c790c3d2b0
This test uses the PMU to count branch prediction hits/misses for a
known loop, and compare the result to the reported spectre v2
mitigation.
This gives us a way of sanity checking that the reported mitigation is
actually in effect.
Sample output for some cases, eg:
Power9:
sysfs reports: 'Vulnerable'
PM_BR_PRED_CCACHE: result 368 running/enabled 5792777124
PM_BR_MPRED_CCACHE: result 319 running/enabled 5792775546
PM_BR_PRED_PCACHE: result 2147483281 running/enabled 5792773128
PM_BR_MPRED_PCACHE: result 213604201 running/enabled 5792771640
Miss percent 9 %
OK - Measured branch prediction rates match reported spectre v2 mitigation.
sysfs reports: 'Mitigation: Indirect branch serialisation (kernel only)'
PM_BR_PRED_CCACHE: result 895 running/enabled 5780320920
PM_BR_MPRED_CCACHE: result 822 running/enabled 5780312414
PM_BR_PRED_PCACHE: result 2147482754 running/enabled 5780308836
PM_BR_MPRED_PCACHE: result 213639731 running/enabled 5780307912
Miss percent 9 %
OK - Measured branch prediction rates match reported spectre v2 mitigation.
sysfs reports: 'Mitigation: Indirect branch cache disabled'
PM_BR_PRED_CCACHE: result 2147483649 running/enabled 20540186160
PM_BR_MPRED_CCACHE: result 2147483649 running/enabled 20540180056
PM_BR_PRED_PCACHE: result 0 running/enabled 20540176090
PM_BR_MPRED_PCACHE: result 0 running/enabled 20540174182
Miss percent 100 %
OK - Measured branch prediction rates match reported spectre v2 mitigation.
Power8:
sysfs reports: 'Vulnerable'
PM_BR_PRED_CCACHE: result 2147483649 running/enabled 3505888142
PM_BR_MPRED_CCACHE: result 9 running/enabled 3505882788
Miss percent 0 %
OK - Measured branch prediction rates match reported spectre v2 mitigation.
sysfs reports: 'Mitigation: Indirect branch cache disabled'
PM_BR_PRED_CCACHE: result 2147483649 running/enabled 16931421988
PM_BR_MPRED_CCACHE: result 2147483649 running/enabled 16931416478
Miss percent 100 %
OK - Measured branch prediction rates match reported spectre v2 mitigation.
success: spectre_v2
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190520105520.22274-1-mpe@ellerman.id.au
115 lines
2.8 KiB
C
115 lines
2.8 KiB
C
/* SPDX-License-Identifier: GPL-2.0-only */
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/*
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* Copyright 2013, Michael Ellerman, IBM Corp.
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*/
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#ifndef _SELFTESTS_POWERPC_UTILS_H
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#define _SELFTESTS_POWERPC_UTILS_H
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#define __cacheline_aligned __attribute__((aligned(128)))
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#include <stdint.h>
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#include <stdbool.h>
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#include <linux/auxvec.h>
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#include <linux/perf_event.h>
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#include "reg.h"
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/* Avoid headaches with PRI?64 - just use %ll? always */
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typedef unsigned long long u64;
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typedef signed long long s64;
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/* Just for familiarity */
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typedef uint32_t u32;
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typedef uint16_t u16;
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typedef uint8_t u8;
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void test_harness_set_timeout(uint64_t time);
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int test_harness(int (test_function)(void), char *name);
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int read_auxv(char *buf, ssize_t buf_size);
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void *find_auxv_entry(int type, char *auxv);
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void *get_auxv_entry(int type);
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int pick_online_cpu(void);
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int read_debugfs_file(char *debugfs_file, int *result);
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int write_debugfs_file(char *debugfs_file, int result);
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int read_sysfs_file(char *debugfs_file, char *result, size_t result_size);
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void set_dscr(unsigned long val);
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int perf_event_open_counter(unsigned int type,
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unsigned long config, int group_fd);
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int perf_event_enable(int fd);
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int perf_event_disable(int fd);
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int perf_event_reset(int fd);
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static inline bool have_hwcap(unsigned long ftr)
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{
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return ((unsigned long)get_auxv_entry(AT_HWCAP) & ftr) == ftr;
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}
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#ifdef AT_HWCAP2
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static inline bool have_hwcap2(unsigned long ftr2)
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{
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return ((unsigned long)get_auxv_entry(AT_HWCAP2) & ftr2) == ftr2;
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}
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#else
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static inline bool have_hwcap2(unsigned long ftr2)
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{
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return false;
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}
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#endif
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bool is_ppc64le(void);
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/* Yes, this is evil */
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#define FAIL_IF(x) \
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do { \
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if ((x)) { \
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fprintf(stderr, \
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"[FAIL] Test FAILED on line %d\n", __LINE__); \
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return 1; \
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} \
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} while (0)
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/* The test harness uses this, yes it's gross */
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#define MAGIC_SKIP_RETURN_VALUE 99
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#define SKIP_IF(x) \
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do { \
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if ((x)) { \
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fprintf(stderr, \
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"[SKIP] Test skipped on line %d\n", __LINE__); \
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return MAGIC_SKIP_RETURN_VALUE; \
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} \
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} while (0)
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#define SKIP_IF_MSG(x, msg) \
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do { \
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if ((x)) { \
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fprintf(stderr, \
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"[SKIP] Test skipped on line %d: %s\n", \
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__LINE__, msg); \
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return MAGIC_SKIP_RETURN_VALUE; \
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} \
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} while (0)
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#define _str(s) #s
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#define str(s) _str(s)
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/* POWER9 feature */
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#ifndef PPC_FEATURE2_ARCH_3_00
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#define PPC_FEATURE2_ARCH_3_00 0x00800000
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#endif
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#if defined(__powerpc64__)
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#define UCONTEXT_NIA(UC) (UC)->uc_mcontext.gp_regs[PT_NIP]
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#define UCONTEXT_MSR(UC) (UC)->uc_mcontext.gp_regs[PT_MSR]
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#elif defined(__powerpc__)
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#define UCONTEXT_NIA(UC) (UC)->uc_mcontext.uc_regs->gregs[PT_NIP]
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#define UCONTEXT_MSR(UC) (UC)->uc_mcontext.uc_regs->gregs[PT_MSR]
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#else
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#error implement UCONTEXT_NIA
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#endif
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#endif /* _SELFTESTS_POWERPC_UTILS_H */
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