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-rw-r--r--tools/testing/selftests/kvm/dirty_log_test.c308
1 files changed, 308 insertions, 0 deletions
diff --git a/tools/testing/selftests/kvm/dirty_log_test.c b/tools/testing/selftests/kvm/dirty_log_test.c
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+++ b/tools/testing/selftests/kvm/dirty_log_test.c
@@ -0,0 +1,308 @@
+// 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"
+
+#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 (1ULL << 30) /* 1G */
+/* Size of the testing memory slot */
+#define TEST_MEM_PAGES (1ULL << 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 variables. We use these variables to share data between host
+ * and guest. There are two copies of the variables, one in host memory
+ * (which is unused) and one in guest memory. When the host wants to
+ * access these variables, it needs to call addr_gva2hva() to access the
+ * guest copy.
+ */
+uint64_t guest_random_array[TEST_PAGES_PER_LOOP];
+uint64_t guest_iteration;
+uint64_t guest_page_size;
+
+/*
+ * Writes to the first byte of a random page within the testing memory
+ * region continuously.
+ */
+void guest_code(void)
+{
+ int i = 0;
+ uint64_t volatile *array = guest_random_array;
+ uint64_t volatile *guest_addr;
+
+ while (true) {
+ for (i = 0; i < TEST_PAGES_PER_LOOP; i++) {
+ /*
+ * Write to the first 8 bytes of a random page
+ * on the testing memory region.
+ */
+ guest_addr = (uint64_t *)
+ (TEST_MEM_OFFSET +
+ (array[i] % TEST_MEM_PAGES) * guest_page_size);
+ *guest_addr = guest_iteration;
+ }
+ /* Tell the host that we need more random numbers */
+ GUEST_SYNC(1);
+ }
+}
+
+/*
+ * Host variables. These variables should only be used by the host
+ * rather than the guest.
+ */
+bool host_quit;
+
+/* Points to the test VM memory region on which we track dirty logs */
+void *host_test_mem;
+
+/* For statistics only */
+uint64_t host_dirty_count;
+uint64_t host_clear_count;
+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.
+ */
+unsigned long *host_bmap_track;
+
+void generate_random_array(uint64_t *guest_array, uint64_t size)
+{
+ uint64_t i;
+
+ for (i = 0; i < size; i++) {
+ guest_array[i] = random();
+ }
+}
+
+void *vcpu_worker(void *data)
+{
+ int ret;
+ uint64_t loops, *guest_array, pages_count = 0;
+ struct kvm_vm *vm = data;
+ struct kvm_run *run;
+ struct guest_args args;
+
+ run = vcpu_state(vm, VCPU_ID);
+
+ /* Retrieve the guest random array pointer and cache it */
+ guest_array = addr_gva2hva(vm, (vm_vaddr_t)guest_random_array);
+
+ DEBUG("VCPU starts\n");
+
+ generate_random_array(guest_array, TEST_PAGES_PER_LOOP);
+
+ while (!READ_ONCE(host_quit)) {
+ /* Let the guest to dirty these random pages */
+ ret = _vcpu_run(vm, VCPU_ID);
+ guest_args_read(vm, VCPU_ID, &args);
+ if (run->exit_reason == KVM_EXIT_IO &&
+ args.port == GUEST_PORT_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("VCPU exits, dirtied %"PRIu64" pages\n", pages_count);
+
+ return NULL;
+}
+
+void vm_dirty_log_verify(unsigned long *bmap, uint64_t iteration)
+{
+ uint64_t page;
+ uint64_t volatile *value_ptr;
+
+ for (page = 0; page < TEST_MEM_PAGES; page++) {
+ value_ptr = host_test_mem + page * getpagesize();
+
+ /* 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);
+ }
+ }
+ }
+}
+
+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;
+ uint64_t volatile *psize, *iteration;
+ unsigned long *bmap, iterations = TEST_HOST_LOOP_N,
+ interval = TEST_HOST_LOOP_INTERVAL;
+ 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, "Iteration must be bigger than zero\n");
+ TEST_ASSERT(interval > 0, "Interval must be bigger than zero");
+
+ DEBUG("Test iterations: %"PRIu64", interval: %"PRIu64" (ms)\n",
+ iterations, interval);
+
+ srandom(time(0));
+
+ bmap = bitmap_alloc(TEST_MEM_PAGES);
+ host_bmap_track = bitmap_alloc(TEST_MEM_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);
+ /* Cache the HVA pointer of the region */
+ host_test_mem = addr_gpa2hva(vm, (vm_paddr_t)TEST_MEM_OFFSET);
+
+ /* Do 1:1 mapping for the dirty track memory slot */
+ virt_map(vm, TEST_MEM_OFFSET, TEST_MEM_OFFSET,
+ TEST_MEM_PAGES * getpagesize(), 0);
+
+ vcpu_set_cpuid(vm, VCPU_ID, kvm_get_supported_cpuid());
+
+ /* Tell the guest about the page size on the system */
+ psize = addr_gva2hva(vm, (vm_vaddr_t)&guest_page_size);
+ *psize = getpagesize();
+
+ /* Start the iterations */
+ iteration = addr_gva2hva(vm, (vm_vaddr_t)&guest_iteration);
+ *iteration = 1;
+
+ /* Start dirtying pages */
+ 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);
+ (*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);
+ kvm_vm_free(vm);
+
+ return 0;
+}