diff options
Diffstat (limited to 'tools/testing/selftests/kvm/kvm_page_table_test.c')
-rw-r--r-- | tools/testing/selftests/kvm/kvm_page_table_test.c | 479 |
1 files changed, 479 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 0000000000..69f26d80c8 --- /dev/null +++ b/tools/testing/selftests/kvm/kvm_page_table_test.c @@ -0,0 +1,479 @@ +// 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, &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 */ + 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, &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, &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, &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); + 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_positive("Number of vCPUs", optarg); + TEST_ASSERT(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; +} |