2018-03-05 09:33-0800, Sean Christopherson:
> Segment registers must be synchronized prior to any code that may
> trigger a call to emulation_required()/guest_state_valid(), e.g.
> vmx_set_cr0(). Because preparing vmcs02 writes segmentation fields
> directly, i.e. doesn't use vmx_set_segment(), emulation_required
> will not be re-evaluated when synchronizing the segment registers,
> which can result in L0 incorrectly starting emulation of L2.
>
> Fixes: 8665c3f97320 ("KVM: nVMX: initialize descriptor cache fields in prepare_vmcs02_full")
>
> Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
> ---
> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
> @@ -10563,11 +10563,8 @@ static int nested_vmx_load_cr3(struct kvm_vcpu *vcpu, unsigned long cr3, bool ne
> return 0;
> }
>
> -static void prepare_vmcs02_full(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12,
> - bool from_vmentry)
Nice catch!
Paolo, was there a reason to that prevented prepare_vmcs02_full at the
beginning of prepare_vmcs02?
Thanks.
