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

Janis Schoetterl-Glausch
2022-05-05T12:47:10Z

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 | 277 ++++++++++++++++++++++++++++++++++++++++++++
s390x/unittests.cfg | 1 +
2 files changed, 278 insertions(+)

diff --git a/s390x/skey.c b/s390x/skey.c
index 56bf5f45..d50470a8 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 +285,114 @@ 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 channel_subsystem_call_key_1(void *communication_block)
+{
+ uint32_t program_mask;
+
+ asm volatile (
+ "spka 0x10\n\t"
+ ".insn rre,0xb25f0000,%[communication_block],0\n\t"
+ "spka 0\n\t"
+ "ipm %[program_mask]\n"
+ : [program_mask] "=d" (program_mask)
+ : [communication_block] "d" (communication_block)
+ : "memory"
+ );
+ return program_mask >> 28;
+}
+
+static void init_store_channel_subsystem_characteristics(uint16_t *communication_block)
+{
+ memset(communication_block, 0, PAGE_SIZE);
+ communication_block[0] = 0x10;
+ communication_block[1] = 0x10;
+ communication_block[9] = 0;
+}
+
+static void test_channel_subsystem_call(void)
+{
+ static const char request_name[] = "Store channel-subsystem-characteristics";
+ uint16_t *communication_block = (uint16_t *)&pagebuf;
+ unsigned int cc;
+
+ report_prefix_push("CHANNEL SUBSYSTEM CALL");
+
+ report_prefix_push("zero key");
+ init_store_channel_subsystem_characteristics(communication_block);
+ set_storage_key(communication_block, 0x10, 0);
+ asm volatile (
+ ".insn rre,0xb25f0000,%[communication_block],0\n\t"
+ "ipm %[cc]\n"
+ : [cc] "=d" (cc)
+ : [communication_block] "d" (communication_block)
+ : "memory"
+ );
+ cc = cc >> 28;
+ report(cc == 0 && communication_block[9], request_name);
+ report_prefix_pop();
+
+ report_prefix_push("matching key");
+ init_store_channel_subsystem_characteristics(communication_block);
+ set_storage_key(communication_block, 0x10, 0);
+ cc = channel_subsystem_call_key_1(communication_block);
+ report(cc == 0 && communication_block[9], request_name);
+ report_prefix_pop();
+
+ report_prefix_push("mismatching key");
+
+ report_prefix_push("no fetch protection");
+ init_store_channel_subsystem_characteristics(communication_block);
+ set_storage_key(communication_block, 0x20, 0);
+ expect_pgm_int();
+ channel_subsystem_call_key_1(communication_block);
+ check_key_prot_exc(ACC_UPDATE, PROT_STORE);
+ report_prefix_pop();
+
+ report_prefix_push("fetch protection");
+ init_store_channel_subsystem_characteristics(communication_block);
+ set_storage_key(communication_block, 0x28, 0);
+ expect_pgm_int();
+ channel_subsystem_call_key_1(communication_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(communication_block, 0x20, 0);
+ init_store_channel_subsystem_characteristics(communication_block);
+ expect_pgm_int();
+ channel_subsystem_call_key_1(communication_block);
+ check_key_prot_exc(ACC_UPDATE, PROT_STORE);
+ report_prefix_pop();
+
+ report_prefix_push("storage-protection override, override key");
+ init_store_channel_subsystem_characteristics(communication_block);
+ set_storage_key(communication_block, 0x90, 0);
+ cc = channel_subsystem_call_key_1(communication_block);
+ report(cc == 0 && communication_block[9], request_name);
+ report_prefix_pop();
+
+ ctl_clear_bit(0, CTL0_STORAGE_PROTECTION_OVERRIDE);
+
+ report_prefix_push("storage-protection override disabled, override key");
+ init_store_channel_subsystem_characteristics(communication_block);
+ set_storage_key(communication_block, 0x90, 0);
+ expect_pgm_int();
+ channel_subsystem_call_key_1(communication_block);
+ check_key_prot_exc(ACC_UPDATE, PROT_STORE);
+ report_prefix_pop();
+
+ report_prefix_pop();
+
+ set_storage_key(communication_block, 0x00, 0);
+ report_prefix_pop();
+}
+
/*
* Perform SET PREFIX (SPX) instruction while temporarily executing
* with access key 1.
@@ -410,6 +519,172 @@ 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);
+ 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");
@@ -424,9 +699,11 @@ 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 743013b2..069c41a7 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