[kvm-unit-tests PATCH v3 3/4] s390x: topology: Check the Perform Topology Function

Pierre Morel
2022-01-10T13:36:40Z

We check the PTF instruction.

- We do not expect to support vertical polarization.

- We do not expect the Modified Topology Change Report to be
pending or not at the moment the first PTF instruction with
PTF_CHECK function code is done as some code already did run
a polarization change may have occur.

Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
---
s390x/Makefile | 1 +
s390x/topology.c | 115 ++++++++++++++++++++++++++++++++++++++++++++
s390x/unittests.cfg | 3 ++
3 files changed, 119 insertions(+)
create mode 100644 s390x/topology.c

diff --git a/s390x/Makefile b/s390x/Makefile
index 1e567c11..fa21a882 100644
--- a/s390x/Makefile
+++ b/s390x/Makefile
@@ -26,6 +26,7 @@ tests += $(TEST_DIR)/edat.elf
tests += $(TEST_DIR)/mvpg-sie.elf
tests += $(TEST_DIR)/spec_ex-sie.elf
tests += $(TEST_DIR)/firq.elf
+tests += $(TEST_DIR)/topology.elf

tests_binary = $(patsubst %.elf,%.bin,$(tests))
ifneq ($(HOST_KEY_DOCUMENT),)
diff --git a/s390x/topology.c b/s390x/topology.c
new file mode 100644
index 00000000..a227555e
--- /dev/null
+++ b/s390x/topology.c
@@ -0,0 +1,115 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * CPU Topology
+ *
+ * Copyright (c) 2021 IBM Corp
+ *
+ * Authors:
+ * Pierre Morel <pmorel@linux.ibm.com>
+ */
+
+#include <libcflat.h>
+#include <asm/page.h>
+#include <asm/asm-offsets.h>
+#include <asm/interrupt.h>
+#include <asm/facility.h>
+#include <smp.h>
+#include <sclp.h>
+#include <s390x/vm.h>
+
+#define PTF_REQ_HORIZONTAL 0
+#define PTF_REQ_VERTICAL 1
+#define PTF_REQ_CHECK 2
+
+#define PTF_ERR_NO_REASON 0
+#define PTF_ERR_ALRDY_POLARIZED 1
+#define PTF_ERR_IN_PROGRESS 2
+
+static int ptf(unsigned long fc, unsigned long *rc)
+{
+ int cc;
+
+ asm volatile(
+ " .insn rre,0xb9a20000,%1,0\n"
+ " ipm %0\n"
+ " srl %0,28\n"
+ : "=d" (cc), "+d" (fc)
+ : "d" (fc)
+ : "cc");
+
+ *rc = fc >> 8;
+ return cc;
+}
+
+static void test_ptf(void)
+{
+ unsigned long rc;
+ int cc;
+
+ report_prefix_push("Topology Report pending");
+ /*
+ * At this moment the topology may already have changed
+ * since the VM has been started.
+ * However, we can test if a second PTF instruction
+ * reports that the topology did not change since the
+ * preceding PFT instruction.
+ */
+ ptf(PTF_REQ_CHECK, &rc);
+ cc = ptf(PTF_REQ_CHECK, &rc);
+ report(cc == 0, "PTF check should clear topology report");
+
+ report_prefix_pop();
+
+ report_prefix_push("Topology polarisation check");
+ /*
+ * We can not assume the state of the polarization for
+ * any Virtual Machine but KVM.
+ * Let's skip the polarisation tests for other VMs.
+ */
+ if (!vm_is_kvm()) {
+ report_skip("Topology polarisation check is done for KVM only");
+ goto end;
+ }
+
+ cc = ptf(PTF_REQ_HORIZONTAL, &rc);
+ report(cc == 2 && rc == PTF_ERR_ALRDY_POLARIZED,
+ "KVM always provides horizontal polarization");
+
+ cc = ptf(PTF_REQ_VERTICAL, &rc);
+ report(cc == 2 && rc == PTF_ERR_NO_REASON,
+ "KVM doesn't support vertical polarization.");
+
+end:
+ report_prefix_pop();
+}
+
+static struct {
+ const char *name;
+ void (*func)(void);
+} tests[] = {
+ { "PTF", test_ptf},
+ { NULL, NULL }
+};
+
+int main(int argc, char *argv[])
+{
+ int i;
+
+ report_prefix_push("CPU Topology");
+
+ if (!test_facility(11)) {
+ report_skip("Topology facility not present");
+ goto end;
+ }
+
+ report_info("Machine level %ld", stsi_get_fc());
+
+ for (i = 0; tests[i].name; i++) {
+ report_prefix_push(tests[i].name);
+ tests[i].func();
+ report_prefix_pop();
+ }
+end:
+ report_prefix_pop();
+ return report_summary();
+}
diff --git a/s390x/unittests.cfg b/s390x/unittests.cfg
index 054560c2..e2d3e6a5 100644
--- a/s390x/unittests.cfg
+++ b/s390x/unittests.cfg
@@ -122,3 +122,6 @@ extra_params = -smp 1,maxcpus=3 -cpu qemu -device qemu-s390x-cpu,core-id=1 -devi
file = firq.elf
timeout = 20
extra_params = -smp 1,maxcpus=3 -cpu qemu -device qemu-s390x-cpu,core-id=2 -device qemu-s390x-cpu,core-id=1
+
+[topology]
+file = topology.elf
--
2.27.0