Re: [PATCH V3 2/2] perf/x86: Reset the dirty counter to prevent the leak for an RDPMC task

[Andy Lutomirski]

On Tue, Apr 13, 2021 at 12:05 PM <kan.liang@xxxxxxxxxxxxxxx> wrote:
>
> From: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
>
> The counter value of a perf task may leak to another RDPMC task.
> For example, a perf stat task as below is running on CPU 0.
>
>     perf stat -e 'branches,cycles' -- taskset -c 0 ./workload

I assume this doesn't fix the leak if the sensitive counter is systemwide?

Could Intel please add proper security and ideally virtualization for
this?  Ideally RDPMC permission would be a bitmask for all RDPMC-able
counters, not just a single on/off switch.

-Andy