1 files changed, 315 insertions, 0 deletions
diff --git a/tools/testing/selftests/kvm/dirty_log_test.c b/tools/testing/selftests/kvm/dirty_log_test.c
new file mode 100644
index 000000000000..d90f1091f687
--- /dev/null
+++ b/tools/testing/selftests/kvm/dirty_log_test.c
@@ -0,0 +1,315 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * KVM dirty page logging test
+ *
+ * Copyright (C) 2018, Red Hat, Inc.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <time.h>
+#include <pthread.h>
+#include <linux/bitmap.h>
+#include <linux/bitops.h>
+
+#include "test_util.h"
+#include "kvm_util.h"
+#include "processor.h"
+
+#define DEBUG printf
+
+#define VCPU_ID				1
+
+/* The memory slot index to track dirty pages */
+#define TEST_MEM_SLOT_INDEX		1
+
+/*
+ * GPA offset of the testing memory slot. Must be bigger than the
+ * default vm mem slot, which is DEFAULT_GUEST_PHY_PAGES.
+ */
+#define TEST_MEM_OFFSET			(1ul << 30) /* 1G */
+
+/* Size of the testing memory slot */
+#define TEST_MEM_PAGES			(1ul << 18) /* 1G for 4K pages */
+
+/* How many pages to dirty for each guest loop */
+#define TEST_PAGES_PER_LOOP		1024
+
+/* How many host loops to run (one KVM_GET_DIRTY_LOG for each loop) */
+#define TEST_HOST_LOOP_N		32
+
+/* Interval for each host loop (ms) */
+#define TEST_HOST_LOOP_INTERVAL		10
+
+/*
+ * Guest/Host shared variables. Ensure addr_gva2hva() and/or
+ * sync_global_to/from_guest() are used when accessing from
+ * the host. READ/WRITE_ONCE() should also be used with anything
+ * that may change.
+ */
+static uint64_t host_page_size;
+static uint64_t guest_page_size;
+static uint64_t random_array[TEST_PAGES_PER_LOOP];
+static uint64_t iteration;
+
+/*
+ * Continuously write to the first 8 bytes of a random pages within
+ * the testing memory region.
+ */
+static void guest_code(void)
+{
+	int i;
+
+	while (true) {
+		for (i = 0; i < TEST_PAGES_PER_LOOP; i++) {
+			uint64_t addr = TEST_MEM_OFFSET;
+			addr += (READ_ONCE(random_array[i]) % TEST_MEM_PAGES)
+				* guest_page_size;
+			addr &= ~(host_page_size - 1);
+			*(uint64_t *)addr = READ_ONCE(iteration);
+		}
+
+		/* Tell the host that we need more random numbers */
+		GUEST_SYNC(1);
+	}
+}
+
+/* Host variables */
+static bool host_quit;
+
+/* Points to the test VM memory region on which we track dirty logs */
+static void *host_test_mem;
+static uint64_t host_num_pages;
+
+/* For statistics only */
+static uint64_t host_dirty_count;
+static uint64_t host_clear_count;
+static uint64_t host_track_next_count;
+
+/*
+ * We use this bitmap to track some pages that should have its dirty
+ * bit set in the _next_ iteration.  For example, if we detected the
+ * page value changed to current iteration but at the same time the
+ * page bit is cleared in the latest bitmap, then the system must
+ * report that write in the next get dirty log call.
+ */
+static unsigned long *host_bmap_track;
+
+static void generate_random_array(uint64_t *guest_array, uint64_t size)
+{
+	uint64_t i;
+
+	for (i = 0; i < size; i++)
+		guest_array[i] = random();
+}
+
+static void *vcpu_worker(void *data)
+{
+	int ret;
+	struct kvm_vm *vm = data;
+	uint64_t *guest_array;
+	uint64_t pages_count = 0;
+	struct kvm_run *run;
+	struct ucall uc;
+
+	run = vcpu_state(vm, VCPU_ID);
+
+	guest_array = addr_gva2hva(vm, (vm_vaddr_t)random_array);
+	generate_random_array(guest_array, TEST_PAGES_PER_LOOP);
+
+	while (!READ_ONCE(host_quit)) {
+		/* Let the guest dirty the random pages */
+		ret = _vcpu_run(vm, VCPU_ID);
+		if (get_ucall(vm, VCPU_ID, &uc) == UCALL_SYNC) {
+			pages_count += TEST_PAGES_PER_LOOP;
+			generate_random_array(guest_array, TEST_PAGES_PER_LOOP);
+		} else {
+			TEST_ASSERT(false,
+				    "Invalid guest sync status: "
+				    "exit_reason=%s\n",
+				    exit_reason_str(run->exit_reason));
+		}
+	}
+
+	DEBUG("Dirtied %"PRIu64" pages\n", pages_count);
+
+	return NULL;
+}
+
+static void vm_dirty_log_verify(unsigned long *bmap)
+{
+	uint64_t page;
+	uint64_t *value_ptr;
+
+	for (page = 0; page < host_num_pages; page++) {
+		value_ptr = host_test_mem + page * host_page_size;
+
+		/* If this is a special page that we were tracking... */
+		if (test_and_clear_bit(page, host_bmap_track)) {
+			host_track_next_count++;
+			TEST_ASSERT(test_bit(page, bmap),
+				    "Page %"PRIu64" should have its dirty bit "
+				    "set in this iteration but it is missing",
+				    page);
+		}
+
+		if (test_bit(page, bmap)) {
+			host_dirty_count++;
+			/*
+			 * If the bit is set, the value written onto
+			 * the corresponding page should be either the
+			 * previous iteration number or the current one.
+			 */
+			TEST_ASSERT(*value_ptr == iteration ||
+				    *value_ptr == iteration - 1,
+				    "Set page %"PRIu64" value %"PRIu64
+				    " incorrect (iteration=%"PRIu64")",
+				    page, *value_ptr, iteration);
+		} else {
+			host_clear_count++;
+			/*
+			 * If cleared, the value written can be any
+			 * value smaller or equals to the iteration
+			 * number.  Note that the value can be exactly
+			 * (iteration-1) if that write can happen
+			 * like this:
+			 *
+			 * (1) increase loop count to "iteration-1"
+			 * (2) write to page P happens (with value
+			 *     "iteration-1")
+			 * (3) get dirty log for "iteration-1"; we'll
+			 *     see that page P bit is set (dirtied),
+			 *     and not set the bit in host_bmap_track
+			 * (4) increase loop count to "iteration"
+			 *     (which is current iteration)
+			 * (5) get dirty log for current iteration,
+			 *     we'll see that page P is cleared, with
+			 *     value "iteration-1".
+			 */
+			TEST_ASSERT(*value_ptr <= iteration,
+				    "Clear page %"PRIu64" value %"PRIu64
+				    " incorrect (iteration=%"PRIu64")",
+				    page, *value_ptr, iteration);
+			if (*value_ptr == iteration) {
+				/*
+				 * This page is _just_ modified; it
+				 * should report its dirtyness in the
+				 * next run
+				 */
+				set_bit(page, host_bmap_track);
+			}
+		}
+	}
+}
+
+static void help(char *name)
+{
+	puts("");
+	printf("usage: %s [-i iterations] [-I interval] [-h]\n", name);
+	puts("");
+	printf(" -i: specify iteration counts (default: %"PRIu64")\n",
+	       TEST_HOST_LOOP_N);
+	printf(" -I: specify interval in ms (default: %"PRIu64" ms)\n",
+	       TEST_HOST_LOOP_INTERVAL);
+	puts("");
+	exit(0);
+}
+
+int main(int argc, char *argv[])
+{
+	pthread_t vcpu_thread;
+	struct kvm_vm *vm;
+	unsigned long iterations = TEST_HOST_LOOP_N;
+	unsigned long interval = TEST_HOST_LOOP_INTERVAL;
+	unsigned long *bmap;
+	int opt;
+
+	while ((opt = getopt(argc, argv, "hi:I:")) != -1) {
+		switch (opt) {
+		case 'i':
+			iterations = strtol(optarg, NULL, 10);
+			break;
+		case 'I':
+			interval = strtol(optarg, NULL, 10);
+			break;
+		case 'h':
+		default:
+			help(argv[0]);
+			break;
+		}
+	}
+
+	TEST_ASSERT(iterations > 2, "Iterations must be greater than two");
+	TEST_ASSERT(interval > 0, "Interval must be greater than zero");
+
+	DEBUG("Test iterations: %"PRIu64", interval: %"PRIu64" (ms)\n",
+	      iterations, interval);
+
+	srandom(time(0));
+
+	guest_page_size = 4096;
+	host_page_size = getpagesize();
+	host_num_pages = (TEST_MEM_PAGES * guest_page_size) / host_page_size +
+			 !!((TEST_MEM_PAGES * guest_page_size) % host_page_size);
+
+	bmap = bitmap_alloc(host_num_pages);
+	host_bmap_track = bitmap_alloc(host_num_pages);
+
+	vm = vm_create_default(VCPU_ID, TEST_MEM_PAGES, guest_code);
+
+	/* Add an extra memory slot for testing dirty logging */
+	vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS,
+				    TEST_MEM_OFFSET,
+				    TEST_MEM_SLOT_INDEX,
+				    TEST_MEM_PAGES,
+				    KVM_MEM_LOG_DIRTY_PAGES);
+
+	/* Do 1:1 mapping for the dirty track memory slot */
+	virt_map(vm, TEST_MEM_OFFSET, TEST_MEM_OFFSET,
+		 TEST_MEM_PAGES * guest_page_size, 0);
+
+	/* Cache the HVA pointer of the region */
+	host_test_mem = addr_gpa2hva(vm, (vm_paddr_t)TEST_MEM_OFFSET);
+
+#ifdef __x86_64__
+	vcpu_set_cpuid(vm, VCPU_ID, kvm_get_supported_cpuid());
+#endif
+#ifdef __aarch64__
+	ucall_init(vm, UCALL_MMIO, NULL);
+#endif
+
+	/* Tell the guest about the page sizes */
+	sync_global_to_guest(vm, host_page_size);
+	sync_global_to_guest(vm, guest_page_size);
+
+	/* Start the iterations */
+	iteration = 1;
+	sync_global_to_guest(vm, iteration);
+
+	pthread_create(&vcpu_thread, NULL, vcpu_worker, vm);
+
+	while (iteration < iterations) {
+		/* Give the vcpu thread some time to dirty some pages */
+		usleep(interval * 1000);
+		kvm_vm_get_dirty_log(vm, TEST_MEM_SLOT_INDEX, bmap);
+		vm_dirty_log_verify(bmap);
+		iteration++;
+		sync_global_to_guest(vm, iteration);
+	}
+
+	/* Tell the vcpu thread to quit */
+	host_quit = true;
+	pthread_join(vcpu_thread, NULL);
+
+	DEBUG("Total bits checked: dirty (%"PRIu64"), clear (%"PRIu64"), "
+	      "track_next (%"PRIu64")\n", host_dirty_count, host_clear_count,
+	      host_track_next_count);
+
+	free(bmap);
+	free(host_bmap_track);
+	ucall_uninit(vm);
+	kvm_vm_free(vm);
+
+	return 0;
+}