[kvm-unit-tests PATCH v3 7/7] s390x: Add test for STFLE interpretive execution (format-0)

Nina Schoetterl-Glausch
2024-06-20T14:17:14Z

The STFLE instruction indicates installed facilities.
SIE can interpretively execute STFLE.
Use a snippet guest executing STFLE to get the result of
interpretive execution and check the result.

Signed-off-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com>
---
s390x/Makefile | 2 +
lib/s390x/asm/facility.h | 10 ++-
s390x/snippets/c/stfle.c | 26 ++++++++
s390x/stfle-sie.c | 134 +++++++++++++++++++++++++++++++++++++++
s390x/unittests.cfg | 3 +
5 files changed, 174 insertions(+), 1 deletion(-)
create mode 100644 s390x/snippets/c/stfle.c
create mode 100644 s390x/stfle-sie.c

diff --git a/s390x/Makefile b/s390x/Makefile
index 12445fb5..7c38d66a 100644
--- a/s390x/Makefile
+++ b/s390x/Makefile
@@ -44,6 +44,7 @@ tests += $(TEST_DIR)/exittime.elf
tests += $(TEST_DIR)/ex.elf
tests += $(TEST_DIR)/topology.elf
tests += $(TEST_DIR)/sie-dat.elf
+tests += $(TEST_DIR)/stfle-sie.elf

pv-tests += $(TEST_DIR)/pv-diags.elf
pv-tests += $(TEST_DIR)/pv-icptcode.elf
@@ -129,6 +130,7 @@ snippet_lib = $(snippet_asmlib) lib/auxinfo.o
$(TEST_DIR)/mvpg-sie.elf: snippets = $(SNIPPET_DIR)/c/mvpg-snippet.gbin
$(TEST_DIR)/sie-dat.elf: snippets = $(SNIPPET_DIR)/c/sie-dat.gbin
$(TEST_DIR)/spec_ex-sie.elf: snippets = $(SNIPPET_DIR)/c/spec_ex.gbin
+$(TEST_DIR)/stfle-sie.elf: snippets = $(SNIPPET_DIR)/c/stfle.gbin

$(TEST_DIR)/pv-diags.elf: pv-snippets += $(SNIPPET_DIR)/asm/pv-diag-yield.gbin
$(TEST_DIR)/pv-diags.elf: pv-snippets += $(SNIPPET_DIR)/asm/pv-diag-288.gbin
diff --git a/lib/s390x/asm/facility.h b/lib/s390x/asm/facility.h
index a66fe56a..2bad05c5 100644
--- a/lib/s390x/asm/facility.h
+++ b/lib/s390x/asm/facility.h
@@ -27,12 +27,20 @@ static inline void stfl(void)
asm volatile(" stfl 0(0)\n" : : : "memory");
}

-static inline void stfle(uint64_t *fac, unsigned int nb_doublewords)
+static inline unsigned int stfle(uint64_t *fac, unsigned int nb_doublewords)
{
register unsigned long r0 asm("0") = nb_doublewords - 1;

asm volatile(" .insn s,0xb2b00000,0(%1)\n"
: "+d" (r0) : "a" (fac) : "memory", "cc");
+ return r0 + 1;
+}
+
+static inline unsigned long stfle_size(void)
+{
+ uint64_t dummy;
+
+ return stfle(&dummy, 1);
}

static inline void setup_facilities(void)
diff --git a/s390x/snippets/c/stfle.c b/s390x/snippets/c/stfle.c
new file mode 100644
index 00000000..eb024a6a
--- /dev/null
+++ b/s390x/snippets/c/stfle.c
@@ -0,0 +1,26 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright IBM Corp. 2023
+ *
+ * Snippet used by the STLFE interpretive execution facilities test.
+ */
+#include <libcflat.h>
+#include <snippet-guest.h>
+
+int main(void)
+{
+ const unsigned int max_fac_len = 8;
+ uint64_t res[max_fac_len + 1];
+
+ res[0] = max_fac_len - 1;
+ asm volatile ( "lg 0,%[len]\n"
+ " stfle %[fac]\n"
+ " stg 0,%[len]\n"
+ : [fac] "=QS"(*(uint64_t(*)[max_fac_len])&res[1]),
+ [len] "+RT"(res[0])
+ :
+ : "%r0", "cc"
+ );
+ force_exit_value((uint64_t)&res);
+ return 0;
+}
diff --git a/s390x/stfle-sie.c b/s390x/stfle-sie.c
new file mode 100644
index 00000000..a3e7f1c9
--- /dev/null
+++ b/s390x/stfle-sie.c
@@ -0,0 +1,134 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright IBM Corp. 2023
+ *
+ * SIE with STLFE interpretive execution facilities test.
+ */
+#include <libcflat.h>
+#include <stdlib.h>
+#include <asm/facility.h>
+#include <asm/time.h>
+#include <snippet-host.h>
+#include <alloc_page.h>
+#include <sclp.h>
+#include <rand.h>
+
+static struct vm vm;
+static uint64_t (*fac)[PAGE_SIZE / sizeof(uint64_t)];
+static prng_state prng_s;
+
+static void setup_guest(void)
+{
+ extern const char SNIPPET_NAME_START(c, stfle)[];
+ extern const char SNIPPET_NAME_END(c, stfle)[];
+
+ setup_vm();
+ fac = alloc_pages_flags(0, AREA_DMA31);
+
+ snippet_setup_guest(&vm, false);
+ snippet_init(&vm, SNIPPET_NAME_START(c, stfle),
+ SNIPPET_LEN(c, stfle), SNIPPET_UNPACK_OFF);
+}
+
+struct guest_stfle_res {
+ uint16_t len;
+ uint64_t reg;
+ unsigned char *mem;
+};
+
+static struct guest_stfle_res run_guest(void)
+{
+ struct guest_stfle_res res;
+ uint64_t guest_stfle_addr;
+
+ sie(&vm);
+ assert(snippet_is_force_exit_value(&vm));
+ guest_stfle_addr = snippet_get_force_exit_value(&vm);
+ res.mem = &vm.guest_mem[guest_stfle_addr];
+ memcpy(&res.reg, res.mem, sizeof(res.reg));
+ res.len = (res.reg & 0xff) + 1;
+ res.mem += sizeof(res.reg);
+ return res;
+}
+
+static void test_stfle_format_0(void)
+{
+ struct guest_stfle_res res;
+
+ report_prefix_push("format-0");
+ for (int j = 0; j < stfle_size(); j++)
+ WRITE_ONCE((*fac)[j], prng64(&prng_s));
+ vm.sblk->fac = (uint32_t)(uint64_t)fac;
+ res = run_guest();
+ report(res.len == stfle_size(), "stfle len correct");
+ report(!memcmp(*fac, res.mem, res.len * sizeof(uint64_t)),
+ "Guest facility list as specified");
+ report_prefix_pop();
+}
+
+struct args {
+ uint64_t seed;
+};
+
+static bool parse_uint64_t(const char *arg, uint64_t *out)
+{
+ char *end;
+ uint64_t num;
+
+ if (arg[0] == '\0')
+ return false;
+ num = strtoul(arg, &end, 0);
+ if (end[0] != '\0')
+ return false;
+ *out = num;
+ return true;
+}
+
+static struct args parse_args(int argc, char **argv)
+{
+ struct args args;
+ const char *flag;
+ unsigned int i;
+ uint64_t arg;
+ bool has_arg;
+
+ stck(&args.seed);
+
+ for (i = 1; i < argc; i++) {
+ if (i + 1 < argc)
+ has_arg = parse_uint64_t(argv[i + 1], &arg);
+ else
+ has_arg = false;
+
+ flag = "--seed";
+ if (!strcmp(flag, argv[i])) {
+ if (!has_arg)
+ report_abort("%s needs an uint64_t parameter", flag);
+ args.seed = arg;
+ ++i;
+ continue;
+ }
+ report_abort("Unsupported parameter '%s'",
+ argv[i]);
+ }
+
+ return args;
+}
+
+int main(int argc, char **argv)
+{
+ struct args args = parse_args(argc, argv);
+
+ if (!sclp_facilities.has_sief2) {
+ report_skip("SIEF2 facility unavailable");
+ goto out;
+ }
+
+ report_info("PRNG seed: 0x%lx", args.seed);
+ prng_s = prng_init(args.seed);
+ setup_guest();
+ if (test_facility(7))
+ test_stfle_format_0();
+out:
+ return report_summary();
+}
diff --git a/s390x/unittests.cfg b/s390x/unittests.cfg
index 3a9decc9..f2203069 100644
--- a/s390x/unittests.cfg
+++ b/s390x/unittests.cfg
@@ -392,3 +392,6 @@ file = sie-dat.elf

[pv-attest]
file = pv-attest.elf
+
+[stfle-sie]
+file = stfle-sie.elf
--
2.44.0