Re: KVM: x86: use kvm_set_cr3/cr4 in ioctl_set_sregs

Avi Kivity
2009-04-16T09:24:00Z

Marcelo Tosatti wrote:
> Humpf. And something like this? Or GP# instead of triple fault?
>
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index 148cde2..3e63bac 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -3986,7 +3986,10 @@ int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
>
> vcpu->arch.cr2 = sregs->cr2;
> mmu_reset_needed |= vcpu->arch.cr3 != sregs->cr3;
> - vcpu->arch.cr3 = sregs->cr3;
> + if (gfn_to_memslot(vcpu->kvm, sregs->cr3 >> PAGE_SHIFT))
> + vcpu->arch.cr3 = sregs->cr3;
> + else
> + set_bit(KVM_REQ_TRIPLE_FAULT, &vcpu->requests);
>
> kvm_set_cr8(vcpu, sregs->cr8);
>

Well, that plugs the hole. Triple fault is better than #GP IMO.

We're still missing checks on reserved bits, etc., but that can come later.