On Thu, 2023-02-02 at 10:28 +0100, 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
Maybe also give the CC codes names for improved readability.
> +
> +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"
> + " ipm %0\n"
> + " srl %0,28\n"
> + : "=d" (cc), "+d" (fc)
> + :
> + : "cc");
Personally I always name asm arguments, but it is a very short snippet,
so still very readable. Could also pull the shift into C code,
but again, small difference.
> +
> + *rc = fc >> 8;
> + return cc;
> +}
> +
> +static void test_ptf(void)
> +{
> + unsigned long rc;
> + int cc;
> +
> + /* PTF is a privilege instruction */
> + 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();
IMO, you should repeat this test for all FCs, since some are emulated,
others interpreted by SIE.
> +
> + report_prefix_push("Wrong fc");
"Undefined fc" is more informative IMO.
> + 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();
> +
> + 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.
Random Capitalization :)
Why can you not test the same thing for other hypervisors/LPAR?
> + * 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.
> + */
You might want to do a reset here also, since there could be some other
test case that could have run before and modified the polarization.
There isn't right now of course, but doing a reset improves separation of tests.
> + 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();
> +}
> +
> +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("Virtual 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 3caf81e..3530cc4 100644
> --- a/s390x/unittests.cfg
> +++ b/s390x/unittests.cfg
> @@ -208,3 +208,6 @@ groups = migration
> [exittime]
> file = exittime.elf
> smp = 2
> +
> +[topology]
> +file = topology.elf
