Re: [Xen-devel] [PATCH v3 7/8] x86/HVM: don't needlessly intercept APERF/MPERF/TSC MSR reads

2020-01-20 Thread Tian, Kevin
> From: Jan Beulich > Sent: Monday, January 20, 2020 4:33 PM > > On 19.01.2020 03:44, Tian, Kevin wrote: > >> From: Jan Beulich > >> Sent: Tuesday, January 7, 2020 12:39 AM > >> > >> If the hardware can handle accesses, we should allow it to do so. This > >> way we can expose EFRO to HVM guests,

Re: [Xen-devel] [PATCH v3 7/8] x86/HVM: don't needlessly intercept APERF/MPERF/TSC MSR reads

2020-01-20 Thread Jan Beulich
On 19.01.2020 03:44, Tian, Kevin wrote: >> From: Jan Beulich >> Sent: Tuesday, January 7, 2020 12:39 AM >> >> If the hardware can handle accesses, we should allow it to do so. This >> way we can expose EFRO to HVM guests, and "all" that's left for exposing >> APERF/MPERF is to figure out how to ha

Re: [Xen-devel] [PATCH v3 7/8] x86/HVM: don't needlessly intercept APERF/MPERF/TSC MSR reads

2020-01-18 Thread Tian, Kevin
> From: Jan Beulich > Sent: Tuesday, January 7, 2020 12:39 AM > > If the hardware can handle accesses, we should allow it to do so. This > way we can expose EFRO to HVM guests, and "all" that's left for exposing > APERF/MPERF is to figure out how to handle writes to these MSRs. (Note > that the l

[Xen-devel] [PATCH v3 7/8] x86/HVM: don't needlessly intercept APERF/MPERF/TSC MSR reads

2020-01-06 Thread Jan Beulich
If the hardware can handle accesses, we should allow it to do so. This way we can expose EFRO to HVM guests, and "all" that's left for exposing APERF/MPERF is to figure out how to handle writes to these MSRs. (Note that the leaf 6 guest CPUID checks will evaluate to false for now, as recalculate_mi