* 0001-perf-x86-amd-Do-not-touch-the-AMD64_EVENTSEL_HOSTONL.patchFrom 9f724a38754d3f99a1b332c11e72e9dd213289d7 Mon Sep 17 00:00:00 2001
@ 2021-07-20 3:20 Like Xu
2021-07-20 3:28 ` Like Xu
0 siblings, 1 reply; 3+ messages in thread
From: Like Xu @ 2021-07-20 3:20 UTC (permalink / raw)
To: Peter Zijlstra, Joerg Roedel
Cc: Ingo Molnar, Arnaldo Carvalho de Melo, Mark Rutland,
Alexander Shishkin, Jiri Olsa, Namhyung Kim, Thomas Gleixner,
Borislav Petkov, x86, H . Peter Anvin, linux-perf-users,
linux-kernel
From: Like Xu <likexu@tencent.com>
If we use "perf record" in an AMD Milan guest, dmesg reports a #GP warning
from an unchecked MSR access error on MSR_F15H_PERF_CTLx:
[] unchecked MSR access error: WRMSR to 0xc0010200 (tried to write
0x0000020000110076) at rIP: 0xffffffff8106ddb4 (native_write_msr+0x4/0x20)
[] Call Trace:
[] amd_pmu_disable_event+0x22/0x90
[] x86_pmu_stop+0x4c/0xa0
[] x86_pmu_del+0x3a/0x140
The AMD64_EVENTSEL_HOSTONLY bit is defined and used on the host,
while the guest perf driver should avoid such use.
Signed-off-by: Like Xu <likexu@tencent.com>
---
arch/x86/events/perf_event.h | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/x86/events/perf_event.h b/arch/x86/events/perf_event.h
index 2bf1c7ea2758..795f4779023c 100644
--- a/arch/x86/events/perf_event.h
+++ b/arch/x86/events/perf_event.h
@@ -1116,8 +1116,9 @@ void x86_pmu_stop(struct perf_event *event, int flags);
static inline void x86_pmu_disable_event(struct perf_event *event)
{
struct hw_perf_event *hwc = &event->hw;
+ u64 disable_mask = __this_cpu_read(cpu_hw_events.perf_ctr_virt_mask);
- wrmsrl(hwc->config_base, hwc->config);
+ wrmsrl(hwc->config_base, hwc->config & ~disable_mask);
if (is_counter_pair(hwc))
wrmsrl(x86_pmu_config_addr(hwc->idx + 1), 0);
--
2.32.0
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: 0001-perf-x86-amd-Do-not-touch-the-AMD64_EVENTSEL_HOSTONL.patchFrom 9f724a38754d3f99a1b332c11e72e9dd213289d7 Mon Sep 17 00:00:00 2001
2021-07-20 3:20 0001-perf-x86-amd-Do-not-touch-the-AMD64_EVENTSEL_HOSTONL.patchFrom 9f724a38754d3f99a1b332c11e72e9dd213289d7 Mon Sep 17 00:00:00 2001 Like Xu
@ 2021-07-20 3:28 ` Like Xu
2021-07-20 10:25 ` Thomas Gleixner
0 siblings, 1 reply; 3+ messages in thread
From: Like Xu @ 2021-07-20 3:28 UTC (permalink / raw)
To: Peter Zijlstra, Joerg Roedel
Cc: Ingo Molnar, Arnaldo Carvalho de Melo, Mark Rutland,
Alexander Shishkin, Jiri Olsa, Namhyung Kim, Thomas Gleixner,
Borislav Petkov, x86, H . Peter Anvin, linux-perf-users,
linux-kernel
The subject should be:
"perf/x86: Do not touch AMD64_EVENTSEL_HOSTONLY bit inside the guest"
Sorry for the noise.
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: 0001-perf-x86-amd-Do-not-touch-the-AMD64_EVENTSEL_HOSTONL.patchFrom 9f724a38754d3f99a1b332c11e72e9dd213289d7 Mon Sep 17 00:00:00 2001
2021-07-20 3:28 ` Like Xu
@ 2021-07-20 10:25 ` Thomas Gleixner
0 siblings, 0 replies; 3+ messages in thread
From: Thomas Gleixner @ 2021-07-20 10:25 UTC (permalink / raw)
To: Like Xu, Peter Zijlstra, Joerg Roedel
Cc: Ingo Molnar, Arnaldo Carvalho de Melo, Mark Rutland,
Alexander Shishkin, Jiri Olsa, Namhyung Kim, Borislav Petkov,
x86, H . Peter Anvin, linux-perf-users, linux-kernel
On Tue, Jul 20 2021 at 11:28, Like Xu wrote:
> The subject should be:
>
> "perf/x86: Do not touch AMD64_EVENTSEL_HOSTONLY bit inside the guest"
>
> Sorry for the noise.
Please resend proper.
Thanks,
tglx
^ permalink raw reply [flat|nested] 3+ messages in thread
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2021-07-20 3:20 0001-perf-x86-amd-Do-not-touch-the-AMD64_EVENTSEL_HOSTONL.patchFrom 9f724a38754d3f99a1b332c11e72e9dd213289d7 Mon Sep 17 00:00:00 2001 Like Xu
2021-07-20 3:28 ` Like Xu
2021-07-20 10:25 ` Thomas Gleixner
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