diff --git a/tools/testing/selftests/kvm/s390x/memop.c b/tools/testing/selftests/kvm/s390x/memop.c
index 88ce2d670ed5..c46d47672e2a 100644
--- a/tools/testing/selftests/kvm/s390x/memop.c
+++ b/tools/testing/selftests/kvm/s390x/memop.c
@@ -195,13 +195,21 @@ static int err_memop_ioctl(struct test_vcpu vcpu, struct kvm_s390_mem_op *ksmo)
 #define AR(a) ._ar = 1, .ar = (a)
 #define KEY(a) .f_key = 1, .key = (a)
 
+#define CHECK_N_DO(f, ...) ({ f(__VA_ARGS__, CHECK_ONLY); f(__VA_ARGS__); })
+
 #define VCPU_ID 1
+#define PAGE_SHIFT 12
+#define PAGE_SIZE (1ULL << PAGE_SHIFT)
+#define PAGE_MASK (~(PAGE_SIZE - 1))
+#define CR0_FETCH_PROTECTION_OVERRIDE	(1UL << (63 - 38))
+#define CR0_STORAGE_PROTECTION_OVERRIDE	(1UL << (63 - 39))
 
 static uint8_t mem1[65536];
 static uint8_t mem2[65536];
 
 struct test_default {
 	struct kvm_vm *kvm_vm;
+	struct test_vcpu vm;
 	struct test_vcpu vcpu;
 	struct kvm_run *run;
 	int size;
@@ -213,6 +221,7 @@ static struct test_default test_default_init(void *guest_code)
 
 	t.size = min((size_t)kvm_check_cap(KVM_CAP_S390_MEM_OP), sizeof(mem1));
 	t.kvm_vm = vm_create_default(VCPU_ID, 0, guest_code);
+	t.vm = (struct test_vcpu) { t.kvm_vm, VM_VCPU_ID };
 	t.vcpu = (struct test_vcpu) { t.kvm_vm, VCPU_ID };
 	t.run = vcpu_state(t.kvm_vm, VCPU_ID);
 	return t;
@@ -223,6 +232,8 @@ enum stage {
 	STAGE_INITED,
 	/* Guest did nothing */
 	STAGE_IDLED,
+	/* Guest set storage keys (specifics up to test case) */
+	STAGE_SKEYS_SET,
 	/* Guest copied memory (locations up to test case) */
 	STAGE_COPIED,
 };
@@ -239,6 +250,47 @@ enum stage {
 	ASSERT_EQ(uc.args[1], __stage);					\
 })									\
 
+static void prepare_mem12(void)
+{
+	int i;
+
+	for (i = 0; i < sizeof(mem1); i++)
+		mem1[i] = rand();
+	memset(mem2, 0xaa, sizeof(mem2));
+}
+
+#define ASSERT_MEM_EQ(p1, p2, size) \
+	TEST_ASSERT(!memcmp(p1, p2, size), "Memory contents do not match!")
+
+#define DEFAULT_WRITE_READ(copy_cpu, mop_cpu, mop_target_p, size, ...)		\
+({										\
+	struct test_vcpu __copy_cpu = (copy_cpu), __mop_cpu = (mop_cpu);	\
+	enum mop_target __target = (mop_target_p);				\
+	uint32_t __size = (size);						\
+										\
+	prepare_mem12();							\
+	CHECK_N_DO(MOP, __mop_cpu, __target, WRITE, mem1, __size,		\
+			GADDR_V(mem1), ##__VA_ARGS__);				\
+	HOST_SYNC(__copy_cpu, STAGE_COPIED);					\
+	CHECK_N_DO(MOP, __mop_cpu, __target, READ, mem2, __size,		\
+			GADDR_V(mem2), ##__VA_ARGS__);				\
+	ASSERT_MEM_EQ(mem1, mem2, __size);					\
+})
+
+#define DEFAULT_READ(copy_cpu, mop_cpu, mop_target_p, size, ...)		\
+({										\
+	struct test_vcpu __copy_cpu = (copy_cpu), __mop_cpu = (mop_cpu);	\
+	enum mop_target __target = (mop_target_p);				\
+	uint32_t __size = (size);						\
+										\
+	prepare_mem12();							\
+	CHECK_N_DO(MOP, __mop_cpu, __target, WRITE, mem1, __size,		\
+			GADDR_V(mem1));						\
+	HOST_SYNC(__copy_cpu, STAGE_COPIED);					\
+	CHECK_N_DO(MOP, __mop_cpu, __target, READ, mem2, __size, ##__VA_ARGS__);\
+	ASSERT_MEM_EQ(mem1, mem2, __size);					\
+})
+
 static void guest_copy(void)
 {
 	GUEST_SYNC(STAGE_INITED);
@@ -249,30 +301,186 @@ static void guest_copy(void)
 static void test_copy(void)
 {
 	struct test_default t = test_default_init(guest_copy);
-	int i;
 
-	for (i = 0; i < sizeof(mem1); i++)
-		mem1[i] = i * i + i;
+	HOST_SYNC(t.vcpu, STAGE_INITED);
+
+	DEFAULT_WRITE_READ(t.vcpu, t.vcpu, LOGICAL, t.size);
+
+	kvm_vm_free(t.kvm_vm);
+}
+
+static void set_storage_key_range(void *addr, size_t len, uint8_t key)
+{
+	uintptr_t _addr, abs, i;
+	int not_mapped = 0;
+
+	_addr = (uintptr_t)addr;
+	for (i = _addr & PAGE_MASK; i < _addr + len; i += PAGE_SIZE) {
+		abs = i;
+		asm volatile (
+			       "lra	%[abs], 0(0,%[abs])\n"
+			"	jz	0f\n"
+			"	llill	%[not_mapped],1\n"
+			"	j	1f\n"
+			"0:	sske	%[key], %[abs]\n"
+			"1:"
+			: [abs] "+&a" (abs), [not_mapped] "+r" (not_mapped)
+			: [key] "r" (key)
+			: "cc"
+		);
+		GUEST_ASSERT_EQ(not_mapped, 0);
+	}
+}
+
+static void guest_copy_key(void)
+{
+	set_storage_key_range(mem1, sizeof(mem1), 0x90);
+	set_storage_key_range(mem2, sizeof(mem2), 0x90);
+	GUEST_SYNC(STAGE_SKEYS_SET);
+
+	for (;;) {
+		memcpy(&mem2, &mem1, sizeof(mem2));
+		GUEST_SYNC(STAGE_COPIED);
+	}
+}
+
+static void test_copy_key(void)
+{
+	struct test_default t = test_default_init(guest_copy_key);
+
+	HOST_SYNC(t.vcpu, STAGE_SKEYS_SET);
+
+	/* vm, no key */
+	DEFAULT_WRITE_READ(t.vcpu, t.vm, ABSOLUTE, t.size);
+
+	/* vm/vcpu, machting key or key 0 */
+	DEFAULT_WRITE_READ(t.vcpu, t.vcpu, LOGICAL, t.size, KEY(0));
+	DEFAULT_WRITE_READ(t.vcpu, t.vcpu, LOGICAL, t.size, KEY(9));
+	DEFAULT_WRITE_READ(t.vcpu, t.vm, ABSOLUTE, t.size, KEY(0));
+	DEFAULT_WRITE_READ(t.vcpu, t.vm, ABSOLUTE, t.size, KEY(9));
+	/*
+	 * There used to be different code paths for key handling depending on
+	 * if the region crossed a page boundary.
+	 * There currently are not, but the more tests the merrier.
+	 */
+	DEFAULT_WRITE_READ(t.vcpu, t.vcpu, LOGICAL, 1, KEY(0));
+	DEFAULT_WRITE_READ(t.vcpu, t.vcpu, LOGICAL, 1, KEY(9));
+	DEFAULT_WRITE_READ(t.vcpu, t.vm, ABSOLUTE, 1, KEY(0));
+	DEFAULT_WRITE_READ(t.vcpu, t.vm, ABSOLUTE, 1, KEY(9));
+
+	/* vm/vcpu, mismatching keys on read, but no fetch protection */
+	DEFAULT_READ(t.vcpu, t.vcpu, LOGICAL, t.size, GADDR_V(mem2), KEY(2));
+	DEFAULT_READ(t.vcpu, t.vm, ABSOLUTE, t.size, GADDR_V(mem1), KEY(2));
+
+	kvm_vm_free(t.kvm_vm);
+}
+
+static void guest_copy_key_fetch_prot(void)
+{
+	/*
+	 * For some reason combining the first sync with override enablement
+	 * results in an exception when calling HOST_SYNC.
+	 */
+	GUEST_SYNC(STAGE_INITED);
+	/* Storage protection override applies to both store and fetch. */
+	set_storage_key_range(mem1, sizeof(mem1), 0x98);
+	set_storage_key_range(mem2, sizeof(mem2), 0x98);
+	GUEST_SYNC(STAGE_SKEYS_SET);
+
+	for (;;) {
+		memcpy(&mem2, &mem1, sizeof(mem2));
+		GUEST_SYNC(STAGE_COPIED);
+	}
+}
+
+static void test_copy_key_storage_prot_override(void)
+{
+	struct test_default t = test_default_init(guest_copy_key_fetch_prot);
 
 	HOST_SYNC(t.vcpu, STAGE_INITED);
+	t.run->s.regs.crs[0] |= CR0_STORAGE_PROTECTION_OVERRIDE;
+	t.run->kvm_dirty_regs = KVM_SYNC_CRS;
+	HOST_SYNC(t.vcpu, STAGE_SKEYS_SET);
 
-	/* Set the first array */
-	MOP(t.vcpu, LOGICAL, WRITE, mem1, t.size, GADDR_V(mem1));
+	/* vcpu, mismatching keys, storage protection override in effect */
+	DEFAULT_WRITE_READ(t.vcpu, t.vcpu, LOGICAL, t.size, KEY(2));
 
-	/* Let the guest code copy the first array to the second */
-	HOST_SYNC(t.vcpu, STAGE_COPIED);
+	kvm_vm_free(t.kvm_vm);
+}
 
-	memset(mem2, 0xaa, sizeof(mem2));
+static void test_copy_key_fetch_prot(void)
+{
+	struct test_default t = test_default_init(guest_copy_key_fetch_prot);
 
-	/* Get the second array */
-	MOP(t.vcpu, LOGICAL, READ, mem2, t.size, GADDR_V(mem2));
+	HOST_SYNC(t.vcpu, STAGE_INITED);
+	HOST_SYNC(t.vcpu, STAGE_SKEYS_SET);
 
-	TEST_ASSERT(!memcmp(mem1, mem2, t.size),
-		    "Memory contents do not match!");
+	/* vm/vcpu, matching key, fetch protection in effect */
+	DEFAULT_READ(t.vcpu, t.vcpu, LOGICAL, t.size, GADDR_V(mem2), KEY(9));
+	DEFAULT_READ(t.vcpu, t.vm, ABSOLUTE, t.size, GADDR_V(mem2), KEY(9));
 
 	kvm_vm_free(t.kvm_vm);
 }
 
+const uint64_t last_page_addr = -PAGE_SIZE;
+
+static void guest_copy_key_fetch_prot_override(void)
+{
+	int i;
+	char *page_0 = 0;
+
+	GUEST_SYNC(STAGE_INITED);
+	set_storage_key_range(0, PAGE_SIZE, 0x18);
+	set_storage_key_range((void *)last_page_addr, PAGE_SIZE, 0x0);
+	asm volatile ("sske %[key],%[addr]\n" :: [addr] "r"(0), [key] "r"(0x18) : "cc");
+	GUEST_SYNC(STAGE_SKEYS_SET);
+
+	for (;;) {
+		for (i = 0; i < PAGE_SIZE; i++)
+			page_0[i] = mem1[i];
+		GUEST_SYNC(STAGE_COPIED);
+	}
+}
+
+static void test_copy_key_fetch_prot_override(void)
+{
+	struct test_default t = test_default_init(guest_copy_key_fetch_prot_override);
+	vm_vaddr_t guest_0_page, guest_last_page;
+
+	guest_0_page = vm_vaddr_alloc(t.kvm_vm, PAGE_SIZE, 0);
+	guest_last_page = vm_vaddr_alloc(t.kvm_vm, PAGE_SIZE, last_page_addr);
+	if (guest_0_page != 0 || guest_last_page != last_page_addr) {
+		print_skip("did not allocate guest pages at required positions");
+		goto out;
+	}
+
+	HOST_SYNC(t.vcpu, STAGE_INITED);
+	t.run->s.regs.crs[0] |= CR0_FETCH_PROTECTION_OVERRIDE;
+	t.run->kvm_dirty_regs = KVM_SYNC_CRS;
+	HOST_SYNC(t.vcpu, STAGE_SKEYS_SET);
+
+	/* vcpu, mismatching keys on fetch, fetch protection override applies */
+	prepare_mem12();
+	MOP(t.vcpu, LOGICAL, WRITE, mem1, PAGE_SIZE, GADDR_V(mem1));
+	HOST_SYNC(t.vcpu, STAGE_COPIED);
+	CHECK_N_DO(MOP, t.vcpu, LOGICAL, READ, mem2, 2048, GADDR_V(guest_0_page), KEY(2));
+	ASSERT_MEM_EQ(mem1, mem2, 2048);
+
+	/*
+	 * vcpu, mismatching keys on fetch, fetch protection override applies,
+	 * wraparound
+	 */
+	prepare_mem12();
+	MOP(t.vcpu, LOGICAL, WRITE, mem1, 2 * PAGE_SIZE, GADDR_V(guest_last_page));
+	HOST_SYNC(t.vcpu, STAGE_COPIED);
+	CHECK_N_DO(MOP, t.vcpu, LOGICAL, READ, mem2, PAGE_SIZE + 2048,
+			GADDR_V(guest_last_page), KEY(2));
+	ASSERT_MEM_EQ(mem1, mem2, 2048);
+
+out:
+	kvm_vm_free(t.kvm_vm);
+}
+
 static void guest_idle(void)
 {
 	GUEST_SYNC(STAGE_INITED); /* for consistency's sake */
@@ -335,17 +543,26 @@ static void test_errors(void)
 
 int main(int argc, char *argv[])
 {
-	int memop_cap;
+	int memop_cap, extension_cap;
 
 	setbuf(stdout, NULL);	/* Tell stdout not to buffer its content */
 
 	memop_cap = kvm_check_cap(KVM_CAP_S390_MEM_OP);
+	extension_cap = kvm_check_cap(KVM_CAP_S390_MEM_OP_EXTENSION);
 	if (!memop_cap) {
 		print_skip("CAP_S390_MEM_OP not supported");
 		exit(KSFT_SKIP);
 	}
 
 	test_copy();
+	if (extension_cap > 0) {
+		test_copy_key();
+		test_copy_key_storage_prot_override();
+		test_copy_key_fetch_prot();
+		test_copy_key_fetch_prot_override();
+	} else {
+		print_skip("storage key memop extension not supported");
+	}
 	test_errors();
 
 	return 0;
