diff options
| -rw-r--r-- | arch/x86/events/intel/pt.c | 38 |
1 files changed, 21 insertions, 17 deletions
diff --git a/arch/x86/events/intel/pt.c b/arch/x86/events/intel/pt.c index 0218728be37a..354e9ff2978c 100644 --- a/arch/x86/events/intel/pt.c +++ b/arch/x86/events/intel/pt.c @@ -411,6 +411,7 @@ static u64 pt_config_filters(struct perf_event *event) static void pt_config(struct perf_event *event) { + struct pt *pt = this_cpu_ptr(&pt_ctx); u64 reg; if (!event->hw.itrace_started) { @@ -429,11 +430,15 @@ static void pt_config(struct perf_event *event) reg |= (event->attr.config & PT_CONFIG_MASK); event->hw.config = reg; - wrmsrl(MSR_IA32_RTIT_CTL, reg); + if (READ_ONCE(pt->vmx_on)) + perf_aux_output_flag(&pt->handle, PERF_AUX_FLAG_PARTIAL); + else + wrmsrl(MSR_IA32_RTIT_CTL, reg); } static void pt_config_stop(struct perf_event *event) { + struct pt *pt = this_cpu_ptr(&pt_ctx); u64 ctl = READ_ONCE(event->hw.config); /* may be already stopped by a PMI */ @@ -441,7 +446,8 @@ static void pt_config_stop(struct perf_event *event) return; ctl &= ~RTIT_CTL_TRACEEN; - wrmsrl(MSR_IA32_RTIT_CTL, ctl); + if (!READ_ONCE(pt->vmx_on)) + wrmsrl(MSR_IA32_RTIT_CTL, ctl); WRITE_ONCE(event->hw.config, ctl); @@ -1174,12 +1180,6 @@ void intel_pt_interrupt(void) if (!READ_ONCE(pt->handle_nmi)) return; - /* - * If VMX is on and PT does not support it, don't touch anything. - */ - if (READ_ONCE(pt->vmx_on)) - return; - if (!event) return; @@ -1239,12 +1239,19 @@ void intel_pt_handle_vmx(int on) local_irq_save(flags); WRITE_ONCE(pt->vmx_on, on); - if (on) { - /* prevent pt_config_stop() from writing RTIT_CTL */ - event = pt->handle.event; - if (event) - event->hw.config = 0; - } + /* + * If an AUX transaction is in progress, it will contain + * gap(s), so flag it PARTIAL to inform the user. + */ + event = pt->handle.event; + if (event) + perf_aux_output_flag(&pt->handle, + PERF_AUX_FLAG_PARTIAL); + + /* Turn PTs back on */ + if (!on && event) + wrmsrl(MSR_IA32_RTIT_CTL, event->hw.config); + local_irq_restore(flags); } EXPORT_SYMBOL_GPL(intel_pt_handle_vmx); @@ -1259,9 +1266,6 @@ static void pt_event_start(struct perf_event *event, int mode) struct pt *pt = this_cpu_ptr(&pt_ctx); struct pt_buffer *buf; - if (READ_ONCE(pt->vmx_on)) - return; - buf = perf_aux_output_begin(&pt->handle, event); if (!buf) goto fail_stop; |