linux-kernel - [PATCH 5.15 098/279] perf/x86/vlbr: Add c->flags to vlbr event constraints

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Date:   Wed, 24 Nov 2021 12:56:25 +0100
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Wanpeng Li <wanpengli@...cent.com>,
        Like Xu <likexu@...cent.com>,
        "Peter Zijlstra (Intel)" <peterz@...radead.org>,
        Sasha Levin <sashal@...nel.org>
Subject: [PATCH 5.15 098/279] perf/x86/vlbr: Add c->flags to vlbr event constraints

From: Like Xu <likexu@...cent.com>

[ Upstream commit 5863702561e625903ec678551cb056a4b19e0b8a ]

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.

Fixes: 097e4311cda9 ("perf/x86: Add constraint to create guest LBR event without hw counter")
Reported-by: Wanpeng Li <wanpengli@...cent.com>
Signed-off-by: Like Xu <likexu@...cent.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@...radead.org>
Tested-by: Wanpeng Li <wanpengli@...cent.com>
Link: https://lore.kernel.org/r/20211103091716.59906-1-likexu@tencent.com
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 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 bc3f97f834011..c7f1cc433a6aa 100644
--- a/arch/x86/events/intel/core.c
+++ b/arch/x86/events/intel/core.c
@@ -2999,8 +2999,10 @@ 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