cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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evsel.c (1759B)


      1// SPDX-License-Identifier: GPL-2.0
      2#include <stdio.h>
      3#include <stdlib.h>
      4#include "util/evsel.h"
      5#include "util/env.h"
      6#include "util/pmu.h"
      7#include "linux/string.h"
      8#include "evsel.h"
      9
     10void arch_evsel__set_sample_weight(struct evsel *evsel)
     11{
     12	evsel__set_sample_bit(evsel, WEIGHT_STRUCT);
     13}
     14
     15void arch_evsel__fixup_new_cycles(struct perf_event_attr *attr)
     16{
     17	struct perf_env env = { .total_mem = 0, } ;
     18
     19	if (!perf_env__cpuid(&env))
     20		return;
     21
     22	/*
     23	 * On AMD, precise cycles event sampling internally uses IBS pmu.
     24	 * But IBS does not have filtering capabilities and perf by default
     25	 * sets exclude_guest = 1. This makes IBS pmu event init fail and
     26	 * thus perf ends up doing non-precise sampling. Avoid it by clearing
     27	 * exclude_guest.
     28	 */
     29	if (env.cpuid && strstarts(env.cpuid, "AuthenticAMD"))
     30		attr->exclude_guest = 0;
     31
     32	free(env.cpuid);
     33}
     34
     35/* Check whether the evsel's PMU supports the perf metrics */
     36bool evsel__sys_has_perf_metrics(const struct evsel *evsel)
     37{
     38	const char *pmu_name = evsel->pmu_name ? evsel->pmu_name : "cpu";
     39
     40	/*
     41	 * The PERF_TYPE_RAW type is the core PMU type, e.g., "cpu" PMU
     42	 * on a non-hybrid machine, "cpu_core" PMU on a hybrid machine.
     43	 * The slots event is only available for the core PMU, which
     44	 * supports the perf metrics feature.
     45	 * Checking both the PERF_TYPE_RAW type and the slots event
     46	 * should be good enough to detect the perf metrics feature.
     47	 */
     48	if ((evsel->core.attr.type == PERF_TYPE_RAW) &&
     49	    pmu_have_event(pmu_name, "slots"))
     50		return true;
     51
     52	return false;
     53}
     54
     55bool arch_evsel__must_be_in_group(const struct evsel *evsel)
     56{
     57	if (!evsel__sys_has_perf_metrics(evsel))
     58		return false;
     59
     60	return evsel->name &&
     61		(strcasestr(evsel->name, "slots") ||
     62		 strcasestr(evsel->name, "topdown"));
     63}