From: Like Xu likexu@tencent.com
commit df51fe7ea1c1c2c3bfdb81279712fdd2e4ea6c27 upstream.
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.
Fixes: 1018faa6cf23 ("perf/x86/kvm: Fix Host-Only/Guest-Only counting with SVM disabled") Signed-off-by: Like Xu likexu@tencent.com Signed-off-by: Peter Zijlstra (Intel) peterz@infradead.org Reviewed-by: Liam Merwick liam.merwick@oracle.com Tested-by: Kim Phillips kim.phillips@amd.com Tested-by: Liam Merwick liam.merwick@oracle.com Link: https://lkml.kernel.org/r/20210802070850.35295-1-likexu@tencent.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/x86/events/perf_event.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/arch/x86/events/perf_event.h +++ b/arch/x86/events/perf_event.h @@ -771,9 +771,10 @@ void x86_pmu_stop(struct perf_event *eve
static inline void x86_pmu_disable_event(struct perf_event *event) { + u64 disable_mask = __this_cpu_read(cpu_hw_events.perf_ctr_virt_mask); struct hw_perf_event *hwc = &event->hw;
- wrmsrl(hwc->config_base, hwc->config); + wrmsrl(hwc->config_base, hwc->config & ~disable_mask); }
void x86_pmu_enable_event(struct perf_event *event);