| Message ID | 20230208144827.131300-3-nrb@linux.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: s390: CMMA migration selftest and small bugfix | expand |
On Wed, 8 Feb 2023 15:48:27 +0100 Nico Boehr <nrb@linux.ibm.com> wrote: > Add a selftest for CMMA migration on s390. > > The tests cover: > - interaction of dirty tracking and migration mode, see my recent patch > "KVM: s390: disable migration mode when dirty tracking is disabled" [1], > - several invalid calls of KVM_S390_GET_CMMA_BITS, for example: invalid > flags, CMMA support off, with/without peeking > - ensure KVM_S390_GET_CMMA_BITS initally reports all pages as dirty, > - ensure KVM_S390_GET_CMMA_BITS properly skips over holes in memslots, but > also non-dirty pages > > Note that without the patch at [1] and the small fix in this series, the > selftests will fail. > > [1] https://lore.kernel.org/all/20230127140532.230651-2-nrb@linux.ibm.com/ > > Signed-off-by: Nico Boehr <nrb@linux.ibm.com> > --- > tools/testing/selftests/kvm/Makefile | 1 + > tools/testing/selftests/kvm/s390x/cmma_test.c | 679 ++++++++++++++++++ > 2 files changed, 680 insertions(+) > create mode 100644 tools/testing/selftests/kvm/s390x/cmma_test.c > > diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile > index 1750f91dd936..fc9223b04d5f 100644 > --- a/tools/testing/selftests/kvm/Makefile > +++ b/tools/testing/selftests/kvm/Makefile > @@ -160,6 +160,7 @@ TEST_GEN_PROGS_s390x = s390x/memop > TEST_GEN_PROGS_s390x += s390x/resets > TEST_GEN_PROGS_s390x += s390x/sync_regs_test > TEST_GEN_PROGS_s390x += s390x/tprot > +TEST_GEN_PROGS_s390x += s390x/cmma_test > TEST_GEN_PROGS_s390x += demand_paging_test > TEST_GEN_PROGS_s390x += dirty_log_test > TEST_GEN_PROGS_s390x += kvm_create_max_vcpus > diff --git a/tools/testing/selftests/kvm/s390x/cmma_test.c b/tools/testing/selftests/kvm/s390x/cmma_test.c > new file mode 100644 > index 000000000000..76751abf2331 > --- /dev/null > +++ b/tools/testing/selftests/kvm/s390x/cmma_test.c > @@ -0,0 +1,679 @@ > +// 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); > + for (i = 0; i < NR_MEM_REGIONS; i++) > + vm->memslots[i] = 0; can you explain why you are zeroing all memslots? > +} > + > +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); > + ASSERT_EQ(rc, -1); > + 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); > + ASSERT_EQ(rc, -1); > + 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); > + ASSERT_EQ(rc, 0); > + 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); > + ASSERT_EQ(rc, -1); > + ASSERT_EQ(errno_out, EINVAL); > + > + kvm_vm_free(vm); > +} > + > +static void assert_exit_was_hypercall(struct kvm_vcpu *vcpu) > +{ > + ASSERT_EQ(vcpu->run->exit_reason, 13); > + ASSERT_EQ(vcpu->run->s390_sieic.icptcode, 4); > + ASSERT_EQ(vcpu->run->s390_sieic.ipa, 0x8300); > + 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); > + ASSERT_EQ(rc, -1); > + 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); > + ASSERT_EQ(rc, -1); > + 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); > + 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); > + 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); > + ASSERT_EQ(args.count, MAIN_PAGE_COUNT); > + ASSERT_EQ(args.remaining, TEST_DATA_PAGE_COUNT); > + 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); > + ASSERT_EQ(args.count, TEST_DATA_PAGE_COUNT); > + ASSERT_EQ(args.start_gfn, TEST_DATA_START_GFN); > + 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); > + ASSERT_EQ(args.count, 0); > + ASSERT_EQ(args.start_gfn, 0); > + 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) > +{ > + ASSERT_EQ(res->start_gfn, first_dirty_gfn); > + ASSERT_EQ(res->count, dirty_gfn_count); > + for (size_t i = 0; i < dirty_gfn_count; i++) > + ASSERT_EQ(cmma_value_buf[0], 0x0); /* stable state */ > + 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 }, > +}; > + > +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)); > + > + 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 */ > +}
Quoting Claudio Imbrenda (2023-03-23 15:36:44) > > diff --git a/tools/testing/selftests/kvm/s390x/cmma_test.c b/tools/testing/selftests/kvm/s390x/cmma_test.c > > new file mode 100644 > > index 000000000000..76751abf2331 > > --- /dev/null > > +++ b/tools/testing/selftests/kvm/s390x/cmma_test.c [...] > > +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); > > + for (i = 0; i < NR_MEM_REGIONS; i++) > > + vm->memslots[i] = 0; > > can you explain why you are zeroing all memslots? I think it's not all memslots, this array only contains IDs of some memslots. I think the IDs are set to 0 to indicate "this slot is unused". I did this here, because that's what __vm_create does. Since I can't use __vm_create (I want my custom memslots), I have to use ____vm_create and I thought it's good to just do the same thing here.
On Fri, 24 Mar 2023 14:31:15 +0100 Nico Boehr <nrb@linux.ibm.com> wrote: > Quoting Claudio Imbrenda (2023-03-23 15:36:44) > > > diff --git a/tools/testing/selftests/kvm/s390x/cmma_test.c b/tools/testing/selftests/kvm/s390x/cmma_test.c > > > new file mode 100644 > > > index 000000000000..76751abf2331 > > > --- /dev/null > > > +++ b/tools/testing/selftests/kvm/s390x/cmma_test.c > [...] > > > +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); > > > + for (i = 0; i < NR_MEM_REGIONS; i++) > > > + vm->memslots[i] = 0; > > > > can you explain why you are zeroing all memslots? > > I think it's not all memslots, this array only contains IDs of some memslots. I think the IDs are set to 0 to indicate "this slot is unused". > > I did this here, because that's what __vm_create does. Since I can't use __vm_create (I want my custom memslots), I have to use ____vm_create and I thought it's good to just do the same thing here. can you please add a comment to explain this
diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile index 1750f91dd936..fc9223b04d5f 100644 --- a/tools/testing/selftests/kvm/Makefile +++ b/tools/testing/selftests/kvm/Makefile @@ -160,6 +160,7 @@ TEST_GEN_PROGS_s390x = s390x/memop TEST_GEN_PROGS_s390x += s390x/resets TEST_GEN_PROGS_s390x += s390x/sync_regs_test TEST_GEN_PROGS_s390x += s390x/tprot +TEST_GEN_PROGS_s390x += s390x/cmma_test TEST_GEN_PROGS_s390x += demand_paging_test TEST_GEN_PROGS_s390x += dirty_log_test TEST_GEN_PROGS_s390x += kvm_create_max_vcpus diff --git a/tools/testing/selftests/kvm/s390x/cmma_test.c b/tools/testing/selftests/kvm/s390x/cmma_test.c new file mode 100644 index 000000000000..76751abf2331 --- /dev/null +++ b/tools/testing/selftests/kvm/s390x/cmma_test.c @@ -0,0 +1,679 @@ +// 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); + 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); + ASSERT_EQ(rc, -1); + 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); + ASSERT_EQ(rc, -1); + 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); + ASSERT_EQ(rc, 0); + 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); + ASSERT_EQ(rc, -1); + ASSERT_EQ(errno_out, EINVAL); + + kvm_vm_free(vm); +} + +static void assert_exit_was_hypercall(struct kvm_vcpu *vcpu) +{ + ASSERT_EQ(vcpu->run->exit_reason, 13); + ASSERT_EQ(vcpu->run->s390_sieic.icptcode, 4); + ASSERT_EQ(vcpu->run->s390_sieic.ipa, 0x8300); + 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); + ASSERT_EQ(rc, -1); + 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); + ASSERT_EQ(rc, -1); + 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); + 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); + 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); + ASSERT_EQ(args.count, MAIN_PAGE_COUNT); + ASSERT_EQ(args.remaining, TEST_DATA_PAGE_COUNT); + 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); + ASSERT_EQ(args.count, TEST_DATA_PAGE_COUNT); + ASSERT_EQ(args.start_gfn, TEST_DATA_START_GFN); + 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); + ASSERT_EQ(args.count, 0); + ASSERT_EQ(args.start_gfn, 0); + 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) +{ + ASSERT_EQ(res->start_gfn, first_dirty_gfn); + ASSERT_EQ(res->count, dirty_gfn_count); + for (size_t i = 0; i < dirty_gfn_count; i++) + ASSERT_EQ(cmma_value_buf[0], 0x0); /* stable state */ + 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 }, +}; + +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)); + + 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 */ +}
Add a selftest for CMMA migration on s390. The tests cover: - interaction of dirty tracking and migration mode, see my recent patch "KVM: s390: disable migration mode when dirty tracking is disabled" [1], - several invalid calls of KVM_S390_GET_CMMA_BITS, for example: invalid flags, CMMA support off, with/without peeking - ensure KVM_S390_GET_CMMA_BITS initally reports all pages as dirty, - ensure KVM_S390_GET_CMMA_BITS properly skips over holes in memslots, but also non-dirty pages Note that without the patch at [1] and the small fix in this series, the selftests will fail. [1] https://lore.kernel.org/all/20230127140532.230651-2-nrb@linux.ibm.com/ Signed-off-by: Nico Boehr <nrb@linux.ibm.com> --- tools/testing/selftests/kvm/Makefile | 1 + tools/testing/selftests/kvm/s390x/cmma_test.c | 679 ++++++++++++++++++ 2 files changed, 680 insertions(+) create mode 100644 tools/testing/selftests/kvm/s390x/cmma_test.c