Commit 2aab4b35 authored by David Matlack's avatar David Matlack Committed by Paolo Bonzini
Browse files

KVM: selftests: Print a message if /dev/kvm is missing 



If a KVM selftest is run on a machine without /dev/kvm, it will exit
silently. Make it easy to tell what's happening by printing an error
message.

Opportunistically consolidate all codepaths that open /dev/kvm into a
single function so they all print the same message.

This slightly changes the semantics of vm_is_unrestricted_guest() by
changing a TEST_ASSERT() to exit(KSFT_SKIP). However
vm_is_unrestricted_guest() is only called in one place
(x86_64/mmio_warning_test.c) and that is to determine if the test should
be skipped or not.

Signed-off-by: default avatarDavid Matlack <dmatlack@google.com>
Message-Id: <20210511202120.1371800-1-dmatlack@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent c887d6a1

tools/testing/selftests/kvm/include/kvm_util.h

+1 −0
Original line number Diff line number Diff line
@@ -77,6 +77,7 @@ struct vm_guest_mode_params { 
};

extern const struct vm_guest_mode_params vm_guest_mode_params[];



int open_kvm_dev_path_or_exit(void);

int kvm_check_cap(long cap);

int vm_enable_cap(struct kvm_vm *vm, struct kvm_enable_cap *cap);

int vcpu_enable_cap(struct kvm_vm *vm, uint32_t vcpu_id,

tools/testing/selftests/kvm/lib/kvm_util.c

+32 −14
Original line number Diff line number Diff line
@@ -31,6 +31,34 @@ static void *align(void *x, size_t size) 
	return (void *) (((size_t) x + mask) & ~mask);

}



/*

 * Open KVM_DEV_PATH if available, otherwise exit the entire program.

 *

 * Input Args:

 *   flags - The flags to pass when opening KVM_DEV_PATH.

 *

 * Return:

 *   The opened file descriptor of /dev/kvm.

 */

static int _open_kvm_dev_path_or_exit(int flags)

{

	int fd;



	fd = open(KVM_DEV_PATH, flags);

	if (fd < 0) {

		print_skip("%s not available, is KVM loaded? (errno: %d)",

			   KVM_DEV_PATH, errno);

		exit(KSFT_SKIP);

	}



	return fd;

}



int open_kvm_dev_path_or_exit(void)

{

	return _open_kvm_dev_path_or_exit(O_RDONLY);

}



/*

 * Capability

 *
@@ -52,10 +80,7 @@ int kvm_check_cap(long cap) 
	int ret;

	int kvm_fd;



	kvm_fd = open(KVM_DEV_PATH, O_RDONLY);

	if (kvm_fd < 0)

		exit(KSFT_SKIP);



	kvm_fd = open_kvm_dev_path_or_exit();

	ret = ioctl(kvm_fd, KVM_CHECK_EXTENSION, cap);

	TEST_ASSERT(ret != -1, "KVM_CHECK_EXTENSION IOCTL failed,\n"

		"  rc: %i errno: %i", ret, errno);
@@ -128,9 +153,7 @@ void vm_enable_dirty_ring(struct kvm_vm *vm, uint32_t ring_size) 


static void vm_open(struct kvm_vm *vm, int perm)

{

	vm->kvm_fd = open(KVM_DEV_PATH, perm);

	if (vm->kvm_fd < 0)

		exit(KSFT_SKIP);

	vm->kvm_fd = _open_kvm_dev_path_or_exit(perm);



	if (!kvm_check_cap(KVM_CAP_IMMEDIATE_EXIT)) {

		print_skip("immediate_exit not available");
@@ -996,9 +1019,7 @@ static int vcpu_mmap_sz(void) 
{

	int dev_fd, ret;



	dev_fd = open(KVM_DEV_PATH, O_RDONLY);

	if (dev_fd < 0)

		exit(KSFT_SKIP);

	dev_fd = open_kvm_dev_path_or_exit();



	ret = ioctl(dev_fd, KVM_GET_VCPU_MMAP_SIZE, NULL);

	TEST_ASSERT(ret >= sizeof(struct kvm_run),
@@ -2091,10 +2112,7 @@ bool vm_is_unrestricted_guest(struct kvm_vm *vm) 


	if (vm == NULL) {

		/* Ensure that the KVM vendor-specific module is loaded. */

		f = fopen(KVM_DEV_PATH, "r");

		TEST_ASSERT(f != NULL, "Error in opening KVM dev file: %d",

			    errno);

		fclose(f);

		close(open_kvm_dev_path_or_exit());

	}



	f = fopen("/sys/module/kvm_intel/parameters/unrestricted_guest", "r");

tools/testing/selftests/kvm/lib/x86_64/processor.c

+4 −12
Original line number Diff line number Diff line
@@ -657,9 +657,7 @@ struct kvm_cpuid2 *kvm_get_supported_cpuid(void) 
		return cpuid;



	cpuid = allocate_kvm_cpuid2();

	kvm_fd = open(KVM_DEV_PATH, O_RDONLY);

	if (kvm_fd < 0)

		exit(KSFT_SKIP);

	kvm_fd = open_kvm_dev_path_or_exit();



	ret = ioctl(kvm_fd, KVM_GET_SUPPORTED_CPUID, cpuid);

	TEST_ASSERT(ret == 0, "KVM_GET_SUPPORTED_CPUID failed %d %d\n",
@@ -691,9 +689,7 @@ uint64_t kvm_get_feature_msr(uint64_t msr_index) 


	buffer.header.nmsrs = 1;

	buffer.entry.index = msr_index;

	kvm_fd = open(KVM_DEV_PATH, O_RDONLY);

	if (kvm_fd < 0)

		exit(KSFT_SKIP);

	kvm_fd = open_kvm_dev_path_or_exit();



	r = ioctl(kvm_fd, KVM_GET_MSRS, &buffer.header);

	TEST_ASSERT(r == 1, "KVM_GET_MSRS IOCTL failed,\n"
@@ -986,9 +982,7 @@ struct kvm_msr_list *kvm_get_msr_index_list(void) 
	struct kvm_msr_list *list;

	int nmsrs, r, kvm_fd;



	kvm_fd = open(KVM_DEV_PATH, O_RDONLY);

	if (kvm_fd < 0)

		exit(KSFT_SKIP);

	kvm_fd = open_kvm_dev_path_or_exit();



	nmsrs = kvm_get_num_msrs_fd(kvm_fd);

	list = malloc(sizeof(*list) + nmsrs * sizeof(list->indices[0]));
@@ -1312,9 +1306,7 @@ struct kvm_cpuid2 *kvm_get_supported_hv_cpuid(void) 
		return cpuid;



	cpuid = allocate_kvm_cpuid2();

	kvm_fd = open(KVM_DEV_PATH, O_RDONLY);

	if (kvm_fd < 0)

		exit(KSFT_SKIP);

	kvm_fd = open_kvm_dev_path_or_exit();



	ret = ioctl(kvm_fd, KVM_GET_SUPPORTED_HV_CPUID, cpuid);

	TEST_ASSERT(ret == 0, "KVM_GET_SUPPORTED_HV_CPUID failed %d %d\n",

tools/testing/selftests/kvm/x86_64/get_msr_index_features.c

+2 −6
Original line number Diff line number Diff line
@@ -37,9 +37,7 @@ static void test_get_msr_index(void) 
	int old_res, res, kvm_fd, r;

	struct kvm_msr_list *list;



	kvm_fd = open(KVM_DEV_PATH, O_RDONLY);

	if (kvm_fd < 0)

		exit(KSFT_SKIP);

	kvm_fd = open_kvm_dev_path_or_exit();



	old_res = kvm_num_index_msrs(kvm_fd, 0);

	TEST_ASSERT(old_res != 0, "Expecting nmsrs to be > 0");
@@ -101,9 +99,7 @@ static void test_get_msr_feature(void) 
	int res, old_res, i, kvm_fd;

	struct kvm_msr_list *feature_list;



	kvm_fd = open(KVM_DEV_PATH, O_RDONLY);

	if (kvm_fd < 0)

		exit(KSFT_SKIP);

	kvm_fd = open_kvm_dev_path_or_exit();



	old_res = kvm_num_feature_msrs(kvm_fd, 0);

	TEST_ASSERT(old_res != 0, "Expecting nmsrs to be > 0");