// SPDX-License-Identifier: GPL-2.0
/*
* KVM dirty page logging test
*
* Copyright (C) 2018, Red Hat, Inc.
*/
#define _GNU_SOURCE /* for program_invocation_name */
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <time.h>
#include <pthread.h>
#include <linux/bitmap.h>
#include <linux/bitops.h>
#include "test_util.h"
#include "kvm_util.h"
#include "processor.h"
#define VCPU_ID 1
/* The memory slot index to track dirty pages */
#define TEST_MEM_SLOT_INDEX 1
/* Default guest test virtual memory offset */
#define DEFAULT_GUEST_TEST_MEM 0xc0000000
/* How many pages to dirty for each guest loop */
#define TEST_PAGES_PER_LOOP 1024
/* How many host loops to run (one KVM_GET_DIRTY_LOG for each loop) */
#define TEST_HOST_LOOP_N 32UL
/* Interval for each host loop (ms) */
#define TEST_HOST_LOOP_INTERVAL 10UL
/* Dirty bitmaps are always little endian, so we need to swap on big endian */
#if defined(__s390x__)
# define BITOP_LE_SWIZZLE ((BITS_PER_LONG-1) & ~0x7)
# define test_bit_le(nr, addr) \
test_bit((nr) ^ BITOP_LE_SWIZZLE, addr)
# define set_bit_le(nr, addr) \
set_bit((nr) ^ BITOP_LE_SWIZZLE, addr)
# define clear_bit_le(nr, addr) \
clear_bit((nr) ^ BITOP_LE_SWIZZLE, addr)
# define test_and_set_bit_le(nr, addr) \
test_and_set_bit((nr) ^ BITOP_LE_SWIZZLE, addr)
# define test_and_clear_bit_le(nr, addr) \
test_and_clear_bit((nr) ^ BITOP_LE_SWIZZLE, addr)
#else
# define test_bit_le test_bit
# define set_bit_le set_bit
# define clear_bit_le clear_bit
# define test_and_set_bit_le test_and_set_bit
# define test_and_clear_bit_le test_and_clear_bit
#endif
/*
* Guest/Host shared variables. Ensure addr_gva2hva() and/or
* sync_global_to/from_guest() are used when accessing from
* the host. READ/WRITE_ONCE() should also be used with anything
* that may change.
*/
static uint64_t host_page_size;
static uint64_t guest_page_size;
static uint64_t guest_num_pages;
static uint64_t random_array[TEST_PAGES_PER_LOOP];
static uint64_t iteration;
/*
* Guest physical memory offset of the testing memory slot.
* This will be set to the topmost valid physical address minus
* the test memory size.
*/
static uint64_t guest_test_phys_mem;
/*
* Guest virtual memory offset of the testing memory slot.
* Must not conflict with identity mapped test code.
*/
static uint64_t guest_test_virt_mem = DEFAULT_GUEST_TEST_MEM;
/*
* Continuously write to the first 8 bytes of a random pages within
* the testing memory region.
*/
static void guest_code(void)
{
uint64_t addr;
int i;
/*
* On s390x, all pages of a 1M segment are initially marked as dirty
* when a page of the segment is written to for the very first time.
* To compensate this specialty in this test, we need to touch all
* pages during the first iteration.
*/
for (i = 0; i < guest_num_pages; i++) {
addr = guest_test_virt_mem + i * guest_page_size;
*(uint64_t *)addr = READ_ONCE(iteration);
}
while (true) {
for (i = 0; i < TEST_PAGES_PER_LOOP; i++) {
addr = guest_test_virt_mem;
addr += (READ_ONCE(random_array[i]) % guest_num_pages)
* guest_page_size;
addr &= ~(host_page_size - 1);
*(uint64_t *)addr = READ_ONCE(iteration);
}
/* Tell the host that we need more random numbers */
GUEST_SYNC(1);
}
}
/* Host variables */
static bool host_quit;
/* Points to the test VM memory region on which we track dirty logs */
static void *host_test_mem;
static uint64_t host_num_pages;
/* For statistics only */
static uint64_t host_dirty_count;
static uint64_t host_clear_count;
static uint64_t host_track_next_count;
/*
* We use this bitmap to track some pages that should have its dirty
* bit set in the _next_ iteration. For example, if we detected the
* page value changed to current iteration but at the same time the
* page bit is cleared in the latest bitmap, then the system must
* report that write in the next get dirty log call.
*/
static unsigned long *host_bmap_track;
static void generate_random_array(uint64_t *guest_array, uint64_t size)
{
uint64_t i;
for (i = 0; i < size; i++)
guest_array[i] = random();
}
static void *vcpu_worker(void *data)
{
int ret;
struct kvm_vm *vm = data;
uint64_t *guest_array;
uint64_t pages_count = 0;
struct kvm_run *run;
run = vcpu_state(vm, VCPU_ID);
guest_array = addr_gva2hva(vm, (vm_vaddr_t)random_array);
generate_random_array(guest_array, TEST_PAGES_PER_LOOP);
while (!READ_ONCE(host_quit)) {
/* Let the guest dirty the random pages */
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) {
pages_count += TEST_PAGES_PER_LOOP;
generate_random_array(guest_array, TEST_PAGES_PER_LOOP);
} else {
TEST_FAIL("Invalid guest sync status: "
"exit_reason=%s\n",
exit_reason_str(run->exit_reason));
}
}
pr_info("Dirtied %"PRIu64" pages\n", pages_count);
return NULL;
}
static void vm_dirty_log_verify(enum vm_guest_mode mode, unsigned long *bmap)
{
uint64_t step = vm_num_host_pages(mode, 1);
uint64_t page;
uint64_t *value_ptr;
for (page = 0; page < host_num_pages; page += step) {
value_ptr = host_test_mem + page * host_page_size;
/* If this is a special page that we were tracking... */
if (test_and_clear_bit_le(page, host_bmap_track)) {
host_track_next_count++;
TEST_ASSERT(test_bit_le(page, bmap),
"Page %"PRIu64" should have its dirty bit "
"set in this iteration but it is missing",
page);
}
if (test_bit_le(page, bmap)) {
host_dirty_count++;
/*
* If the bit is set, the value written onto
* the corresponding page should be either the
* previous iteration number or the current one.
*/
TEST_ASSERT(*value_ptr == iteration ||
*value_ptr == iteration - 1,
"Set page %"PRIu64" value %"PRIu64
" incorrect (iteration=%"PRIu64")",
page, *value_ptr, iteration);
} else {
host_clear_count++;
/*
* If cleared, the value written can be any
* value smaller or equals to the iteration
* number. Note that the value can be exactly
* (iteration-1) if that write can happen
* like this:
*
* (1) increase loop count to "iteration-1"
* (2) write to page P happens (with value
* "iteration-1")
* (3) get dirty log for "iteration-1"; we'll
* see that page P bit is set (dirtied),
* and not set the bit in host_bmap_track
* (4) increase loop count to "iteration"
* (which is current iteration)
* (5) get dirty log for current iteration,
* we'll see that page P is cleared, with
* value "iteration-1".
*/
TEST_ASSERT(*value_ptr <= iteration,
"Clear page %"PRIu64" value %"PRIu64
" incorrect (iteration=%"PRIu64")",
page, *value_ptr, iteration);
if (*value_ptr == iteration) {
/*
* This page is _just_ modified; it
* should report its dirtyness in the
* next run
*/
set_bit_le(page, host_bmap_track);
}
}
}
}
static struct kvm_vm *create_vm(enum vm_guest_mode mode, uint32_t vcpuid,
uint64_t extra_mem_pages, void *guest_code)
{
struct kvm_vm *vm;
uint64_t extra_pg_pages = extra_mem_pages / 512 * 2;
pr_info("Testing guest mode: %s\n", vm_guest_mode_string(mode));
vm = _vm_create(mode, DEFAULT_GUEST_PHY_PAGES + extra_pg_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;
}
#define DIRTY_MEM_BITS 30 /* 1G */
#define PAGE_SHIFT_4K 12
#ifdef USE_CLEAR_DIRTY_LOG
static u64 dirty_log_manual_caps;
#endif
static void run_test(enum vm_guest_mode mode, unsigned long iterations,
unsigned long interval, uint64_t phys_offset)
{
pthread_t vcpu_thread;
struct kvm_vm *vm;
unsigned long *bmap;
/*
* We reserve page table for 2 times of extra dirty mem which
* will definitely cover the original (1G+) test range. 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,
2ul << (DIRTY_MEM_BITS - PAGE_SHIFT_4K),
guest_code);
guest_page_size = vm_get_page_size(vm);
/*
* A little more than 1G of guest page sized pages. Cover the
* case where the size is not aligned to 64 pages.
*/
guest_num_pages = (1ul << (DIRTY_MEM_BITS -
vm_get_page_shift(vm))) + 3;
guest_num_pages = vm_adjust_num_guest_pages(mode, guest_num_pages);
host_page_size = getpagesize();
host_num_pages = vm_num_host_pages(mode, guest_num_pages);
if (!phys_offset) {
guest_test_phys_mem = (vm_get_max_gfn(vm) -
guest_num_pages) * guest_page_size;
guest_test_phys_mem &= ~(host_page_size - 1);
} else {
guest_test_phys_mem = phys_offset;
}
#ifdef __s390x__
/* Align to 1M (segment size) */
guest_test_phys_mem &= ~((1 << 20) - 1);
#endif
pr_info("guest physical test memory offset: 0x%lx\n", guest_test_phys_mem);
bmap = bitmap_alloc(host_num_pages);
host_bmap_track = bitmap_alloc(host_num_pages);
#ifdef USE_CLEAR_DIRTY_LOG
struct kvm_enable_cap cap = {};
cap.cap = KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2;
cap.args[0] = dirty_log_manual_caps;
vm_enable_cap(vm, &cap);
#endif
/* Add an extra memory slot for testing dirty logging */
vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS,
guest_test_phys_mem,
TEST_MEM_SLOT_INDEX,
guest_num_pages,
KVM_MEM_LOG_DIRTY_PAGES);
/* Do mapping for the dirty track memory slot */
virt_map(vm, guest_test_virt_mem, guest_test_phys_mem, guest_num_pages, 0);
/* Cache the HVA pointer of the region */
host_test_mem = addr_gpa2hva(vm, (vm_paddr_t)guest_test_phys_mem);
#ifdef __x86_64__
vcpu_set_cpuid(vm, VCPU_ID, kvm_get_supported_cpuid());
#endif
ucall_init(vm, NULL);
/* Export the shared variables to the guest */
sync_global_to_guest(vm, host_page_size);
sync_global_to_guest(vm, guest_page_size);
sync_global_to_guest(vm, guest_test_virt_mem);
sync_global_to_guest(vm, guest_num_pages);
/* Start the iterations */
iteration = 1;
sync_global_to_guest(vm, iteration);
host_quit = false;
host_dirty_count = 0;
host_clear_count = 0;
host_track_next_count = 0;
pthread_create(&vcpu_thread, NULL, vcpu_worker, vm);
while (iteration < iterations) {
/* Give the vcpu thread some time to dirty some pages */
usleep(interval * 1000);
kvm_vm_get_dirty_log(vm, TEST_MEM_SLOT_INDEX, bmap);
#ifdef USE_CLEAR_DIRTY_LOG
kvm_vm_clear_dirty_log(vm, TEST_MEM_SLOT_INDEX, bmap, 0,
host_num_pages);
#endif
vm_dirty_log_verify(mode, bmap);
iteration++;
sync_global_to_guest(vm, iteration);
}
/* Tell the vcpu thread to quit */
host_quit = true;
pthread_join(vcpu_thread, NULL);
pr_info("Total bits checked: dirty (%"PRIu64"), clear (%"PRIu64"), "
"track_next (%"PRIu64")\n", host_dirty_count, host_clear_count,
host_track_next_count);
free(bmap);
free(host_bmap_track);
ucall_uninit(vm);
kvm_vm_free(vm);
}
struct guest_mode {
bool supported;
bool enabled;
};
static struct guest_mode guest_modes[NUM_VM_MODES];
#define guest_mode_init(mode, supported, enabled) ({ \
guest_modes[mode] = (struct guest_mode){ supported, enabled }; \
})
static void help(char *name)
{
int i;
puts("");
printf("usage: %s [-h] [-i iterations] [-I interval] "
"[-p offset] [-m mode]\n", name);
puts("");
printf(" -i: specify iteration counts (default: %"PRIu64")\n",
TEST_HOST_LOOP_N);
printf(" -I: specify interval in ms (default: %"PRIu64" ms)\n",
TEST_HOST_LOOP_INTERVAL);
printf(" -p: specify guest physical test memory offset\n"
" Warning: a low offset can conflict with the loaded test code.\n");
printf(" -m: specify the guest mode ID to test "
"(default: test all supported modes)\n"
" This option may be used multiple times.\n"
" Guest mode IDs:\n");
for (i = 0; i < NUM_VM_MODES; ++i) {
printf(" %d: %s%s\n", i, vm_guest_mode_string(i),
guest_modes[i].supported ? " (supported)" : "");
}
puts("");
exit(0);
}
int main(int argc, char *argv[])
{
unsigned long iterations = TEST_HOST_LOOP_N;
unsigned long interval = TEST_HOST_LOOP_INTERVAL;
bool mode_selected = false;
uint64_t phys_offset = 0;
unsigned int mode;
int opt, i;
#ifdef USE_CLEAR_DIRTY_LOG
dirty_log_manual_caps =
kvm_check_cap(KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2);
if (!dirty_log_manual_caps) {
print_skip("KVM_CLEAR_DIRTY_LOG not available");
exit(KSFT_SKIP);
}
dirty_log_manual_caps &= (KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE |
KVM_DIRTY_LOG_INITIALLY_SET);
#endif
#ifdef __x86_64__
guest_mode_init(VM_MODE_PXXV48_4K, true, true);
#endif
#ifdef __aarch64__
guest_mode_init(VM_MODE_P40V48_4K, true, true);
guest_mode_init(VM_MODE_P40V48_64K, true, true);
{
unsigned int limit = kvm_check_cap(KVM_CAP_ARM_VM_IPA_SIZE);
if (limit >= 52)
guest_mode_init(VM_MODE_P52V48_64K, true, true);
if (limit >= 48) {
guest_mode_init(VM_MODE_P48V48_4K, true, true);
guest_mode_init(VM_MODE_P48V48_64K, true, true);
}
}
#endif
#ifdef __s390x__
guest_mode_init(VM_MODE_P40V48_4K, true, true);
#endif
while ((opt = getopt(argc, argv, "hi:I:p:m:")) != -1) {
switch (opt) {
case 'i':
iterations = strtol(optarg, NULL, 10);
break;
case 'I':
interval = strtol(optarg, NULL, 10);
break;
case 'p':
phys_offset = strtoull(optarg, NULL, 0);
break;
case 'm':
if (!mode_selected) {
for (i = 0; i < NUM_VM_MODES; ++i)
guest_modes[i].enabled = false;
mode_selected = true;
}
mode = strtoul(optarg, NULL, 10);
TEST_ASSERT(mode < NUM_VM_MODES,
"Guest mode ID %d too big", mode);
guest_modes[mode].enabled = true;
break;
case 'h':
default:
help(argv[0]);
break;
}
}
TEST_ASSERT(iterations > 2, "Iterations must be greater than two");
TEST_ASSERT(interval > 0, "Interval must be greater than zero");
pr_info("Test iterations: %"PRIu64", interval: %"PRIu64" (ms)\n",
iterations, interval);
srandom(time(0));
for (i = 0; i < NUM_VM_MODES; ++i) {
if (!guest_modes[i].enabled)
continue;
TEST_ASSERT(guest_modes[i].supported,
"Guest mode ID %d (%s) not supported.",
i, vm_guest_mode_string(i));
run_test(i, iterations, interval, phys_offset);
}
return 0;
}
