Re: [PATCH RFC 0/2] ignore LBR-related MSRs

From: Konrad Rzeszutek Wilk
Date: Wed Dec 06 2017 - 10:07:58 EST


On Wed, Dec 06, 2017 at 02:43:01PM +0300, Jan Dakinevich wrote:
> w2k16 essentials fails to boot if underlying hypervisor lacks of support for
> LBR MSRs. To workaround the issue, it suggessted to ignore these MSRs (but not
> all).

This is without any hyperv enablement? Meaning normal stock guest?

>
> The information, which MSRs are supported for specific platform is taken from
> perf, it is the subject of the first patch. The second patch adds ignoring for
> these MSRs to pmu_intel code of KVM.
>
> TODO: use MSR load/store areas to make full support of LBR debug.
>
> Jan Dakinevich (2):
> perf/x86/intel: make reusable LBR initialization code
> KVM: x86/vPMU: ignore access to LBR-related MSRs
>
> arch/x86/events/core.c | 8 +-
> arch/x86/events/intel/core.c | 59 +++------
> arch/x86/events/intel/lbr.c | 272 +++++++++++++++++++++++++-------------
> arch/x86/events/perf_event.h | 27 +---
> arch/x86/include/asm/kvm_host.h | 2 +
> arch/x86/include/asm/perf_event.h | 11 ++
> arch/x86/kvm/pmu_intel.c | 33 +++++
> 7 files changed, 250 insertions(+), 162 deletions(-)
>
> --
> 2.1.4
>