On 02/02/2023 10.28, Pierre Morel wrote:
We check that the PTF instruction is working correctly when
the cpu topology facility is available.
For KVM only, we test changing of the polarity between horizontal
and vertical and that a reset set the horizontal polarity.
Signed-off-by: Pierre Morel <pmorel@xxxxxxxxxxxxx>
---
s390x/Makefile | 1 +
s390x/topology.c | 155 ++++++++++++++++++++++++++++++++++++++++++++
s390x/unittests.cfg | 3 +
3 files changed, 159 insertions(+)
create mode 100644 s390x/topology.c
diff --git a/s390x/Makefile b/s390x/Makefile
index 52a9d82..b5fe8a3 100644
--- a/s390x/Makefile
+++ b/s390x/Makefile
@@ -39,6 +39,7 @@ tests += $(TEST_DIR)/panic-loop-extint.elf
tests += $(TEST_DIR)/panic-loop-pgm.elf
tests += $(TEST_DIR)/migration-sck.elf
tests += $(TEST_DIR)/exittime.elf
+tests += $(TEST_DIR)/topology.elf
pv-tests += $(TEST_DIR)/pv-diags.elf
diff --git a/s390x/topology.c b/s390x/topology.c
new file mode 100644
index 0000000..20f7ba2
--- /dev/null
+++ b/s390x/topology.c
@@ -0,0 +1,155 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * CPU Topology
+ *
+ * Copyright IBM Corp. 2022
+ *
+ * Authors:
+ * Pierre Morel <pmorel@xxxxxxxxxxxxx>
+ */
+
+#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/hardware.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
+
+extern int diag308_load_reset(u64);
+
+static int ptf(unsigned long fc, unsigned long *rc)
+{
+ int cc;
+
+ asm volatile(
+ " .insn rre,0xb9a20000,%1,0\n"
Why are you specifying the instruction manually? I think both, GCC and Clang
should know the "ptf" mnemonic, shouldn't they?
+ " ipm %0\n"
+ " srl %0,28\n"
+ : "=d" (cc), "+d" (fc)
+ :
+ : "cc");
+
+ *rc = fc >> 8;
+ return cc;
+}
+
+static void test_ptf(void)
+{
+ unsigned long rc;
+ int cc;
+
+ /* PTF is a privilege instruction */
s/privilege/privileged/ ?
+ report_prefix_push("Privilege");
+ enter_pstate();
+ expect_pgm_int();
+ ptf(PTF_REQ_CHECK, &rc);
+ check_pgm_int_code(PGM_INT_CODE_PRIVILEGED_OPERATION);
+ report_prefix_pop();
+
+ report_prefix_push("Wrong fc");
+ expect_pgm_int();
+ ptf(0xff, &rc);
+ check_pgm_int_code(PGM_INT_CODE_SPECIFICATION);
+ report_prefix_pop();
+
+ report_prefix_push("Reserved bits");
+ expect_pgm_int();
+ ptf(0xffffffffffffff00UL, &rc);
+ check_pgm_int_code(PGM_INT_CODE_SPECIFICATION);
+ report_prefix_pop();
This function is quite big ... I'd maybe group the above checks for error
conditions into a separate function instead.
+ 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
s/can not/cannot/ ?
Also, you sometimes write polarization with "z" and sometimes with "s". I'd
suggest to standardize on "z" (as in "IBM Z" ;-))
+ * any Virtual Machine but KVM.
+ * Let's skip the polarisation tests for other VMs.
+ */
+ if (!host_is_kvm()) {
+ report_skip("Topology polarisation check is done for KVM only");
+ goto end;
+ }
+
+ /*
+ * Set vertical polarization to verify that RESET sets
+ * horizontal polarization back.
+ */
+ cc = ptf(PTF_REQ_VERTICAL, &rc);
+ report(cc == 0, "Set vertical polarization.");
+
+ report(diag308_load_reset(1), "load normal reset done");
+
+ cc = ptf(PTF_REQ_CHECK, &rc);
+ report(cc == 0, "Reset should clear topology report");
+
+ cc = ptf(PTF_REQ_HORIZONTAL, &rc);
+ report(cc == 2 && rc == PTF_ERR_ALRDY_POLARIZED,
+ "After RESET polarization is horizontal");
+
+ /* Flip between vertical and horizontal polarization */
+ cc = ptf(PTF_REQ_VERTICAL, &rc);
+ report(cc == 0, "Change to vertical polarization.");
+
+ cc = ptf(PTF_REQ_CHECK, &rc);
+ report(cc == 1, "Polarization change should set topology report");
+
+ cc = ptf(PTF_REQ_HORIZONTAL, &rc);
+ report(cc == 0, "Change to horizontal polarization.");
+
+end:
+ report_prefix_pop();
+}
Apart from the nits, the patch looks fine to me.
Thomas
