IBS MSRs are classified as Swap Type C, which requires the hypervisor
to save and restore its own IBS state before VMENTRY and after VMEXIT.
To support this, set the ibs_op and ibs_fetch PMUs with the
PERF_PMU_CAP_MEDIATED_VPMU capability. This ensures that these PMUs are
exclusively owned by the guest while it is running, allowing the
hypervisor to manage IBS state transitions correctly.
Signed-off-by: Manali Shukla <manali.shukla@xxxxxxx>
---
arch/x86/events/amd/ibs.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/arch/x86/events/amd/ibs.c b/arch/x86/events/amd/ibs.c
index c998f68eeddc..00c36ce16957 100644
--- a/arch/x86/events/amd/ibs.c
+++ b/arch/x86/events/amd/ibs.c
@@ -792,6 +792,7 @@ static struct perf_ibs perf_ibs_fetch = {
.stop = perf_ibs_stop,
.read = perf_ibs_read,
.check_period = perf_ibs_check_period,
+ .capabilities = PERF_PMU_CAP_MEDIATED_VPMU,
},
.msr = MSR_AMD64_IBSFETCHCTL,
.config_mask = IBS_FETCH_MAX_CNT | IBS_FETCH_RAND_EN,
@@ -817,6 +818,7 @@ static struct perf_ibs perf_ibs_op = {
.stop = perf_ibs_stop,
.read = perf_ibs_read,
.check_period = perf_ibs_check_period,
+ .capabilities = PERF_PMU_CAP_MEDIATED_VPMU,
},
.msr = MSR_AMD64_IBSOPCTL,
.config_mask = IBS_OP_MAX_CNT,
--
2.43.0
