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perf/x86/amd/core: Fix reloading events for SVM

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Commit 1018faa6cf ("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: 9622e67e39 ("perf/x86/amd/core: Add PerfMonV2 counter control")
Reported-by: Like Xu <likexu@tencent.com>
Signed-off-by: Sandipan Das <sandipan.das@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20220518084327.464005-1-sandipan.das@amd.com
This commit is contained in:
Sandipan Das 2022-05-18 14:13:27 +05:30 committed by Peter Zijlstra
parent 841b51e4a3
commit bae19fdd7e
1 changed files with 20 additions and 4 deletions
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24
arch/x86/events/amd/core.c
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@ -1472,6 +1472,24 @@ __init int amd_pmu_init(void)
return 0; 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) void amd_pmu_enable_virt(void)
{ {
struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
@ -1479,8 +1497,7 @@ void amd_pmu_enable_virt(void)
cpuc->perf_ctr_virt_mask = 0; cpuc->perf_ctr_virt_mask = 0;
/* Reload all events */ /* Reload all events */
amd_pmu_disable_all(); amd_pmu_reload_virt();
x86_pmu_enable_all(0);
} }
EXPORT_SYMBOL_GPL(amd_pmu_enable_virt); EXPORT_SYMBOL_GPL(amd_pmu_enable_virt);
@ -1497,7 +1514,6 @@ void amd_pmu_disable_virt(void)
cpuc->perf_ctr_virt_mask = AMD64_EVENTSEL_HOSTONLY; cpuc->perf_ctr_virt_mask = AMD64_EVENTSEL_HOSTONLY;
/* Reload all events */ /* Reload all events */
amd_pmu_disable_all(); amd_pmu_reload_virt();
x86_pmu_enable_all(0);
} }
EXPORT_SYMBOL_GPL(amd_pmu_disable_virt); EXPORT_SYMBOL_GPL(amd_pmu_disable_virt);