Re: [PATCH] KVM: x86: Fix reserved x2apic registers

["Radim Krčmář" <rkrcmar@redhat.com>]

2014-11-26 17:11+0200, Nadav Amit:
> x2APIC has no registers for DFR and ICR (see Intel SDM 10.12.1.2 "x2APIC
> Register Address Space"). KVM needs to cause #GP on such accesses.

We should to take care of write to ICR2 as well.

> Fix it.
> 
> Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
> ---
>  arch/x86/kvm/lapic.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
> index e0e5642..7611b75 100644
> --- a/arch/x86/kvm/lapic.c
> +++ b/arch/x86/kvm/lapic.c
> @@ -1897,6 +1897,12 @@ int kvm_x2apic_msr_read(struct kvm_vcpu *vcpu, u32 msr, u64 *data)
>  	if (!irqchip_in_kernel(vcpu->kvm) || !apic_x2apic_mode(apic))
>  		return 1;
>  
> +	if (reg == APIC_DFR || reg == APIC_ICR2) {
> +		apic_debug("KVM_APIC_READ: read x2apic reserved register %x\n",
> +			   reg);
> +		return 1;
> +	}
> +
>  	if (apic_reg_read(apic, reg, 4, &low))
>  		return 1;
>  	if (msr == 0x830)
> -- 
> 1.9.1
> 
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