Subject: [PATCH v8 00/20] KVM: ARM64: Add guest PMU support

From: [email-masked] (Marc Zyngier)
Date: Thu, 07 Jan 2016 14:10:38 +0000

On 22/12/15 08:07, Shannon Zhao wrote:
> From: Shannon Zhao <[email-masked]>
> 
> This patchset adds guest PMU support for KVM on ARM64. It takes
> trap-and-emulate approach. When guest wants to monitor one event, it
> will be trapped by KVM and KVM will call perf_event API to create a perf
> event and call relevant perf_event APIs to get the count value of event.
> 
> Use perf to test this patchset in guest. When using "perf list", it
> shows the list of the hardware events and hardware cache events perf
> supports. Then use "perf stat -e EVENT" to monitor some event. For
> example, use "perf stat -e cycles" to count cpu cycles and
> "perf stat -e cache-misses" to count cache misses.

I finally feel like we're pretty close to something we could merge. My
current concerns are:

- the 32bit bugs, and the fact that it has obviously not been tested
with a 32bit guest. It would be good to give it a go (you'll probably
have to lie about the nature of the PMU in your QEMU code by pretending
it is a Cortex-A15 PMU, for example).

- The UNDEF path and the patch I've posted today. I've quickly tested
it, and it seems to do the right thing, but this warrant a thorough review.

- I'd like Peter Maydell (cc'd) to give his Ack to the last patch, as we
need the userspace ABI to be agreed upon.

Thanks,

	M.
-- 
Jazz is not dead. It just smells funny...