Re: [kvm-unit-tests PATCH v1 3/4] s390x: topology: check the Perform Topology Function

Pierre Morel
2021-08-09T15:25:11Z

On 8/9/21 12:03 PM, Claudio Imbrenda wrote:
> On Mon, 9 Aug 2021 10:48:53 +0200
> Pierre Morel <pmorel@linux.ibm.com> wrote:
>
>> 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 | 87
>> +++++++++++++++++++++++++++++++++++++++++++++ s390x/unittests.cfg |
>> 3 ++ 3 files changed, 91 insertions(+)
>> create mode 100644 s390x/topology.c
>>
>> diff --git a/s390x/Makefile b/s390x/Makefile
>> index 6565561b..c82b7dbf 100644
>> --- a/s390x/Makefile
>> +++ b/s390x/Makefile
>> @@ -24,6 +24,7 @@ tests += $(TEST_DIR)/mvpg.elf
>> tests += $(TEST_DIR)/uv-host.elf
>> tests += $(TEST_DIR)/edat.elf
>> tests += $(TEST_DIR)/mvpg-sie.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..4146189a
>> --- /dev/null
>> +++ b/s390x/topology.c
>> @@ -0,0 +1,87 @@
>> +/* 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>
>> +
>> +static uint8_t pagebuf[PAGE_SIZE * 2]
>> __attribute__((aligned(PAGE_SIZE * 2))); +int machine_level;
>> +int mnest;
>> +
>> +#define PTF_HORIZONTAL 0
>> +#define PTF_VERTICAL 1
>> +#define PTF_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,%1\n"
>
> I know you copied this from the kernel, but the second argument is not
> really there according to the PoP, so maybe it's better to have this
> instead?
>
> .insn rre,0xb9a20000,%1,0\n

OK, thanks.

>
>> + " 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_CHECK, &rc);
>> + cc = ptf(PTF_CHECK, &rc);
>> + report(cc == 0, "PTF check clear");
>> + cc = ptf(PTF_HORIZONTAL, &rc);
>> + report(cc == 2 && rc == PTF_ERR_ALRDY_POLARIZED,
>> + "PTF horizontal already configured");
>> + cc = ptf(PTF_VERTICAL, &rc);
>> + report(cc == 2 && rc == PTF_ERR_NO_REASON,
>> + "PTF vertical non possible");
>
> *not possible

Oh yes :)

>
>> +
>> + report_prefix_pop();
>> +}
>> +
>> +int main(int argc, char *argv[])
>> +{
>> + report_prefix_push("stsi");
>
> should this really be "stsi" ?

No, I think CPU-Topology should be better.

--
Pierre Morel
IBM Lab Boeblingen