KVM: selftests: Convert dirty_log_test away from VCPU_ID

Convert dirty_log_test to pass around a 'struct kvm_vcpu' object instead
of using a global VCPU_ID.  Note, this is a "functional" change in the
sense that the test now creates a vCPU with vcpu_id==0 instead of
vcpu_id==5.  The non-zero VCPU_ID was 100% arbitrary and added little to
no validation coverage.  If testing non-zero vCPU IDs is desirable for
generic tests, that can be done in the future by tweaking the VM creation
helpers.

The test still hardcodes usage of vcpu_id==0, but only for a few lines.
That wart will be removed in the not-too-distant future.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

tools/testing/selftests/kvm/dirty_log_test.c

@@ -23,8 +23,6 @@
 #include "guest_modes.h"
 #include "processor.h"
 
-#define VCPU_ID				1
-
 /* The memory slot index to track dirty pages */
 #define TEST_MEM_SLOT_INDEX		1
 
@@ -226,17 +224,17 @@ static void clear_log_create_vm_done(struct kvm_vm *vm)
 	vm_enable_cap(vm, KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2, manual_caps);
 }
 
-static void dirty_log_collect_dirty_pages(struct kvm_vm *vm, int slot,
+static void dirty_log_collect_dirty_pages(struct kvm_vcpu *vcpu, int slot,
 					  void *bitmap, uint32_t num_pages)
 {
-	kvm_vm_get_dirty_log(vm, slot, bitmap);
+	kvm_vm_get_dirty_log(vcpu->vm, slot, bitmap);
 }
 
-static void clear_log_collect_dirty_pages(struct kvm_vm *vm, int slot,
+static void clear_log_collect_dirty_pages(struct kvm_vcpu *vcpu, int slot,
 					  void *bitmap, uint32_t num_pages)
 {
-	kvm_vm_get_dirty_log(vm, slot, bitmap);
-	kvm_vm_clear_dirty_log(vm, slot, bitmap, 0, num_pages);
+	kvm_vm_get_dirty_log(vcpu->vm, slot, bitmap);
+	kvm_vm_clear_dirty_log(vcpu->vm, slot, bitmap, 0, num_pages);
 }
 
 /* Should only be called after a GUEST_SYNC */
@@ -250,14 +248,14 @@ static void vcpu_handle_sync_stop(void)
 	}
 }
 
-static void default_after_vcpu_run(struct kvm_vm *vm, int ret, int err)
+static void default_after_vcpu_run(struct kvm_vcpu *vcpu, int ret, int err)
 {
-	struct kvm_run *run = vcpu_state(vm, VCPU_ID);
+	struct kvm_run *run = vcpu->run;
 
 	TEST_ASSERT(ret == 0 || (ret == -1 && err == EINTR),
 		    "vcpu run failed: errno=%d", err);
 
-	TEST_ASSERT(get_ucall(vm, VCPU_ID, NULL) == UCALL_SYNC,
+	TEST_ASSERT(get_ucall(vcpu->vm, vcpu->id, NULL) == UCALL_SYNC,
 		    "Invalid guest sync status: exit_reason=%s\n",
 		    exit_reason_str(run->exit_reason));
 
@@ -328,7 +326,7 @@ static void dirty_ring_continue_vcpu(void)
 	sem_post(&sem_vcpu_cont);
 }
 
-static void dirty_ring_collect_dirty_pages(struct kvm_vm *vm, int slot,
+static void dirty_ring_collect_dirty_pages(struct kvm_vcpu *vcpu, int slot,
 					   void *bitmap, uint32_t num_pages)
 {
 	/* We only have one vcpu */
@@ -348,10 +346,10 @@ static void dirty_ring_collect_dirty_pages(struct kvm_vm *vm, int slot,
 	}
 
 	/* Only have one vcpu */
-	count = dirty_ring_collect_one(vcpu_map_dirty_ring(vm, VCPU_ID),
+	count = dirty_ring_collect_one(vcpu_map_dirty_ring(vcpu->vm, vcpu->id),
 				       slot, bitmap, num_pages, &fetch_index);
 
-	cleared = kvm_vm_reset_dirty_ring(vm);
+	cleared = kvm_vm_reset_dirty_ring(vcpu->vm);
 
 	/* Cleared pages should be the same as collected */
 	TEST_ASSERT(cleared == count, "Reset dirty pages (%u) mismatch "
@@ -366,12 +364,12 @@ static void dirty_ring_collect_dirty_pages(struct kvm_vm *vm, int slot,
 	pr_info("Iteration %ld collected %u pages\n", iteration, count);
 }
 
-static void dirty_ring_after_vcpu_run(struct kvm_vm *vm, int ret, int err)
+static void dirty_ring_after_vcpu_run(struct kvm_vcpu *vcpu, int ret, int err)
 {
-	struct kvm_run *run = vcpu_state(vm, VCPU_ID);
+	struct kvm_run *run = vcpu->run;
 
 	/* A ucall-sync or ring-full event is allowed */
-	if (get_ucall(vm, VCPU_ID, NULL) == UCALL_SYNC) {
+	if (get_ucall(vcpu->vm, vcpu->id, NULL) == UCALL_SYNC) {
 		/* We should allow this to continue */
 		;
 	} else if (run->exit_reason == KVM_EXIT_DIRTY_RING_FULL ||
@@ -405,10 +403,10 @@ struct log_mode {
 	/* Hook when the vm creation is done (before vcpu creation) */
 	void (*create_vm_done)(struct kvm_vm *vm);
 	/* Hook to collect the dirty pages into the bitmap provided */
-	void (*collect_dirty_pages) (struct kvm_vm *vm, int slot,
+	void (*collect_dirty_pages) (struct kvm_vcpu *vcpu, int slot,
 				     void *bitmap, uint32_t num_pages);
 	/* Hook to call when after each vcpu run */
-	void (*after_vcpu_run)(struct kvm_vm *vm, int ret, int err);
+	void (*after_vcpu_run)(struct kvm_vcpu *vcpu, int ret, int err);
 	void (*before_vcpu_join) (void);
 } log_modes[LOG_MODE_NUM] = {
 	{
@@ -470,22 +468,22 @@ static void log_mode_create_vm_done(struct kvm_vm *vm)
 		mode->create_vm_done(vm);
 }
 
-static void log_mode_collect_dirty_pages(struct kvm_vm *vm, int slot,
+static void log_mode_collect_dirty_pages(struct kvm_vcpu *vcpu, int slot,
 					 void *bitmap, uint32_t num_pages)
 {
 	struct log_mode *mode = &log_modes[host_log_mode];
 
 	TEST_ASSERT(mode->collect_dirty_pages != NULL,
 		    "collect_dirty_pages() is required for any log mode!");
-	mode->collect_dirty_pages(vm, slot, bitmap, num_pages);
+	mode->collect_dirty_pages(vcpu, slot, bitmap, num_pages);
 }
 
-static void log_mode_after_vcpu_run(struct kvm_vm *vm, int ret, int err)
+static void log_mode_after_vcpu_run(struct kvm_vcpu *vcpu, int ret, int err)
 {
 	struct log_mode *mode = &log_modes[host_log_mode];
 
 	if (mode->after_vcpu_run)
-		mode->after_vcpu_run(vm, ret, err);
+		mode->after_vcpu_run(vcpu, ret, err);
 }
 
 static void log_mode_before_vcpu_join(void)
@@ -507,7 +505,8 @@ static void generate_random_array(uint64_t *guest_array, uint64_t size)
 static void *vcpu_worker(void *data)
 {
 	int ret;
-	struct kvm_vm *vm = data;
+	struct kvm_vcpu *vcpu = data;
+	struct kvm_vm *vm = vcpu->vm;
 	uint64_t *guest_array;
 	uint64_t pages_count = 0;
 	struct kvm_signal_mask *sigmask = alloca(offsetof(struct kvm_signal_mask, sigset)
@@ -522,7 +521,7 @@ static void *vcpu_worker(void *data)
 	sigmask->len = 8;
 	pthread_sigmask(0, NULL, sigset);
 	sigdelset(sigset, SIG_IPI);
-	vcpu_ioctl(vm, VCPU_ID, KVM_SET_SIGNAL_MASK, sigmask);
+	vcpu_ioctl(vm, vcpu->id, KVM_SET_SIGNAL_MASK, sigmask);
 
 	sigemptyset(sigset);
 	sigaddset(sigset, SIG_IPI);
@@ -534,13 +533,13 @@ static void *vcpu_worker(void *data)
 		generate_random_array(guest_array, TEST_PAGES_PER_LOOP);
 		pages_count += TEST_PAGES_PER_LOOP;
 		/* Let the guest dirty the random pages */
-		ret = __vcpu_run(vm, VCPU_ID);
+		ret = __vcpu_run(vm, vcpu->id);
 		if (ret == -1 && errno == EINTR) {
 			int sig = -1;
 			sigwait(sigset, &sig);
 			assert(sig == SIG_IPI);
 		}
-		log_mode_after_vcpu_run(vm, ret, errno);
+		log_mode_after_vcpu_run(vcpu, ret, errno);
 	}
 
 	pr_info("Dirtied %"PRIu64" pages\n", pages_count);
@@ -693,6 +692,7 @@ struct test_params {
 static void run_test(enum vm_guest_mode mode, void *arg)
 {
 	struct test_params *p = arg;
+	struct kvm_vcpu *vcpu;
 	struct kvm_vm *vm;
 	unsigned long *bmap;
 
@@ -710,9 +710,10 @@ static void run_test(enum vm_guest_mode mode, void *arg)
 	 * (e.g., 64K page size guest will need even less memory for
 	 * page tables).
 	 */
-	vm = create_vm(mode, VCPU_ID,
+	vm = create_vm(mode, 0,
 		       2ul << (DIRTY_MEM_BITS - PAGE_SHIFT_4K),
 		       guest_code);
+	vcpu = vcpu_get(vm, 0);
 
 	guest_page_size = vm_get_page_size(vm);
 	/*
@@ -773,12 +774,12 @@ static void run_test(enum vm_guest_mode mode, void *arg)
 	host_clear_count = 0;
 	host_track_next_count = 0;
 
-	pthread_create(&vcpu_thread, NULL, vcpu_worker, vm);
+	pthread_create(&vcpu_thread, NULL, vcpu_worker, vcpu);
 
 	while (iteration < p->iterations) {
 		/* Give the vcpu thread some time to dirty some pages */
 		usleep(p->interval * 1000);
-		log_mode_collect_dirty_pages(vm, TEST_MEM_SLOT_INDEX,
+		log_mode_collect_dirty_pages(vcpu, TEST_MEM_SLOT_INDEX,
 					     bmap, host_num_pages);
 
 		/*