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 <mtosatti@xxxxxxxxxx>
>
> 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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