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Subject[PATCH] perf/x86/intel: Save/restore cpuc->active_pebs_data_cfg when using guest PEBS
Date
From: Like Xu <likexu@tencent.com>

After commit b752ea0c28e3 ("perf/x86/intel/ds: Flush PEBS DS when changing
PEBS_DATA_CFG"), the cpuc->pebs_data_cfg may save some bits that are not
supported by real hardware, such as PEBS_UPDATE_DS_SW. This would cause
the VMX hardware MSR switching mechanism to save/restore invalid values
for PEBS_DATA_CFG MSR, thus crashing the host when PEBS is used for guest.
Fix it by using the active host value from cpuc->active_pebs_data_cfg.

Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Like Xu <likexu@tencent.com>
---
arch/x86/events/intel/core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c
index 070cc4ef2672..89b9c1cebb61 100644
--- a/arch/x86/events/intel/core.c
+++ b/arch/x86/events/intel/core.c
@@ -4074,7 +4074,7 @@ static struct perf_guest_switch_msr *intel_guest_get_msrs(int *nr, void *data)
if (x86_pmu.intel_cap.pebs_baseline) {
arr[(*nr)++] = (struct perf_guest_switch_msr){
.msr = MSR_PEBS_DATA_CFG,
- .host = cpuc->pebs_data_cfg,
+ .host = cpuc->active_pebs_data_cfg,
.guest = kvm_pmu->pebs_data_cfg,
};
}
--
2.40.1
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