xref: /linux/tools/testing/selftests/kvm/lib/x86/pmu.c (revision 1f2bbbbbda57f1939d757f5021ec0e3ea782ccf6)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2023, Tencent, Inc.
4  */
5 
6 #include <stdint.h>
7 
8 #include <linux/kernel.h>
9 
10 #include "kvm_util.h"
11 #include "processor.h"
12 #include "pmu.h"
13 
14 const uint64_t intel_pmu_arch_events[] = {
15 	INTEL_ARCH_CPU_CYCLES,
16 	INTEL_ARCH_INSTRUCTIONS_RETIRED,
17 	INTEL_ARCH_REFERENCE_CYCLES,
18 	INTEL_ARCH_LLC_REFERENCES,
19 	INTEL_ARCH_LLC_MISSES,
20 	INTEL_ARCH_BRANCHES_RETIRED,
21 	INTEL_ARCH_BRANCHES_MISPREDICTED,
22 	INTEL_ARCH_TOPDOWN_SLOTS,
23 	INTEL_ARCH_TOPDOWN_BE_BOUND,
24 	INTEL_ARCH_TOPDOWN_BAD_SPEC,
25 	INTEL_ARCH_TOPDOWN_FE_BOUND,
26 	INTEL_ARCH_TOPDOWN_RETIRING,
27 	INTEL_ARCH_LBR_INSERTS,
28 };
29 kvm_static_assert(ARRAY_SIZE(intel_pmu_arch_events) == NR_INTEL_ARCH_EVENTS);
30 
31 const uint64_t amd_pmu_zen_events[] = {
32 	AMD_ZEN_CORE_CYCLES,
33 	AMD_ZEN_INSTRUCTIONS_RETIRED,
34 	AMD_ZEN_BRANCHES_RETIRED,
35 	AMD_ZEN_BRANCHES_MISPREDICTED,
36 };
37 kvm_static_assert(ARRAY_SIZE(amd_pmu_zen_events) == NR_AMD_ZEN_EVENTS);
38 
39 /*
40  * For Intel Atom CPUs, the PMU events "Instruction Retired" or
41  * "Branch Instruction Retired" may be overcounted for some certain
42  * instructions, like FAR CALL/JMP, RETF, IRET, VMENTRY/VMEXIT/VMPTRLD
43  * and complex SGX/SMX/CSTATE instructions/flows.
44  *
45  * The detailed information can be found in the errata (section SRF7):
46  * https://edc.intel.com/content/www/us/en/design/products-and-solutions/processors-and-chipsets/sierra-forest/xeon-6700-series-processor-with-e-cores-specification-update/errata-details/
47  *
48  * For the Atom platforms before Sierra Forest (including Sierra Forest),
49  * Both 2 events "Instruction Retired" and "Branch Instruction Retired" would
50  * be overcounted on these certain instructions, but for Clearwater Forest
51  * only "Instruction Retired" event is overcounted on these instructions.
52  */
get_pmu_errata(void)53 static uint64_t get_pmu_errata(void)
54 {
55 	if (!this_cpu_is_intel())
56 		return 0;
57 
58 	if (this_cpu_family() != 0x6)
59 		return 0;
60 
61 	switch (this_cpu_model()) {
62 	case 0xDD: /* Clearwater Forest */
63 		return BIT_ULL(INSTRUCTIONS_RETIRED_OVERCOUNT);
64 	case 0xAF: /* Sierra Forest */
65 	case 0x4D: /* Avaton, Rangely */
66 	case 0x5F: /* Denverton */
67 	case 0x86: /* Jacobsville */
68 		return BIT_ULL(INSTRUCTIONS_RETIRED_OVERCOUNT) |
69 		       BIT_ULL(BRANCHES_RETIRED_OVERCOUNT);
70 	default:
71 		return 0;
72 	}
73 }
74 
75 uint64_t pmu_errata_mask;
76 
kvm_init_pmu_errata(void)77 void kvm_init_pmu_errata(void)
78 {
79 	pmu_errata_mask = get_pmu_errata();
80 }
81