[PATCH v2 00/22] KVM: ARM64: Add guest PMU support

Wei Huang wei at redhat.com
Wed Sep 16 22:56:54 PDT 2015



On 09/16/2015 08:32 PM, Shannon Zhao wrote:
> Hi Wei,
> 
> On 2015/9/17 5:07, Wei Huang wrote:
>> I am testing this series. 
> Thanks for your time and help.
> 
>> The first question is: do you plan to add ACPI
>> support in QEMU?

I saw "KVM_{SET/GET}_DEVICE_ATTR failed: Invalid argument" while using
your QEMU tree (PMU_v2 branch). A quick debugging:

(1) dmesg on host kernel didn't show any vPMU initialization errors. So
I suspect the problem is related to QEMU.
(2) Commit 58771bc2a78 worked fine. So probably the problem was
introduced by new PMU code.

Have you seen it before?

Thanks,
-Wei

> To the completeness, this should be added. Maybe this could be added at
> v3. But I have a look at the kernel PMU driver, it doesn't support
> probing through ACPI, although there are some patches[1] out-of-tree.
> 
>> My in-house kernel uses ACPI for device probing. I had
>> to force "acpi=off" when I test this patch series.
> Guest kernel only boots with ACPI when you add "acpi=force". No need to
> add "acpi=off".
> 
> Thanks,
> 
> [1] http://marc.info/?l=linaro-acpi&m=137949337925645&w=2
> 



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