4 files changed, 356 insertions, 0 deletions

diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
index c367bd06a5b3..03b0f551bedf 100644
--- a/tools/testing/selftests/kvm/Makefile
+++ b/tools/testing/selftests/kvm/Makefile
@@ -11,6 +11,7 @@ TEST_GEN_PROGS_x86_64 += sync_regs_test
 TEST_GEN_PROGS_x86_64 += vmx_tsc_adjust_test
 TEST_GEN_PROGS_x86_64 += cr4_cpuid_sync_test
 TEST_GEN_PROGS_x86_64 += state_test
+TEST_GEN_PROGS_x86_64 += dirty_log_test
 
 TEST_GEN_PROGS += $(TEST_GEN_PROGS_$(UNAME_M))
 LIBKVM += $(LIBKVM_$(UNAME_M))
@@ -19,6 +20,7 @@ INSTALL_HDR_PATH = $(top_srcdir)/usr
 LINUX_HDR_PATH = $(INSTALL_HDR_PATH)/include/
 LINUX_TOOL_INCLUDE = $(top_srcdir)tools/include
 CFLAGS += -O2 -g -std=gnu99 -I$(LINUX_TOOL_INCLUDE) -I$(LINUX_HDR_PATH) -Iinclude -I$(<D) -I..
+LDFLAGS += -lpthread
 
 # After inclusion, $(OUTPUT) is defined and
 # $(TEST_GEN_PROGS) starts with $(OUTPUT)/
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..0c2cdc105f96
--- /dev/null
+++ 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;
+}
diff --git a/tools/testing/selftests/kvm/include/kvm_util.h b/tools/testing/selftests/kvm/include/kvm_util.h
index bd06d63a8fdf..bb5a25fb82c6 100644
--- a/tools/testing/selftests/kvm/include/kvm_util.h
+++ b/tools/testing/selftests/kvm/include/kvm_util.h
@@ -55,6 +55,7 @@ struct kvm_vm *vm_create(enum vm_guest_mode mode, uint64_t phy_pages, int perm);
 void kvm_vm_free(struct kvm_vm *vmp);
 void kvm_vm_restart(struct kvm_vm *vmp, int perm);
 void kvm_vm_release(struct kvm_vm *vmp);
+void kvm_vm_get_dirty_log(struct kvm_vm *vm, int slot, void *log);
 
 int kvm_memcmp_hva_gva(void *hva,
         struct kvm_vm *vm, const vm_vaddr_t gva, size_t len);
@@ -80,6 +81,8 @@ void vm_mem_region_set_flags(struct kvm_vm *vm, uint32_t slot, uint32_t flags);
 void vm_vcpu_add(struct kvm_vm *vm, uint32_t vcpuid, int pgd_memslot, int gdt_memslot);
 vm_vaddr_t vm_vaddr_alloc(struct kvm_vm *vm, size_t sz, vm_vaddr_t vaddr_min,
         uint32_t data_memslot, uint32_t pgd_memslot);
+void virt_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr,
+              size_t size, uint32_t pgd_memslot);
 void *addr_gpa2hva(struct kvm_vm *vm, vm_paddr_t gpa);
 void *addr_gva2hva(struct kvm_vm *vm, vm_vaddr_t gva);
 vm_paddr_t addr_hva2gpa(struct kvm_vm *vm, void *hva);
diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
index fa61afffcc8d..e9ba389c48db 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -169,6 +169,16 @@ void kvm_vm_restart(struct kvm_vm *vmp, int perm)
         }
 }
 
+void kvm_vm_get_dirty_log(struct kvm_vm *vm, int slot, void *log)
+{
+        struct kvm_dirty_log args = { .dirty_bitmap = log, .slot = slot };
+        int ret;
+
+        ret = ioctl(vm->fd, KVM_GET_DIRTY_LOG, &args);
+        TEST_ASSERT(ret == 0, "%s: KVM_GET_DIRTY_LOG failed: %s",
+                    strerror(-ret));
+}
+
 /* Userspace Memory Region Find
  *
  * Input Args:
@@ -924,6 +934,39 @@ vm_vaddr_t vm_vaddr_alloc(struct kvm_vm *vm, size_t sz, vm_vaddr_t vaddr_min,
         return vaddr_start;
 }
 
+/*
+ * Map a range of VM virtual address to the VM's physical address
+ *
+ * Input Args:
+ *   vm - Virtual Machine
+ *   vaddr - Virtuall address to map
+ *   paddr - VM Physical Address
+ *   size - The size of the range to map
+ *   pgd_memslot - Memory region slot for new virtual translation tables
+ *
+ * Output Args: None
+ *
+ * Return: None
+ *
+ * Within the VM given by vm, creates a virtual translation for the
+ * page range starting at vaddr to the page range starting at paddr.
+ */
+void virt_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr,
+              size_t size, uint32_t pgd_memslot)
+{
+        size_t page_size = vm->page_size;
+        size_t npages = size / page_size;
+
+        TEST_ASSERT(vaddr + size > vaddr, "Vaddr overflow");
+        TEST_ASSERT(paddr + size > paddr, "Paddr overflow");
+
+        while (npages--) {
+                virt_pg_map(vm, vaddr, paddr, pgd_memslot);
+                vaddr += page_size;
+                paddr += page_size;
+        }
+}
+
 /* Address VM Physical to Host Virtual
  *
  * Input Args: