The effective values of the guest CR0 and CR4 registers may differ from
those included in the VMCS12. In particular, disabling EPT forces
CR4.PAE=1 and disabling unrestricted guest mode forces CR0.PG=CR0.PE=1.
Therefore, checks on these bits cannot be delegated to the processor
and must be performed by KVM.
Reported-by: Reima ISHII <ishiir@xxxxxxxxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
---
arch/x86/kvm/vmx/nested.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index d93c715cda6a..bceb5ad409c6 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -3021,7 +3021,7 @@ static int nested_vmx_check_guest_state(struct kvm_vcpu *vcpu,
struct vmcs12 *vmcs12,
enum vm_entry_failure_code *entry_failure_code)
{
- bool ia32e;
+ bool ia32e = !!(vmcs12->vm_entry_controls & VM_ENTRY_IA32E_MODE);
*entry_failure_code = ENTRY_FAIL_DEFAULT;
@@ -3047,6 +3047,13 @@ static int nested_vmx_check_guest_state(struct kvm_vcpu *vcpu,
vmcs12->guest_ia32_perf_global_ctrl)))
return -EINVAL;
+ if (CC((vmcs12->guest_cr0 & (X86_CR0_PG | X86_CR0_PE)) == X86_CR0_PG))
+ return -EINVAL;
+
+ if (CC(ia32e && !(vmcs12->guest_cr4 & X86_CR4_PAE)) ||
+ CC(ia32e && !(vmcs12->guest_cr0 & X86_CR0_PG)))
+ return -EINVAL;
+
/*
* If the load IA32_EFER VM-entry control is 1, the following checks
* are performed on the field for the IA32_EFER MSR:
@@ -3058,7 +3065,6 @@ static int nested_vmx_check_guest_state(struct kvm_vcpu *vcpu,
*/
if (to_vmx(vcpu)->nested.nested_run_pending &&
(vmcs12->vm_entry_controls & VM_ENTRY_LOAD_IA32_EFER)) {
- ia32e = (vmcs12->vm_entry_controls & VM_ENTRY_IA32E_MODE) != 0;
if (CC(!kvm_valid_efer(vcpu, vmcs12->guest_ia32_efer)) ||
CC(ia32e != !!(vmcs12->guest_ia32_efer & EFER_LMA)) ||
CC(((vmcs12->guest_cr0 & X86_CR0_PG) &&
--
2.39.1
