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
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
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
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:
"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);
+}
--- /dev/null
+// 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;
+}
+
projects / kernel.git / commitdiff