KVM: x86/svm: Account for family 17h event renumberings in amd_pmc_perf_hw_id
authorKyle Huey <me@kylehuey.com>
Tue, 3 May 2022 05:01:36 +0000 (22:01 -0700)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 12 May 2022 10:30:03 +0000 (12:30 +0200)
commit91a97c86a8f01d85ec34ca001da429cfc1d60ca4
treea061f09ff2ed59dcf1f8f0acb8113fd163b38ced
parent2e4d4123c8618cb150944ec7739bcb23d838d9a1
KVM: x86/svm: Account for family 17h event renumberings in amd_pmc_perf_hw_id

commit 5eb849322d7f7ae9d5c587c7bc3b4f7c6872cd2f upstream.

Zen renumbered some of the performance counters that correspond to the
well known events in perf_hw_id. This code in KVM was never updated for
that, so guest that attempt to use counters on Zen that correspond to the
pre-Zen perf_hw_id values will silently receive the wrong values.

This has been observed in the wild with rr[0] when running in Zen 3
guests. rr uses the retired conditional branch counter 00d1 which is
incorrectly recognized by KVM as PERF_COUNT_HW_STALLED_CYCLES_BACKEND.

[0] https://rr-project.org/

Signed-off-by: Kyle Huey <me@kylehuey.com>
Message-Id: <20220503050136.86298-1-khuey@kylehuey.com>
Cc: stable@vger.kernel.org
[Check guest family, not host. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
arch/x86/kvm/svm/pmu.c