Add an argument to allow the demand paging test to work on larger and smaller guest sizes.
Signed-off-by: Ben Gardon bgardon@google.com --- .../selftests/kvm/demand_paging_test.c | 55 ++++++++++++------- 1 file changed, 34 insertions(+), 21 deletions(-)
diff --git a/tools/testing/selftests/kvm/demand_paging_test.c b/tools/testing/selftests/kvm/demand_paging_test.c index 61ba4e6a8214a..19982a33a0ca2 100644 --- a/tools/testing/selftests/kvm/demand_paging_test.c +++ b/tools/testing/selftests/kvm/demand_paging_test.c @@ -32,6 +32,8 @@ /* Default guest test virtual memory offset */ #define DEFAULT_GUEST_TEST_MEM 0xc0000000
+#define DEFAULT_GUEST_TEST_MEM_SIZE (1 << 30) /* 1G */ + #define __NR_userfaultfd 323
/* @@ -255,10 +257,9 @@ 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) +static void run_test(enum vm_guest_mode mode, uint64_t guest_memory_bytes) { pthread_t vcpu_thread; pthread_t uffd_handler_thread; @@ -266,33 +267,40 @@ static void run_test(enum vm_guest_mode mode) 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; @@ -369,7 +377,7 @@ static void help(char *name) int i;
puts(""); - printf("usage: %s [-h] [-m mode]\n", name); + printf("usage: %s [-h] [-m mode] [-b bytes test 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" @@ -378,6 +386,8 @@ static void help(char *name) printf(" %d: %s%s\n", i, vm_guest_mode_string(i), vm_guest_mode_params[i].supported ? " (supported)" : ""); } + printf(" -b: specify the number of bytes of memory which should be\n" + " allocated to the guest.\n"); puts(""); exit(0); } @@ -385,6 +395,7 @@ 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; #ifdef __aarch64__ @@ -410,7 +421,7 @@ int main(int argc, char *argv[]) vm_guest_mode_params_init(VM_MODE_P40V48_4K, true, true); #endif
- while ((opt = getopt(argc, argv, "hm:")) != -1) { + while ((opt = getopt(argc, argv, "hm:b:")) != -1) { switch (opt) { case 'm': if (!mode_selected) { @@ -423,6 +434,8 @@ int main(int argc, char *argv[]) "Guest mode ID %d too big", mode); vm_guest_mode_params[mode].enabled = true; break; + case 'b': + guest_memory_bytes = strtoull(optarg, NULL, 0); case 'h': default: help(argv[0]); @@ -436,7 +449,7 @@ int main(int argc, char *argv[]) TEST_ASSERT(vm_guest_mode_params[i].supported, "Guest mode ID %d (%s) not supported.", i, vm_guest_mode_string(i)); - run_test(i); + run_test(i, guest_memory_bytes); }
return 0;