Re: [kvm-unit-tests PATCH v9 10/12] s390x: css: stsch, enumeration test

Cornelia Huck
2020-06-17T08:49:11Z

On Mon, 15 Jun 2020 11:31:59 +0200
Pierre Morel <pmorel@linux.ibm.com> wrote:

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

Maybe worth adding a note:

"We currently don't enable multiple subchannel sets and therefore only
look in subchannel set 0."

>
> 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 | 55 +++++++++++++++++++++++++++++++++++
> s390x/unittests.cfg | 4 +++
> 4 files changed, 131 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..b0a0294
> --- /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 */

s/happened/happen/

> + report_abort("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/css.c b/s390x/css.c
> new file mode 100644
> index 0000000..230adf5
> --- /dev/null
> +++ b/s390x/css.c
> @@ -0,0 +1,55 @@
> +/*
> + * 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);

Maybe "Schid of first I/O device" ?

> + return;
> + }
> + report(0, "No I/O device found");
> +}
> +
> +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();
> +}

Reviewed-by: Cornelia Huck <cohuck@redhat.com>