// SPDX-License-Identifier: GPL-2.0-only /* * Test for s390x CMMA migration * * Copyright IBM Corp. 2023 * * Authors: * Nico Boehr <nrb@linux.ibm.com> */ #define _GNU_SOURCE /* for program_invocation_short_name */ #include <fcntl.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <sys/ioctl.h> #include "test_util.h" #include "kvm_util.h" #include "kselftest.h" #define MAIN_PAGE_COUNT 512 #define TEST_DATA_PAGE_COUNT 512 #define TEST_DATA_MEMSLOT 1 #define TEST_DATA_START_GFN 4096 #define TEST_DATA_TWO_PAGE_COUNT 256 #define TEST_DATA_TWO_MEMSLOT 2 #define TEST_DATA_TWO_START_GFN 8192 static char cmma_value_buf[MAIN_PAGE_COUNT + TEST_DATA_PAGE_COUNT]; /** * Dirty CMMA attributes of exactly one page in the TEST_DATA memslot, * so use_cmma goes on and the CMMA related ioctls do something. */ static void guest_do_one_essa(void) { asm volatile( /* load TEST_DATA_START_GFN into r1 */ " llilf 1,%[start_gfn]\n" /* calculate the address from the gfn */ " sllg 1,1,12(0)\n" /* set the first page in TEST_DATA memslot to STABLE */ " .insn rrf,0xb9ab0000,2,1,1,0\n" /* hypercall */ " diag 0,0,0x501\n" "0: j 0b" : : [start_gfn] "L"(TEST_DATA_START_GFN) : "r1", "r2", "memory", "cc" ); } /** * Touch CMMA attributes of all pages in TEST_DATA memslot. Set them to stable * state. */ static void guest_dirty_test_data(void) { asm volatile( /* r1 = TEST_DATA_START_GFN */ " xgr 1,1\n" " llilf 1,%[start_gfn]\n" /* r5 = TEST_DATA_PAGE_COUNT */ " lghi 5,%[page_count]\n" /* r5 += r1 */ "2: agfr 5,1\n" /* r2 = r1 << 12 */ "1: sllg 2,1,12(0)\n" /* essa(r4, r2, SET_STABLE) */ " .insn rrf,0xb9ab0000,4,2,1,0\n" /* i++ */ " agfi 1,1\n" /* if r1 < r5 goto 1 */ " cgrjl 1,5,1b\n" /* hypercall */ " diag 0,0,0x501\n" "0: j 0b" : : [start_gfn] "L"(TEST_DATA_START_GFN), [page_count] "L"(TEST_DATA_PAGE_COUNT) : /* the counter in our loop over the pages */ "r1", /* the calculated page physical address */ "r2", /* ESSA output register */ "r4", /* last page */ "r5", "cc", "memory" ); } static struct kvm_vm *create_vm(void) { return ____vm_create(VM_MODE_DEFAULT); } static void create_main_memslot(struct kvm_vm *vm) { int i; vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, 0, 0, MAIN_PAGE_COUNT, 0); /* set the array of memslots to zero like __vm_create does */ for (i = 0; i < NR_MEM_REGIONS; i++) vm->memslots[i] = 0; } static void create_test_memslot(struct kvm_vm *vm) { vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, TEST_DATA_START_GFN << vm->page_shift, TEST_DATA_MEMSLOT, TEST_DATA_PAGE_COUNT, 0 ); vm->memslots[MEM_REGION_TEST_DATA] = TEST_DATA_MEMSLOT; } static void create_memslots(struct kvm_vm *vm) { /* * Our VM has the following memory layout: * +------+---------------------------+ * | GFN | Memslot | * +------+---------------------------+ * | 0 | | * | ... | MAIN (Code, Stack, ...) | * | 511 | | * +------+---------------------------+ * | 4096 | | * | ... | TEST_DATA | * | 4607 | | * +------+---------------------------+ */ create_main_memslot(vm); create_test_memslot(vm); } static void finish_vm_setup(struct kvm_vm *vm) { struct userspace_mem_region *slot0; kvm_vm_elf_load(vm, program_invocation_name); slot0 = memslot2region(vm, 0); ucall_init(vm, slot0->region.guest_phys_addr + slot0->region.memory_size); kvm_arch_vm_post_create(vm); } static struct kvm_vm *create_vm_two_memslots(void) { struct kvm_vm *vm; vm = create_vm(); create_memslots(vm); finish_vm_setup(vm); return vm; } static void enable_cmma(struct kvm_vm *vm) { int r; r = __kvm_device_attr_set(vm->fd, KVM_S390_VM_MEM_CTRL, KVM_S390_VM_MEM_ENABLE_CMMA, NULL); TEST_ASSERT(!r, "enabling cmma failed r=%d errno=%d", r, errno); } static void enable_dirty_tracking(struct kvm_vm *vm) { vm_mem_region_set_flags(vm, 0, KVM_MEM_LOG_DIRTY_PAGES); vm_mem_region_set_flags(vm, TEST_DATA_MEMSLOT, KVM_MEM_LOG_DIRTY_PAGES); } static int __enable_migration_mode(struct kvm_vm *vm) { return __kvm_device_attr_set(vm->fd, KVM_S390_VM_MIGRATION, KVM_S390_VM_MIGRATION_START, NULL ); } static void enable_migration_mode(struct kvm_vm *vm) { int r = __enable_migration_mode(vm); TEST_ASSERT(!r, "enabling migration mode failed r=%d errno=%d", r, errno); } static bool is_migration_mode_on(struct kvm_vm *vm) { u64 out; int r; r = __kvm_device_attr_get(vm->fd, KVM_S390_VM_MIGRATION, KVM_S390_VM_MIGRATION_STATUS, &out ); TEST_ASSERT(!r, "getting migration mode status failed r=%d errno=%d", r, errno); return out; } static int vm_get_cmma_bits(struct kvm_vm *vm, u64 flags, int *errno_out) { struct kvm_s390_cmma_log args; int rc; errno = 0; args = (struct kvm_s390_cmma_log){ .start_gfn = 0, .count = sizeof(cmma_value_buf), .flags = flags, .values = (__u64)&cmma_value_buf[0] }; rc = __vm_ioctl(vm, KVM_S390_GET_CMMA_BITS, &args); *errno_out = errno; return rc; } static void test_get_cmma_basic(void) { struct kvm_vm *vm = create_vm_two_memslots(); struct kvm_vcpu *vcpu; int rc, errno_out; /* GET_CMMA_BITS without CMMA enabled should fail */ rc = vm_get_cmma_bits(vm, 0, &errno_out); TEST_ASSERT_EQ(rc, -1); TEST_ASSERT_EQ(errno_out, ENXIO); enable_cmma(vm); vcpu = vm_vcpu_add(vm, 1, guest_do_one_essa); vcpu_run(vcpu); /* GET_CMMA_BITS without migration mode and without peeking should fail */ rc = vm_get_cmma_bits(vm, 0, &errno_out); TEST_ASSERT_EQ(rc, -1); TEST_ASSERT_EQ(errno_out, EINVAL); /* GET_CMMA_BITS without migration mode and with peeking should work */ rc = vm_get_cmma_bits(vm, KVM_S390_CMMA_PEEK, &errno_out); TEST_ASSERT_EQ(rc, 0); TEST_ASSERT_EQ(errno_out, 0); enable_dirty_tracking(vm); enable_migration_mode(vm); /* GET_CMMA_BITS with invalid flags */ rc = vm_get_cmma_bits(vm, 0xfeedc0fe, &errno_out); TEST_ASSERT_EQ(rc, -1); TEST_ASSERT_EQ(errno_out, EINVAL); kvm_vm_free(vm); } static void assert_exit_was_hypercall(struct kvm_vcpu *vcpu) { TEST_ASSERT_EQ(vcpu->run->exit_reason, 13); TEST_ASSERT_EQ(vcpu->run->s390_sieic.icptcode, 4); TEST_ASSERT_EQ(vcpu->run->s390_sieic.ipa, 0x8300); TEST_ASSERT_EQ(vcpu->run->s390_sieic.ipb, 0x5010000); } static void test_migration_mode(void) { struct kvm_vm *vm = create_vm(); struct kvm_vcpu *vcpu; u64 orig_psw; int rc; /* enabling migration mode on a VM without memory should fail */ rc = __enable_migration_mode(vm); TEST_ASSERT_EQ(rc, -1); TEST_ASSERT_EQ(errno, EINVAL); TEST_ASSERT(!is_migration_mode_on(vm), "migration mode should still be off"); errno = 0; create_memslots(vm); finish_vm_setup(vm); enable_cmma(vm); vcpu = vm_vcpu_add(vm, 1, guest_do_one_essa); orig_psw = vcpu->run->psw_addr; /* * Execute one essa instruction in the guest. Otherwise the guest will * not have use_cmm enabled and GET_CMMA_BITS will return no pages. */ vcpu_run(vcpu); assert_exit_was_hypercall(vcpu); /* migration mode when memslots have dirty tracking off should fail */ rc = __enable_migration_mode(vm); TEST_ASSERT_EQ(rc, -1); TEST_ASSERT_EQ(errno, EINVAL); TEST_ASSERT(!is_migration_mode_on(vm), "migration mode should still be off"); errno = 0; /* enable dirty tracking */ enable_dirty_tracking(vm); /* enabling migration mode should work now */ rc = __enable_migration_mode(vm); TEST_ASSERT_EQ(rc, 0); TEST_ASSERT(is_migration_mode_on(vm), "migration mode should be on"); errno = 0; /* execute another ESSA instruction to see this goes fine */ vcpu->run->psw_addr = orig_psw; vcpu_run(vcpu); assert_exit_was_hypercall(vcpu); /* * With migration mode on, create a new memslot with dirty tracking off. * This should turn off migration mode. */ TEST_ASSERT(is_migration_mode_on(vm), "migration mode should be on"); vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, TEST_DATA_TWO_START_GFN << vm->page_shift, TEST_DATA_TWO_MEMSLOT, TEST_DATA_TWO_PAGE_COUNT, 0 ); TEST_ASSERT(!is_migration_mode_on(vm), "creating memslot without dirty tracking turns off migration mode" ); /* ESSA instructions should still execute fine */ vcpu->run->psw_addr = orig_psw; vcpu_run(vcpu); assert_exit_was_hypercall(vcpu); /* * Turn on dirty tracking on the new memslot. * It should be possible to turn migration mode back on again. */ vm_mem_region_set_flags(vm, TEST_DATA_TWO_MEMSLOT, KVM_MEM_LOG_DIRTY_PAGES); rc = __enable_migration_mode(vm); TEST_ASSERT_EQ(rc, 0); TEST_ASSERT(is_migration_mode_on(vm), "migration mode should be on"); errno = 0; /* * Turn off dirty tracking again, this time with just a flag change. * Again, migration mode should turn off. */ TEST_ASSERT(is_migration_mode_on(vm), "migration mode should be on"); vm_mem_region_set_flags(vm, TEST_DATA_TWO_MEMSLOT, 0); TEST_ASSERT(!is_migration_mode_on(vm), "disabling dirty tracking should turn off migration mode" ); /* ESSA instructions should still execute fine */ vcpu->run->psw_addr = orig_psw; vcpu_run(vcpu); assert_exit_was_hypercall(vcpu); kvm_vm_free(vm); } /** * Given a VM with the MAIN and TEST_DATA memslot, assert that both slots have * CMMA attributes of all pages in both memslots and nothing more dirty. * This has the useful side effect of ensuring nothing is CMMA dirty after this * function. */ static void assert_all_slots_cmma_dirty(struct kvm_vm *vm) { struct kvm_s390_cmma_log args; /* * First iteration - everything should be dirty. * Start at the main memslot... */ args = (struct kvm_s390_cmma_log){ .start_gfn = 0, .count = sizeof(cmma_value_buf), .flags = 0, .values = (__u64)&cmma_value_buf[0] }; memset(cmma_value_buf, 0xff, sizeof(cmma_value_buf)); vm_ioctl(vm, KVM_S390_GET_CMMA_BITS, &args); TEST_ASSERT_EQ(args.count, MAIN_PAGE_COUNT); TEST_ASSERT_EQ(args.remaining, TEST_DATA_PAGE_COUNT); TEST_ASSERT_EQ(args.start_gfn, 0); /* ...and then - after a hole - the TEST_DATA memslot should follow */ args = (struct kvm_s390_cmma_log){ .start_gfn = MAIN_PAGE_COUNT, .count = sizeof(cmma_value_buf), .flags = 0, .values = (__u64)&cmma_value_buf[0] }; memset(cmma_value_buf, 0xff, sizeof(cmma_value_buf)); vm_ioctl(vm, KVM_S390_GET_CMMA_BITS, &args); TEST_ASSERT_EQ(args.count, TEST_DATA_PAGE_COUNT); TEST_ASSERT_EQ(args.start_gfn, TEST_DATA_START_GFN); TEST_ASSERT_EQ(args.remaining, 0); /* ...and nothing else should be there */ args = (struct kvm_s390_cmma_log){ .start_gfn = TEST_DATA_START_GFN + TEST_DATA_PAGE_COUNT, .count = sizeof(cmma_value_buf), .flags = 0, .values = (__u64)&cmma_value_buf[0] }; memset(cmma_value_buf, 0xff, sizeof(cmma_value_buf)); vm_ioctl(vm, KVM_S390_GET_CMMA_BITS, &args); TEST_ASSERT_EQ(args.count, 0); TEST_ASSERT_EQ(args.start_gfn, 0); TEST_ASSERT_EQ(args.remaining, 0); } /** * Given a VM, assert no pages are CMMA dirty. */ static void assert_no_pages_cmma_dirty(struct kvm_vm *vm) { struct kvm_s390_cmma_log args; /* If we start from GFN 0 again, nothing should be dirty. */ args = (struct kvm_s390_cmma_log){ .start_gfn = 0, .count = sizeof(cmma_value_buf), .flags = 0, .values = (__u64)&cmma_value_buf[0] }; memset(cmma_value_buf, 0xff, sizeof(cmma_value_buf)); vm_ioctl(vm, KVM_S390_GET_CMMA_BITS, &args); if (args.count || args.remaining || args.start_gfn) TEST_FAIL("pages are still dirty start_gfn=0x%llx count=%u remaining=%llu", args.start_gfn, args.count, args.remaining ); } static void test_get_inital_dirty(void) { struct kvm_vm *vm = create_vm_two_memslots(); struct kvm_vcpu *vcpu; enable_cmma(vm); vcpu = vm_vcpu_add(vm, 1, guest_do_one_essa); /* * Execute one essa instruction in the guest. Otherwise the guest will * not have use_cmm enabled and GET_CMMA_BITS will return no pages. */ vcpu_run(vcpu); assert_exit_was_hypercall(vcpu); enable_dirty_tracking(vm); enable_migration_mode(vm); assert_all_slots_cmma_dirty(vm); /* Start from the beginning again and make sure nothing else is dirty */ assert_no_pages_cmma_dirty(vm); kvm_vm_free(vm); } static void query_cmma_range(struct kvm_vm *vm, u64 start_gfn, u64 gfn_count, struct kvm_s390_cmma_log *res_out) { *res_out = (struct kvm_s390_cmma_log){ .start_gfn = start_gfn, .count = gfn_count, .flags = 0, .values = (__u64)&cmma_value_buf[0] }; memset(cmma_value_buf, 0xff, sizeof(cmma_value_buf)); vm_ioctl(vm, KVM_S390_GET_CMMA_BITS, res_out); } /** * Assert the given cmma_log struct that was executed by query_cmma_range() * indicates the first dirty gfn is at first_dirty_gfn and contains exactly * dirty_gfn_count CMMA values. */ static void assert_cmma_dirty(u64 first_dirty_gfn, u64 dirty_gfn_count, const struct kvm_s390_cmma_log *res) { TEST_ASSERT_EQ(res->start_gfn, first_dirty_gfn); TEST_ASSERT_EQ(res->count, dirty_gfn_count); for (size_t i = 0; i < dirty_gfn_count; i++) TEST_ASSERT_EQ(cmma_value_buf[0], 0x0); /* stable state */ TEST_ASSERT_EQ(cmma_value_buf[dirty_gfn_count], 0xff); /* not touched */ } static void test_get_skip_holes(void) { size_t gfn_offset; struct kvm_vm *vm = create_vm_two_memslots(); struct kvm_s390_cmma_log log; struct kvm_vcpu *vcpu; u64 orig_psw; enable_cmma(vm); vcpu = vm_vcpu_add(vm, 1, guest_dirty_test_data); orig_psw = vcpu->run->psw_addr; /* * Execute some essa instructions in the guest. Otherwise the guest will * not have use_cmm enabled and GET_CMMA_BITS will return no pages. */ vcpu_run(vcpu); assert_exit_was_hypercall(vcpu); enable_dirty_tracking(vm); enable_migration_mode(vm); /* un-dirty all pages */ assert_all_slots_cmma_dirty(vm); /* Then, dirty just the TEST_DATA memslot */ vcpu->run->psw_addr = orig_psw; vcpu_run(vcpu); gfn_offset = TEST_DATA_START_GFN; /** * Query CMMA attributes of one page, starting at page 0. Since the * main memslot was not touched by the VM, this should yield the first * page of the TEST_DATA memslot. * The dirty bitmap should now look like this: * 0: not dirty * [0x1, 0x200): dirty */ query_cmma_range(vm, 0, 1, &log); assert_cmma_dirty(gfn_offset, 1, &log); gfn_offset++; /** * Query CMMA attributes of 32 (0x20) pages past the end of the TEST_DATA * memslot. This should wrap back to the beginning of the TEST_DATA * memslot, page 1. * The dirty bitmap should now look like this: * [0, 0x21): not dirty * [0x21, 0x200): dirty */ query_cmma_range(vm, TEST_DATA_START_GFN + TEST_DATA_PAGE_COUNT, 0x20, &log); assert_cmma_dirty(gfn_offset, 0x20, &log); gfn_offset += 0x20; /* Skip 32 pages */ gfn_offset += 0x20; /** * After skipping 32 pages, query the next 32 (0x20) pages. * The dirty bitmap should now look like this: * [0, 0x21): not dirty * [0x21, 0x41): dirty * [0x41, 0x61): not dirty * [0x61, 0x200): dirty */ query_cmma_range(vm, gfn_offset, 0x20, &log); assert_cmma_dirty(gfn_offset, 0x20, &log); gfn_offset += 0x20; /** * Query 1 page from the beginning of the TEST_DATA memslot. This should * yield page 0x21. * The dirty bitmap should now look like this: * [0, 0x22): not dirty * [0x22, 0x41): dirty * [0x41, 0x61): not dirty * [0x61, 0x200): dirty */ query_cmma_range(vm, TEST_DATA_START_GFN, 1, &log); assert_cmma_dirty(TEST_DATA_START_GFN + 0x21, 1, &log); gfn_offset++; /** * Query 15 (0xF) pages from page 0x23 in TEST_DATA memslot. * This should yield pages [0x23, 0x33). * The dirty bitmap should now look like this: * [0, 0x22): not dirty * 0x22: dirty * [0x23, 0x33): not dirty * [0x33, 0x41): dirty * [0x41, 0x61): not dirty * [0x61, 0x200): dirty */ gfn_offset = TEST_DATA_START_GFN + 0x23; query_cmma_range(vm, gfn_offset, 15, &log); assert_cmma_dirty(gfn_offset, 15, &log); /** * Query 17 (0x11) pages from page 0x22 in TEST_DATA memslot. * This should yield page [0x22, 0x33) * The dirty bitmap should now look like this: * [0, 0x33): not dirty * [0x33, 0x41): dirty * [0x41, 0x61): not dirty * [0x61, 0x200): dirty */ gfn_offset = TEST_DATA_START_GFN + 0x22; query_cmma_range(vm, gfn_offset, 17, &log); assert_cmma_dirty(gfn_offset, 17, &log); /** * Query 25 (0x19) pages from page 0x40 in TEST_DATA memslot. * This should yield page 0x40 and nothing more, since there are more * than 16 non-dirty pages after page 0x40. * The dirty bitmap should now look like this: * [0, 0x33): not dirty * [0x33, 0x40): dirty * [0x40, 0x61): not dirty * [0x61, 0x200): dirty */ gfn_offset = TEST_DATA_START_GFN + 0x40; query_cmma_range(vm, gfn_offset, 25, &log); assert_cmma_dirty(gfn_offset, 1, &log); /** * Query pages [0x33, 0x40). * The dirty bitmap should now look like this: * [0, 0x61): not dirty * [0x61, 0x200): dirty */ gfn_offset = TEST_DATA_START_GFN + 0x33; query_cmma_range(vm, gfn_offset, 0x40 - 0x33, &log); assert_cmma_dirty(gfn_offset, 0x40 - 0x33, &log); /** * Query the remaining pages [0x61, 0x200). */ gfn_offset = TEST_DATA_START_GFN; query_cmma_range(vm, gfn_offset, TEST_DATA_PAGE_COUNT - 0x61, &log); assert_cmma_dirty(TEST_DATA_START_GFN + 0x61, TEST_DATA_PAGE_COUNT - 0x61, &log); assert_no_pages_cmma_dirty(vm); } struct testdef { const char *name; void (*test)(void); } testlist[] = { { "migration mode and dirty tracking", test_migration_mode }, { "GET_CMMA_BITS: basic calls", test_get_cmma_basic }, { "GET_CMMA_BITS: all pages are dirty initally", test_get_inital_dirty }, { "GET_CMMA_BITS: holes are skipped", test_get_skip_holes }, }; /** * The kernel may support CMMA, but the machine may not (i.e. if running as * guest-3). * * In this case, the CMMA capabilities are all there, but the CMMA-related * ioctls fail. To find out whether the machine supports CMMA, create a * temporary VM and then query the CMMA feature of the VM. */ static int machine_has_cmma(void) { struct kvm_vm *vm = create_vm(); int r; r = !__kvm_has_device_attr(vm->fd, KVM_S390_VM_MEM_CTRL, KVM_S390_VM_MEM_ENABLE_CMMA); kvm_vm_free(vm); return r; } int main(int argc, char *argv[]) { int idx; TEST_REQUIRE(kvm_has_cap(KVM_CAP_SYNC_REGS)); TEST_REQUIRE(kvm_has_cap(KVM_CAP_S390_CMMA_MIGRATION)); TEST_REQUIRE(machine_has_cmma()); ksft_print_header(); ksft_set_plan(ARRAY_SIZE(testlist)); for (idx = 0; idx < ARRAY_SIZE(testlist); idx++) { testlist[idx].test(); ksft_test_result_pass("%s\n", testlist[idx].name); } ksft_finished(); /* Print results and exit() accordingly */ }