提交 ddae1ff6 编写于 作者: L Like Xu 提交者: Yang Yingliang

perf/x86/amd: Don't touch the AMD64_EVENTSEL_HOSTONLY bit inside the guest

mainline inclusion
from mainline-v5.14-rc5
commit df51fe7e
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I4MKP4
CVE: NA

--------------------------------

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: 1018faa6 ("perf/x86/kvm: Fix Host-Only/Guest-Only counting with SVM disabled")
Signed-off-by: NLike Xu <likexu@tencent.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: NLiam Merwick <liam.merwick@oracle.com>
Tested-by: NKim Phillips <kim.phillips@amd.com>
Tested-by: NLiam Merwick <liam.merwick@oracle.com>
Link: https://lkml.kernel.org/r/20210802070850.35295-1-likexu@tencent.com
Signed-off-by: Jackie Liu <liuyun01@kylinos.cn> #openEuler_contributor
Signed-off-by: NLaibin Qiu <qiulaibin@huawei.com>
Reviewed-by: NYang Jihong <yangjihong1@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>
上级 4cbf650e
......@@ -912,9 +912,10 @@ void x86_pmu_stop(struct perf_event *event, int flags);
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);
if (is_counter_pair(hwc))
wrmsrl(x86_pmu_config_addr(hwc->idx + 1), 0);
......
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