kvm: selftest: add dirty logging test (3b4cd0ff) · Commits · 戴 / test

tools/testing/selftests/kvm/Makefile

+2 −0

Original line number	Diff line number	Diff line
		@@ -11,6 +11,7 @@ TEST_GEN_PROGS_x86_64 += sync_regs_test
		TEST_GEN_PROGS_x86_64 += vmx_tsc_adjust_test
		TEST_GEN_PROGS_x86_64 += cr4_cpuid_sync_test
		TEST_GEN_PROGS_x86_64 += state_test
		TEST_GEN_PROGS_x86_64 += dirty_log_test

		TEST_GEN_PROGS += $(TEST_GEN_PROGS_$(UNAME_M))
		LIBKVM += $(LIBKVM_$(UNAME_M))
		@@ -19,6 +20,7 @@ INSTALL_HDR_PATH = $(top_srcdir)/usr
		LINUX_HDR_PATH = $(INSTALL_HDR_PATH)/include/
		LINUX_TOOL_INCLUDE = $(top_srcdir)tools/include
		CFLAGS += -O2 -g -std=gnu99 -I$(LINUX_TOOL_INCLUDE) -I$(LINUX_HDR_PATH) -Iinclude -I$(<D) -I..
		LDFLAGS += -lpthread

		# After inclusion, $(OUTPUT) is defined and
		# $(TEST_GEN_PROGS) starts with $(OUTPUT)/

tools/testing/selftests/kvm/dirty_log_test.c

0 → 100644

+308 −0

Original line number	Diff line number	Diff line
		// 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;
		}

tools/testing/selftests/kvm/include/kvm_util.h

+3 −0

Original line number	Diff line number	Diff line
		@@ -55,6 +55,7 @@ struct kvm_vm *vm_create(enum vm_guest_mode mode, uint64_t phy_pages, int perm);
		void kvm_vm_free(struct kvm_vm *vmp);
		void kvm_vm_restart(struct kvm_vm *vmp, int perm);
		void kvm_vm_release(struct kvm_vm *vmp);
		void kvm_vm_get_dirty_log(struct kvm_vm vm, int slot, void log);

		int kvm_memcmp_hva_gva(void *hva,
		struct kvm_vm *vm, const vm_vaddr_t gva, size_t len);
		@@ -80,6 +81,8 @@ void vm_mem_region_set_flags(struct kvm_vm *vm, uint32_t slot, uint32_t flags);
		void vm_vcpu_add(struct kvm_vm *vm, uint32_t vcpuid, int pgd_memslot, int gdt_memslot);
		vm_vaddr_t vm_vaddr_alloc(struct kvm_vm *vm, size_t sz, vm_vaddr_t vaddr_min,
		uint32_t data_memslot, uint32_t pgd_memslot);
		void virt_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr,
		size_t size, uint32_t pgd_memslot);
		void addr_gpa2hva(struct kvm_vm vm, vm_paddr_t gpa);
		void addr_gva2hva(struct kvm_vm vm, vm_vaddr_t gva);
		vm_paddr_t addr_hva2gpa(struct kvm_vm vm, void hva);

tools/testing/selftests/kvm/lib/kvm_util.c

+43 −0

Original line number	Diff line number	Diff line
		@@ -169,6 +169,16 @@ void kvm_vm_restart(struct kvm_vm *vmp, int perm)
		}
		}

		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));
		}

		/* Userspace Memory Region Find
		*
		* Input Args:
		@@ -924,6 +934,39 @@ vm_vaddr_t vm_vaddr_alloc(struct kvm_vm *vm, size_t sz, vm_vaddr_t vaddr_min,
		return vaddr_start;
		}

		/*
		* Map a range of VM virtual address to the VM's physical address
		*
		* Input Args:
		* vm - Virtual Machine
		* vaddr - Virtuall address to map
		* paddr - VM Physical Address
		* size - The size of the range to map
		* pgd_memslot - Memory region slot for new virtual translation tables
		*
		* Output Args: None
		*
		* Return: None
		*
		* Within the VM given by vm, creates a virtual translation for the
		* page range starting at vaddr to the page range starting at paddr.
		*/
		void virt_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr,
		size_t size, uint32_t pgd_memslot)
		{
		size_t page_size = vm->page_size;
		size_t npages = size / page_size;

		TEST_ASSERT(vaddr + size > vaddr, "Vaddr overflow");
		TEST_ASSERT(paddr + size > paddr, "Paddr overflow");

		while (npages--) {
		virt_pg_map(vm, vaddr, paddr, pgd_memslot);
		vaddr += page_size;
		paddr += page_size;
		}
		}

		/* Address VM Physical to Host Virtual
		*
		* Input Args:

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