Messages in this thread Patch in this message | | | From | Sandipan Das <> | Subject | [PATCH] perf/x86/amd/core: Fix reloading events for SVM | Date | Wed, 18 May 2022 14:13:27 +0530 |
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Commit 1018faa6cf23 ("perf/x86/kvm: Fix Host-Only/Guest-Only counting with SVM disabled") addresses an issue in which the Host-Only bit in the counter control registers needs to be masked off when SVM is not enabled.
The events need to be reloaded whenever SVM is enabled or disabled for a CPU and this requires the PERF_CTL registers to be reprogrammed using {enable,disable}_all(). However, PerfMonV2 variants of these functions do not reprogram the PERF_CTL registers. Hence, the legacy enable_all() function should also be called.
Fixes: 9622e67e3980 ("perf/x86/amd/core: Add PerfMonV2 counter control") Reported-by: Like Xu <likexu@tencent.com> Signed-off-by: Sandipan Das <sandipan.das@amd.com> --- arch/x86/events/amd/core.c | 24 ++++++++++++++++++++---- 1 file changed, 20 insertions(+), 4 deletions(-)
diff --git a/arch/x86/events/amd/core.c b/arch/x86/events/amd/core.c index 359d575c27e2..37b175870ee8 100644 --- a/arch/x86/events/amd/core.c +++ b/arch/x86/events/amd/core.c @@ -1467,6 +1467,24 @@ __init int amd_pmu_init(void) return 0; } +static inline void amd_pmu_reload_virt(void) +{ + if (x86_pmu.version >= 2) { + /* + * Clear global enable bits, reprogram the PERF_CTL + * registers with updated perf_ctr_virt_mask and then + * set global enable bits once again + */ + amd_pmu_v2_disable_all(); + amd_pmu_enable_all(0); + amd_pmu_v2_enable_all(0); + return; + } + + amd_pmu_disable_all(); + amd_pmu_enable_all(0); +} + void amd_pmu_enable_virt(void) { struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); @@ -1474,8 +1492,7 @@ void amd_pmu_enable_virt(void) cpuc->perf_ctr_virt_mask = 0; /* Reload all events */ - amd_pmu_disable_all(); - x86_pmu_enable_all(0); + amd_pmu_reload_virt(); } EXPORT_SYMBOL_GPL(amd_pmu_enable_virt); @@ -1492,7 +1509,6 @@ void amd_pmu_disable_virt(void) cpuc->perf_ctr_virt_mask = AMD64_EVENTSEL_HOSTONLY; /* Reload all events */ - amd_pmu_disable_all(); - x86_pmu_enable_all(0); + amd_pmu_reload_virt(); } EXPORT_SYMBOL_GPL(amd_pmu_disable_virt); -- 2.34.1
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