* use of PMU in guest generates messages in host
@ 2012-01-11 20:47 David Ahern
2012-01-12 6:26 ` Gleb Natapov
0 siblings, 1 reply; 6+ messages in thread
From: David Ahern @ 2012-01-11 20:47 UTC (permalink / raw)
To: KVM mailing list
Using latest kernel tree (e343a895a9f342f239c5e3c5ffc6c0b1707e6244)
which has KVM bits for using PMU in the guest. Host and guest are both
running Fedora 16, 64-bit, with this kernel.
Running this command in the guest:
perf stat -ddd -- openssl speed aes
Generates this in the host:
[74728.221863] kvm_set_msr_common: 2760 callbacks suppressed
[74728.221950] kvm: 28217: cpu2 unhandled wrmsr: 0x1a6 data f701
[74728.222115] kvm: 28217: cpu2 unhandled wrmsr: 0x1a6 data f701
[74728.222858] kvm: 28217: cpu2 unhandled wrmsr: 0x1a6 data f701
[74728.223018] kvm: 28217: cpu2 unhandled wrmsr: 0x1a6 data f701
[74728.223851] kvm: 28217: cpu2 unhandled wrmsr: 0x1a6 data f701
[74728.224009] kvm: 28217: cpu2 unhandled wrmsr: 0x1a6 data f701
[74728.224843] kvm: 28217: cpu2 unhandled wrmsr: 0x1a6 data f701
[74728.224997] kvm: 28217: cpu2 unhandled wrmsr: 0x1a6 data f701
[74728.225842] kvm: 28217: cpu2 unhandled wrmsr: 0x1a6 data f001
[74728.226010] kvm: 28217: cpu2 unhandled wrmsr: 0x1a6 data f001
David
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: use of PMU in guest generates messages in host
2012-01-11 20:47 use of PMU in guest generates messages in host David Ahern
@ 2012-01-12 6:26 ` Gleb Natapov
2012-01-12 14:02 ` David Ahern
0 siblings, 1 reply; 6+ messages in thread
From: Gleb Natapov @ 2012-01-12 6:26 UTC (permalink / raw)
To: David Ahern; +Cc: KVM mailing list
On Wed, Jan 11, 2012 at 01:47:55PM -0700, David Ahern wrote:
> Using latest kernel tree (e343a895a9f342f239c5e3c5ffc6c0b1707e6244)
> which has KVM bits for using PMU in the guest. Host and guest are both
> running Fedora 16, 64-bit, with this kernel.
>
> Running this command in the guest:
> perf stat -ddd -- openssl speed aes
>
> Generates this in the host:
> [74728.221863] kvm_set_msr_common: 2760 callbacks suppressed
> [74728.221950] kvm: 28217: cpu2 unhandled wrmsr: 0x1a6 data f701
> [74728.222115] kvm: 28217: cpu2 unhandled wrmsr: 0x1a6 data f701
> [74728.222858] kvm: 28217: cpu2 unhandled wrmsr: 0x1a6 data f701
> [74728.223018] kvm: 28217: cpu2 unhandled wrmsr: 0x1a6 data f701
> [74728.223851] kvm: 28217: cpu2 unhandled wrmsr: 0x1a6 data f701
> [74728.224009] kvm: 28217: cpu2 unhandled wrmsr: 0x1a6 data f701
> [74728.224843] kvm: 28217: cpu2 unhandled wrmsr: 0x1a6 data f701
> [74728.224997] kvm: 28217: cpu2 unhandled wrmsr: 0x1a6 data f701
> [74728.225842] kvm: 28217: cpu2 unhandled wrmsr: 0x1a6 data f001
> [74728.226010] kvm: 28217: cpu2 unhandled wrmsr: 0x1a6 data f001
>
This is MSR_OFFCORE_RSP_0 MSR which is not (yet?) supported. What is
your host cpu and qemu command line?
--
Gleb.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: use of PMU in guest generates messages in host
2012-01-12 6:26 ` Gleb Natapov
@ 2012-01-12 14:02 ` David Ahern
2012-01-12 14:14 ` Gleb Natapov
0 siblings, 1 reply; 6+ messages in thread
From: David Ahern @ 2012-01-12 14:02 UTC (permalink / raw)
To: Gleb Natapov; +Cc: KVM mailing list
On 01/11/2012 11:26 PM, Gleb Natapov wrote:
> On Wed, Jan 11, 2012 at 01:47:55PM -0700, David Ahern wrote:
>> Using latest kernel tree (e343a895a9f342f239c5e3c5ffc6c0b1707e6244)
>> which has KVM bits for using PMU in the guest. Host and guest are both
>> running Fedora 16, 64-bit, with this kernel.
>>
>> Running this command in the guest:
>> perf stat -ddd -- openssl speed aes
>>
>> Generates this in the host:
>> [74728.221863] kvm_set_msr_common: 2760 callbacks suppressed
>> [74728.221950] kvm: 28217: cpu2 unhandled wrmsr: 0x1a6 data f701
>> [74728.222115] kvm: 28217: cpu2 unhandled wrmsr: 0x1a6 data f701
>> [74728.222858] kvm: 28217: cpu2 unhandled wrmsr: 0x1a6 data f701
>> [74728.223018] kvm: 28217: cpu2 unhandled wrmsr: 0x1a6 data f701
>> [74728.223851] kvm: 28217: cpu2 unhandled wrmsr: 0x1a6 data f701
>> [74728.224009] kvm: 28217: cpu2 unhandled wrmsr: 0x1a6 data f701
>> [74728.224843] kvm: 28217: cpu2 unhandled wrmsr: 0x1a6 data f701
>> [74728.224997] kvm: 28217: cpu2 unhandled wrmsr: 0x1a6 data f701
>> [74728.225842] kvm: 28217: cpu2 unhandled wrmsr: 0x1a6 data f001
>> [74728.226010] kvm: 28217: cpu2 unhandled wrmsr: 0x1a6 data f001
>>
> This is MSR_OFFCORE_RSP_0 MSR which is not (yet?) supported. What is
> your host cpu and qemu command line?
Host CPU: Intel(R) Xeon(R) CPU E5540 @ 2.53GHz
and '-cpu host' is used on the qemu command line.
David
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: use of PMU in guest generates messages in host
2012-01-12 14:02 ` David Ahern
@ 2012-01-12 14:14 ` Gleb Natapov
2012-01-12 17:07 ` David Ahern
0 siblings, 1 reply; 6+ messages in thread
From: Gleb Natapov @ 2012-01-12 14:14 UTC (permalink / raw)
To: David Ahern; +Cc: KVM mailing list
On Thu, Jan 12, 2012 at 07:02:12AM -0700, David Ahern wrote:
>
> On 01/11/2012 11:26 PM, Gleb Natapov wrote:
> > On Wed, Jan 11, 2012 at 01:47:55PM -0700, David Ahern wrote:
> >> Using latest kernel tree (e343a895a9f342f239c5e3c5ffc6c0b1707e6244)
> >> which has KVM bits for using PMU in the guest. Host and guest are both
> >> running Fedora 16, 64-bit, with this kernel.
> >>
> >> Running this command in the guest:
> >> perf stat -ddd -- openssl speed aes
> >>
> >> Generates this in the host:
> >> [74728.221863] kvm_set_msr_common: 2760 callbacks suppressed
> >> [74728.221950] kvm: 28217: cpu2 unhandled wrmsr: 0x1a6 data f701
> >> [74728.222115] kvm: 28217: cpu2 unhandled wrmsr: 0x1a6 data f701
> >> [74728.222858] kvm: 28217: cpu2 unhandled wrmsr: 0x1a6 data f701
> >> [74728.223018] kvm: 28217: cpu2 unhandled wrmsr: 0x1a6 data f701
> >> [74728.223851] kvm: 28217: cpu2 unhandled wrmsr: 0x1a6 data f701
> >> [74728.224009] kvm: 28217: cpu2 unhandled wrmsr: 0x1a6 data f701
> >> [74728.224843] kvm: 28217: cpu2 unhandled wrmsr: 0x1a6 data f701
> >> [74728.224997] kvm: 28217: cpu2 unhandled wrmsr: 0x1a6 data f701
> >> [74728.225842] kvm: 28217: cpu2 unhandled wrmsr: 0x1a6 data f001
> >> [74728.226010] kvm: 28217: cpu2 unhandled wrmsr: 0x1a6 data f001
> >>
> > This is MSR_OFFCORE_RSP_0 MSR which is not (yet?) supported. What is
> > your host cpu and qemu command line?
>
> Host CPU: Intel(R) Xeon(R) CPU E5540 @ 2.53GHz
> and '-cpu host' is used on the qemu command line.
>
Use "-cpu host,model=29" should avid this message. We need to teach
guest to not use non architectural MSRs.
--
Gleb.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: use of PMU in guest generates messages in host
2012-01-12 14:14 ` Gleb Natapov
@ 2012-01-12 17:07 ` David Ahern
2012-01-12 17:17 ` Avi Kivity
0 siblings, 1 reply; 6+ messages in thread
From: David Ahern @ 2012-01-12 17:07 UTC (permalink / raw)
To: Gleb Natapov; +Cc: KVM mailing list
On 01/12/2012 07:14 AM, Gleb Natapov wrote:
>>> This is MSR_OFFCORE_RSP_0 MSR which is not (yet?) supported. What is
>>> your host cpu and qemu command line?
>>
>> Host CPU: Intel(R) Xeon(R) CPU E5540 @ 2.53GHz
>> and '-cpu host' is used on the qemu command line.
>>
> Use "-cpu host,model=29" should avid this message. We need to teach
> guest to not use non architectural MSRs.
Rather than teaching (changing guest code) why not change KVM to not log
a message on these writes until it is supported by KVM?
David
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: use of PMU in guest generates messages in host
2012-01-12 17:07 ` David Ahern
@ 2012-01-12 17:17 ` Avi Kivity
0 siblings, 0 replies; 6+ messages in thread
From: Avi Kivity @ 2012-01-12 17:17 UTC (permalink / raw)
To: David Ahern; +Cc: Gleb Natapov, KVM mailing list
On 01/12/2012 07:07 PM, David Ahern wrote:
> On 01/12/2012 07:14 AM, Gleb Natapov wrote:
> >>> This is MSR_OFFCORE_RSP_0 MSR which is not (yet?) supported. What is
> >>> your host cpu and qemu command line?
> >>
> >> Host CPU: Intel(R) Xeon(R) CPU E5540 @ 2.53GHz
> >> and '-cpu host' is used on the qemu command line.
> >>
> > Use "-cpu host,model=29" should avid this message. We need to teach
> > guest to not use non architectural MSRs.
>
> Rather than teaching (changing guest code) why not change KVM to not log
> a message on these writes until it is supported by KVM?
Since we aren't properly emulating these registers, the guest may
mulfunction. Linux does not, but another guest may. If we silence the
messages, then we have a malfunctioning guest with no hint in dmesg.
--
error compiling committee.c: too many arguments to function
^ permalink raw reply [flat|nested] 6+ messages in thread
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2012-01-11 20:47 use of PMU in guest generates messages in host David Ahern
2012-01-12 6:26 ` Gleb Natapov
2012-01-12 14:02 ` David Ahern
2012-01-12 14:14 ` Gleb Natapov
2012-01-12 17:07 ` David Ahern
2012-01-12 17:17 ` Avi Kivity
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