KVM: selftests: Convert kvm_page_table_test away from reliance on vcpu_id

Reference vCPUs by their 'struct kvm_vcpu' object in kvm_page_table_test
instead of by their ID.  This moves selftests one step closer towards
taking a 'struct kvm_vcpu *' instead of VM+vcpu_id for vCPU helpers.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

tools/testing/selftests/kvm/kvm_page_table_test.c

@@ -46,11 +46,6 @@ static const char * const test_stage_string[] = {
 	"KVM_ADJUST_MAPPINGS",
 };
 
-struct vcpu_args {
-	int vcpu_id;
-	bool vcpu_write;
-};
-
 struct test_args {
 	struct kvm_vm *vm;
 	uint64_t guest_test_virt_mem;
@@ -60,7 +55,7 @@ struct test_args {
 	uint64_t large_num_pages;
 	uint64_t host_pages_per_lpage;
 	enum vm_mem_backing_src_type src_type;
-	struct vcpu_args vcpu_args[KVM_MAX_VCPUS];
+	struct kvm_vcpu *vcpus[KVM_MAX_VCPUS];
 };
 
 /*
@@ -92,17 +87,13 @@ static uint64_t guest_test_phys_mem;
  */
 static uint64_t guest_test_virt_mem = DEFAULT_GUEST_TEST_MEM;
 
-static void guest_code(int vcpu_id)
+static void guest_code(bool do_write)
 {
 	struct test_args *p = &test_args;
-	struct vcpu_args *vcpu_args = &p->vcpu_args[vcpu_id];
 	enum test_stage *current_stage = &guest_test_stage;
 	uint64_t addr;
 	int i, j;
 
-	/* Make sure vCPU args data structure is not corrupt */
-	GUEST_ASSERT(vcpu_args->vcpu_id == vcpu_id);
-
 	while (true) {
 		addr = p->guest_test_virt_mem;
 
@@ -123,7 +114,7 @@ static void guest_code(int vcpu_id)
 		 */
 		case KVM_CREATE_MAPPINGS:
 			for (i = 0; i < p->large_num_pages; i++) {
-				if (vcpu_args->vcpu_write)
+				if (do_write)
 					*(uint64_t *)addr = 0x0123456789ABCDEF;
 				else
 					READ_ONCE(*(uint64_t *)addr);
@@ -193,17 +184,15 @@ static void guest_code(int vcpu_id)
 
 static void *vcpu_worker(void *data)
 {
-	int ret;
-	struct vcpu_args *vcpu_args = data;
 	struct kvm_vm *vm = test_args.vm;
-	int vcpu_id = vcpu_args->vcpu_id;
-	struct kvm_run *run;
+	struct kvm_vcpu *vcpu = data;
+	bool do_write = !(vcpu->id % 2);
 	struct timespec start;
 	struct timespec ts_diff;
 	enum test_stage stage;
+	int ret;
 
-	vcpu_args_set(vm, vcpu_id, 1, vcpu_id);
-	run = vcpu_state(vm, vcpu_id);
+	vcpu_args_set(vm, vcpu->id, 1, do_write);
 
 	while (!READ_ONCE(host_quit)) {
 		ret = sem_wait(&test_stage_updated);
@@ -213,15 +202,15 @@ static void *vcpu_worker(void *data)
 			return NULL;
 
 		clock_gettime(CLOCK_MONOTONIC_RAW, &start);
-		ret = _vcpu_run(vm, vcpu_id);
+		ret = _vcpu_run(vm, vcpu->id);
 		ts_diff = timespec_elapsed(start);
 
 		TEST_ASSERT(ret == 0, "vcpu_run failed: %d\n", ret);
-		TEST_ASSERT(get_ucall(vm, vcpu_id, NULL) == UCALL_SYNC,
+		TEST_ASSERT(get_ucall(vm, vcpu->id, NULL) == UCALL_SYNC,
 			    "Invalid guest sync status: exit_reason=%s\n",
-			    exit_reason_str(run->exit_reason));
+			    exit_reason_str(vcpu->run->exit_reason));
 
-		pr_debug("Got sync event from vCPU %d\n", vcpu_id);
+		pr_debug("Got sync event from vCPU %d\n", vcpu->id);
 		stage = READ_ONCE(*current_stage);
 
 		/*
@@ -230,7 +219,7 @@ static void *vcpu_worker(void *data)
 		 */
 		pr_debug("vCPU %d has completed stage %s\n"
 			 "execution time is: %ld.%.9lds\n\n",
-			 vcpu_id, test_stage_string[stage],
+			 vcpu->id, test_stage_string[stage],
 			 ts_diff.tv_sec, ts_diff.tv_nsec);
 
 		ret = sem_post(&test_stage_completed);
@@ -250,7 +239,6 @@ static struct kvm_vm *pre_init_before_test(enum vm_guest_mode mode, void *arg)
 {
 	int ret;
 	struct test_params *p = arg;
-	struct vcpu_args *vcpu_args;
 	enum vm_mem_backing_src_type src_type = p->src_type;
 	uint64_t large_page_size = get_backing_src_pagesz(src_type);
 	uint64_t guest_page_size = vm_guest_mode_params[mode].page_size;
@@ -260,7 +248,6 @@ static struct kvm_vm *pre_init_before_test(enum vm_guest_mode mode, void *arg)
 	uint64_t alignment;
 	void *host_test_mem;
 	struct kvm_vm *vm;
-	int vcpu_id;
 
 	/* Align up the test memory size */
 	alignment = max(large_page_size, guest_page_size);
@@ -269,7 +256,8 @@ static struct kvm_vm *pre_init_before_test(enum vm_guest_mode mode, void *arg)
 	/* Create a VM with enough guest pages */
 	guest_num_pages = test_mem_size / guest_page_size;
 	vm = __vm_create_with_vcpus(mode, nr_vcpus, DEFAULT_GUEST_PHY_PAGES,
-				    guest_num_pages, 0, guest_code, NULL);
+				    guest_num_pages, 0, guest_code,
+				    test_args.vcpus);
 
 	/* Align down GPA of the testing memslot */
 	if (!p->phys_offset)
@@ -292,12 +280,6 @@ static struct kvm_vm *pre_init_before_test(enum vm_guest_mode mode, void *arg)
 	test_args.host_pages_per_lpage = large_page_size / host_page_size;
 	test_args.src_type = src_type;
 
-	for (vcpu_id = 0; vcpu_id < KVM_MAX_VCPUS; vcpu_id++) {
-		vcpu_args = &test_args.vcpu_args[vcpu_id];
-		vcpu_args->vcpu_id = vcpu_id;
-		vcpu_args->vcpu_write = !(vcpu_id % 2);
-	}
-
 	/* Add an extra memory slot with specified backing src type */
 	vm_userspace_mem_region_add(vm, src_type, guest_test_phys_mem,
 				    TEST_MEM_SLOT_INDEX, guest_num_pages, 0);
@@ -363,12 +345,11 @@ static void vcpus_complete_new_stage(enum test_stage stage)
 
 static void run_test(enum vm_guest_mode mode, void *arg)
 {
-	int ret;
 	pthread_t *vcpu_threads;
 	struct kvm_vm *vm;
-	int vcpu_id;
 	struct timespec start;
 	struct timespec ts_diff;
+	int ret, i;
 
 	/* Create VM with vCPUs and make some pre-initialization */
 	vm = pre_init_before_test(mode, arg);
@@ -379,10 +360,9 @@ static void run_test(enum vm_guest_mode mode, void *arg)
 	host_quit = false;
 	*current_stage = KVM_BEFORE_MAPPINGS;
 
-	for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++) {
-		pthread_create(&vcpu_threads[vcpu_id], NULL, vcpu_worker,
-			       &test_args.vcpu_args[vcpu_id]);
-	}
+	for (i = 0; i < nr_vcpus; i++)
+		pthread_create(&vcpu_threads[i], NULL, vcpu_worker,
+			       test_args.vcpus[i]);
 
 	vcpus_complete_new_stage(*current_stage);
 	pr_info("Started all vCPUs successfully\n");
@@ -424,13 +404,13 @@ static void run_test(enum vm_guest_mode mode, void *arg)
 
 	/* Tell the vcpu thread to quit */
 	host_quit = true;
-	for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++) {
+	for (i = 0; i < nr_vcpus; i++) {
 		ret = sem_post(&test_stage_updated);
 		TEST_ASSERT(ret == 0, "Error in sem_post");
 	}
 
-	for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++)
-		pthread_join(vcpu_threads[vcpu_id], NULL);
+	for (i = 0; i < nr_vcpus; i++)
+		pthread_join(vcpu_threads[i], NULL);
 
 	ret = sem_destroy(&test_stage_updated);
 	TEST_ASSERT(ret == 0, "Error in sem_destroy");