KVM: x86/pmu: Cap kvm_pmu_cap.num_counters_gp at KVM's internal max

Browse source

Limit kvm_pmu_cap.num_counters_gp during kvm_init_pmu_capability() based
on the vendor PMU capabilities so that consuming num_counters_gp naturally
does the right thing.  This fixes a mostly theoretical bug where KVM could
over-report its PMU support in KVM_GET_SUPPORTED_CPUID for leaf 0xA, e.g.
if the number of counters reported by perf is greater than KVM's
hardcoded internal limit.  Incorporating input from the AMD PMU also
avoids over-reporting MSRs to save when running on AMD.

Link: https://lore.kernel.org/r/20230124234905.3774678-2-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

...

This commit is contained in:

Sean Christopherson 2023-01-24 23:49:00 +00:00

parent 2a3003e950

commit 8911ce6669

4 changed files with 9 additions and 4 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

5

arch/x86/kvm/pmu.h

View file

1

arch/x86/kvm/svm/pmu.c

View file

1

arch/x86/kvm/vmx/pmu_intel.c

View file

6

arch/x86/kvm/x86.c

View file