[kvm-unit-tests PATCH v8 10/12] s390x: css: stsch, enumeration test

Pierre Morel
2020-06-08T08:13:13Z

First step for testing the channel subsystem is to enumerate the css and
retrieve the css devices.

This tests the success of STSCH I/O instruction, we do not test the
reaction of the VM for an instruction with wrong parameters.

Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
---
lib/s390x/css_lib.c | 70 +++++++++++++++++++++++++++++++++++++++++++++
s390x/Makefile | 2 ++
s390x/css.c | 64 +++++++++++++++++++++++++++++++++++++++++
s390x/unittests.cfg | 4 +++
4 files changed, 140 insertions(+)
create mode 100644 lib/s390x/css_lib.c
create mode 100644 s390x/css.c

diff --git a/lib/s390x/css_lib.c b/lib/s390x/css_lib.c
new file mode 100644
index 0000000..dc5a512
--- /dev/null
+++ b/lib/s390x/css_lib.c
@@ -0,0 +1,70 @@
+/*
+ * Channel Subsystem tests library
+ *
+ * Copyright (c) 2020 IBM Corp
+ *
+ * Authors:
+ * Pierre Morel <pmorel@linux.ibm.com>
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2.
+ */
+#include <libcflat.h>
+#include <alloc_phys.h>
+#include <asm/page.h>
+#include <string.h>
+#include <interrupt.h>
+#include <asm/arch_def.h>
+
+#include <css.h>
+
+static struct schib schib;
+
+/*
+ * css_enumerate:
+ * On success return the first subchannel ID found.
+ * On error return an invalid subchannel ID containing cc
+ */
+int css_enumerate(void)
+{
+ struct pmcw *pmcw = &schib.pmcw;
+ int scn_found = 0;
+ int dev_found = 0;
+ int schid = 0;
+ int cc;
+ int scn;
+
+ for (scn = 0; scn < 0xffff; scn++) {
+ cc = stsch(scn | SCHID_ONE, &schib);
+ switch (cc) {
+ case 0: /* 0 means SCHIB stored */
+ break;
+ case 3: /* 3 means no more channels */
+ goto out;
+ default: /* 1 or 2 should never happened for STSCH */
+ report_info("Unexpected error %d on subchannel %08x",
+ cc, scn | SCHID_ONE);
+ return cc;
+ }
+
+ /* We currently only support type 0, a.k.a. I/O channels */
+ if (PMCW_CHANNEL_TYPE(pmcw) != 0)
+ continue;
+
+ /* We ignore I/O channels without valid devices */
+ scn_found++;
+ if (!(pmcw->flags & PMCW_DNV))
+ continue;
+
+ /* We keep track of the first device as our test device */
+ if (!schid)
+ schid = scn | SCHID_ONE;
+ report_info("Found subchannel %08x", scn | SCHID_ONE);
+ dev_found++;
+ }
+
+out:
+ report_info("Tested subchannels: %d, I/O subchannels: %d, I/O devices: %d",
+ scn, scn_found, dev_found);
+ return schid;
+}
diff --git a/s390x/Makefile b/s390x/Makefile
index 3cb97da..afd2c9b 100644
--- a/s390x/Makefile
+++ b/s390x/Makefile
@@ -17,6 +17,7 @@ tests += $(TEST_DIR)/stsi.elf
tests += $(TEST_DIR)/skrf.elf
tests += $(TEST_DIR)/smp.elf
tests += $(TEST_DIR)/sclp.elf
+tests += $(TEST_DIR)/css.elf
tests_binary = $(patsubst %.elf,%.bin,$(tests))

all: directories test_cases test_cases_binary
@@ -53,6 +54,7 @@ cflatobjs += lib/s390x/mmu.o
cflatobjs += lib/s390x/smp.o
cflatobjs += lib/s390x/kernel-args.o
cflatobjs += lib/s390x/css_dump.o
+cflatobjs += lib/s390x/css_lib.o

OBJDIRS += lib/s390x

diff --git a/s390x/css.c b/s390x/css.c
new file mode 100644
index 0000000..f0e8f47
--- /dev/null
+++ b/s390x/css.c
@@ -0,0 +1,64 @@
+/*
+ * Channel Subsystem tests
+ *
+ * Copyright (c) 2020 IBM Corp
+ *
+ * Authors:
+ * Pierre Morel <pmorel@linux.ibm.com>
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2.
+ */
+
+#include <libcflat.h>
+#include <alloc_phys.h>
+#include <asm/page.h>
+#include <string.h>
+#include <interrupt.h>
+#include <asm/arch_def.h>
+
+#include <css.h>
+
+static int test_device_sid;
+
+static void test_enumerate(void)
+{
+ test_device_sid = css_enumerate();
+ if (test_device_sid & SCHID_ONE) {
+ report(1, "First device schid: 0x%08x", test_device_sid);
+ return;
+ }
+
+ switch (test_device_sid) {
+ case 0:
+ report (0, "No I/O device found");
+ break;
+ default: /* 1 or 2 should never happened for STSCH */
+ report(0, "Unexpected cc=%d during enumeration",
+ test_device_sid);
+ return;
+ }
+}
+
+static struct {
+ const char *name;
+ void (*func)(void);
+} tests[] = {
+ { "enumerate (stsch)", test_enumerate },
+ { NULL, NULL }
+};
+
+int main(int argc, char *argv[])
+{
+ int i;
+
+ report_prefix_push("Channel Subsystem");
+ for (i = 0; tests[i].name; i++) {
+ report_prefix_push(tests[i].name);
+ tests[i].func();
+ report_prefix_pop();
+ }
+ report_prefix_pop();
+
+ return report_summary();
+}
diff --git a/s390x/unittests.cfg b/s390x/unittests.cfg
index b307329..0f156af 100644
--- a/s390x/unittests.cfg
+++ b/s390x/unittests.cfg
@@ -84,3 +84,7 @@ extra_params = -m 1G
[sclp-3g]
file = sclp.elf
extra_params = -m 3G
+
+[css]
+file = css.elf
+extra_params = -device virtio-net-ccw
--
2.25.1