Messages in this thread | | | Date | Tue, 14 Feb 2017 15:02:20 +0100 | From | Peter Zijlstra <> | Subject | Re: [PATCH 2/2] perf/x86/intel/pt: Fail event creation if VMX operation is on |
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On Tue, Feb 14, 2017 at 03:24:16PM +0200, Alexander Shishkin wrote: > On systems where PT does not coexist with VMX, users get confused when > PT turns up with no data because they forgot they're running a kvm > session at the same time. > > This patch adds a preemptive check for any active VMX operations that > will fail event creation. This does not provide any guarantees or > protection against racing with a kvm starting in parallel, but is > intended to serve as a hint for the user. If VMXON happens after an > event had been created, the event will still produce an empty trace. >
Would it not be more sensible to write fake PT packets in intel_pt_handle_vmx() to demarcate VMX regions in the trace?
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