--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+#define _GNU_SOURCE
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <pthread.h>
+#include <semaphore.h>
+#include <sys/types.h>
+#include <signal.h>
+#include <errno.h>
+#include <linux/bitmap.h>
+#include <linux/bitops.h>
+#include <linux/atomic.h>
+
+#include "kvm_util.h"
+#include "test_util.h"
+#include "guest_modes.h"
+#include "processor.h"
+
+static void guest_code(uint64_t start_gpa, uint64_t end_gpa, uint64_t stride)
+{
+ uint64_t gpa;
+
+ for (gpa = start_gpa; gpa < end_gpa; gpa += stride)
+ *((volatile uint64_t *)gpa) = gpa;
+
+ GUEST_DONE();
+}
+
+struct vcpu_info {
+ struct kvm_vm *vm;
+ uint32_t id;
+ uint64_t start_gpa;
+ uint64_t end_gpa;
+};
+
+static int nr_vcpus;
+static atomic_t rendezvous;
+
+static void rendezvous_with_boss(void)
+{
+ int orig = atomic_read(&rendezvous);
+
+ if (orig > 0) {
+ atomic_dec_and_test(&rendezvous);
+ while (atomic_read(&rendezvous) > 0)
+ cpu_relax();
+ } else {
+ atomic_inc(&rendezvous);
+ while (atomic_read(&rendezvous) < 0)
+ cpu_relax();
+ }
+}
+
+static void run_vcpu(struct kvm_vm *vm, uint32_t vcpu_id)
+{
+ vcpu_run(vm, vcpu_id);
+ ASSERT_EQ(get_ucall(vm, vcpu_id, NULL), UCALL_DONE);
+}
+
+static void *vcpu_worker(void *data)
+{
+ struct vcpu_info *vcpu = data;
+ struct kvm_vm *vm = vcpu->vm;
+ struct kvm_sregs sregs;
+ struct kvm_regs regs;
+
+ vcpu_args_set(vm, vcpu->id, 3, vcpu->start_gpa, vcpu->end_gpa,
+ vm_get_page_size(vm));
+
+ /* Snapshot regs before the first run. */
+ vcpu_regs_get(vm, vcpu->id, ®s);
+ rendezvous_with_boss();
+
+ run_vcpu(vm, vcpu->id);
+ rendezvous_with_boss();
+ vcpu_regs_set(vm, vcpu->id, ®s);
+ vcpu_sregs_get(vm, vcpu->id, &sregs);
+#ifdef __x86_64__
+ /* Toggle CR0.WP to trigger a MMU context reset. */
+ sregs.cr0 ^= X86_CR0_WP;
+#endif
+ vcpu_sregs_set(vm, vcpu->id, &sregs);
+ rendezvous_with_boss();
+
+ run_vcpu(vm, vcpu->id);
+ rendezvous_with_boss();
+
+ return NULL;
+}
+
+static pthread_t *spawn_workers(struct kvm_vm *vm, uint64_t start_gpa,
+ uint64_t end_gpa)
+{
+ struct vcpu_info *info;
+ uint64_t gpa, nr_bytes;
+ pthread_t *threads;
+ int i;
+
+ threads = malloc(nr_vcpus * sizeof(*threads));
+ TEST_ASSERT(threads, "Failed to allocate vCPU threads");
+
+ info = malloc(nr_vcpus * sizeof(*info));
+ TEST_ASSERT(info, "Failed to allocate vCPU gpa ranges");
+
+ nr_bytes = ((end_gpa - start_gpa) / nr_vcpus) &
+ ~((uint64_t)vm_get_page_size(vm) - 1);
+ TEST_ASSERT(nr_bytes, "C'mon, no way you have %d CPUs", nr_vcpus);
+
+ for (i = 0, gpa = start_gpa; i < nr_vcpus; i++, gpa += nr_bytes) {
+ info[i].vm = vm;
+ info[i].id = i;
+ info[i].start_gpa = gpa;
+ info[i].end_gpa = gpa + nr_bytes;
+ pthread_create(&threads[i], NULL, vcpu_worker, &info[i]);
+ }
+ return threads;
+}
+
+static void rendezvous_with_vcpus(struct timespec *time, const char *name)
+{
+ int i, rendezvoused;
+
+ pr_info("Waiting for vCPUs to finish %s...\n", name);
+
+ rendezvoused = atomic_read(&rendezvous);
+ for (i = 0; abs(rendezvoused) != 1; i++) {
+ usleep(100);
+ if (!(i & 0x3f))
+ pr_info("\r%d vCPUs haven't rendezvoused...",
+ abs(rendezvoused) - 1);
+ rendezvoused = atomic_read(&rendezvous);
+ }
+
+ clock_gettime(CLOCK_MONOTONIC, time);
+
+ /* Release the vCPUs after getting the time of the previous action. */
+ pr_info("\rAll vCPUs finished %s, releasing...\n", name);
+ if (rendezvoused > 0)
+ atomic_set(&rendezvous, -nr_vcpus - 1);
+ else
+ atomic_set(&rendezvous, nr_vcpus + 1);
+}
+
+static void calc_default_nr_vcpus(void)
+{
+ cpu_set_t possible_mask;
+ int r;
+
+ r = sched_getaffinity(0, sizeof(possible_mask), &possible_mask);
+ TEST_ASSERT(!r, "sched_getaffinity failed, errno = %d (%s)",
+ errno, strerror(errno));
+
+ nr_vcpus = CPU_COUNT(&possible_mask) * 3/4;
+ TEST_ASSERT(nr_vcpus > 0, "Uh, no CPUs?");
+}
+
+int main(int argc, char *argv[])
+{
+ /*
+ * Skip the first 4gb and slot0. slot0 maps <1gb and is used to back
+ * the guest's code, stack, and page tables. Because selftests creates
+ * an IRQCHIP, a.k.a. a local APIC, KVM creates an internal memslot
+ * just below the 4gb boundary. This test could create memory at
+ * 1gb-3gb,but it's simpler to skip straight to 4gb.
+ */
+ const uint64_t size_1gb = (1 << 30);
+ const uint64_t start_gpa = (4ull * size_1gb);
+ const int first_slot = 1;
+
+ struct timespec time_start, time_run1, time_reset, time_run2;
+ uint64_t max_gpa, gpa, slot_size, max_mem, i;
+ int max_slots, slot, opt, fd;
+ bool hugepages = false;
+ pthread_t *threads;
+ struct kvm_vm *vm;
+ void *mem;
+
+ /*
+ * Default to 2gb so that maxing out systems with MAXPHADDR=46, which
+ * are quite common for x86, requires changing only max_mem (KVM allows
+ * 32k memslots, 32k * 2gb == ~64tb of guest memory).
+ */
+ slot_size = 2 * size_1gb;
+
+ max_slots = kvm_check_cap(KVM_CAP_NR_MEMSLOTS);
+ TEST_ASSERT(max_slots > first_slot, "KVM is broken");
+
+ /* All KVM MMUs should be able to survive a 128gb guest. */
+ max_mem = 128 * size_1gb;
+
+ calc_default_nr_vcpus();
+
+ while ((opt = getopt(argc, argv, "c:h:m:s:H")) != -1) {
+ switch (opt) {
+ case 'c':
+ nr_vcpus = atoi(optarg);
+ TEST_ASSERT(nr_vcpus > 0, "number of vcpus must be >0");
+ break;
+ case 'm':
+ max_mem = atoi(optarg) * size_1gb;
+ TEST_ASSERT(max_mem > 0, "memory size must be >0");
+ break;
+ case 's':
+ slot_size = atoi(optarg) * size_1gb;
+ TEST_ASSERT(slot_size > 0, "slot size must be >0");
+ break;
+ case 'H':
+ hugepages = true;
+ break;
+ case 'h':
+ default:
+ printf("usage: %s [-c nr_vcpus] [-m max_mem_in_gb] [-s slot_size_in_gb] [-H]\n", argv[0]);
+ exit(1);
+ }
+ }
+
+ vm = vm_create_default_with_vcpus(nr_vcpus, 0, 0, guest_code, NULL);
+
+ max_gpa = vm_get_max_gfn(vm) << vm_get_page_shift(vm);
+ TEST_ASSERT(max_gpa > (4 * slot_size), "MAXPHYADDR <4gb ");
+
+ fd = kvm_memfd_alloc(slot_size, hugepages);
+ mem = mmap(NULL, slot_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
+ TEST_ASSERT(mem != MAP_FAILED, "mmap() failed");
+
+ TEST_ASSERT(!madvise(mem, slot_size, MADV_NOHUGEPAGE), "madvise() failed");
+
+ /* Pre-fault the memory to avoid taking mmap_sem on guest page faults. */
+ for (i = 0; i < slot_size; i += vm_get_page_size(vm))
+ ((uint8_t *)mem)[i] = 0xaa;
+
+ gpa = 0;
+ for (slot = first_slot; slot < max_slots; slot++) {
+ gpa = start_gpa + ((slot - first_slot) * slot_size);
+ if (gpa + slot_size > max_gpa)
+ break;
+
+ if ((gpa - start_gpa) >= max_mem)
+ break;
+
+ vm_set_user_memory_region(vm, slot, 0, gpa, slot_size, mem);
+
+#ifdef __x86_64__
+ /* Identity map memory in the guest using 1gb pages. */
+ for (i = 0; i < slot_size; i += size_1gb)
+ __virt_pg_map(vm, gpa + i, gpa + i, X86_PAGE_SIZE_1G);
+#else
+ for (i = 0; i < slot_size; i += vm_get_page_size(vm))
+ virt_pg_map(vm, gpa + i, gpa + i);
+#endif
+ }
+
+ atomic_set(&rendezvous, nr_vcpus + 1);
+ threads = spawn_workers(vm, start_gpa, gpa);
+
+ pr_info("Running with %lugb of guest memory and %u vCPUs\n",
+ (gpa - start_gpa) / size_1gb, nr_vcpus);
+
+ rendezvous_with_vcpus(&time_start, "spawning");
+ rendezvous_with_vcpus(&time_run1, "run 1");
+ rendezvous_with_vcpus(&time_reset, "reset");
+ rendezvous_with_vcpus(&time_run2, "run 2");
+
+ time_run2 = timespec_sub(time_run2, time_reset);
+ time_reset = timespec_sub(time_reset, time_run1);
+ time_run1 = timespec_sub(time_run1, time_start);
+
+ pr_info("run1 = %ld.%.9lds, reset = %ld.%.9lds, run2 = %ld.%.9lds\n",
+ time_run1.tv_sec, time_run1.tv_nsec,
+ time_reset.tv_sec, time_reset.tv_nsec,
+ time_run2.tv_sec, time_run2.tv_nsec);
+
+ /*
+ * Delete even numbered slots (arbitrary) and unmap the first half of
+ * the backing (also arbitrary) to verify KVM correctly drops all
+ * references to the removed regions.
+ */
+ for (slot = (slot - 1) & ~1ull; slot >= first_slot; slot -= 2)
+ vm_set_user_memory_region(vm, slot, 0, 0, 0, NULL);
+
+ munmap(mem, slot_size / 2);
+
+ /* Sanity check that the vCPUs actually ran. */
+ for (i = 0; i < nr_vcpus; i++)
+ pthread_join(threads[i], NULL);
+
+ /*
+ * Deliberately exit without deleting the remaining memslots or closing
+ * kvm_fd to test cleanup via mmu_notifier.release.
+ */
+}
projects / kernel.git / commitdiff