Re: [PATCH 3/3] tests: kvm: Add tests for KVM_SET_NESTED_STATE

[Sean Christopherson <sean.j.christopherson@intel.com>]

On Thu, May 02, 2019 at 11:31:41AM -0700, Aaron Lewis wrote:
> Add tests for KVM_SET_NESTED_STATE and for various code paths in its implementation in vmx_set_nested_state().
> 
> Signed-off-by: Aaron Lewis <aaronlewis@google.com>
> Reviewed-by: Marc Orr <marcorr@google.com>
> Reviewed-by: Peter Shier <pshier@google.com>
> ---

...

> +int main(int argc, char *argv[])
> +{
> +	struct kvm_vm *vm;
> +	struct kvm_nested_state state;
> +	struct kvm_cpuid_entry2 *entry = kvm_get_supported_cpuid_entry(1);
> +
> +	/*
> +	 * AMD currently does not implement set_nested_state, so for now we
> +	 * just early out.
> +	 */
> +	if (!(entry->ecx & CPUID_VMX)) {
> +		fprintf(stderr, "nested VMX not enabled, skipping test\n");
> +		exit(KSFT_SKIP);
> +	}

Hmm, probably better to check KVM_CAP_NESTED_STATE.  If/when support for
AMD is added it'd be good to automatically pick up whatever testing we can.
As a bonus it'll test the cap code.

> +
> +	vm = vm_create_default(VCPU_ID, 0, 0);
> +
> +	/* Passing a NULL kvm_nested_state causes a EFAULT. */
> +	test_nested_state_expect_efault(vm, NULL);
> +
> +	/* 'size' cannot be smaller than sizeof(kvm_nested_state). */
> +	set_default_state(&state);
> +	state.size = 0;
> +	test_nested_state_expect_einval(vm, &state);
> +
> +	/*
> +	 * Setting the flags 0xf fails the flags check.  The only flags that
> +	 * can be used are:
> +	 *     KVM_STATE_NESTED_GUEST_MODE
> +	 *     KVM_STATE_NESTED_RUN_PENDING
> +	 *     KVM_STATE_NESTED_EVMCS
> +	 */
> +	set_default_state(&state);
> +	state.flags = 0xf;
> +	test_nested_state_expect_einval(vm, &state);
> +
> +	/*
> +	 * If KVM_STATE_NESTED_RUN_PENDING is set then
> +	 * KVM_STATE_NESTED_GUEST_MODE has to be set as well.
> +	 */
> +	set_default_state(&state);
> +	state.flags = KVM_STATE_NESTED_RUN_PENDING;
> +	test_nested_state_expect_einval(vm, &state);
> +
> +	/*
> +	 * TODO: When SVM support is added for KVM_SET_NESTED_STATE
> +	 *       add tests here to support it like VMX.
> +	 */
> +	if (entry->ecx & CPUID_VMX)
> +		test_vmx_nested_state(vm);
> +
> +	kvm_vm_free(vm);
> +	return 0;
> +}
> -- 
> 2.21.0.593.g511ec345e18-goog
>