kvm.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Dapeng Mi <dapeng1.mi@linux.intel.com>
To: Sean Christopherson <seanjc@google.com>,
	Paolo Bonzini <pbonzini@redhat.com>
Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
	Jim Mattson <jmattson@google.com>,
	Mingwei Zhang <mizhang@google.com>,
	Xiong Zhang <xiong.y.zhang@intel.com>,
	Zhenyu Wang <zhenyuw@linux.intel.com>,
	Like Xu <like.xu.linux@gmail.com>,
	Jinrong Liang <cloudliang@tencent.com>,
	Yongwei Ma <yongwei.ma@intel.com>,
	Dapeng Mi <dapeng1.mi@intel.com>,
	Dapeng Mi <dapeng1.mi@linux.intel.com>
Subject: [kvm-unit-tests patch v6 05/18] x86: pmu: Enlarge cnt[] length to 48 in check_counters_many()
Date: Sat, 14 Sep 2024 10:17:15 +0000	[thread overview]
Message-ID: <20240914101728.33148-6-dapeng1.mi@linux.intel.com> (raw)
In-Reply-To: <20240914101728.33148-1-dapeng1.mi@linux.intel.com>

Considering there are already 8 GP counters and 4 fixed counters on
latest Intel processors, like Sapphire Rapids. The original cnt[] array
length 10 is definitely not enough to cover all supported PMU counters on
these new processors even through currently KVM only supports 3 fixed
counters at most. This would cause out of bound memory access and may trigger
false alarm on PMU counter validation

It's probably more and more GP and fixed counters are introduced in the
future and then directly extends the cnt[] array length to 48 once and
for all. Base on the layout of IA32_PERF_GLOBAL_CTRL and
IA32_PERF_GLOBAL_STATUS, 48 looks enough in near feature.

Reviewed-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
---
 x86/pmu.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/x86/pmu.c b/x86/pmu.c
index a0268db8..b4de2680 100644
--- a/x86/pmu.c
+++ b/x86/pmu.c
@@ -255,7 +255,7 @@ static void check_fixed_counters(void)
 
 static void check_counters_many(void)
 {
-	pmu_counter_t cnt[10];
+	pmu_counter_t cnt[48];
 	int i, n;
 
 	for (i = 0, n = 0; n < pmu.nr_gp_counters; i++) {
-- 
2.40.1


  parent reply	other threads:[~2024-09-14  7:01 UTC|newest]

Thread overview: 33+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-09-14 10:17 [kvm-unit-tests patch v6 00/18] pmu test bugs fix and improvements Dapeng Mi
2024-09-14 10:17 ` [kvm-unit-tests patch v6 01/18] x86: pmu: Remove duplicate code in pmu_init() Dapeng Mi
2024-09-14 10:17 ` [kvm-unit-tests patch v6 02/18] x86: pmu: Remove blank line and redundant space Dapeng Mi
2024-09-14 10:17 ` [kvm-unit-tests patch v6 03/18] x86: pmu: Refine fixed_events[] names Dapeng Mi
2024-09-14 10:17 ` [kvm-unit-tests patch v6 04/18] x86: pmu: Fix the issue that pmu_counter_t.config crosses cache line Dapeng Mi
2025-02-14 21:05   ` Sean Christopherson
2025-02-18  9:07     ` Mi, Dapeng
2024-09-14 10:17 ` Dapeng Mi [this message]
2025-02-14 21:06   ` [kvm-unit-tests patch v6 05/18] x86: pmu: Enlarge cnt[] length to 48 in check_counters_many() Sean Christopherson
2025-02-18  9:24     ` Mi, Dapeng
2025-02-18 15:56       ` Sean Christopherson
2024-09-14 10:17 ` [kvm-unit-tests patch v6 06/18] x86: pmu: Print measured event count if test fails Dapeng Mi
2024-09-14 10:17 ` [kvm-unit-tests patch v6 07/18] x86: pmu: Fix potential out of bound access for fixed events Dapeng Mi
2025-02-14 21:07   ` Sean Christopherson
2025-02-18  9:34     ` Mi, Dapeng
2025-02-18 15:04       ` Sean Christopherson
2024-09-14 10:17 ` [kvm-unit-tests patch v6 08/18] x86: pmu: Fix cycles event validation failure Dapeng Mi
2025-02-14 21:07   ` Sean Christopherson
2025-02-18  9:36     ` Mi, Dapeng
2024-09-14 10:17 ` [kvm-unit-tests patch v6 09/18] x86: pmu: Use macro to replace hard-coded branches event index Dapeng Mi
2024-09-14 10:17 ` [kvm-unit-tests patch v6 10/18] x86: pmu: Use macro to replace hard-coded ref-cycles " Dapeng Mi
2024-09-14 10:17 ` [kvm-unit-tests patch v6 11/18] x86: pmu: Use macro to replace hard-coded instructions " Dapeng Mi
2024-09-14 10:17 ` [kvm-unit-tests patch v6 12/18] x86: pmu: Enable and disable PMCs in loop() asm blob Dapeng Mi
2024-09-14 10:17 ` [kvm-unit-tests patch v6 13/18] x86: pmu: Improve instruction and branches events verification Dapeng Mi
2025-02-14 21:08   ` Sean Christopherson
2025-02-18  9:40     ` Mi, Dapeng
2024-09-14 10:17 ` [kvm-unit-tests patch v6 14/18] x86: pmu: Improve LLC misses event verification Dapeng Mi
2024-09-14 10:17 ` [kvm-unit-tests patch v6 15/18] x86: pmu: Adjust lower boundary of llc-misses event to 0 for legacy CPUs Dapeng Mi
2024-09-14 10:17 ` [kvm-unit-tests patch v6 16/18] x86: pmu: Add IBPB indirect jump asm blob Dapeng Mi
2024-09-14 10:17 ` [kvm-unit-tests patch v6 17/18] x86: pmu: Adjust lower boundary of branch-misses event Dapeng Mi
2025-02-14 21:09   ` Sean Christopherson
2025-02-18  9:42     ` Mi, Dapeng
2024-09-14 10:17 ` [kvm-unit-tests patch v6 18/18] x86: pmu: Optimize emulated instruction validation Dapeng Mi

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20240914101728.33148-6-dapeng1.mi@linux.intel.com \
    --to=dapeng1.mi@linux.intel.com \
    --cc=cloudliang@tencent.com \
    --cc=dapeng1.mi@intel.com \
    --cc=jmattson@google.com \
    --cc=kvm@vger.kernel.org \
    --cc=like.xu.linux@gmail.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mizhang@google.com \
    --cc=pbonzini@redhat.com \
    --cc=seanjc@google.com \
    --cc=xiong.y.zhang@intel.com \
    --cc=yongwei.ma@intel.com \
    --cc=zhenyuw@linux.intel.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).