KVM: selftests: Support multiple vCPUs in demand paging test

#include "processor.h"

#ifdef __NR_userfaultfd

#define VCPU_ID				1

/* The memory slot index demand page */

#define TEST_MEM_SLOT_INDEX		1

#define DEFAULT_GUEST_TEST_MEM_SIZE (1 << 30) /* 1G */

#ifdef PRINT_PER_VCPU_UPDATES

#define PER_VCPU_DEBUG(...) DEBUG(__VA_ARGS__)

#else

#define PER_VCPU_DEBUG(...)

#endif

#define MAX_VCPUS 512

/*

 * Guest/Host shared variables. Ensure addr_gva2hva() and/or

 * sync_global_to/from_guest() are used when accessing from

	struct kvm_vm *vm;

};

static struct vcpu_args vcpu_args;

static struct vcpu_args vcpu_args[MAX_VCPUS];

/*

 * Continuously write to the first 8 bytes of each page in the demand paging

 * memory region.

 */

static void guest_code(void)

static void guest_code(uint32_t vcpu_id)

{

	uint64_t gva = vcpu_args.gva;

	uint64_t pages = vcpu_args.pages;

	uint64_t gva;

	uint64_t pages;

	int i;

	/* Make sure vCPU args data structure is not corrupt. */

	GUEST_ASSERT(vcpu_args[vcpu_id].vcpu_id == vcpu_id);

	gva = vcpu_args[vcpu_id].gva;

	pages = vcpu_args[vcpu_id].pages;

	for (i = 0; i < pages; i++) {

		uint64_t addr = gva + (i * guest_page_size);

	GUEST_SYNC(1);

}

/* Points to the test VM memory region on which we are doing demand paging */

static void *host_test_mem;

static uint64_t host_num_pages;

static void *vcpu_worker(void *data)

{

	int ret;

	struct kvm_vm *vm = vcpu_args.vm;

	int vcpu_id = vcpu_args.vcpu_id;

	struct vcpu_args *args = (struct vcpu_args *)data;

	struct kvm_vm *vm = args->vm;

	int vcpu_id = args->vcpu_id;

	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 */

	return NULL;

}

static struct kvm_vm *create_vm(enum vm_guest_mode mode, uint32_t vcpuid,

				uint64_t extra_mem_pages, void *guest_code)

#define PAGE_SHIFT_4K  12

#define PTES_PER_4K_PT 512

static struct kvm_vm *create_vm(enum vm_guest_mode mode, int vcpus,

				uint64_t vcpu_memory_bytes)

{

	struct kvm_vm *vm;

	uint64_t extra_pg_pages = extra_mem_pages / 512 * 2;

	uint64_t pages = DEFAULT_GUEST_PHY_PAGES;

	vm = _vm_create(mode, DEFAULT_GUEST_PHY_PAGES + extra_pg_pages, O_RDWR);

	/* Account for a few pages per-vCPU for stacks */

	pages += DEFAULT_STACK_PGS * vcpus;

	/*

	 * Reserve twice the ammount of memory needed to map the test region and

	 * the page table / stacks region, at 4k, for page tables. Do the

	 * calculation with 4K page size: the smallest of all archs. (e.g., 64K

	 * page size guest will need even less memory for page tables).

	 */

	pages += (2 * pages) / PTES_PER_4K_PT;

	pages += ((2 * vcpus * vcpu_memory_bytes) >> PAGE_SHIFT_4K) /

		 PTES_PER_4K_PT;

	pages = vm_adjust_num_guest_pages(mode, pages);

	vm = _vm_create(mode, pages, O_RDWR);

	kvm_vm_elf_load(vm, program_invocation_name, 0, 0);

#ifdef __x86_64__

	vm_create_irqchip(vm);

#endif

	vm_vcpu_add_default(vm, vcpuid, guest_code);

	return vm;

}

static int setup_demand_paging(struct kvm_vm *vm,

			       pthread_t *uffd_handler_thread, int pipefd,

			       useconds_t uffd_delay)

			       useconds_t uffd_delay,

			       struct uffd_handler_args *uffd_args,

			       void *hva, uint64_t len)

{

	int uffd;

	struct uffdio_api uffdio_api;

	struct uffdio_register uffdio_register;

	struct uffd_handler_args uffd_args;

	guest_data_prototype = malloc(host_page_size);

	TEST_ASSERT(guest_data_prototype,

		    "Failed to allocate buffer for guest data pattern");

	memset(guest_data_prototype, 0xAB, host_page_size);

	uffd = syscall(__NR_userfaultfd, O_CLOEXEC | O_NONBLOCK);

	if (uffd == -1) {

		return -1;

	}

	uffdio_register.range.start = (uint64_t)host_test_mem;

	uffdio_register.range.len = host_num_pages * host_page_size;

	uffdio_register.range.start = (uint64_t)hva;

	uffdio_register.range.len = len;

	uffdio_register.mode = UFFDIO_REGISTER_MODE_MISSING;

	if (ioctl(uffd, UFFDIO_REGISTER, &uffdio_register) == -1) {

		DEBUG("ioctl uffdio_register failed\n");

		return -1;

	}

	uffd_args.uffd = uffd;

	uffd_args.pipefd = pipefd;

	uffd_args.delay = uffd_delay;

	uffd_args->uffd = uffd;

	uffd_args->pipefd = pipefd;

	uffd_args->delay = uffd_delay;

	pthread_create(uffd_handler_thread, NULL, uffd_handler_thread_fn,

		       &uffd_args);

		       uffd_args);

	PER_VCPU_DEBUG("Created uffd thread for HVA range [%p, %p)\n",

		       hva, hva + len);

	return 0;

}

#define PAGE_SHIFT_4K  12

static void run_test(enum vm_guest_mode mode, bool use_uffd,

		     useconds_t uffd_delay, uint64_t guest_memory_bytes)

		     useconds_t uffd_delay, int vcpus,

		     uint64_t vcpu_memory_bytes)

{

	pthread_t vcpu_thread;

	pthread_t uffd_handler_thread;

	int pipefd[2];

	pthread_t *vcpu_threads;

	pthread_t *uffd_handler_threads = NULL;

	struct uffd_handler_args *uffd_args = NULL;

	int *pipefds = NULL;

	struct kvm_vm *vm;

	uint64_t guest_num_pages;

	int vcpu_id;

	int r;

	/*

	 * We reserve page table for twice the ammount of memory we intend

	 * to use in the test region for demand paging. Here we do the

	 * calculation with 4K page size which is the smallest so the page

	 * number will be enough for all archs. (e.g., 64K page size guest

	 * will need even less memory for page tables).

	 */

	vm = create_vm(mode, VCPU_ID,

		       (2 * guest_memory_bytes) >> PAGE_SHIFT_4K,

		       guest_code);

	vm = create_vm(mode, vcpus, vcpu_memory_bytes);

	guest_page_size = vm_get_page_size(vm);

	TEST_ASSERT(guest_memory_bytes % guest_page_size == 0,

	TEST_ASSERT(vcpu_memory_bytes % guest_page_size == 0,

		    "Guest memory size is not guest page size aligned.");

	guest_num_pages = guest_memory_bytes / guest_page_size;

	guest_num_pages = (vcpus * vcpu_memory_bytes) / guest_page_size;

	guest_num_pages = vm_adjust_num_guest_pages(mode, guest_num_pages);

#ifdef __s390x__

	/* Round up to multiple of 1M (segment size) */

	 */

	TEST_ASSERT(guest_num_pages < vm_get_max_gfn(vm),

		    "Requested more guest memory than address space allows.\n"

		    "    guest pages: %lx max gfn: %lx\n",

		    guest_num_pages, vm_get_max_gfn(vm));

		    "    guest pages: %lx max gfn: %lx vcpus: %d wss: %lx]\n",

		    guest_num_pages, vm_get_max_gfn(vm), vcpus,

		    vcpu_memory_bytes);

	host_page_size = getpagesize();

	TEST_ASSERT(guest_memory_bytes % host_page_size == 0,

	TEST_ASSERT(vcpu_memory_bytes % host_page_size == 0,

		    "Guest memory size is not host page size aligned.");

	host_num_pages = guest_memory_bytes / host_page_size;

	guest_test_phys_mem = (vm_get_max_gfn(vm) - guest_num_pages) *

			      guest_page_size;

	virt_map(vm, guest_test_virt_mem, guest_test_phys_mem,

		 guest_num_pages * guest_page_size, 0);

	ucall_init(vm, NULL);

	guest_data_prototype = malloc(host_page_size);

	TEST_ASSERT(guest_data_prototype,

		    "Failed to allocate buffer for guest data pattern");

	memset(guest_data_prototype, 0xAB, host_page_size);

	vcpu_threads = malloc(vcpus * sizeof(*vcpu_threads));

	TEST_ASSERT(vcpu_threads, "Memory allocation failed");

	if (use_uffd) {

		uffd_handler_threads =

			malloc(vcpus * sizeof(*uffd_handler_threads));

		TEST_ASSERT(uffd_handler_threads, "Memory allocation failed");

		uffd_args = malloc(vcpus * sizeof(*uffd_args));

		TEST_ASSERT(uffd_args, "Memory allocation failed");

		pipefds = malloc(sizeof(int) * vcpus * 2);

		TEST_ASSERT(pipefds, "Unable to allocate memory for pipefd");

	}

	for (vcpu_id = 0; vcpu_id < vcpus; vcpu_id++) {

		vm_paddr_t vcpu_gpa;

		void *vcpu_hva;

		vm_vcpu_add_default(vm, vcpu_id, guest_code);

		vcpu_gpa = guest_test_phys_mem + (vcpu_id * vcpu_memory_bytes);

		PER_VCPU_DEBUG("Added VCPU %d with test mem gpa [%lx, %lx)\n",

			       vcpu_id, vcpu_gpa, vcpu_gpa + vcpu_memory_bytes);

		/* Cache the HVA pointer of the region */

	host_test_mem = addr_gpa2hva(vm, (vm_paddr_t)guest_test_phys_mem);

		vcpu_hva = addr_gpa2hva(vm, vcpu_gpa);

		if (use_uffd) {

		/* Set up user fault fd to handle demand paging requests. */

		r = pipe2(pipefd, O_CLOEXEC | O_NONBLOCK);

			/*

			 * Set up user fault fd to handle demand paging

			 * requests.

			 */

			r = pipe2(&pipefds[vcpu_id * 2],

				  O_CLOEXEC | O_NONBLOCK);

			TEST_ASSERT(!r, "Failed to set up pipefd");

		r = setup_demand_paging(vm, &uffd_handler_thread, pipefd[0],

					uffd_delay);

			r = setup_demand_paging(vm,

						&uffd_handler_threads[vcpu_id],

						pipefds[vcpu_id * 2],

						uffd_delay, &uffd_args[vcpu_id],

						vcpu_hva, vcpu_memory_bytes);

			if (r < 0)

				exit(-r);

		}

#ifdef __x86_64__

	vcpu_set_cpuid(vm, VCPU_ID, kvm_get_supported_cpuid());

#endif

#ifdef __aarch64__

	ucall_init(vm, NULL);

		vcpu_set_cpuid(vm, vcpu_id, kvm_get_supported_cpuid());

#endif

		vcpu_args[vcpu_id].vm = vm;

		vcpu_args[vcpu_id].vcpu_id = vcpu_id;

		vcpu_args[vcpu_id].gva = guest_test_virt_mem +

					 (vcpu_id * vcpu_memory_bytes);

		vcpu_args[vcpu_id].pages = vcpu_memory_bytes / guest_page_size;

	}

	/* Export the shared variables to the guest */

	sync_global_to_guest(vm, host_page_size);

	sync_global_to_guest(vm, guest_page_size);

	vcpu_args.vm = vm;

	vcpu_args.vcpu_id = VCPU_ID;

	vcpu_args.gva = guest_test_virt_mem;

	vcpu_args.pages = guest_num_pages;

	sync_global_to_guest(vm, vcpu_args);

	pthread_create(&vcpu_thread, NULL, vcpu_worker, &vcpu_args);

	/* Wait for the vcpu thread to quit */

	pthread_join(vcpu_thread, NULL);

	DEBUG("Finished creating vCPUs and starting uffd threads\n");

	for (vcpu_id = 0; vcpu_id < vcpus; vcpu_id++) {

		pthread_create(&vcpu_threads[vcpu_id], NULL, vcpu_worker,

			       &vcpu_args[vcpu_id]);

	}

	DEBUG("Started all vCPUs\n");

	/* Wait for the vcpu threads to quit */

	for (vcpu_id = 0; vcpu_id < vcpus; vcpu_id++) {

		pthread_join(vcpu_threads[vcpu_id], NULL);

		PER_VCPU_DEBUG("Joined thread for vCPU %d\n", vcpu_id);

	}

	DEBUG("All vCPU threads joined\n");

	if (use_uffd) {

		char c;

		/* Tell the user fault fd handler thread to quit */

		r = write(pipefd[1], &c, 1);

		/* Tell the user fault fd handler threads to quit */

		for (vcpu_id = 0; vcpu_id < vcpus; vcpu_id++) {

			r = write(pipefds[vcpu_id * 2 + 1], &c, 1);

			TEST_ASSERT(r == 1, "Unable to write to pipefd");

		pthread_join(uffd_handler_thread, NULL);

			pthread_join(uffd_handler_threads[vcpu_id], NULL);

		}

	}

	ucall_uninit(vm);

	kvm_vm_free(vm);

	free(guest_data_prototype);

	free(vcpu_threads);

	if (use_uffd) {

		free(uffd_handler_threads);

		free(uffd_args);

		free(pipefds);

	}

}

struct guest_mode {

	puts("");

	printf("usage: %s [-h] [-m mode] [-u] [-d uffd_delay_usec]\n"

	       "          [-b memory]\n", name);

	       "          [-b memory] [-v vcpus]\n", name);

	printf(" -m: specify the guest mode ID to test\n"

	       "     (default: test all supported modes)\n"

	       "     This option may be used multiple times.\n"

	       "     FD handler to simulate demand paging\n"

	       "     overheads. Ignored without -u.\n");

	printf(" -b: specify the size of the memory region which should be\n"

	       "     demand paged. e.g. 10M or 3G. Default: 1G\n");

	       "     demand paged by each vCPU. e.g. 10M or 3G.\n"

	       "     Default: 1G\n");

	printf(" -v: specify the number of vCPUs to run.\n");

	puts("");

	exit(0);

}

int main(int argc, char *argv[])

{

	bool mode_selected = false;

	uint64_t guest_memory_bytes = DEFAULT_GUEST_TEST_MEM_SIZE;

	uint64_t vcpu_memory_bytes = DEFAULT_GUEST_TEST_MEM_SIZE;

	int vcpus = 1;

	unsigned int mode;

	int opt, i;

	bool use_uffd = false;

	guest_mode_init(VM_MODE_P40V48_4K, true, true);

#endif

	while ((opt = getopt(argc, argv, "hm:ud:b:")) != -1) {

	while ((opt = getopt(argc, argv, "hm:ud:b:v:")) != -1) {

		switch (opt) {

		case 'm':

			if (!mode_selected) {

				    "A negative UFFD delay is not supported.");

			break;

		case 'b':

			guest_memory_bytes = parse_size(optarg);

			vcpu_memory_bytes = parse_size(optarg);

			break;

		case 'v':

			vcpus = atoi(optarg);

			TEST_ASSERT(vcpus > 0,

				    "Must have a positive number of vCPUs");

			TEST_ASSERT(vcpus <= MAX_VCPUS,

				    "This test does not currently support\n"

				    "more than %d vCPUs.", MAX_VCPUS);

			break;

		case 'h':

		default:

		TEST_ASSERT(guest_modes[i].supported,

			    "Guest mode ID %d (%s) not supported.",

			    i, vm_guest_mode_string(i));

		run_test(i, use_uffd, uffd_delay, guest_memory_bytes);

		run_test(i, use_uffd, uffd_delay, vcpus, vcpu_memory_bytes);

	}

	return 0;