KVM: selftests: Add memory size parameter to the demand paging test (af99e1ad) · Commits · 戴 / test

tools/testing/selftests/kvm/Makefile

+1 −1

Original line number	Diff line number	Diff line
		@@ -7,7 +7,7 @@ top_srcdir = ../../../..
		KSFT_KHDR_INSTALL := 1
		UNAME_M := $(shell uname -m)

		LIBKVM = lib/assert.c lib/elf.c lib/io.c lib/kvm_util.c lib/sparsebit.c
		LIBKVM = lib/assert.c lib/elf.c lib/io.c lib/kvm_util.c lib/sparsebit.c lib/test_util.c
		LIBKVM_x86_64 = lib/x86_64/processor.c lib/x86_64/vmx.c lib/x86_64/svm.c lib/x86_64/ucall.c
		LIBKVM_aarch64 = lib/aarch64/processor.c lib/aarch64/ucall.c
		LIBKVM_s390x = lib/s390x/processor.c lib/s390x/ucall.c

tools/testing/selftests/kvm/demand_paging_test.c

+36 −21

Original line number	Diff line number	Diff line
		@@ -34,6 +34,8 @@
		/* Default guest test virtual memory offset */
		#define DEFAULT_GUEST_TEST_MEM 0xc0000000

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

		/*
		* Guest/Host shared variables. Ensure addr_gva2hva() and/or
		* sync_global_to/from_guest() are used when accessing from
		@@ -276,11 +278,10 @@ static int setup_demand_paging(struct kvm_vm *vm,
		return 0;
		}

		#define GUEST_MEM_SHIFT 30 /* 1G */
		#define PAGE_SHIFT_4K 12

		static void run_test(enum vm_guest_mode mode, bool use_uffd,
		useconds_t uffd_delay)
		useconds_t uffd_delay, uint64_t guest_memory_bytes)
		{
		pthread_t vcpu_thread;
		pthread_t uffd_handler_thread;
		@@ -289,33 +290,40 @@ static void run_test(enum vm_guest_mode mode, bool use_uffd,
		int r;

		/*
		* 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).
		* 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,
		2ul << (GUEST_MEM_SHIFT - PAGE_SHIFT_4K),
		(2 * guest_memory_bytes) >> 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 << (GUEST_MEM_SHIFT -
		vm_get_page_shift(vm))) + 16;

		TEST_ASSERT(guest_memory_bytes % guest_page_size == 0,
		"Guest memory size is not guest page size aligned.");

		guest_num_pages = guest_memory_bytes / guest_page_size;

		#ifdef __s390x__
		/* Round up to multiple of 1M (segment size) */
		guest_num_pages = (guest_num_pages + 0xff) & ~0xffUL;
		#endif
		/*
		* If there should be more memory in the guest test region than there
		* can be pages in the guest, it will definitely cause problems.
		*/
		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));

		host_page_size = getpagesize();
		host_num_pages = (guest_num_pages * guest_page_size) / host_page_size +
		!!((guest_num_pages * guest_page_size) %
		host_page_size);
		TEST_ASSERT(guest_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;
		@@ -403,7 +411,8 @@ static void help(char *name)
		int i;

		puts("");
		printf("usage: %s [-h] [-m mode] [-u] [-d uffd_delay_usec]\n", name);
		printf("usage: %s [-h] [-m mode] [-u] [-d uffd_delay_usec]\n"
		" [-b memory]\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"
		@@ -417,6 +426,8 @@ static void help(char *name)
		printf(" -d: add a delay in usec to the User Fault\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");
		puts("");
		exit(0);
		}
		@@ -424,6 +435,7 @@ static void help(char *name)
		int main(int argc, char *argv[])
		{
		bool mode_selected = false;
		uint64_t guest_memory_bytes = DEFAULT_GUEST_TEST_MEM_SIZE;
		unsigned int mode;
		int opt, i;
		bool use_uffd = false;
		@@ -450,7 +462,7 @@ int main(int argc, char *argv[])
		guest_mode_init(VM_MODE_P40V48_4K, true, true);
		#endif

		while ((opt = getopt(argc, argv, "hm:ud:")) != -1) {
		while ((opt = getopt(argc, argv, "hm:ud:b:")) != -1) {
		switch (opt) {
		case 'm':
		if (!mode_selected) {
		@@ -471,6 +483,9 @@ int main(int argc, char *argv[])
		TEST_ASSERT(uffd_delay >= 0,
		"A negative UFFD delay is not supported.");
		break;
		case 'b':
		guest_memory_bytes = parse_size(optarg);
		break;
		case 'h':
		default:
		help(argv[0]);
		@@ -484,7 +499,7 @@ int main(int argc, char *argv[])
		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);
		run_test(i, use_uffd, uffd_delay, guest_memory_bytes);
		}

		return 0;

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

+2 −0

Original line number	Diff line number	Diff line
		@@ -39,4 +39,6 @@ void test_assert(bool exp, const char *exp_str,
		#a, #b, #a, (unsigned long) __a, #b, (unsigned long) __b); \
		} while (0)

		size_t parse_size(const char *size);

		#endif /* SELFTEST_KVM_TEST_UTIL_H */

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

0 → 100644

+51 −0

Original line number	Diff line number	Diff line
		// SPDX-License-Identifier: GPL-2.0-only
		/*
		* tools/testing/selftests/kvm/lib/test_util.c
		*
		* Copyright (C) 2020, Google LLC.
		*/
		#include <stdlib.h>
		#include <ctype.h>
		#include <limits.h>
		#include "test_util.h"

		/*
		* Parses "[0-9]+[kmgt]?".
		*/
		size_t parse_size(const char *size)
		{
		size_t base;
		char *scale;
		int shift = 0;

		TEST_ASSERT(size && isdigit(size[0]), "Need at least one digit in '%s'", size);

		base = strtoull(size, &scale, 0);

		TEST_ASSERT(base != ULLONG_MAX, "Overflow parsing size!");

		switch (tolower(*scale)) {
		case 't':
		shift = 40;
		break;
		case 'g':
		shift = 30;
		break;
		case 'm':
		shift = 20;
		break;
		case 'k':
		shift = 10;
		break;
		case 'b':
		case '\0':
		shift = 0;
		break;
		default:
		TEST_ASSERT(false, "Unknown size letter %c", *scale);
		}

		TEST_ASSERT((base << shift) >> shift == base, "Overflow scaling size!");

		return base << shift;
		}

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