diff options
| -rw-r--r-- | tools/testing/selftests/kvm/.gitignore | 1 | ||||
| -rw-r--r-- | tools/testing/selftests/kvm/Makefile | 10 | ||||
| -rw-r--r-- | tools/testing/selftests/kvm/include/kvm_util_base.h | 11 | ||||
| -rw-r--r-- | tools/testing/selftests/kvm/lib/kvm_util.c | 46 | ||||
| -rw-r--r-- | tools/testing/selftests/kvm/x86_64/nx_huge_pages_test.c | 229 | ||||
| -rwxr-xr-x | tools/testing/selftests/kvm/x86_64/nx_huge_pages_test.sh | 40 |
6 files changed, 337 insertions, 0 deletions
diff --git a/tools/testing/selftests/kvm/.gitignore b/tools/testing/selftests/kvm/.gitignore index f3c2f074b948..c478b4fefc57 100644 --- a/tools/testing/selftests/kvm/.gitignore +++ b/tools/testing/selftests/kvm/.gitignore @@ -29,6 +29,7 @@ /x86_64/mmio_warning_test /x86_64/mmu_role_test /x86_64/monitor_mwait_test +/x86_64/nx_huge_pages_test /x86_64/platform_info_test /x86_64/pmu_event_filter_test /x86_64/set_boot_cpu_id diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile index ad1634e5659f..fa3e0687e9d5 100644 --- a/tools/testing/selftests/kvm/Makefile +++ b/tools/testing/selftests/kvm/Makefile @@ -70,6 +70,10 @@ LIBKVM_s390x += lib/s390x/ucall.c LIBKVM_riscv += lib/riscv/processor.c LIBKVM_riscv += lib/riscv/ucall.c +# Non-compiled test targets +TEST_PROGS_x86_64 += x86_64/nx_huge_pages_test.sh + +# Compiled test targets TEST_GEN_PROGS_x86_64 = x86_64/cpuid_test TEST_GEN_PROGS_x86_64 += x86_64/cr4_cpuid_sync_test TEST_GEN_PROGS_x86_64 += x86_64/get_msr_index_features @@ -135,6 +139,9 @@ TEST_GEN_PROGS_x86_64 += steal_time TEST_GEN_PROGS_x86_64 += kvm_binary_stats_test TEST_GEN_PROGS_x86_64 += system_counter_offset_test +# Compiled outputs used by test targets +TEST_GEN_PROGS_EXTENDED_x86_64 += x86_64/nx_huge_pages_test + TEST_GEN_PROGS_aarch64 += aarch64/arch_timer TEST_GEN_PROGS_aarch64 += aarch64/debug-exceptions TEST_GEN_PROGS_aarch64 += aarch64/get-reg-list @@ -174,7 +181,9 @@ TEST_GEN_PROGS_riscv += kvm_page_table_test TEST_GEN_PROGS_riscv += set_memory_region_test TEST_GEN_PROGS_riscv += kvm_binary_stats_test +TEST_PROGS += $(TEST_PROGS_$(UNAME_M)) TEST_GEN_PROGS += $(TEST_GEN_PROGS_$(UNAME_M)) +TEST_GEN_PROGS_EXTENDED += $(TEST_GEN_PROGS_EXTENDED_$(UNAME_M)) LIBKVM += $(LIBKVM_$(UNAME_M)) INSTALL_HDR_PATH = $(top_srcdir)/usr @@ -221,6 +230,7 @@ $(LIBKVM_S_OBJ): $(OUTPUT)/%.o: %.S x := $(shell mkdir -p $(sort $(dir $(TEST_GEN_PROGS)))) $(TEST_GEN_PROGS): $(LIBKVM_OBJS) +$(TEST_GEN_PROGS_EXTENDED): $(LIBKVM_OBJS) cscope: include_paths = $(LINUX_TOOL_INCLUDE) $(LINUX_HDR_PATH) include lib .. cscope: diff --git a/tools/testing/selftests/kvm/include/kvm_util_base.h b/tools/testing/selftests/kvm/include/kvm_util_base.h index cec3af45e18d..c6c1d66136d6 100644 --- a/tools/testing/selftests/kvm/include/kvm_util_base.h +++ b/tools/testing/selftests/kvm/include/kvm_util_base.h @@ -345,6 +345,17 @@ void read_stat_data(int stats_fd, struct kvm_stats_header *header, struct kvm_stats_desc *desc, uint64_t *data, size_t max_elements); +void __vm_get_stat(struct kvm_vm *vm, const char *stat_name, uint64_t *data, + size_t max_elements); + +static inline uint64_t vm_get_stat(struct kvm_vm *vm, const char *stat_name) +{ + uint64_t data; + + __vm_get_stat(vm, stat_name, &data, 1); + return data; +} + void vm_create_irqchip(struct kvm_vm *vm); void vm_set_user_memory_region(struct kvm_vm *vm, uint32_t slot, uint32_t flags, diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c index e44eb510fcc1..5a0fd368503f 100644 --- a/tools/testing/selftests/kvm/lib/kvm_util.c +++ b/tools/testing/selftests/kvm/lib/kvm_util.c @@ -1918,3 +1918,49 @@ void read_stat_data(int stats_fd, struct kvm_stats_header *header, "pread() on stat '%s' read %ld bytes, wanted %lu bytes", desc->name, size, ret); } + +/* + * Read the data of the named stat + * + * Input Args: + * vm - the VM for which the stat should be read + * stat_name - the name of the stat to read + * max_elements - the maximum number of 8-byte values to read into data + * + * Output Args: + * data - the buffer into which stat data should be read + * + * Read the data values of a specified stat from the binary stats interface. + */ +void __vm_get_stat(struct kvm_vm *vm, const char *stat_name, uint64_t *data, + size_t max_elements) +{ + struct kvm_stats_desc *stats_desc; + struct kvm_stats_header header; + struct kvm_stats_desc *desc; + size_t size_desc; + int stats_fd; + int i; + + stats_fd = vm_get_stats_fd(vm); + + read_stats_header(stats_fd, &header); + + stats_desc = read_stats_descriptors(stats_fd, &header); + + size_desc = get_stats_descriptor_size(&header); + + for (i = 0; i < header.num_desc; ++i) { + desc = (void *)stats_desc + (i * size_desc); + + if (strcmp(desc->name, stat_name)) + continue; + + read_stat_data(stats_fd, &header, desc, data, max_elements); + + break; + } + + free(stats_desc); + close(stats_fd); +} diff --git a/tools/testing/selftests/kvm/x86_64/nx_huge_pages_test.c b/tools/testing/selftests/kvm/x86_64/nx_huge_pages_test.c new file mode 100644 index 000000000000..5fa61d225787 --- /dev/null +++ b/tools/testing/selftests/kvm/x86_64/nx_huge_pages_test.c @@ -0,0 +1,229 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * tools/testing/selftests/kvm/nx_huge_page_test.c + * + * Usage: to be run via nx_huge_page_test.sh, which does the necessary + * environment setup and teardown + * + * Copyright (C) 2022, Google LLC. + */ + +#define _GNU_SOURCE + +#include <fcntl.h> +#include <stdint.h> +#include <time.h> + +#include <test_util.h> +#include "kvm_util.h" +#include "processor.h" + +#define HPAGE_SLOT 10 +#define HPAGE_GPA (4UL << 30) /* 4G prevents collision w/ slot 0 */ +#define HPAGE_GVA HPAGE_GPA /* GVA is arbitrary, so use GPA. */ +#define PAGES_PER_2MB_HUGE_PAGE 512 +#define HPAGE_SLOT_NPAGES (3 * PAGES_PER_2MB_HUGE_PAGE) + +/* + * Passed by nx_huge_pages_test.sh to provide an easy warning if this test is + * being run without it. + */ +#define MAGIC_TOKEN 887563923 + +/* + * x86 opcode for the return instruction. Used to call into, and then + * immediately return from, memory backed with hugepages. + */ +#define RETURN_OPCODE 0xC3 + +/* Call the specified memory address. */ +static void guest_do_CALL(uint64_t target) +{ + ((void (*)(void)) target)(); +} + +/* + * Exit the VM after each memory access so that the userspace component of the + * test can make assertions about the pages backing the VM. + * + * See the below for an explanation of how each access should affect the + * backing mappings. + */ +void guest_code(void) +{ + uint64_t hpage_1 = HPAGE_GVA; + uint64_t hpage_2 = hpage_1 + (PAGE_SIZE * 512); + uint64_t hpage_3 = hpage_2 + (PAGE_SIZE * 512); + + READ_ONCE(*(uint64_t *)hpage_1); + GUEST_SYNC(1); + + READ_ONCE(*(uint64_t *)hpage_2); + GUEST_SYNC(2); + + guest_do_CALL(hpage_1); + GUEST_SYNC(3); + + guest_do_CALL(hpage_3); + GUEST_SYNC(4); + + READ_ONCE(*(uint64_t *)hpage_1); + GUEST_SYNC(5); + + READ_ONCE(*(uint64_t *)hpage_3); + GUEST_SYNC(6); +} + +static void check_2m_page_count(struct kvm_vm *vm, int expected_pages_2m) +{ + int actual_pages_2m; + + actual_pages_2m = vm_get_stat(vm, "pages_2m"); + + TEST_ASSERT(actual_pages_2m == expected_pages_2m, + "Unexpected 2m page count. Expected %d, got %d", + expected_pages_2m, actual_pages_2m); +} + +static void check_split_count(struct kvm_vm *vm, int expected_splits) +{ + int actual_splits; + + actual_splits = vm_get_stat(vm, "nx_lpage_splits"); + + TEST_ASSERT(actual_splits == expected_splits, + "Unexpected NX huge page split count. Expected %d, got %d", + expected_splits, actual_splits); +} + +static void wait_for_reclaim(int reclaim_period_ms) +{ + long reclaim_wait_ms; + struct timespec ts; + + reclaim_wait_ms = reclaim_period_ms * 5; + ts.tv_sec = reclaim_wait_ms / 1000; + ts.tv_nsec = (reclaim_wait_ms - (ts.tv_sec * 1000)) * 1000000; + nanosleep(&ts, NULL); +} + +static void help(char *name) +{ + puts(""); + printf("usage: %s [-h] [-p period_ms] [-t token]\n", name); + puts(""); + printf(" -p: The NX reclaim period in miliseconds.\n"); + printf(" -t: The magic token to indicate environment setup is done.\n"); + puts(""); + exit(0); +} + +int main(int argc, char **argv) +{ + int reclaim_period_ms = 0, token = 0, opt; + struct kvm_vcpu *vcpu; + struct kvm_vm *vm; + void *hva; + + while ((opt = getopt(argc, argv, "hp:t:")) != -1) { + switch (opt) { + case 'p': + reclaim_period_ms = atoi(optarg); + break; + case 't': + token = atoi(optarg); + break; + case 'h': + default: + help(argv[0]); + break; + } + } + + if (token != MAGIC_TOKEN) { + print_skip("This test must be run with the magic token %d.\n" + "This is done by nx_huge_pages_test.sh, which\n" + "also handles environment setup for the test.", + MAGIC_TOKEN); + exit(KSFT_SKIP); + } + + if (!reclaim_period_ms) { + print_skip("The NX reclaim period must be specified and non-zero"); + exit(KSFT_SKIP); + } + + vm = vm_create(1); + vcpu = vm_vcpu_add(vm, 0, guest_code); + + vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS_HUGETLB, + HPAGE_GPA, HPAGE_SLOT, + HPAGE_SLOT_NPAGES, 0); + + virt_map(vm, HPAGE_GVA, HPAGE_GPA, HPAGE_SLOT_NPAGES); + + hva = addr_gpa2hva(vm, HPAGE_GPA); + memset(hva, RETURN_OPCODE, HPAGE_SLOT_NPAGES * PAGE_SIZE); + + check_2m_page_count(vm, 0); + check_split_count(vm, 0); + + /* + * The guest code will first read from the first hugepage, resulting + * in a huge page mapping being created. + */ + vcpu_run(vcpu); + check_2m_page_count(vm, 1); + check_split_count(vm, 0); + + /* + * Then the guest code will read from the second hugepage, resulting + * in another huge page mapping being created. + */ + vcpu_run(vcpu); + check_2m_page_count(vm, 2); + check_split_count(vm, 0); + + /* + * Next, the guest will execute from the first huge page, causing it + * to be remapped at 4k. + */ + vcpu_run(vcpu); + check_2m_page_count(vm, 1); + check_split_count(vm, 1); + + /* + * Executing from the third huge page (previously unaccessed) will + * cause part to be mapped at 4k. + */ + vcpu_run(vcpu); + check_2m_page_count(vm, 1); + check_split_count(vm, 2); + + /* Reading from the first huge page again should have no effect. */ + vcpu_run(vcpu); + check_2m_page_count(vm, 1); + check_split_count(vm, 2); + + /* Give recovery thread time to run. */ + wait_for_reclaim(reclaim_period_ms); + + /* + * Now that the reclaimer has run, all the split pages should be gone. + */ + check_2m_page_count(vm, 1); + check_split_count(vm, 0); + + /* + * The 4k mapping on hpage 3 should have been removed, so check that + * reading from it causes a huge page mapping to be installed. + */ + vcpu_run(vcpu); + check_2m_page_count(vm, 2); + check_split_count(vm, 0); + + kvm_vm_free(vm); + + return 0; +} + diff --git a/tools/testing/selftests/kvm/x86_64/nx_huge_pages_test.sh b/tools/testing/selftests/kvm/x86_64/nx_huge_pages_test.sh new file mode 100755 index 000000000000..4e090a84f5f3 --- /dev/null +++ b/tools/testing/selftests/kvm/x86_64/nx_huge_pages_test.sh @@ -0,0 +1,40 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0-only */ +# +# Wrapper script which performs setup and cleanup for nx_huge_pages_test. +# Makes use of root privileges to set up huge pages and KVM module parameters. +# +# tools/testing/selftests/kvm/nx_huge_page_test.sh +# Copyright (C) 2022, Google LLC. + +set -e + +NX_HUGE_PAGES=$(cat /sys/module/kvm/parameters/nx_huge_pages) +NX_HUGE_PAGES_RECOVERY_RATIO=$(cat /sys/module/kvm/parameters/nx_huge_pages_recovery_ratio) +NX_HUGE_PAGES_RECOVERY_PERIOD=$(cat /sys/module/kvm/parameters/nx_huge_pages_recovery_period_ms) +HUGE_PAGES=$(cat /sys/kernel/mm/hugepages/hugepages-2048kB/nr_hugepages) + +set +e + +function sudo_echo () { + echo "$1" | sudo tee -a "$2" > /dev/null +} + +( + set -e + + sudo_echo 1 /sys/module/kvm/parameters/nx_huge_pages + sudo_echo 1 /sys/module/kvm/parameters/nx_huge_pages_recovery_ratio + sudo_echo 100 /sys/module/kvm/parameters/nx_huge_pages_recovery_period_ms + sudo_echo "$(( $HUGE_PAGES + 3 ))" /sys/kernel/mm/hugepages/hugepages-2048kB/nr_hugepages + + "$(dirname $0)"/nx_huge_pages_test -t 887563923 -p 100 +) +RET=$? + +sudo_echo "$NX_HUGE_PAGES" /sys/module/kvm/parameters/nx_huge_pages +sudo_echo "$NX_HUGE_PAGES_RECOVERY_RATIO" /sys/module/kvm/parameters/nx_huge_pages_recovery_ratio +sudo_echo "$NX_HUGE_PAGES_RECOVERY_PERIOD" /sys/module/kvm/parameters/nx_huge_pages_recovery_period_ms +sudo_echo "$HUGE_PAGES" /sys/kernel/mm/hugepages/hugepages-2048kB/nr_hugepages + +exit $RET |