It is never correct for a VMX instruction to fail with "invalid VMCS"
if there is, in fact, a current VMCS. Reads from unbacked addresses
return all 1's, which means that an unbacked VMCS will not have the
correct VMCS revision ID (i.e. VMCS12_REVISION).
Fixes: 63846663eac78 ("KVM: nVMX: Implement VMPTRLD")
Signed-off-by: Jim Mattson <jmattson@xxxxxxxxxx>
---
arch/x86/kvm/vmx.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 98e82ee1e699..2c21181c8a70 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -7604,7 +7604,14 @@ static int handle_vmptrld(struct kvm_vcpu *vcpu)
struct page *page;
page = nested_get_page(vcpu, vmptr);
if (page == NULL) {
- nested_vmx_failInvalid(vcpu);
+ /*
+ * Reads from an unbacked page return all 1s,
+ * which means that the 32 bits located at the
+ * given physical address won't match the required
+ * VMCS12_REVISION identifier.
+ */
+ nested_vmx_failValid(vcpu,
+ VMXERR_VMPTRLD_INCORRECT_VMCS_REVISION_ID);
return kvm_skip_emulated_instruction(vcpu);
}
new_vmcs12 = kmap(page);
--
2.12.0.367.g23dc2f6d3c-goog
