On 08/23/2012 02:16 PM, Marcelo Tosatti wrote:
> 
> In case an invalid or disabled gpa is written to the SYSTEM_TIME
> MSR, do not retain its value. This is not documented behaviour, 
> nor should be supported.
> 
> Also clear it on system reset. Not doing so can hide bugs.
> 
> Signed-off-by: Marcelo Tosatti <[email protected]>
> 
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index e00050c..ed4bfb7 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -1528,6 +1528,7 @@ static int kvm_pv_enable_async_pf(struct kvm_vcpu 
> *vcpu, u64 data)
>  
>  static void kvmclock_reset(struct kvm_vcpu *vcpu)
>  {
> +     vcpu->arch.time = 0;
>       if (vcpu->arch.time_page) {
>               kvm_release_page_dirty(vcpu->arch.time_page);
>               vcpu->arch.time_page = NULL;
> @@ -1632,8 +1633,10 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, u32 msr, 
> u64 data)
>               kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu);
>  
>               /* we verify if the enable bit is set... */
> -             if (!(data & 1))
> +             if (!(data & 1)) {
> +                     vcpu->arch.time = 0;

Should we not just assign data to vcpu->arch.time?  That's how the real
MSRs work.

>                       break;
> +             }
>  
>               /* ...but clean it before doing the actual write */
>               vcpu->arch.time_offset = data & ~(PAGE_MASK | 1);
> @@ -1641,8 +1644,10 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, u32 msr, 
> u64 data)
>               vcpu->arch.time_page =
>                               gfn_to_page(vcpu->kvm, data >> PAGE_SHIFT);
>  
> -             if (is_error_page(vcpu->arch.time_page))
> +             if (is_error_page(vcpu->arch.time_page)) {
>                       vcpu->arch.time_page = NULL;
> +                     vcpu->arch.time = 0;
> +             }
>  

Don't see why.


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