Re: [PATCH] kvm: x86: fix apic_base enable check

[Paolo Bonzini <pbonzini@redhat.com>]

Il 15/01/2014 13:39, Andrew Jones ha scritto:
> Commit e66d2ae7c67bd moved the assignment
> vcpu->arch.apic_base = value above a condition with
> (vcpu->arch.apic_base ^ value), causing that check
> to always fail. Use old_value, vcpu->arch.apic_base's
> old value, in the condition instead.
> 
> Signed-off-by: Andrew Jones <drjones@redhat.com>
> ---
>  arch/x86/kvm/lapic.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
> index 1673940cf9c35..775702f649ca6 100644
> --- a/arch/x86/kvm/lapic.c
> +++ b/arch/x86/kvm/lapic.c
> @@ -1355,7 +1355,7 @@ void kvm_lapic_set_base(struct kvm_vcpu *vcpu, u64 value)
>  	vcpu->arch.apic_base = value;
>  
>  	/* update jump label if enable bit changes */
> -	if ((vcpu->arch.apic_base ^ value) & MSR_IA32_APICBASE_ENABLE) {
> +	if ((old_value ^ value) & MSR_IA32_APICBASE_ENABLE) {
>  		if (value & MSR_IA32_APICBASE_ENABLE)
>  			static_key_slow_dec_deferred(&apic_hw_disabled);
>  		else
> 

Thanks Drew, applying this patch to master branch.