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    Subject[PATCH] perf/x86/vlbr: Add c->flags to vlbr event constraints
    Date
    From: Like Xu <likexu@tencent.com>

    Just like what we do in the x86_get_event_constraints(), the
    PERF_X86_EVENT_LBR_SELECT flag should also be propagated
    to event->hw.flags so that the host lbr driver can save/restore
    MSR_LBR_SELECT for the special vlbr event created by KVM or BPF.

    Reported-by: Wanpeng Li <wanpengli@tencent.com>
    Fixes: 097e4311cda9 ("perf/x86: Add constraint to create guest LBR event without hw counter")
    Signed-off-by: Like Xu <likexu@tencent.com>
    ---
    arch/x86/events/intel/core.c | 4 +++-
    1 file changed, 3 insertions(+), 1 deletion(-)

    diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c
    index 7011e87be6d0..30b5d1b3cb03 100644
    --- a/arch/x86/events/intel/core.c
    +++ b/arch/x86/events/intel/core.c
    @@ -2997,8 +2997,10 @@ intel_vlbr_constraints(struct perf_event *event)
    {
    struct event_constraint *c = &vlbr_constraint;

    - if (unlikely(constraint_match(c, event->hw.config)))
    + if (unlikely(constraint_match(c, event->hw.config))) {
    + event->hw.flags |= c->flags;
    return c;
    + }

    return NULL;
    }
    --
    2.33.0
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