OpenCloudOS-Kernel/tools/testing/selftests/kvm/dirty_log_test.c

309 lines
8.4 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* KVM dirty page logging test
*
* Copyright (C) 2018, Red Hat, Inc.
*/
#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"
#define DEBUG printf
#define VCPU_ID 1
/* The memory slot index to track dirty pages */
#define TEST_MEM_SLOT_INDEX 1
/*
* GPA offset of the testing memory slot. Must be bigger than the
* default vm mem slot, which is DEFAULT_GUEST_PHY_PAGES.
*/
#define TEST_MEM_OFFSET (1ULL << 30) /* 1G */
/* Size of the testing memory slot */
#define TEST_MEM_PAGES (1ULL << 18) /* 1G for 4K pages */
/* 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 32
/* Interval for each host loop (ms) */
#define TEST_HOST_LOOP_INTERVAL 10
/*
* Guest variables. We use these variables to share data between host
* and guest. There are two copies of the variables, one in host memory
* (which is unused) and one in guest memory. When the host wants to
* access these variables, it needs to call addr_gva2hva() to access the
* guest copy.
*/
uint64_t guest_random_array[TEST_PAGES_PER_LOOP];
uint64_t guest_iteration;
uint64_t guest_page_size;
/*
* Writes to the first byte of a random page within the testing memory
* region continuously.
*/
void guest_code(void)
{
int i = 0;
uint64_t volatile *array = guest_random_array;
uint64_t volatile *guest_addr;
while (true) {
for (i = 0; i < TEST_PAGES_PER_LOOP; i++) {
/*
* Write to the first 8 bytes of a random page
* on the testing memory region.
*/
guest_addr = (uint64_t *)
(TEST_MEM_OFFSET +
(array[i] % TEST_MEM_PAGES) * guest_page_size);
*guest_addr = guest_iteration;
}
/* Tell the host that we need more random numbers */
GUEST_SYNC(1);
}
}
/*
* Host variables. These variables should only be used by the host
* rather than the guest.
*/
bool host_quit;
/* Points to the test VM memory region on which we track dirty logs */
void *host_test_mem;
/* For statistics only */
uint64_t host_dirty_count;
uint64_t host_clear_count;
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.
*/
unsigned long *host_bmap_track;
void generate_random_array(uint64_t *guest_array, uint64_t size)
{
uint64_t i;
for (i = 0; i < size; i++) {
guest_array[i] = random();
}
}
void *vcpu_worker(void *data)
{
int ret;
uint64_t loops, *guest_array, pages_count = 0;
struct kvm_vm *vm = data;
struct kvm_run *run;
struct guest_args args;
run = vcpu_state(vm, VCPU_ID);
/* Retrieve the guest random array pointer and cache it */
guest_array = addr_gva2hva(vm, (vm_vaddr_t)guest_random_array);
DEBUG("VCPU starts\n");
generate_random_array(guest_array, TEST_PAGES_PER_LOOP);
while (!READ_ONCE(host_quit)) {
/* Let the guest to dirty these random pages */
ret = _vcpu_run(vm, VCPU_ID);
guest_args_read(vm, VCPU_ID, &args);
if (run->exit_reason == KVM_EXIT_IO &&
args.port == GUEST_PORT_SYNC) {
pages_count += TEST_PAGES_PER_LOOP;
generate_random_array(guest_array, TEST_PAGES_PER_LOOP);
} else {
TEST_ASSERT(false,
"Invalid guest sync status: "
"exit_reason=%s\n",
exit_reason_str(run->exit_reason));
}
}
DEBUG("VCPU exits, dirtied %"PRIu64" pages\n", pages_count);
return NULL;
}
void vm_dirty_log_verify(unsigned long *bmap, uint64_t iteration)
{
uint64_t page;
uint64_t volatile *value_ptr;
for (page = 0; page < TEST_MEM_PAGES; page++) {
value_ptr = host_test_mem + page * getpagesize();
/* If this is a special page that we were tracking... */
if (test_and_clear_bit(page, host_bmap_track)) {
host_track_next_count++;
TEST_ASSERT(test_bit(page, bmap),
"Page %"PRIu64" should have its dirty bit "
"set in this iteration but it is missing",
page);
}
if (test_bit(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(page, host_bmap_track);
}
}
}
}
void help(char *name)
{
puts("");
printf("usage: %s [-i iterations] [-I interval] [-h]\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);
puts("");
exit(0);
}
int main(int argc, char *argv[])
{
pthread_t vcpu_thread;
struct kvm_vm *vm;
uint64_t volatile *psize, *iteration;
unsigned long *bmap, iterations = TEST_HOST_LOOP_N,
interval = TEST_HOST_LOOP_INTERVAL;
int opt;
while ((opt = getopt(argc, argv, "hi:I:")) != -1) {
switch (opt) {
case 'i':
iterations = strtol(optarg, NULL, 10);
break;
case 'I':
interval = strtol(optarg, NULL, 10);
break;
case 'h':
default:
help(argv[0]);
break;
}
}
TEST_ASSERT(iterations > 2, "Iteration must be bigger than zero\n");
TEST_ASSERT(interval > 0, "Interval must be bigger than zero");
DEBUG("Test iterations: %"PRIu64", interval: %"PRIu64" (ms)\n",
iterations, interval);
srandom(time(0));
bmap = bitmap_alloc(TEST_MEM_PAGES);
host_bmap_track = bitmap_alloc(TEST_MEM_PAGES);
vm = vm_create_default(VCPU_ID, TEST_MEM_PAGES, guest_code);
/* Add an extra memory slot for testing dirty logging */
vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS,
TEST_MEM_OFFSET,
TEST_MEM_SLOT_INDEX,
TEST_MEM_PAGES,
KVM_MEM_LOG_DIRTY_PAGES);
/* Cache the HVA pointer of the region */
host_test_mem = addr_gpa2hva(vm, (vm_paddr_t)TEST_MEM_OFFSET);
/* Do 1:1 mapping for the dirty track memory slot */
virt_map(vm, TEST_MEM_OFFSET, TEST_MEM_OFFSET,
TEST_MEM_PAGES * getpagesize(), 0);
vcpu_set_cpuid(vm, VCPU_ID, kvm_get_supported_cpuid());
/* Tell the guest about the page size on the system */
psize = addr_gva2hva(vm, (vm_vaddr_t)&guest_page_size);
*psize = getpagesize();
/* Start the iterations */
iteration = addr_gva2hva(vm, (vm_vaddr_t)&guest_iteration);
*iteration = 1;
/* Start dirtying pages */
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);
vm_dirty_log_verify(bmap, *iteration);
(*iteration)++;
}
/* Tell the vcpu thread to quit */
host_quit = true;
pthread_join(vcpu_thread, NULL);
DEBUG("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);
kvm_vm_free(vm);
return 0;
}