On Thu, Aug 08, 2013 at 04:26:30PM +0200, Jan Kiszka wrote:
> We need to update EFER.NX before building the nEPT state via
> nested_ept_init_mmu_context. Otherwise, we risk to create an MMU context
> that claims to have NX disabled while the guest EPT used NX. This will
> cause spurious faults for L2.
>
Hmm, I do not see how nested ept mmu depends on guests EFER.NX setting.
It just sets mmu->nx to true.
> Signed-off-by: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>
> ---
> arch/x86/kvm/vmx.c | 10 +++++-----
> 1 files changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
> index 6c42518..363fe19 100644
> --- a/arch/x86/kvm/vmx.c
> +++ b/arch/x86/kvm/vmx.c
> @@ -7727,11 +7727,6 @@ static void prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12)
> vmx_flush_tlb(vcpu);
> }
>
> - if (nested_cpu_has_ept(vmcs12)) {
> - kvm_mmu_unload(vcpu);
> - nested_ept_init_mmu_context(vcpu);
> - }
> -
> if (vmcs12->vm_entry_controls & VM_ENTRY_LOAD_IA32_EFER)
> vcpu->arch.efer = vmcs12->guest_ia32_efer;
> else if (vmcs12->vm_entry_controls & VM_ENTRY_IA32E_MODE)
> @@ -7741,6 +7736,11 @@ static void prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12)
> /* Note: modifies VM_ENTRY/EXIT_CONTROLS and GUEST/HOST_IA32_EFER */
> vmx_set_efer(vcpu, vcpu->arch.efer);
>
> + if (nested_cpu_has_ept(vmcs12)) {
> + kvm_mmu_unload(vcpu);
> + nested_ept_init_mmu_context(vcpu);
> + }
> +
> /*
> * This sets GUEST_CR0 to vmcs12->guest_cr0, with possibly a modified
> * TS bit (for lazy fpu) and bits which we consider mandatory enabled.
> --
> 1.7.3.4
--
Gleb.
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