Message ID | 20240104193303.3175844-7-seanjc@google.com (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
Series | [GIT,PULL] KVM: x86: PMU changes for 6.8 | expand |
On Thu, Jan 4, 2024 at 8:33 PM Sean Christopherson <seanjc@google.com> wrote: > > PMU fixes and cleanups. The highlight is a fix for a double-overflow PMI bug > when KVM manually emulates counter events, which was made mostly benign by > commit a16eb25b09c0 ("KVM: x86: Mask LVTPC when handling a PMI"), but is still > a bug. > > Note, the "Track emulated counter events instead of previous counter" fix > breaks the PMU KVM-Unit-Test due to a long-standing "bug" in perf[*]. If need > be, it's trivial to fudge around the shortcomings in the KUT code, I just > haven't carved out time to push things along. > > [*] https://lore.kernel.org/all/20231107183605.409588-1-seanjc@google.com > > The following changes since commit e9e60c82fe391d04db55a91c733df4a017c28b2f: > > selftests/kvm: fix compilation on non-x86_64 platforms (2023-11-21 11:58:25 -0500) > > are available in the Git repository at: > > https://github.com/kvm-x86/linux.git tags/kvm-x86-pmu-6.8 > > for you to fetch changes up to fd89499a5151d197ba30f7b801f6d8f4646cf446: > > KVM: x86/pmu: Track emulated counter events instead of previous counter (2023-11-30 12:52:55 -0800) Pulled, thanks. Paolo > ---------------------------------------------------------------- > KVM x86 PMU changes for 6.8: > > - Fix a variety of bugs where KVM fail to stop/reset counters and other state > prior to refreshing the vPMU model. > > - Fix a double-overflow PMU bug by tracking emulated counter events using a > dedicated field instead of snapshotting the "previous" counter. If the > hardware PMC count triggers overflow that is recognized in the same VM-Exit > that KVM manually bumps an event count, KVM would pend PMIs for both the > hardware-triggered overflow and for KVM-triggered overflow. > > ---------------------------------------------------------------- > Sean Christopherson (6): > KVM: x86/pmu: Move PMU reset logic to common x86 code > KVM: x86/pmu: Reset the PMU, i.e. stop counters, before refreshing > KVM: x86/pmu: Stop calling kvm_pmu_reset() at RESET (it's redundant) > KVM: x86/pmu: Remove manual clearing of fields in kvm_pmu_init() > KVM: x86/pmu: Update sample period in pmc_write_counter() > KVM: x86/pmu: Track emulated counter events instead of previous counter > > arch/x86/include/asm/kvm-x86-pmu-ops.h | 2 +- > arch/x86/include/asm/kvm_host.h | 17 +++- > arch/x86/kvm/pmu.c | 140 +++++++++++++++++++++++++++------ > arch/x86/kvm/pmu.h | 47 +---------- > arch/x86/kvm/svm/pmu.c | 17 ---- > arch/x86/kvm/vmx/pmu_intel.c | 22 ------ > arch/x86/kvm/x86.c | 1 - > 7 files changed, 137 insertions(+), 109 deletions(-) >