aboutsummaryrefslogtreecommitdiffstats
path: root/tools/testing/selftests/kvm/kvm_page_table_test.c
diff options
context:
space:
mode:
Diffstat (limited to 'tools/testing/selftests/kvm/kvm_page_table_test.c')
-rw-r--r--tools/testing/selftests/kvm/kvm_page_table_test.c481
1 files changed, 481 insertions, 0 deletions
diff --git a/tools/testing/selftests/kvm/kvm_page_table_test.c b/tools/testing/selftests/kvm/kvm_page_table_test.c
new file mode 100644
index 000000000000..f42c6ac6d71d
--- /dev/null
+++ b/tools/testing/selftests/kvm/kvm_page_table_test.c
@@ -0,0 +1,481 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * KVM page table test
+ *
+ * Copyright (C) 2021, Huawei, Inc.
+ *
+ * Make sure that THP has been enabled or enough HUGETLB pages with specific
+ * page size have been pre-allocated on your system, if you are planning to
+ * use hugepages to back the guest memory for testing.
+ */
+
+#define _GNU_SOURCE /* for program_invocation_name */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
+#include <pthread.h>
+#include <semaphore.h>
+
+#include "test_util.h"
+#include "kvm_util.h"
+#include "processor.h"
+#include "guest_modes.h"
+
+#define TEST_MEM_SLOT_INDEX 1
+
+/* Default size(1GB) of the memory for testing */
+#define DEFAULT_TEST_MEM_SIZE (1 << 30)
+
+/* Default guest test virtual memory offset */
+#define DEFAULT_GUEST_TEST_MEM 0xc0000000
+
+/* Different guest memory accessing stages */
+enum test_stage {
+ KVM_BEFORE_MAPPINGS,
+ KVM_CREATE_MAPPINGS,
+ KVM_UPDATE_MAPPINGS,
+ KVM_ADJUST_MAPPINGS,
+ NUM_TEST_STAGES,
+};
+
+static const char * const test_stage_string[] = {
+ "KVM_BEFORE_MAPPINGS",
+ "KVM_CREATE_MAPPINGS",
+ "KVM_UPDATE_MAPPINGS",
+ "KVM_ADJUST_MAPPINGS",
+};
+
+struct test_args {
+ struct kvm_vm *vm;
+ uint64_t guest_test_virt_mem;
+ uint64_t host_page_size;
+ uint64_t host_num_pages;
+ uint64_t large_page_size;
+ uint64_t large_num_pages;
+ uint64_t host_pages_per_lpage;
+ enum vm_mem_backing_src_type src_type;
+ struct kvm_vcpu *vcpus[KVM_MAX_VCPUS];
+};
+
+/*
+ * Guest variables. Use addr_gva2hva() if these variables need
+ * to be changed in host.
+ */
+static enum test_stage guest_test_stage;
+
+/* Host variables */
+static uint32_t nr_vcpus = 1;
+static struct test_args test_args;
+static enum test_stage *current_stage;
+static bool host_quit;
+
+/* Whether the test stage is updated, or completed */
+static sem_t test_stage_updated;
+static sem_t test_stage_completed;
+
+/*
+ * Guest physical memory offset of the testing memory slot.
+ * This will be set to the topmost valid physical address minus
+ * the test memory size.
+ */
+static uint64_t guest_test_phys_mem;
+
+/*
+ * Guest virtual memory offset of the testing memory slot.
+ * Must not conflict with identity mapped test code.
+ */
+static uint64_t guest_test_virt_mem = DEFAULT_GUEST_TEST_MEM;
+
+static void guest_code(bool do_write)
+{
+ struct test_args *p = &test_args;
+ enum test_stage *current_stage = &guest_test_stage;
+ uint64_t addr;
+ int i, j;
+
+ while (true) {
+ addr = p->guest_test_virt_mem;
+
+ switch (READ_ONCE(*current_stage)) {
+ /*
+ * All vCPU threads will be started in this stage,
+ * where guest code of each vCPU will do nothing.
+ */
+ case KVM_BEFORE_MAPPINGS:
+ break;
+
+ /*
+ * Before dirty logging, vCPUs concurrently access the first
+ * 8 bytes of each page (host page/large page) within the same
+ * memory region with different accessing types (read/write).
+ * Then KVM will create normal page mappings or huge block
+ * mappings for them.
+ */
+ case KVM_CREATE_MAPPINGS:
+ for (i = 0; i < p->large_num_pages; i++) {
+ if (do_write)
+ *(uint64_t *)addr = 0x0123456789ABCDEF;
+ else
+ READ_ONCE(*(uint64_t *)addr);
+
+ addr += p->large_page_size;
+ }
+ break;
+
+ /*
+ * During dirty logging, KVM will only update attributes of the
+ * normal page mappings from RO to RW if memory backing src type
+ * is anonymous. In other cases, KVM will split the huge block
+ * mappings into normal page mappings if memory backing src type
+ * is THP or HUGETLB.
+ */
+ case KVM_UPDATE_MAPPINGS:
+ if (p->src_type == VM_MEM_SRC_ANONYMOUS) {
+ for (i = 0; i < p->host_num_pages; i++) {
+ *(uint64_t *)addr = 0x0123456789ABCDEF;
+ addr += p->host_page_size;
+ }
+ break;
+ }
+
+ for (i = 0; i < p->large_num_pages; i++) {
+ /*
+ * Write to the first host page in each large
+ * page region, and triger break of large pages.
+ */
+ *(uint64_t *)addr = 0x0123456789ABCDEF;
+
+ /*
+ * Access the middle host pages in each large
+ * page region. Since dirty logging is enabled,
+ * this will create new mappings at the smallest
+ * granularity.
+ */
+ addr += p->large_page_size / 2;
+ for (j = 0; j < p->host_pages_per_lpage / 2; j++) {
+ READ_ONCE(*(uint64_t *)addr);
+ addr += p->host_page_size;
+ }
+ }
+ break;
+
+ /*
+ * After dirty logging is stopped, vCPUs concurrently read
+ * from every single host page. Then KVM will coalesce the
+ * split page mappings back to block mappings. And a TLB
+ * conflict abort could occur here if TLB entries of the
+ * page mappings are not fully invalidated.
+ */
+ case KVM_ADJUST_MAPPINGS:
+ for (i = 0; i < p->host_num_pages; i++) {
+ READ_ONCE(*(uint64_t *)addr);
+ addr += p->host_page_size;
+ }
+ break;
+
+ default:
+ GUEST_ASSERT(0);
+ }
+
+ GUEST_SYNC(1);
+ }
+}
+
+static void *vcpu_worker(void *data)
+{
+ struct kvm_vcpu *vcpu = data;
+ bool do_write = !(vcpu->id % 2);
+ struct timespec start;
+ struct timespec ts_diff;
+ enum test_stage stage;
+ int ret;
+
+ vcpu_args_set(vcpu, 1, do_write);
+
+ while (!READ_ONCE(host_quit)) {
+ ret = sem_wait(&test_stage_updated);
+ TEST_ASSERT(ret == 0, "Error in sem_wait");
+
+ if (READ_ONCE(host_quit))
+ return NULL;
+
+ clock_gettime(CLOCK_MONOTONIC_RAW, &start);
+ ret = _vcpu_run(vcpu);
+ ts_diff = timespec_elapsed(start);
+
+ TEST_ASSERT(ret == 0, "vcpu_run failed: %d\n", ret);
+ TEST_ASSERT(get_ucall(vcpu, NULL) == UCALL_SYNC,
+ "Invalid guest sync status: exit_reason=%s\n",
+ exit_reason_str(vcpu->run->exit_reason));
+
+ pr_debug("Got sync event from vCPU %d\n", vcpu->id);
+ stage = READ_ONCE(*current_stage);
+
+ /*
+ * Here we can know the execution time of every
+ * single vcpu running in different test stages.
+ */
+ pr_debug("vCPU %d has completed stage %s\n"
+ "execution time is: %ld.%.9lds\n\n",
+ vcpu->id, test_stage_string[stage],
+ ts_diff.tv_sec, ts_diff.tv_nsec);
+
+ ret = sem_post(&test_stage_completed);
+ TEST_ASSERT(ret == 0, "Error in sem_post");
+ }
+
+ return NULL;
+}
+
+struct test_params {
+ uint64_t phys_offset;
+ uint64_t test_mem_size;
+ enum vm_mem_backing_src_type src_type;
+};
+
+static struct kvm_vm *pre_init_before_test(enum vm_guest_mode mode, void *arg)
+{
+ int ret;
+ struct test_params *p = arg;
+ enum vm_mem_backing_src_type src_type = p->src_type;
+ uint64_t large_page_size = get_backing_src_pagesz(src_type);
+ uint64_t guest_page_size = vm_guest_mode_params[mode].page_size;
+ uint64_t host_page_size = getpagesize();
+ uint64_t test_mem_size = p->test_mem_size;
+ uint64_t guest_num_pages;
+ uint64_t alignment;
+ void *host_test_mem;
+ struct kvm_vm *vm;
+
+ /* Align up the test memory size */
+ alignment = max(large_page_size, guest_page_size);
+ test_mem_size = (test_mem_size + alignment - 1) & ~(alignment - 1);
+
+ /* Create a VM with enough guest pages */
+ guest_num_pages = test_mem_size / guest_page_size;
+ vm = __vm_create_with_vcpus(mode, nr_vcpus, guest_num_pages,
+ guest_code, test_args.vcpus);
+
+ /* Align down GPA of the testing memslot */
+ if (!p->phys_offset)
+ guest_test_phys_mem = (vm->max_gfn - guest_num_pages) *
+ guest_page_size;
+ else
+ guest_test_phys_mem = p->phys_offset;
+#ifdef __s390x__
+ alignment = max(0x100000UL, alignment);
+#endif
+ guest_test_phys_mem = align_down(guest_test_phys_mem, alignment);
+
+ /* Set up the shared data structure test_args */
+ test_args.vm = vm;
+ test_args.guest_test_virt_mem = guest_test_virt_mem;
+ test_args.host_page_size = host_page_size;
+ test_args.host_num_pages = test_mem_size / host_page_size;
+ test_args.large_page_size = large_page_size;
+ test_args.large_num_pages = test_mem_size / large_page_size;
+ test_args.host_pages_per_lpage = large_page_size / host_page_size;
+ test_args.src_type = src_type;
+
+ /* Add an extra memory slot with specified backing src type */
+ vm_userspace_mem_region_add(vm, src_type, guest_test_phys_mem,
+ TEST_MEM_SLOT_INDEX, guest_num_pages, 0);
+
+ /* Do mapping(GVA->GPA) for the testing memory slot */
+ virt_map(vm, guest_test_virt_mem, guest_test_phys_mem, guest_num_pages);
+
+ /* Cache the HVA pointer of the region */
+ host_test_mem = addr_gpa2hva(vm, (vm_paddr_t)guest_test_phys_mem);
+
+ /* Export shared structure test_args to guest */
+ ucall_init(vm, NULL);
+ sync_global_to_guest(vm, test_args);
+
+ ret = sem_init(&test_stage_updated, 0, 0);
+ TEST_ASSERT(ret == 0, "Error in sem_init");
+
+ ret = sem_init(&test_stage_completed, 0, 0);
+ TEST_ASSERT(ret == 0, "Error in sem_init");
+
+ current_stage = addr_gva2hva(vm, (vm_vaddr_t)(&guest_test_stage));
+ *current_stage = NUM_TEST_STAGES;
+
+ pr_info("Testing guest mode: %s\n", vm_guest_mode_string(mode));
+ pr_info("Testing memory backing src type: %s\n",
+ vm_mem_backing_src_alias(src_type)->name);
+ pr_info("Testing memory backing src granularity: 0x%lx\n",
+ large_page_size);
+ pr_info("Testing memory size(aligned): 0x%lx\n", test_mem_size);
+ pr_info("Guest physical test memory offset: 0x%lx\n",
+ guest_test_phys_mem);
+ pr_info("Host virtual test memory offset: 0x%lx\n",
+ (uint64_t)host_test_mem);
+ pr_info("Number of testing vCPUs: %d\n", nr_vcpus);
+
+ return vm;
+}
+
+static void vcpus_complete_new_stage(enum test_stage stage)
+{
+ int ret;
+ int vcpus;
+
+ /* Wake up all the vcpus to run new test stage */
+ for (vcpus = 0; vcpus < nr_vcpus; vcpus++) {
+ ret = sem_post(&test_stage_updated);
+ TEST_ASSERT(ret == 0, "Error in sem_post");
+ }
+ pr_debug("All vcpus have been notified to continue\n");
+
+ /* Wait for all the vcpus to complete new test stage */
+ for (vcpus = 0; vcpus < nr_vcpus; vcpus++) {
+ ret = sem_wait(&test_stage_completed);
+ TEST_ASSERT(ret == 0, "Error in sem_wait");
+
+ pr_debug("%d vcpus have completed stage %s\n",
+ vcpus + 1, test_stage_string[stage]);
+ }
+
+ pr_debug("All vcpus have completed stage %s\n",
+ test_stage_string[stage]);
+}
+
+static void run_test(enum vm_guest_mode mode, void *arg)
+{
+ pthread_t *vcpu_threads;
+ struct kvm_vm *vm;
+ struct timespec start;
+ struct timespec ts_diff;
+ int ret, i;
+
+ /* Create VM with vCPUs and make some pre-initialization */
+ vm = pre_init_before_test(mode, arg);
+
+ vcpu_threads = malloc(nr_vcpus * sizeof(*vcpu_threads));
+ TEST_ASSERT(vcpu_threads, "Memory allocation failed");
+
+ host_quit = false;
+ *current_stage = KVM_BEFORE_MAPPINGS;
+
+ for (i = 0; i < nr_vcpus; i++)
+ pthread_create(&vcpu_threads[i], NULL, vcpu_worker,
+ test_args.vcpus[i]);
+
+ vcpus_complete_new_stage(*current_stage);
+ pr_info("Started all vCPUs successfully\n");
+
+ /* Test the stage of KVM creating mappings */
+ *current_stage = KVM_CREATE_MAPPINGS;
+
+ clock_gettime(CLOCK_MONOTONIC_RAW, &start);
+ vcpus_complete_new_stage(*current_stage);
+ ts_diff = timespec_elapsed(start);
+
+ pr_info("KVM_CREATE_MAPPINGS: total execution time: %ld.%.9lds\n\n",
+ ts_diff.tv_sec, ts_diff.tv_nsec);
+
+ /* Test the stage of KVM updating mappings */
+ vm_mem_region_set_flags(vm, TEST_MEM_SLOT_INDEX,
+ KVM_MEM_LOG_DIRTY_PAGES);
+
+ *current_stage = KVM_UPDATE_MAPPINGS;
+
+ clock_gettime(CLOCK_MONOTONIC_RAW, &start);
+ vcpus_complete_new_stage(*current_stage);
+ ts_diff = timespec_elapsed(start);
+
+ pr_info("KVM_UPDATE_MAPPINGS: total execution time: %ld.%.9lds\n\n",
+ ts_diff.tv_sec, ts_diff.tv_nsec);
+
+ /* Test the stage of KVM adjusting mappings */
+ vm_mem_region_set_flags(vm, TEST_MEM_SLOT_INDEX, 0);
+
+ *current_stage = KVM_ADJUST_MAPPINGS;
+
+ clock_gettime(CLOCK_MONOTONIC_RAW, &start);
+ vcpus_complete_new_stage(*current_stage);
+ ts_diff = timespec_elapsed(start);
+
+ pr_info("KVM_ADJUST_MAPPINGS: total execution time: %ld.%.9lds\n\n",
+ ts_diff.tv_sec, ts_diff.tv_nsec);
+
+ /* Tell the vcpu thread to quit */
+ host_quit = true;
+ for (i = 0; i < nr_vcpus; i++) {
+ ret = sem_post(&test_stage_updated);
+ TEST_ASSERT(ret == 0, "Error in sem_post");
+ }
+
+ for (i = 0; i < nr_vcpus; i++)
+ pthread_join(vcpu_threads[i], NULL);
+
+ ret = sem_destroy(&test_stage_updated);
+ TEST_ASSERT(ret == 0, "Error in sem_destroy");
+
+ ret = sem_destroy(&test_stage_completed);
+ TEST_ASSERT(ret == 0, "Error in sem_destroy");
+
+ free(vcpu_threads);
+ ucall_uninit(vm);
+ kvm_vm_free(vm);
+}
+
+static void help(char *name)
+{
+ puts("");
+ printf("usage: %s [-h] [-p offset] [-m mode] "
+ "[-b mem-size] [-v vcpus] [-s mem-type]\n", name);
+ puts("");
+ printf(" -p: specify guest physical test memory offset\n"
+ " Warning: a low offset can conflict with the loaded test code.\n");
+ guest_modes_help();
+ printf(" -b: specify size of the memory region for testing. e.g. 10M or 3G.\n"
+ " (default: 1G)\n");
+ printf(" -v: specify the number of vCPUs to run\n"
+ " (default: 1)\n");
+ backing_src_help("-s");
+ puts("");
+}
+
+int main(int argc, char *argv[])
+{
+ int max_vcpus = kvm_check_cap(KVM_CAP_MAX_VCPUS);
+ struct test_params p = {
+ .test_mem_size = DEFAULT_TEST_MEM_SIZE,
+ .src_type = DEFAULT_VM_MEM_SRC,
+ };
+ int opt;
+
+ guest_modes_append_default();
+
+ while ((opt = getopt(argc, argv, "hp:m:b:v:s:")) != -1) {
+ switch (opt) {
+ case 'p':
+ p.phys_offset = strtoull(optarg, NULL, 0);
+ break;
+ case 'm':
+ guest_modes_cmdline(optarg);
+ break;
+ case 'b':
+ p.test_mem_size = parse_size(optarg);
+ break;
+ case 'v':
+ nr_vcpus = atoi(optarg);
+ TEST_ASSERT(nr_vcpus > 0 && nr_vcpus <= max_vcpus,
+ "Invalid number of vcpus, must be between 1 and %d", max_vcpus);
+ break;
+ case 's':
+ p.src_type = parse_backing_src_type(optarg);
+ break;
+ case 'h':
+ default:
+ help(argv[0]);
+ exit(0);
+ }
+ }
+
+ for_each_guest_mode(run_test, &p);
+
+ return 0;
+}
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.