Thread (3 messages) 3 messages, 2 authors, 2021-07-29

Re: [RESEND PATCH] perf/x86/amd: Do not touch the AMD64_EVENTSEL_HOSTONLY bit inside the guest

From: Kim Phillips <hidden>
Date: 2021-07-23 20:16:24
Also in: lkml

+Tom L., Robert R.

On 7/20/21 6:26 AM, Like Xu wrote:
From: Like Xu <redacted>

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 <redacted>
---
Tested-by: Kim Phillips <redacted>

If we were to add a Fixes: tag, would this be the right commit?:

commit 1018faa6cf23b256bf25919ef203cd7c129f06f2

Author: Joerg Roedel [off-list ref]

Date:   Wed Feb 29 14:57:32 2012 +0100



     perf/x86/kvm: Fix Host-Only/Guest-Only counting with SVM disabled


Thanks,

Kim
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