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KVM: x86/pmu: Adjust precise_ip to emulate Ice Lake guest PDIR counter

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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 <like.xu@linux.intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Message-Id: <20220411101946.20262-10-likexu@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Like Xu 2022-04-11 18:19:38 +08:00 committed by Paolo Bonzini
parent 79f3e3b583
commit 6ebe44366b
3 changed files with 11 additions and 1 deletions
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2
arch/x86/events/intel/core.c
View File

@ -4024,8 +4024,8 @@ static struct perf_guest_switch_msr *intel_guest_get_msrs(int *nr, void *data)
if (!x86_pmu.pebs_ept)
return arr;
pebs_enable = (*nr)++;
pebs_enable = (*nr)++;
arr[pebs_enable] = (struct perf_guest_switch_msr){
.msr = MSR_IA32_PEBS_ENABLE,
.host = cpuc->pebs_enabled & ~cpuc->intel_ctrl_guest_mask,

2
arch/x86/kvm/pmu.c
View File

@ -175,6 +175,8 @@ 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,

8
arch/x86/kvm/pmu.h
View File

@ -4,6 +4,8 @@
#include <linux/nospec.h>
#include <asm/cpu_device_id.h>
#define vcpu_to_pmu(vcpu) (&(vcpu)->arch.pmu)
#define pmu_to_vcpu(pmu) (container_of((pmu), struct kvm_vcpu, arch.pmu))
#define pmc_to_pmu(pmc) (&(pmc)->vcpu->arch.pmu)
@ -15,6 +17,12 @@
#define VMWARE_BACKDOOR_PMC_REAL_TIME 0x10001
#define VMWARE_BACKDOOR_PMC_APPARENT_TIME 0x10002
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),
{}
};
struct kvm_event_hw_type_mapping {
u8 eventsel;
u8 unit_mask;