On Mon, 18 May 2020 18:07:27 +0200
Pierre Morel <pmorel@xxxxxxxxxxxxx> wrote:
> First step for testing the channel subsystem is to enumerate the css and
> retrieve the css devices.
>
> 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@xxxxxxxxxxxxx>
> ---
> s390x/Makefile | 1 +
> s390x/css.c | 89 +++++++++++++++++++++++++++++++++++++++++++++
> s390x/unittests.cfg | 4 ++
> 3 files changed, 94 insertions(+)
> create mode 100644 s390x/css.c
(...)
> +static void test_enumerate(void)
> +{
> + struct pmcw *pmcw = &schib.pmcw;
> + int cc;
> + int scn;
> + int scn_found = 0;
> + int dev_found = 0;
> +
> + for (scn = 0; scn < 0xffff; scn++) {
> + cc = stsch(scn|SID_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 */
> + report(0, "Unexpected cc=%d on subchannel number 0x%x",
> + cc, scn);
> + return;
> + }
> +
> + /* 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 (!test_device_sid)
> + test_device_sid = scn | SID_ONE;
> +
> + dev_found++;
> + }
> +
> +out:
> + report(dev_found,
> + "Tested subchannels: %d, I/O subchannels: %d, I/O devices: %d",
> + scn, scn_found, dev_found);
Just wondering: with the current invocation, you expect to find exactly
one subchannel with a valid device, right?
> +}
> +
> +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();
> +}
> diff --git a/s390x/unittests.cfg b/s390x/unittests.cfg
> index 07013b2..a436ec0 100644
> --- a/s390x/unittests.cfg
> +++ b/s390x/unittests.cfg
> @@ -83,3 +83,7 @@ extra_params = -m 1G
> [sclp-3g]
> file = sclp.elf
> extra_params = -m 3G
> +
> +[css]
> +file = css.elf
> +extra_params =-device ccw-pong
Hm... you could test enumeration even with a QEMU that does not include
support for the pong device, right? Would it be worthwhile to split out
a set of css tests that use e.g. a virtio-net-ccw device, and have a
css-pong set of tests that require the pong device?
