Re: [PATCH] Remove MSR_P6_{EVNTSEL0,PERFCTR0} from printk warning list.

[Avi Kivity <avi@redhat.com>]

On 06/30/2010 05:27 PM, Jes.Sorensen@redhat.com wrote:
> From: Jes Sorensen<Jes.Sorensen@redhat.com>
>
> MSR_P6_EVNTSEL0 and MSR_P6_PERFCTR0 are used to probe for the P6 PMU
> for older family 6 CPUs, which is also the default in QEMU. Ie. per
> default we get the noise of these warnings in dmesg, confusing users
> for no reason.
>
>    

For the reason, see the comment above.  The guest may be trying to do 
something with the counters and expect them to work.  Without the 
warning we'd have no idea we are knowningly misemulating something.

> Signed-off-by: Jes Sorensen<Jes.Sorensen@redhat.com>
> ---
>   arch/x86/kvm/x86.c |    2 --
>   1 files changed, 0 insertions(+), 2 deletions(-)
>
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index d0b9252..ac55b92 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -1306,7 +1306,6 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 data)
>   	 * which we perfectly emulate ;-). Any other value should be at least
>   	 * reported, some guests depend on them.
>   	 */
> -	case MSR_P6_EVNTSEL0:
>   	case MSR_P6_EVNTSEL1:
>   	case MSR_K7_EVNTSEL0:
>   	case MSR_K7_EVNTSEL1:
> @@ -1319,7 +1318,6 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 data)
>   	/* at least RHEL 4 unconditionally writes to the perfctr registers,
>   	 * so we ignore writes to make it happy.
>   	 */
> -	case MSR_P6_PERFCTR0:
>   	case MSR_P6_PERFCTR1:
>   	case MSR_K7_PERFCTR0:
>   	case MSR_K7_PERFCTR1:
>    


-- 
error compiling committee.c: too many arguments to function