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| author | Sandipan Das <sandipan.das@amd.com> | 2022-04-27 17:01:49 +0530 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-05-12 12:25:43 +0200 |
| commit | 599fc32e7421d7a591ee78bb4f3b79c54d51065c (patch) | |
| tree | 265f585c6bb4a22ccade6049c206443f8f39bc47 /drivers | |
| parent | 0a960a367216995e3a72899749c1786c6e9a5d7d (diff) | |
kvm: x86/cpuid: Only provide CPUID leaf 0xA if host has architectural PMU
[ Upstream commit 5a1bde46f98b893cda6122b00e94c0c40a6ead3c ]
On some x86 processors, CPUID leaf 0xA provides information
on Architectural Performance Monitoring features. It
advertises a PMU version which Qemu uses to determine the
availability of additional MSRs to manage the PMCs.
Upon receiving a KVM_GET_SUPPORTED_CPUID ioctl request for
the same, the kernel constructs return values based on the
x86_pmu_capability irrespective of the vendor.
This leaf and the additional MSRs are not supported on AMD
and Hygon processors. If AMD PerfMonV2 is detected, the PMU
version is set to 2 and guest startup breaks because of an
attempt to access a non-existent MSR. Return zeros to avoid
this.
Fixes: a6c06ed1a60a ("KVM: Expose the architectural performance monitoring CPUID leaf")
Reported-by: Vasant Hegde <vasant.hegde@amd.com>
Signed-off-by: Sandipan Das <sandipan.das@amd.com>
Message-Id: <3fef83d9c2b2f7516e8ff50d60851f29a4bcb716.1651058600.git.sandipan.das@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers')
0 files changed, 0 insertions, 0 deletions