From: Like Xu <likexu@xxxxxxxxxxx>
The PEBS-PDIR facility on Ice Lake server is supported on IA31_FIXED0 only.
If the guest configures counter 32 and PEBS is enabled, the PEBS-PDIR
facility is supposed to be used, in which case KVM adjusts attr.precise_ip
to 3 and request host perf to assign the exactly requested counter or fail.
The CPU model check is also required since some platforms may place the
PEBS-PDIR facility in another counter index.
Signed-off-by: Like Xu <likexu@xxxxxxxxxxx>
Acked-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
---
v12 -> v13 Changelog:
- Move vmx_icl_pebs_cpu[] from pmu.h to pmu.c;
- Drop unrelated change about arch/x86/events/intel/core.c;
arch/x86/kvm/pmu.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c
index 36487088f72c..0b8fc86839ba 100644
--- a/arch/x86/kvm/pmu.c
+++ b/arch/x86/kvm/pmu.c
@@ -16,6 +16,7 @@
#include <linux/bsearch.h>
#include <linux/sort.h>
#include <asm/perf_event.h>
+#include <asm/cpu_device_id.h>
#include "x86.h"
#include "cpuid.h"
#include "lapic.h"
@@ -24,6 +25,12 @@
/* This is enough to filter the vast majority of currently defined events. */
#define KVM_PMU_EVENT_FILTER_MAX_EVENTS 300
+static const struct x86_cpu_id vmx_icl_pebs_cpu[] = {
+ X86_MATCH_INTEL_FAM6_MODEL(ICELAKE_D, NULL),
+ X86_MATCH_INTEL_FAM6_MODEL(ICELAKE_X, NULL),
+ {}
+};
+
/* NOTE:
* - Each perf counter is defined as "struct kvm_pmc";
* - There are two types of perf counters: general purpose (gp) and fixed.
@@ -175,6 +182,8 @@ static void pmc_reprogram_counter(struct kvm_pmc *pmc, u32 type,
* could possibly care here is unsupported and needs changes.
*/
attr.precise_ip = 1;
+ if (x86_match_cpu(vmx_icl_pebs_cpu) && pmc->idx == 32)
+ attr.precise_ip = 3;
}
event = perf_event_create_kernel_counter(&attr, -1, current,
--
2.36.1
