PEBS for KVM guest

Software Tuning, Performance Optimization & Platform Monitoring

Discussion regarding monitoring and software tuning methodologies, Performance Monitoring Unit (PMU) of Intel microprocessors, and platform updating.

PEBS for KVM guest

893 Views

I was looking into the perf code to enable PEBS sampling for KVM guest. While registering perf_event_attr, I have set exclude_guest = 0 and exclude_host = 1. With this setting I am not receiving any PEBS samples.

After digging into the kernel code, I have found that, in add_atomic_switch_msr function, MSR_IA32_PEBS_ENABLE is being set to 0.

It also states that, "PEBS needs a quiescent period after being disabled (to write a record). Disabling PEBS through VMX MSR swapping doesn't provide that period, so a CPU could write host's record into guest's memory."

Is it possible to enable the PEBS for guest while keeping the host PEBS disabled?

Link Copied

0 Replies

Community support is provided during standard business hours (Monday to Friday 7AM - 5PM PST). Other contact methods are available here.

Intel does not verify all solutions, including but not limited to any file transfers that may appear in this community. Accordingly, Intel disclaims all express and implied warranties, including without limitation, the implied warranties of merchantability, fitness for a particular purpose, and non-infringement, as well as any warranty arising from course of performance, course of dealing, or usage in trade.

For more complete information about compiler optimizations, see our Optimization Notice.