pmu.c

 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
14const 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};
29kvm_static_assert(ARRAY_SIZE(intel_pmu_arch_events) == NR_INTEL_ARCH_EVENTS);
30
31const 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};
37kvm_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 */
53static 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
75uint64_t pmu_errata_mask;
76
77void kvm_init_pmu_errata(void)
78{
79	pmu_errata_mask = get_pmu_errata();
80}