path: root/tools/testing/selftests/kvm/lib/kvm_util.c

/*
 * tools/testing/selftests/kvm/lib/kvm_util.c
 *
 * Copyright (C) 2018, Google LLC.
 *
 * This work is licensed under the terms of the GNU GPL, version 2.
 */

#include "test_util.h"
#include "kvm_util.h"
#include "kvm_util_internal.h"

#include <assert.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <linux/kernel.h>

#define KVM_UTIL_PGS_PER_HUGEPG 512
#define KVM_UTIL_MIN_PFN	2

/* Aligns x up to the next multiple of size. Size must be a power of 2. */
static void *align(void *x, size_t size)
{
	size_t mask = size - 1;
	TEST_ASSERT(size != 0 && !(size & (size - 1)),
		    "size not a power of 2: %lu", size);
	return (void *) (((size_t) x + mask) & ~mask);
}

/*
 * Capability
 *
 * Input Args:
 *   cap - Capability
 *
 * Output Args: None
 *
 * Return:
 *   On success, the Value corresponding to the capability (KVM_CAP_*)
 *   specified by the value of cap.  On failure a TEST_ASSERT failure
 *   is produced.
 *
 * Looks up and returns the value corresponding to the capability
 * (KVM_CAP_*) given by cap.
 */
int kvm_check_cap(long cap)
{
	int ret;
	int kvm_fd;

	kvm_fd = open(KVM_DEV_PATH, O_RDONLY);
	if (kvm_fd < 0)
		exit(KSFT_SKIP);

	ret = ioctl(kvm_fd, KVM_CHECK_EXTENSION, cap);
	TEST_ASSERT(ret != -1, "KVM_CHECK_EXTENSION IOCTL failed,\n"
		"  rc: %i errno: %i", ret, errno);

	close(kvm_fd);

	return ret;
}

/* VM Enable Capability
 *
 * Input Args:
 *   vm - Virtual Machine
 *   cap - Capability
 *
 * Output Args: None
 *
 * Return: On success, 0. On failure a TEST_ASSERT failure is produced.
 *
 * Enables a capability (KVM_CAP_*) on the VM.
 */
int vm_enable_cap(struct kvm_vm *vm, struct kvm_enable_cap *cap)
{
	int ret;

	ret = ioctl(vm->fd, KVM_ENABLE_CAP, cap);
	TEST_ASSERT(ret == 0, "KVM_ENABLE_CAP IOCTL failed,\n"
		"  rc: %i errno: %i", ret, errno);

	return ret;
}

static void vm_open(struct kvm_vm *vm, int perm, unsigned long type)
{
	vm->kvm_fd = open(KVM_DEV_PATH, perm);
	if (vm->kvm_fd < 0)
		exit(KSFT_SKIP);

	vm->fd = ioctl(vm->kvm_fd, KVM_CREATE_VM, type);
	TEST_ASSERT(vm->fd >= 0, "KVM_CREATE_VM ioctl failed, "
		"rc: %i errno: %i", vm->fd, errno);
}

const char * const vm_guest_mode_string[] = {
	"PA-bits:52, VA-bits:48, 4K pages",
	"PA-bits:52, VA-bits:48, 64K pages",
	"PA-bits:48, VA-bits:48, 4K pages",
	"PA-bits:48, VA-bits:48, 64K pages",
	"PA-bits:40, VA-bits:48, 4K pages",
	"PA-bits:40, VA-bits:48, 64K pages",
};
_Static_assert(sizeof(vm_guest_mode_string)/sizeof(char *) == NUM_VM_MODES,
	       "Missing new mode strings?");

/*
 * VM Create
 *
 * Input Args:
 *   mode - VM Mode (e.g. VM_MODE_P52V48_4K)
 *   phy_pages - Physical memory pages
 *   perm - permission
 *
 * Output Args: None
 *
 * Return:
 *   Pointer to opaque structure that describes the created VM.
 *
 * Creates a VM with the mode specified by mode (e.g. VM_MODE_P52V48_4K).
 * When phy_pages is non-zero, a memory region of phy_pages physical pages
 * is created and mapped starting at guest physical address 0.  The file
 * descriptor to control the created VM is created with the permissions
 * given by perm (e.g. O_RDWR).
 */
struct kvm_vm *_vm_create(enum vm_guest_mode mode, uint64_t phy_pages,
			  int perm, unsigned long type)
{
	struct kvm_vm *vm;
	int kvm_fd;

	vm = calloc(1, sizeof(*vm));
	TEST_ASSERT(vm != NULL, "Insufficient Memory");

	vm->mode = mode;
	vm->type = type;
	vm_open(vm, perm, type);

	/* Setup mode specific traits. */
	switch (vm->mode) {
	case VM_MODE_P52V48_4K:
		vm->pgtable_levels = 4;
		vm->pa_bits = 52;
		vm->va_bits = 48;
		vm->page_size = 0x1000;
		vm->page_shift = 12;
		break;
	case VM_MODE_P52V48_64K:
		vm->pgtable_levels = 3;
		vm->pa_bits = 52;
		vm->va_bits = 48;
		vm->page_size = 0x10000;
		vm->page_shift = 16;
		break;
	case VM_MODE_P48V48_4K:
		vm->pgtable_levels = 4;
		vm->pa_bits = 48;
		vm->va_bits = 48;
		vm->page_size = 0x1000;
		vm->page_shift = 12;
		break;
	case VM_MODE_P48V48_64K:
		vm->pgtable_levels = 3;
		vm->pa_bits = 48;
		vm->va_bits = 48;
		vm->page_size = 0x10000;
		vm->page_shift = 16;
		break;
	case VM_MODE_P40V48_4K:
		vm->pgtable_levels = 4;
		vm->pa_bits = 40;
		vm->va_bits = 48;
		vm->page_size = 0x1000;
		vm->page_shift = 12;
		break;
	case VM_MODE_P40V48_64K:
		vm->pgtable_levels = 3;
		vm->pa_bits = 40;
		vm->va_bits = 48;
		vm->page_size = 0x10000;
		vm->page_shift = 16;
		break;
	default:
		TEST_ASSERT(false, "Unknown guest mode, mode: 0x%x", mode);
	}

	/* Limit to VA-bit canonical virtual addresses. */
	vm->vpages_valid = sparsebit_alloc();
	sparsebit_set_num(vm->vpages_valid,
		0, (1ULL << (vm->va_bits - 1)) >> vm->page_shift);
	sparsebit_set_num(vm->vpages_valid,
		(~((1ULL << (vm->va_bits - 1)) - 1)) >> vm->page_shift,
		(1ULL << (vm->va_bits - 1)) >> vm->page_shift);

	/* Limit physical addresses to PA-bits. */
	vm->max_gfn = ((1ULL << vm->pa_bits) >> vm->page_shift) - 1;

	/* Allocate and setup memory for guest. */
	vm->vpages_mapped = sparsebit_alloc();
	if (phy_pages != 0)
		vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS,
					    0, 0, phy_pages, 0);

	return vm;
}

struct kvm_vm *vm_create(enum vm_guest_mode mode, uint64_t phy_pages, int perm)
{
	return _vm_create(mode, phy_pages, perm, 0);
}

/*
 * VM Restart
 *
 * Input Args:
 *   vm - VM that has been released before
 *   perm - permission
 *
 * Output Args: None
 *
 * Reopens the file descriptors associated to the VM and reinstates the
 * global state, such as the irqchip and the memory regions that are mapped
 * into the guest.
 */
void kvm_vm_restart(struct kvm_vm *vmp, int perm)
{
	struct userspace_mem_region *region;

	vm_open(vmp, perm, vmp->type);
	if (vmp->has_irqchip)
		vm_create_irqchip(vmp);

	for (region = vmp->userspace_mem_region_head; region;
		region = region->next) {
		int ret = ioctl(vmp->fd, KVM_SET_USER_MEMORY_REGION, &region->region);
		TEST_ASSERT(ret == 0, "KVM_SET_USER_MEMORY_REGION IOCTL failed,\n"
			    "  rc: %i errno: %i\n"
			    "  slot: %u flags: 0x%x\n"
			    "  guest_phys_addr: 0x%lx size: 0x%lx",
			    ret, errno, region->region.slot,
			    region->region.flags,
			    region->region.guest_phys_addr,
			    region->region.memory_size);
	}
}

void kvm_vm_get_dirty_log(struct kvm_vm *vm, int slot, void *log)
{
	struct kvm_dirty_log args = { .dirty_bitmap = log, .slot = slot };
	int ret;

	ret = ioctl(vm->fd, KVM_GET_DIRTY_LOG, &args);
	TEST_ASSERT(ret == 0, "%s: KVM_GET_DIRTY_LOG failed: %s",
		    strerror(-ret));
}

void kvm_vm_clear_dirty_log(struct kvm_vm *vm, int slot, void *log,
			    uint64_t first_page, uint32_t num_pages)
{
	struct kvm_clear_dirty_log args = { .dirty_bitmap = log, .slot = slot,
		                            .first_page = first_page,