Merge tag 'kvm-s390-next-6.5-1' of https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD

* New uvdevice secret API
* New CMM selftest
* cmm fix
* diag 9c racy access of target cpu fix

2 files changed, 701 insertions, 0 deletions

diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
index 4761b768b773..74e0a44f9216 100644
--- a/tools/testing/selftests/kvm/Makefile
+++ b/tools/testing/selftests/kvm/Makefile
@@ -164,6 +164,7 @@ 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..1d73e78e8fa7
--- /dev/null
+++ b/tools/testing/selftests/kvm/s390x/cmma_test.c
@@ -0,0 +1,700 @@
+// 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);
+	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 },
+};
+
+/**
+ * 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 */
+}