[kvm-unit-tests PATCH v2 3/4] s390x: Test effect of storage keys on some more instructions

[Janis Schoetterl-Glausch <scgl@linux.ibm.com>]

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>
---
 s390x/skey.c        | 285 ++++++++++++++++++++++++++++++++++++++++++++
 s390x/unittests.cfg |   1 +
 2 files changed, 286 insertions(+)

diff --git a/s390x/skey.c b/s390x/skey.c
index 19fa5721..60ae8158 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>
@@ -284,6 +285,115 @@ 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.
@@ -417,6 +527,179 @@ 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;
+
+/*
+ * gcc 12.0.1 warns if schib is < 4k.
+ * We need such addresses to test fetch protection override.
+ */
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Warray-bounds"
+	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"
+	);
+#pragma GCC diagnostic pop
+	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);
+		WRITE_ONCE(schib->pmcw.intparm, 0);
+		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);
+		WRITE_ONCE(schib->pmcw.intparm, 0);
+		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, (struct schib *)2048);
+		install_page(root, 0, 0);
+		check_key_prot_exc(ACC_FETCH, PROT_FETCH_STORE);
+		WRITE_ONCE(schib->pmcw.intparm, 0);
+		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");
@@ -431,9 +714,11 @@ 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