KVM: nVMX: check for invalid hdr.vmx.flags

hdr.vmx.flags is meant for future extensions to the ABI, rejecting
invalid flags is necessary to avoid broken half-loads of the
nVMX state.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 13 insertions, 0 deletions

diff --git a/tools/testing/selftests/kvm/x86_64/vmx_set_nested_state_test.c b/tools/testing/selftests/kvm/x86_64/vmx_set_nested_state_test.c
index 94f28a657569..d59f3eb67c8f 100644
--- a/tools/testing/selftests/kvm/x86_64/vmx_set_nested_state_test.c
+++ b/tools/testing/selftests/kvm/x86_64/vmx_set_nested_state_test.c
@@ -146,6 +146,11 @@ void test_vmx_nested_state(struct kvm_vm *vm)
 	state->hdr.vmx.smm.flags = 1;
 	test_nested_state_expect_einval(vm, state);
 
+	/* Invalid flags are rejected. */
+	set_default_vmx_state(state, state_sz);
+	state->hdr.vmx.flags = ~0;
+	test_nested_state_expect_einval(vm, state);
+
 	/* It is invalid to have vmxon_pa == -1ull and vmcs_pa != -1ull. */
 	set_default_vmx_state(state, state_sz);
 	state->hdr.vmx.vmxon_pa = -1ull;
@@ -206,6 +211,14 @@ void test_vmx_nested_state(struct kvm_vm *vm)
 	state->flags = 0;
 	test_nested_state(vm, state);
 
+	/* Invalid flags are rejected, even if no VMCS loaded. */
+	set_default_vmx_state(state, state_sz);
+	state->size = sizeof(*state);
+	state->flags = 0;
+	state->hdr.vmx.vmcs12_pa = -1;
+	state->hdr.vmx.flags = ~0;
+	test_nested_state_expect_einval(vm, state);
+
 	/* vmxon_pa cannot be the same address as vmcs_pa. */
 	set_default_vmx_state(state, state_sz);
 	state->hdr.vmx.vmxon_pa = 0;