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perf: Capture branch privilege information

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Platforms like arm64 could capture privilege level information for all the
branch records. Hence this adds a new element in the struct branch_entry to
record the privilege level information, which could be requested through a
new event.attr.branch_sample_type based flag PERF_SAMPLE_BRANCH_PRIV_SAVE.
This flag helps user choose whether privilege information is captured.

Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: James Clark <james.clark@arm.com>
Link: https://lkml.kernel.org/r/20220824044822.70230-4-anshuman.khandual@arm.com
This commit is contained in:
Anshuman Khandual 2022-08-24 10:18:17 +05:30 committed by Peter Zijlstra
parent b190bc4ac9
commit 5402d25aa5
1 changed files with 13 additions and 1 deletions
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14
include/uapi/linux/perf_event.h
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@ -204,6 +204,8 @@ enum perf_branch_sample_type_shift {
PERF_SAMPLE_BRANCH_HW_INDEX_SHIFT = 17, /* save low level index of raw branch records */
PERF_SAMPLE_BRANCH_PRIV_SAVE_SHIFT = 18, /* save privilege mode */
PERF_SAMPLE_BRANCH_MAX_SHIFT /* non-ABI */
};
@ -233,6 +235,8 @@ enum perf_branch_sample_type {
PERF_SAMPLE_BRANCH_HW_INDEX = 1U << PERF_SAMPLE_BRANCH_HW_INDEX_SHIFT,
PERF_SAMPLE_BRANCH_PRIV_SAVE = 1U << PERF_SAMPLE_BRANCH_PRIV_SAVE_SHIFT,
PERF_SAMPLE_BRANCH_MAX = 1U << PERF_SAMPLE_BRANCH_MAX_SHIFT,
};
@ -282,6 +286,13 @@ enum {
PERF_BR_NEW_MAX,
};
enum {
PERF_BR_PRIV_UNKNOWN = 0,
PERF_BR_PRIV_USER = 1,
PERF_BR_PRIV_KERNEL = 2,
PERF_BR_PRIV_HV = 3,
};
#define PERF_SAMPLE_BRANCH_PLM_ALL \
(PERF_SAMPLE_BRANCH_USER|\
PERF_SAMPLE_BRANCH_KERNEL|\
@ -1402,7 +1413,8 @@ struct perf_branch_entry {
type:4, /* branch type */
spec:2, /* branch speculation info */
new_type:4, /* additional branch type */
reserved:34;
priv:3, /* privilege level */
reserved:31;
};
union perf_sample_weight {