1 files changed, 51 insertions, 30 deletions

diff --git a/tools/testing/selftests/kvm/dirty_log_perf_test.c b/tools/testing/selftests/kvm/dirty_log_perf_test.c
index d60a34cdfaee..f99e39a672d3 100644
--- a/tools/testing/selftests/kvm/dirty_log_perf_test.c
+++ b/tools/testing/selftests/kvm/dirty_log_perf_test.c
@@ -59,6 +59,7 @@ static void arch_cleanup_vm(struct kvm_vm *vm)
 
 static int nr_vcpus = 1;
 static uint64_t guest_percpu_mem_size = DEFAULT_PER_VCPU_MEM_SIZE;
+static bool run_vcpus_while_disabling_dirty_logging;
 
 /* Host variables */
 static u64 dirty_log_manual_caps;
@@ -68,54 +69,59 @@ static int vcpu_last_completed_iteration[KVM_MAX_VCPUS];
 
 static void vcpu_worker(struct perf_test_vcpu_args *vcpu_args)
 {
-	int ret;
-	struct kvm_vm *vm = perf_test_args.vm;
+	struct kvm_vcpu *vcpu = vcpu_args->vcpu;
+	int vcpu_idx = vcpu_args->vcpu_idx;
 	uint64_t pages_count = 0;
 	struct kvm_run *run;
 	struct timespec start;
 	struct timespec ts_diff;
 	struct timespec total = (struct timespec){0};
 	struct timespec avg;
-	int vcpu_id = vcpu_args->vcpu_id;
+	int ret;
 
-	run = vcpu_state(vm, vcpu_id);
+	run = vcpu->run;
 
 	while (!READ_ONCE(host_quit)) {
 		int current_iteration = READ_ONCE(iteration);
 
 		clock_gettime(CLOCK_MONOTONIC, &start);
-		ret = _vcpu_run(vm, vcpu_id);
+		ret = _vcpu_run(vcpu);
 		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(vcpu, NULL) == UCALL_SYNC,
 			    "Invalid guest sync status: exit_reason=%s\n",
 			    exit_reason_str(run->exit_reason));
 
-		pr_debug("Got sync event from vCPU %d\n", vcpu_id);
-		vcpu_last_completed_iteration[vcpu_id] = current_iteration;
+		pr_debug("Got sync event from vCPU %d\n", vcpu_idx);
+		vcpu_last_completed_iteration[vcpu_idx] = current_iteration;
 		pr_debug("vCPU %d updated last completed iteration to %d\n",
-			 vcpu_id, vcpu_last_completed_iteration[vcpu_id]);
+			 vcpu_idx, vcpu_last_completed_iteration[vcpu_idx]);
 
 		if (current_iteration) {
 			pages_count += vcpu_args->pages;
 			total = timespec_add(total, ts_diff);
 			pr_debug("vCPU %d iteration %d dirty memory time: %ld.%.9lds\n",
-				vcpu_id, current_iteration, ts_diff.tv_sec,
+				vcpu_idx, current_iteration, ts_diff.tv_sec,
 				ts_diff.tv_nsec);
 		} else {
 			pr_debug("vCPU %d iteration %d populate memory time: %ld.%.9lds\n",
-				vcpu_id, current_iteration, ts_diff.tv_sec,
+				vcpu_idx, current_iteration, ts_diff.tv_sec,
 				ts_diff.tv_nsec);
 		}
 
+		/*
+		 * Keep running the guest while dirty logging is being disabled
+		 * (iteration is negative) so that vCPUs are accessing memory
+		 * for the entire duration of zapping collapsible SPTEs.
+		 */
 		while (current_iteration == READ_ONCE(iteration) &&
-		       !READ_ONCE(host_quit)) {}
+		       READ_ONCE(iteration) >= 0 && !READ_ONCE(host_quit)) {}
 	}
 
-	avg = timespec_div(total, vcpu_last_completed_iteration[vcpu_id]);
+	avg = timespec_div(total, vcpu_last_completed_iteration[vcpu_idx]);
 	pr_debug("\nvCPU %d dirtied 0x%lx pages over %d iterations in %ld.%.9lds. (Avg %ld.%.9lds/iteration)\n",
-		vcpu_id, pages_count, vcpu_last_completed_iteration[vcpu_id],
+		vcpu_idx, pages_count, vcpu_last_completed_iteration[vcpu_idx],
 		total.tv_sec, total.tv_nsec, avg.tv_sec, avg.tv_nsec);
 }
 
@@ -207,14 +213,13 @@ static void run_test(enum vm_guest_mode mode, void *arg)
 	uint64_t guest_num_pages;
 	uint64_t host_num_pages;
 	uint64_t pages_per_slot;
-	int vcpu_id;
 	struct timespec start;
 	struct timespec ts_diff;
 	struct timespec get_dirty_log_total = (struct timespec){0};
 	struct timespec vcpu_dirty_total = (struct timespec){0};
 	struct timespec avg;
-	struct kvm_enable_cap cap = {};
 	struct timespec clear_dirty_log_total = (struct timespec){0};
+	int i;
 
 	vm = perf_test_create_vm(mode, nr_vcpus, guest_percpu_mem_size,
 				 p->slots, p->backing_src,
@@ -222,18 +227,16 @@ static void run_test(enum vm_guest_mode mode, void *arg)
 
 	perf_test_set_wr_fract(vm, p->wr_fract);
 
-	guest_num_pages = (nr_vcpus * guest_percpu_mem_size) >> vm_get_page_shift(vm);
+	guest_num_pages = (nr_vcpus * guest_percpu_mem_size) >> vm->page_shift;
 	guest_num_pages = vm_adjust_num_guest_pages(mode, guest_num_pages);
 	host_num_pages = vm_num_host_pages(mode, guest_num_pages);
 	pages_per_slot = host_num_pages / p->slots;
 
 	bitmaps = alloc_bitmaps(p->slots, pages_per_slot);
 
-	if (dirty_log_manual_caps) {
-		cap.cap = KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2;
-		cap.args[0] = dirty_log_manual_caps;
-		vm_enable_cap(vm, &cap);
-	}
+	if (dirty_log_manual_caps)
+		vm_enable_cap(vm, KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2,
+			      dirty_log_manual_caps);
 
 	arch_setup_vm(vm, nr_vcpus);
 
@@ -242,15 +245,15 @@ static void run_test(enum vm_guest_mode mode, void *arg)
 	host_quit = false;
 
 	clock_gettime(CLOCK_MONOTONIC, &start);
-	for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++)
-		vcpu_last_completed_iteration[vcpu_id] = -1;
+	for (i = 0; i < nr_vcpus; i++)
+		vcpu_last_completed_iteration[i] = -1;
 
 	perf_test_start_vcpu_threads(nr_vcpus, vcpu_worker);
 
 	/* Allow the vCPUs to populate memory */
 	pr_debug("Starting iteration %d - Populating\n", iteration);
-	for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++) {
-		while (READ_ONCE(vcpu_last_completed_iteration[vcpu_id]) !=
+	for (i = 0; i < nr_vcpus; i++) {
+		while (READ_ONCE(vcpu_last_completed_iteration[i]) !=
 		       iteration)
 			;
 	}
@@ -275,8 +278,8 @@ static void run_test(enum vm_guest_mode mode, void *arg)
 		iteration++;
 
 		pr_debug("Starting iteration %d\n", iteration);
-		for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++) {
-			while (READ_ONCE(vcpu_last_completed_iteration[vcpu_id])
+		for (i = 0; i < nr_vcpus; i++) {
+			while (READ_ONCE(vcpu_last_completed_iteration[i])
 			       != iteration)
 				;
 		}
@@ -305,6 +308,14 @@ static void run_test(enum vm_guest_mode mode, void *arg)
 		}
 	}
 
+	/*
+	 * Run vCPUs while dirty logging is being disabled to stress disabling
+	 * in terms of both performance and correctness.  Opt-in via command
+	 * line as this significantly increases time to disable dirty logging.
+	 */
+	if (run_vcpus_while_disabling_dirty_logging)
+		WRITE_ONCE(iteration, -1);
+
 	/* Disable dirty logging */
 	clock_gettime(CLOCK_MONOTONIC, &start);
 	disable_dirty_logging(vm, p->slots);
@@ -312,7 +323,11 @@ static void run_test(enum vm_guest_mode mode, void *arg)
 	pr_info("Disabling dirty logging time: %ld.%.9lds\n",
 		ts_diff.tv_sec, ts_diff.tv_nsec);
 
-	/* Tell the vcpu thread to quit */
+	/*
+	 * Tell the vCPU threads to quit.  No need to manually check that vCPUs
+	 * have stopped running after disabling dirty logging, the join will
+	 * wait for them to exit.
+	 */
 	host_quit = true;
 	perf_test_join_vcpu_threads(nr_vcpus);
 
@@ -352,6 +367,9 @@ static void help(char *name)
 	       "     Warning: a low offset can conflict with the loaded test code.\n");
 	guest_modes_help();
 	printf(" -n: Run the vCPUs in nested mode (L2)\n");
+	printf(" -e: Run vCPUs while dirty logging is being disabled.  This\n"
+	       "     can significantly increase runtime, especially if there\n"
+	       "     isn't a dedicated pCPU for the main thread.\n");
 	printf(" -b: specify the size of the memory region which should be\n"
 	       "     dirtied by each vCPU. e.g. 10M or 3G.\n"
 	       "     (default: 1G)\n");
@@ -388,8 +406,11 @@ int main(int argc, char *argv[])
 
 	guest_modes_append_default();
 
-	while ((opt = getopt(argc, argv, "ghi:p:m:nb:f:v:os:x:")) != -1) {
+	while ((opt = getopt(argc, argv, "eghi:p:m:nb:f:v:os:x:")) != -1) {
 		switch (opt) {
+		case 'e':
+			/* 'e' is for evil. */
+			run_vcpus_while_disabling_dirty_logging = true;
 		case 'g':
 			dirty_log_manual_caps = 0;
 			break;