Re: [kvm-unit-tests PATCH v6 07/10] s390x: css: msch, enable test

Janosch Frank
2020-04-27T13:11:20Z

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On 4/24/20 12:45 PM, Pierre Morel wrote:
> A second step when testing the channel subsystem is to prepare a channel
> for use.
> This includes:
> - Get the current SubCHannel Information Block (SCHIB) using STSCH
> - Update it in memory to set the ENABLE bit
> - Tell the CSS that the SCHIB has been modified using MSCH
> - Get the SCHIB from the CSS again to verify that the subchannel is
> enabled.
>
> This tests the MSCH instruction to enable a channel succesfuly.

successfully

> This is NOT a routine to really enable the channel, no retry is done,
> in case of error, a report is made.

Would we expect needing retries for the pong device?

>
> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
> ---
> s390x/css.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 48 insertions(+)
>
> diff --git a/s390x/css.c b/s390x/css.c
> index cc97e79..fa068bf 100644
> --- a/s390x/css.c
> +++ b/s390x/css.c
> @@ -68,11 +68,59 @@ out:
> scn, scn_found, dev_found);
> }
>
> +static void test_enable(void)
> +{
> + struct pmcw *pmcw = &schib.pmcw;
> + int cc;
> +
> + if (!test_device_sid) {
> + report_skip("No device");
> + return;
> + }

If these tests are layered on top of each other and need a device to
work, we should abort or skip and exit the test if the enumeration
doesn't bring up devices

> + /* Read the SCHIB for this subchannel */
> + cc = stsch(test_device_sid, &schib);
> + if (cc) {
> + report(0, "stsch cc=%d", cc);
> + return;
> + }
> +
> + /* Update the SCHIB to enable the channel */
> + pmcw->flags |= PMCW_ENABLE;
> +
> + /* Tell the CSS we want to modify the subchannel */
> + cc = msch(test_device_sid, &schib);
> + if (cc) {
> + /*
> + * If the subchannel is status pending or
> + * if a function is in progress,
> + * we consider both cases as errors.
> + */
> + report(0, "msch cc=%d", cc);
> + return;
> + }
> +
> + /*
> + * Read the SCHIB again to verify the enablement
> + */
> + cc = stsch(test_device_sid, &schib);
> + if (cc) {
> + report(0, "stsch cc=%d", cc);
> + return;
> + }
> +
> + if (!(pmcw->flags & PMCW_ENABLE)) {
> + report(0, "Enable failed. pmcw: %x", pmcw->flags);
> + return;
> + }
> + report(1, "Tested");

s/Tested/Enabled/

> +}
> +
> static struct {
> const char *name;
> void (*func)(void);
> } tests[] = {
> { "enumerate (stsch)", test_enumerate },
> + { "enable (msch)", test_enable },
> { NULL, NULL }
> };
>
>

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