[kvm-unit-tests PATCH v4 0/4] More skey instr. emulation test

[kvm-unit-tests PATCH v4 0/4] More skey instr. emulation test

[Janis Schoetterl-Glausch]

Add test cases similar to those testing the effect of storage keys on
instructions emulated by KVM, but test instructions emulated by user
space/qemu instead.
Test that DIAG 308 is not subject to key protection.
Additionally, check the transaction exception identification on
protection exceptions.

This series is based on v2 of s390x: Rework TEID decoding and usage .
https://lore.kernel.org/kvm/20220608133303.1532166-1-scgl@linux.ibm.com/

v3 -> v4
 * rebase on newest TEID decoding series
 * pick up r-b's (Thanks Claudio)
 * add check for protection code validity in case of basic SOP

v2 -> v3
 * move sclp patch and part of TEID test to series
       s390x: Rework TEID decoding and usage
 * make use of reworked TEID union in skey TEID test
 * get rid of pointer to array for diag 308 test
 * use lowcore symbol and mem_all
 * don't reset intparm when expecting exception in msch test

v1 -> v2
 * don't mixup sclp fix with new bits for the TEID patch
 * address feedback
       * cosmetic changes, i.e. shortening identifiers
       * remove unconditional report_info
 * add DIAG 308 test

Janis Schoetterl-Glausch (3):
  s390x: Test TEID values in storage key test
  s390x: Test effect of storage keys on some more instructions
  s390x: Test effect of storage keys on diag 308

 s390x/skey.c        | 381 +++++++++++++++++++++++++++++++++++++++++++-
 s390x/unittests.cfg |   1 +
 2 files changed, 376 insertions(+), 6 deletions(-)

Range-diff against v3:
1:  073ffb3c ! 1:  fbfd7e3b s390x: Test TEID values in storage key test
    @@ s390x/skey.c: static void test_test_protection(void)
     +{
     +	union teid teid;
     +	int access_code;
    ++	bool dat;
     +
     +	check_pgm_int_code(PGM_INT_CODE_PROTECTION);
     +	report_prefix_push("TEID");
     +	teid.val = lowcore.trans_exc_id;
     +	switch (get_supp_on_prot_facility()) {
     +	case SOP_NONE:
    ++		break;
     +	case SOP_BASIC:
    ++		dat = extract_psw_mask() & PSW_MASK_DAT;
    ++		report(!teid.sop_teid_predictable || !dat || !teid.sop_acc_list,
    ++		       "valid protection code");
     +		break;
     +	case SOP_ENHANCED_1:
    -+		report(!teid.esop1_acc_list_or_dat, "valid protection code");
    ++		report(!teid.sop_teid_predictable, "valid protection code");
     +		break;
     +	case SOP_ENHANCED_2:
     +		switch (teid_esop2_prot_code(teid)) {
    @@ s390x/skey.c: static void test_set_prefix(void)
      
     @@ s390x/skey.c: static void test_set_prefix(void)
      	install_page(root, virt_to_pte_phys(root, pagebuf), 0);
    - 	set_prefix_key_1((uint32_t *)&mem_all[2048]);
    + 	set_prefix_key_1(OPAQUE_PTR(2048));
      	install_page(root, 0, 0);
     -	check_pgm_int_code(PGM_INT_CODE_PROTECTION);
     +	check_key_prot_exc(ACC_FETCH, PROT_FETCH_STORE);
2:  9f300b87 ! 2:  868bb863 s390x: Test effect of storage keys on some more instructions
    @@ Commit message
         fetch protection override.
     
         Signed-off-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com>
    +    Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
     
      ## s390x/skey.c ##
     @@
    @@ s390x/skey.c: static void test_set_prefix(void)
     +		set_storage_key(pagebuf, 0x28, 0);
     +		expect_pgm_int();
     +		install_page(root, virt_to_pte_phys(root, pagebuf), 0);
    -+		modify_subchannel_key_1(test_device_sid, (struct schib *)&mem_all[2048]);
    ++		modify_subchannel_key_1(test_device_sid, OPAQUE_PTR(2048));
     +		install_page(root, 0, 0);
     +		check_key_prot_exc(ACC_FETCH, PROT_FETCH_STORE);
     +		cc = stsch(test_device_sid, schib);
3:  c4ca0619 ! 3:  d49934c0 s390x: Test effect of storage keys on diag 308
    @@ Commit message
         Test that key-controlled protection does not apply to diag 308.
     
         Signed-off-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com>
    +    Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
     
      ## s390x/skey.c ##
     @@ s390x/skey.c: static void test_store_cpu_address(void)

base-commit: 2eed0bf1096077144cc3a0dd9974689487f9511a
prerequisite-patch-id: aa682f50e4eba0e9b6cacd245d568f5bcca05e0f
prerequisite-patch-id: 79a88ac3faff3ae2ef214bf4a90de7463e2fdc8a
prerequisite-patch-id: bebbc71ca3cc8d085e36a049466dba5a420c9c75
prerequisite-patch-id: d38a4fc7bc1fa6e352502f294cb9413f0b738b99
prerequisite-patch-id: 181e4127db838f3a98fd2b27ea4f23c53da908d7
-- 
2.33.1

[kvm-unit-tests PATCH v4 1/3] s390x: Test TEID values in storage key test

[Janis Schoetterl-Glausch]

On a protection exception, test that the Translation-Exception
Identification (TEID) values are correct given the circumstances of the
particular test.
The meaning of the TEID values is dependent on the installed
suppression-on-protection facility.

Signed-off-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com>
---
 s390x/skey.c | 80 ++++++++++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 74 insertions(+), 6 deletions(-)

diff --git a/s390x/skey.c b/s390x/skey.c
index 445476a0..d05ebc09 100644
--- a/s390x/skey.c
+++ b/s390x/skey.c
@@ -8,6 +8,7 @@
  *  Janosch Frank <frankja@linux.vnet.ibm.com>
  */
 #include <libcflat.h>
+#include <asm/arch_def.h>
 #include <asm/asm-offsets.h>
 #include <asm/interrupt.h>
 #include <vmalloc.h>
@@ -158,6 +159,73 @@ static void test_test_protection(void)
 	report_prefix_pop();
 }
 
+enum access {
+	ACC_STORE = 1,
+	ACC_FETCH = 2,
+	ACC_UPDATE = 3,
+};
+
+enum protection {
+	PROT_STORE = 1,
+	PROT_FETCH_STORE = 3,
+};
+
+static void check_key_prot_exc(enum access access, enum protection prot)
+{
+	union teid teid;
+	int access_code;
+	bool dat;
+
+	check_pgm_int_code(PGM_INT_CODE_PROTECTION);
+	report_prefix_push("TEID");
+	teid.val = lowcore.trans_exc_id;
+	switch (get_supp_on_prot_facility()) {
+	case SOP_NONE:
+		break;
+	case SOP_BASIC:
+		dat = extract_psw_mask() & PSW_MASK_DAT;
+		report(!teid.sop_teid_predictable || !dat || !teid.sop_acc_list,
+		       "valid protection code");
+		break;
+	case SOP_ENHANCED_1:
+		report(!teid.sop_teid_predictable, "valid protection code");
+		break;
+	case SOP_ENHANCED_2:
+		switch (teid_esop2_prot_code(teid)) {
+		case PROT_KEY:
+			access_code = teid.acc_exc_f_s;
+
+			switch (access_code) {
+			case 0:
+				report_pass("valid access code");
+				break;
+			case 1:
+			case 2:
+				report((access & access_code) && (prot & access_code),
+				       "valid access code");
+				break;
+			case 3:
+				/*
+				 * This is incorrect in that reserved values
+				 * should be ignored, but kvm should not return
+				 * a reserved value and having a test for that
+				 * is more valuable.
+				 */
+				report_fail("valid access code");
+				break;
+			}
+			/* fallthrough */
+		case PROT_KEY_LAP:
+			report_pass("valid protection code");
+			break;
+		default:
+			report_fail("valid protection code");
+		}
+		break;
+	}
+	report_prefix_pop();
+}
+
 /*
  * Perform STORE CPU ADDRESS (STAP) instruction while temporarily executing
  * with access key 1.
@@ -199,7 +267,7 @@ static void test_store_cpu_address(void)
 	expect_pgm_int();
 	*out = 0xbeef;
 	store_cpu_address_key_1(out);
-	check_pgm_int_code(PGM_INT_CODE_PROTECTION);
+	check_key_prot_exc(ACC_STORE, PROT_STORE);
 	report(*out == 0xbeef, "no store occurred");
 	report_prefix_pop();
 
@@ -210,7 +278,7 @@ static void test_store_cpu_address(void)
 	expect_pgm_int();
 	*out = 0xbeef;
 	store_cpu_address_key_1(out);
-	check_pgm_int_code(PGM_INT_CODE_PROTECTION);
+	check_key_prot_exc(ACC_STORE, PROT_STORE);
 	report(*out == 0xbeef, "no store occurred");
 	report_prefix_pop();
 
@@ -228,7 +296,7 @@ static void test_store_cpu_address(void)
 	expect_pgm_int();
 	*out = 0xbeef;
 	store_cpu_address_key_1(out);
-	check_pgm_int_code(PGM_INT_CODE_PROTECTION);
+	check_key_prot_exc(ACC_STORE, PROT_STORE);
 	report(*out == 0xbeef, "no store occurred");
 	report_prefix_pop();
 
@@ -314,7 +382,7 @@ static void test_set_prefix(void)
 	set_storage_key(pagebuf, 0x28, 0);
 	expect_pgm_int();
 	set_prefix_key_1(prefix_ptr);
-	check_pgm_int_code(PGM_INT_CODE_PROTECTION);
+	check_key_prot_exc(ACC_FETCH, PROT_FETCH_STORE);
 	report(get_prefix() == old_prefix, "did not set prefix");
 	report_prefix_pop();
 
@@ -327,7 +395,7 @@ static void test_set_prefix(void)
 	install_page(root, virt_to_pte_phys(root, pagebuf), 0);
 	set_prefix_key_1((uint32_t *)0);
 	install_page(root, 0, 0);
-	check_pgm_int_code(PGM_INT_CODE_PROTECTION);
+	check_key_prot_exc(ACC_FETCH, PROT_FETCH_STORE);
 	report(get_prefix() == old_prefix, "did not set prefix");
 	report_prefix_pop();
 
@@ -351,7 +419,7 @@ static void test_set_prefix(void)
 	install_page(root, virt_to_pte_phys(root, pagebuf), 0);
 	set_prefix_key_1(OPAQUE_PTR(2048));
 	install_page(root, 0, 0);
-	check_pgm_int_code(PGM_INT_CODE_PROTECTION);
+	check_key_prot_exc(ACC_FETCH, PROT_FETCH_STORE);
 	report(get_prefix() == old_prefix, "did not set prefix");
 	report_prefix_pop();
 
-- 
2.33.1

[kvm-unit-tests PATCH v4 2/3] s390x: Test effect of storage keys on some more instructions

[Janis Schoetterl-Glausch]

Test correctness of some instructions handled by user space instead of
KVM with regards to storage keys.
Test success and error conditions, including coverage of storage and
fetch protection override.

Signed-off-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
---
 s390x/skey.c        | 275 ++++++++++++++++++++++++++++++++++++++++++++
 s390x/unittests.cfg |   1 +
 2 files changed, 276 insertions(+)

diff --git a/s390x/skey.c b/s390x/skey.c
index d05ebc09..36b81cec 100644
--- a/s390x/skey.c
+++ b/s390x/skey.c
@@ -12,6 +12,7 @@
 #include <asm/asm-offsets.h>
 #include <asm/interrupt.h>
 #include <vmalloc.h>
+#include <css.h>
 #include <asm/page.h>
 #include <asm/facility.h>
 #include <asm/mem.h>
@@ -304,6 +305,115 @@ static void test_store_cpu_address(void)
 	report_prefix_pop();
 }
 
+/*
+ * Perform CHANNEL SUBSYSTEM CALL (CHSC)  instruction while temporarily executing
+ * with access key 1.
+ */
+static unsigned int chsc_key_1(void *comm_block)
+{
+	uint32_t program_mask;
+
+	asm volatile (
+		"spka	0x10\n\t"
+		".insn	rre,0xb25f0000,%[comm_block],0\n\t"
+		"spka	0\n\t"
+		"ipm	%[program_mask]\n"
+		: [program_mask] "=d" (program_mask)
+		: [comm_block] "d" (comm_block)
+		: "memory"
+	);
+	return program_mask >> 28;
+}
+
+static const char chsc_msg[] = "Performed store-channel-subsystem-characteristics";
+static void init_comm_block(uint16_t *comm_block)
+{
+	memset(comm_block, 0, PAGE_SIZE);
+	/* store-channel-subsystem-characteristics command */
+	comm_block[0] = 0x10;
+	comm_block[1] = 0x10;
+	comm_block[9] = 0;
+}
+
+static void test_channel_subsystem_call(void)
+{
+	uint16_t *comm_block = (uint16_t *)&pagebuf;
+	unsigned int cc;
+
+	report_prefix_push("CHANNEL SUBSYSTEM CALL");
+
+	report_prefix_push("zero key");
+	init_comm_block(comm_block);
+	set_storage_key(comm_block, 0x10, 0);
+	asm volatile (
+		".insn	rre,0xb25f0000,%[comm_block],0\n\t"
+		"ipm	%[cc]\n"
+		: [cc] "=d" (cc)
+		: [comm_block] "d" (comm_block)
+		: "memory"
+	);
+	cc = cc >> 28;
+	report(cc == 0 && comm_block[9], chsc_msg);
+	report_prefix_pop();
+
+	report_prefix_push("matching key");
+	init_comm_block(comm_block);
+	set_storage_key(comm_block, 0x10, 0);
+	cc = chsc_key_1(comm_block);
+	report(cc == 0 && comm_block[9], chsc_msg);
+	report_prefix_pop();
+
+	report_prefix_push("mismatching key");
+
+	report_prefix_push("no fetch protection");
+	init_comm_block(comm_block);
+	set_storage_key(comm_block, 0x20, 0);
+	expect_pgm_int();
+	chsc_key_1(comm_block);
+	check_key_prot_exc(ACC_UPDATE, PROT_STORE);
+	report_prefix_pop();
+
+	report_prefix_push("fetch protection");
+	init_comm_block(comm_block);
+	set_storage_key(comm_block, 0x28, 0);
+	expect_pgm_int();
+	chsc_key_1(comm_block);
+	check_key_prot_exc(ACC_UPDATE, PROT_FETCH_STORE);
+	report_prefix_pop();
+
+	ctl_set_bit(0, CTL0_STORAGE_PROTECTION_OVERRIDE);
+
+	report_prefix_push("storage-protection override, invalid key");
+	set_storage_key(comm_block, 0x20, 0);
+	init_comm_block(comm_block);
+	expect_pgm_int();
+	chsc_key_1(comm_block);
+	check_key_prot_exc(ACC_UPDATE, PROT_STORE);
+	report_prefix_pop();
+
+	report_prefix_push("storage-protection override, override key");
+	init_comm_block(comm_block);
+	set_storage_key(comm_block, 0x90, 0);
+	cc = chsc_key_1(comm_block);
+	report(cc == 0 && comm_block[9], chsc_msg);
+	report_prefix_pop();
+
+	ctl_clear_bit(0, CTL0_STORAGE_PROTECTION_OVERRIDE);
+
+	report_prefix_push("storage-protection override disabled, override key");
+	init_comm_block(comm_block);
+	set_storage_key(comm_block, 0x90, 0);
+	expect_pgm_int();
+	chsc_key_1(comm_block);
+	check_key_prot_exc(ACC_UPDATE, PROT_STORE);
+	report_prefix_pop();
+
+	report_prefix_pop();
+
+	set_storage_key(comm_block, 0x00, 0);
+	report_prefix_pop();
+}
+
 /*
  * Perform SET PREFIX (SPX) instruction while temporarily executing
  * with access key 1.
@@ -430,6 +540,169 @@ static void test_set_prefix(void)
 	report_prefix_pop();
 }
 
+/*
+ * Perform MODIFY SUBCHANNEL (MSCH) instruction while temporarily executing
+ * with access key 1.
+ */
+static uint32_t modify_subchannel_key_1(uint32_t sid, struct schib *schib)
+{
+	uint32_t program_mask;
+
+	asm volatile (
+		"lr %%r1,%[sid]\n\t"
+		"spka	0x10\n\t"
+		"msch	%[schib]\n\t"
+		"spka	0\n\t"
+		"ipm	%[program_mask]\n"
+		: [program_mask] "=d" (program_mask)
+		: [sid] "d" (sid),
+		  [schib] "Q" (*schib)
+		: "%r1"
+	);
+	return program_mask >> 28;
+}
+
+static void test_msch(void)
+{
+	struct schib *schib = (struct schib *)pagebuf;
+	struct schib *no_override_schib;
+	int test_device_sid;
+	pgd_t *root;
+	int cc;
+
+	report_prefix_push("MSCH");
+	root = (pgd_t *)(stctg(1) & PAGE_MASK);
+	test_device_sid = css_enumerate();
+
+	if (!(test_device_sid & SCHID_ONE)) {
+		report_fail("no I/O device found");
+		return;
+	}
+
+	cc = stsch(test_device_sid, schib);
+	if (cc) {
+		report_fail("could not store SCHIB");
+		return;
+	}
+
+	report_prefix_push("zero key");
+	schib->pmcw.intparm = 100;
+	set_storage_key(schib, 0x28, 0);
+	cc = msch(test_device_sid, schib);
+	if (!cc) {
+		WRITE_ONCE(schib->pmcw.intparm, 0);
+		cc = stsch(test_device_sid, schib);
+		report(!cc && schib->pmcw.intparm == 100, "fetched from SCHIB");
+	} else {
+		report_fail("MSCH cc != 0");
+	}
+	report_prefix_pop();
+
+	report_prefix_push("matching key");
+	schib->pmcw.intparm = 200;
+	set_storage_key(schib, 0x18, 0);
+	cc = modify_subchannel_key_1(test_device_sid, schib);
+	if (!cc) {
+		WRITE_ONCE(schib->pmcw.intparm, 0);
+		cc = stsch(test_device_sid, schib);
+		report(!cc && schib->pmcw.intparm == 200, "fetched from SCHIB");
+	} else {
+		report_fail("MSCH cc != 0");
+	}
+	report_prefix_pop();
+
+	report_prefix_push("mismatching key");
+
+	report_prefix_push("no fetch protection");
+	schib->pmcw.intparm = 300;
+	set_storage_key(schib, 0x20, 0);
+	cc = modify_subchannel_key_1(test_device_sid, schib);
+	if (!cc) {
+		WRITE_ONCE(schib->pmcw.intparm, 0);
+		cc = stsch(test_device_sid, schib);
+		report(!cc && schib->pmcw.intparm == 300, "fetched from SCHIB");
+	} else {
+		report_fail("MSCH cc != 0");
+	}
+	report_prefix_pop();
+
+	schib->pmcw.intparm = 0;
+	if (!msch(test_device_sid, schib)) {
+		report_prefix_push("fetch protection");
+		schib->pmcw.intparm = 400;
+		set_storage_key(schib, 0x28, 0);
+		expect_pgm_int();
+		modify_subchannel_key_1(test_device_sid, schib);
+		check_key_prot_exc(ACC_FETCH, PROT_FETCH_STORE);
+		cc = stsch(test_device_sid, schib);
+		report(!cc && schib->pmcw.intparm == 0, "did not modify subchannel");
+		report_prefix_pop();
+	} else {
+		report_fail("could not reset SCHIB");
+	}
+
+	register_pgm_cleanup_func(dat_fixup_pgm_int);
+
+	schib->pmcw.intparm = 0;
+	if (!msch(test_device_sid, schib)) {
+		report_prefix_push("remapped page, fetch protection");
+		schib->pmcw.intparm = 500;
+		set_storage_key(pagebuf, 0x28, 0);
+		expect_pgm_int();
+		install_page(root, virt_to_pte_phys(root, pagebuf), 0);
+		modify_subchannel_key_1(test_device_sid, (struct schib *)0);
+		install_page(root, 0, 0);
+		check_key_prot_exc(ACC_FETCH, PROT_FETCH_STORE);
+		cc = stsch(test_device_sid, schib);
+		report(!cc && schib->pmcw.intparm == 0, "did not modify subchannel");
+		report_prefix_pop();
+	} else {
+		report_fail("could not reset SCHIB");
+	}
+
+	ctl_set_bit(0, CTL0_FETCH_PROTECTION_OVERRIDE);
+
+	report_prefix_push("fetch-protection override applies");
+	schib->pmcw.intparm = 600;
+	set_storage_key(pagebuf, 0x28, 0);
+	install_page(root, virt_to_pte_phys(root, pagebuf), 0);
+	cc = modify_subchannel_key_1(test_device_sid, (struct schib *)0);
+	install_page(root, 0, 0);
+	if (!cc) {
+		WRITE_ONCE(schib->pmcw.intparm, 0);
+		cc = stsch(test_device_sid, schib);
+		report(!cc && schib->pmcw.intparm == 600, "fetched from SCHIB");
+	} else {
+		report_fail("MSCH cc != 0");
+	}
+	report_prefix_pop();
+
+	schib->pmcw.intparm = 0;
+	if (!msch(test_device_sid, schib)) {
+		report_prefix_push("fetch-protection override does not apply");
+		schib->pmcw.intparm = 700;
+		no_override_schib = (struct schib *)(pagebuf + 2048);
+		memcpy(no_override_schib, schib, sizeof(struct schib));
+		set_storage_key(pagebuf, 0x28, 0);
+		expect_pgm_int();
+		install_page(root, virt_to_pte_phys(root, pagebuf), 0);
+		modify_subchannel_key_1(test_device_sid, OPAQUE_PTR(2048));
+		install_page(root, 0, 0);
+		check_key_prot_exc(ACC_FETCH, PROT_FETCH_STORE);
+		cc = stsch(test_device_sid, schib);
+		report(!cc && schib->pmcw.intparm == 0, "did not modify subchannel");
+		report_prefix_pop();
+	} else {
+		report_fail("could not reset SCHIB");
+	}
+
+	ctl_clear_bit(0, CTL0_FETCH_PROTECTION_OVERRIDE);
+	register_pgm_cleanup_func(NULL);
+	report_prefix_pop();
+	set_storage_key(schib, 0x00, 0);
+	report_prefix_pop();
+}
+
 int main(void)
 {
 	report_prefix_push("skey");
@@ -444,9 +717,11 @@ int main(void)
 	test_chg();
 	test_test_protection();
 	test_store_cpu_address();
+	test_channel_subsystem_call();
 
 	setup_vm();
 	test_set_prefix();
+	test_msch();
 done:
 	report_prefix_pop();
 	return report_summary();
diff --git a/s390x/unittests.cfg b/s390x/unittests.cfg
index b456b288..1280ff0f 100644
--- a/s390x/unittests.cfg
+++ b/s390x/unittests.cfg
@@ -41,6 +41,7 @@ file = sthyi.elf
 
 [skey]
 file = skey.elf
+extra_params = -device virtio-net-ccw
 
 [diag10]
 file = diag10.elf
-- 
2.33.1

[kvm-unit-tests PATCH v4 3/3] s390x: Test effect of storage keys on diag 308

[Janis Schoetterl-Glausch]

Test that key-controlled protection does not apply to diag 308.

Signed-off-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
---
 s390x/skey.c | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/s390x/skey.c b/s390x/skey.c
index 36b81cec..87418f19 100644
--- a/s390x/skey.c
+++ b/s390x/skey.c
@@ -305,6 +305,31 @@ static void test_store_cpu_address(void)
 	report_prefix_pop();
 }
 
+static void test_diag_308(void)
+{
+	uint16_t response;
+	uint32_t *ipib = (uint32_t *)pagebuf;
+
+	report_prefix_push("DIAG 308");
+	WRITE_ONCE(ipib[0], 0); /* Invalid length */
+	set_storage_key(ipib, 0x28, 0);
+	/* key-controlled protection does not apply */
+	asm volatile (
+		"lr	%%r2,%[ipib]\n\t"
+		"spka	0x10\n\t"
+		"diag	%%r2,%[code],0x308\n\t"
+		"spka	0\n\t"
+		"lr	%[response],%%r3\n"
+		: [response] "=d" (response)
+		: [ipib] "d" (ipib),
+		  [code] "d" (5)
+		: "%r2", "%r3"
+	);
+	report(response == 0x402, "no exception on fetch, response: invalid IPIB");
+	set_storage_key(ipib, 0x00, 0);
+	report_prefix_pop();
+}
+
 /*
  * Perform CHANNEL SUBSYSTEM CALL (CHSC)  instruction while temporarily executing
  * with access key 1.
@@ -717,6 +742,7 @@ int main(void)
 	test_chg();
 	test_test_protection();
 	test_store_cpu_address();
+	test_diag_308();
 	test_channel_subsystem_call();
 
 	setup_vm();
-- 
2.33.1