Re: [PATCH v6 07/16] KVM: x86/pmu: Reprogram PEBS event to emulate guest PEBS counter

[Peter Zijlstra]

On Tue, May 11, 2021 at 10:42:05AM +0800, Like Xu wrote:
> +	if (pebs) {
> +		/*
> +		 * The non-zero precision level of guest event makes the ordinary
> +		 * guest event becomes a guest PEBS event and triggers the host
> +		 * PEBS PMI handler to determine whether the PEBS overflow PMI
> +		 * comes from the host counters or the guest.
> +		 *
> +		 * For most PEBS hardware events, the difference in the software
> +		 * precision levels of guest and host PEBS events will not affect
> +		 * the accuracy of the PEBS profiling result, because the "event IP"
> +		 * in the PEBS record is calibrated on the guest side.
> +		 */
> +		attr.precise_ip = 1;
> +	}

You've just destroyed precdist, no?