[PATCH v4 34/38] perf/x86/amd: Support PERF_PMU_CAP_MEDIATED_VPMU for AMD host

[Mingwei Zhang]

From: Sandipan Das <sandipan.das@xxxxxxx>

Apply the PERF_PMU_CAP_MEDIATED_VPMU flag for version 2 and later
implementations of the core PMU. Aside from having Global Control and
Status registers, virtualizing the PMU using the passthrough model
requires an interface to set or clear the overflow bits in the Global
Status MSRs while restoring or saving the PMU context of a vCPU.

PerfMonV2-capable hardware has additional MSRs for this purpose namely,
PerfCntrGlobalStatusSet and PerfCntrGlobalStatusClr, thereby making it
suitable for use with mediated vPMU.

Signed-off-by: Sandipan Das <sandipan.das@xxxxxxx>
Signed-off-by: Mingwei Zhang <mizhang@xxxxxxxxxx>
---
 arch/x86/events/amd/core.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/x86/events/amd/core.c b/arch/x86/events/amd/core.c
index 30d6ceb4c8ad..a8b537dd2ddb 100644
--- a/arch/x86/events/amd/core.c
+++ b/arch/x86/events/amd/core.c
@@ -1433,6 +1433,8 @@ static int __init amd_core_pmu_init(void)
 
 		amd_pmu_global_cntr_mask = x86_pmu.cntr_mask64;
 
+		x86_get_pmu(smp_processor_id())->capabilities |= PERF_PMU_CAP_MEDIATED_VPMU;
+
 		/* Update PMC handling functions */
 		x86_pmu.enable_all = amd_pmu_v2_enable_all;
 		x86_pmu.disable_all = amd_pmu_v2_disable_all;
-- 
2.49.0.395.g12beb8f557-goog