2/4] x86: Introduce MSR_UNHANDLED

2021-01-08 Thread Jan Beulich
On 07.01.2021 21:34, Boris Ostrovsky wrote: > --- a/xen/include/xen/lib/x86/msr.h > +++ b/xen/include/xen/lib/x86/msr.h > @@ -2,8 +2,21 @@ > #ifndef XEN_LIB_X86_MSR_H > #define XEN_LIB_X86_MSR_H > > +/* > + * Behavior on accesses to MSRs that are not handled by emulation: What about ones

[PATCH 2/4] x86: Introduce MSR_UNHANDLED

2021-01-07 Thread Boris Ostrovsky
When toolstack updates MSR policy, this MSR offset (which is an invalid MSR index) is used to indicate hypervisor behavior when a guest accesses an MSR which is not explicitly emulated. Signed-off-by: Boris Ostrovsky --- xen/include/xen/lib/x86/msr.h | 17 - xen/lib/x86/msr.c