x86/kvm/nVMX: allow bare VMXON state migration
It is perfectly valid for a guest to do VMXON and not do VMPTRLD. This
state needs to be preserved on migration.
Cc: stable@vger.kernel.org
Fixes: 8fcc4b5923af5de58b80b53a069453b135693304
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 0b665c7..5df4729 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -14827,13 +14827,6 @@ static int vmx_set_nested_state(struct kvm_vcpu *vcpu,
if (!page_address_valid(vcpu, kvm_state->vmx.vmxon_pa))
return -EINVAL;
- if (kvm_state->size < sizeof(kvm_state) + sizeof(*vmcs12))
- return -EINVAL;
-
- if (kvm_state->vmx.vmcs_pa == kvm_state->vmx.vmxon_pa ||
- !page_address_valid(vcpu, kvm_state->vmx.vmcs_pa))
- return -EINVAL;
-
if ((kvm_state->vmx.smm.flags & KVM_STATE_NESTED_SMM_GUEST_MODE) &&
(kvm_state->flags & KVM_STATE_NESTED_GUEST_MODE))
return -EINVAL;
@@ -14863,6 +14856,14 @@ static int vmx_set_nested_state(struct kvm_vcpu *vcpu,
if (ret)
return ret;
+ /* Empty 'VMXON' state is permitted */
+ if (kvm_state->size < sizeof(kvm_state) + sizeof(*vmcs12))
+ return 0;
+
+ if (kvm_state->vmx.vmcs_pa == kvm_state->vmx.vmxon_pa ||
+ !page_address_valid(vcpu, kvm_state->vmx.vmcs_pa))
+ return -EINVAL;
+
set_current_vmptr(vmx, kvm_state->vmx.vmcs_pa);
if (kvm_state->vmx.smm.flags & KVM_STATE_NESTED_SMM_VMXON) {