1 files changed, 211 insertions, 0 deletions
diff --git a/tools/testing/selftests/kvm/memslot_modification_stress_test.c b/tools/testing/selftests/kvm/memslot_modification_stress_test.c
new file mode 100644
index 000000000000..cae1b90cb63f
--- /dev/null
+++ b/tools/testing/selftests/kvm/memslot_modification_stress_test.c
@@ -0,0 +1,211 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * KVM memslot modification stress test
+ * Adapted from demand_paging_test.c
+ *
+ * Copyright (C) 2018, Red Hat, Inc.
+ * Copyright (C) 2020, Google, Inc.
+ */
+
+#define _GNU_SOURCE /* for program_invocation_name */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/syscall.h>
+#include <unistd.h>
+#include <asm/unistd.h>
+#include <time.h>
+#include <poll.h>
+#include <pthread.h>
+#include <linux/bitmap.h>
+#include <linux/bitops.h>
+#include <linux/userfaultfd.h>
+
+#include "perf_test_util.h"
+#include "processor.h"
+#include "test_util.h"
+#include "guest_modes.h"
+
+#define DUMMY_MEMSLOT_INDEX 7
+
+#define DEFAULT_MEMSLOT_MODIFICATION_ITERATIONS 10
+
+
+static int nr_vcpus = 1;
+static uint64_t guest_percpu_mem_size = DEFAULT_PER_VCPU_MEM_SIZE;
+
+static bool run_vcpus = true;
+
+static void *vcpu_worker(void *data)
+{
+	int ret;
+	struct perf_test_vcpu_args *vcpu_args =
+		(struct perf_test_vcpu_args *)data;
+	int vcpu_id = vcpu_args->vcpu_id;
+	struct kvm_vm *vm = perf_test_args.vm;
+	struct kvm_run *run;
+
+	vcpu_args_set(vm, vcpu_id, 1, vcpu_id);
+	run = vcpu_state(vm, vcpu_id);
+
+	/* Let the guest access its memory until a stop signal is received */
+	while (READ_ONCE(run_vcpus)) {
+		ret = _vcpu_run(vm, vcpu_id);
+		TEST_ASSERT(ret == 0, "vcpu_run failed: %d\n", ret);
+
+		if (get_ucall(vm, vcpu_id, NULL) == UCALL_SYNC)
+			continue;
+
+		TEST_ASSERT(false,
+			    "Invalid guest sync status: exit_reason=%s\n",
+			    exit_reason_str(run->exit_reason));
+	}
+
+	return NULL;
+}
+
+struct memslot_antagonist_args {
+	struct kvm_vm *vm;
+	useconds_t delay;
+	uint64_t nr_modifications;
+};
+
+static void add_remove_memslot(struct kvm_vm *vm, useconds_t delay,
+			      uint64_t nr_modifications, uint64_t gpa)
+{
+	int i;
+
+	for (i = 0; i < nr_modifications; i++) {
+		usleep(delay);
+		vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, gpa,
+					    DUMMY_MEMSLOT_INDEX, 1, 0);
+
+		vm_mem_region_delete(vm, DUMMY_MEMSLOT_INDEX);
+	}
+}
+
+struct test_params {
+	useconds_t memslot_modification_delay;
+	uint64_t nr_memslot_modifications;
+	bool partition_vcpu_memory_access;
+};
+
+static void run_test(enum vm_guest_mode mode, void *arg)
+{
+	struct test_params *p = arg;
+	pthread_t *vcpu_threads;
+	struct kvm_vm *vm;
+	int vcpu_id;
+
+	vm = perf_test_create_vm(mode, nr_vcpus, guest_percpu_mem_size);
+
+	perf_test_args.wr_fract = 1;
+
+	vcpu_threads = malloc(nr_vcpus * sizeof(*vcpu_threads));
+	TEST_ASSERT(vcpu_threads, "Memory allocation failed");
+
+	perf_test_setup_vcpus(vm, nr_vcpus, guest_percpu_mem_size,
+			      p->partition_vcpu_memory_access);
+
+	/* Export the shared variables to the guest */
+	sync_global_to_guest(vm, perf_test_args);
+
+	pr_info("Finished creating vCPUs\n");
+
+	for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++)
+		pthread_create(&vcpu_threads[vcpu_id], NULL, vcpu_worker,
+			       &perf_test_args.vcpu_args[vcpu_id]);
+
+	pr_info("Started all vCPUs\n");
+
+	add_remove_memslot(vm, p->memslot_modification_delay,
+			   p->nr_memslot_modifications,
+			   guest_test_phys_mem +
+			   (guest_percpu_mem_size * nr_vcpus) +
+			   perf_test_args.host_page_size +
+			   perf_test_args.guest_page_size);
+
+	run_vcpus = false;
+
+	/* Wait for the vcpu threads to quit */
+	for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++)
+		pthread_join(vcpu_threads[vcpu_id], NULL);
+
+	pr_info("All vCPU threads joined\n");
+
+	ucall_uninit(vm);
+	kvm_vm_free(vm);
+
+	free(vcpu_threads);
+}
+
+static void help(char *name)
+{
+	puts("");
+	printf("usage: %s [-h] [-m mode] [-d delay_usec]\n"
+	       "          [-b memory] [-v vcpus] [-o] [-i iterations]\n", name);
+	guest_modes_help();
+	printf(" -d: add a delay between each iteration of adding and\n"
+	       "     deleting a memslot in usec.\n");
+	printf(" -b: specify the size of the memory region which should be\n"
+	       "     accessed by each vCPU. e.g. 10M or 3G.\n"
+	       "     Default: 1G\n");
+	printf(" -v: specify the number of vCPUs to run.\n");
+	printf(" -o: Overlap guest memory accesses instead of partitioning\n"
+	       "     them into a separate region of memory for each vCPU.\n");
+	printf(" -i: specify the number of iterations of adding and removing\n"
+	       "     a memslot.\n"
+	       "     Default: %d\n", DEFAULT_MEMSLOT_MODIFICATION_ITERATIONS);
+	puts("");
+	exit(0);
+}
+
+int main(int argc, char *argv[])
+{
+	int max_vcpus = kvm_check_cap(KVM_CAP_MAX_VCPUS);
+	int opt;
+	struct test_params p = {
+		.memslot_modification_delay = 0,
+		.nr_memslot_modifications =
+			DEFAULT_MEMSLOT_MODIFICATION_ITERATIONS,
+		.partition_vcpu_memory_access = true
+	};
+
+	guest_modes_append_default();
+
+	while ((opt = getopt(argc, argv, "hm:d:b:v:oi:")) != -1) {
+		switch (opt) {
+		case 'm':
+			guest_modes_cmdline(optarg);
+			break;
+		case 'd':
+			p.memslot_modification_delay = strtoul(optarg, NULL, 0);
+			TEST_ASSERT(p.memslot_modification_delay >= 0,
+				    "A negative delay is not supported.");
+			break;
+		case 'b':
+			guest_percpu_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 'o':
+			p.partition_vcpu_memory_access = false;
+			break;
+		case 'i':
+			p.nr_memslot_modifications = atoi(optarg);
+			break;
+		case 'h':
+		default:
+			help(argv[0]);
+			break;
+		}
+	}
+
+	for_each_guest_mode(run_test, &p);
+
+	return 0;
+}