Re: [kvm-unit-tests PATCH v6 10/10] s390x: css: ping pong

Janosch Frank
2020-04-27T13:14:50Z

[-- Attachment #1.1: Type: text/plain, Size: 2634 bytes --]

On 4/24/20 12:45 PM, Pierre Morel wrote:
> To test a write command with the SSCH instruction we need a QEMU device,
> with control unit type 0xC0CA. The PONG device is such a device.
>
> This type of device responds to PONG_WRITE requests by incrementing an
> integer, stored as a string at offset 0 of the CCW data.
>
> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
> ---
> s390x/css.c | 54 +++++++++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 54 insertions(+)
>
> diff --git a/s390x/css.c b/s390x/css.c
> index b9dbf01..7cd8731 100644
> --- a/s390x/css.c
> +++ b/s390x/css.c
> @@ -23,6 +23,12 @@
> #define PSW_PRG_MASK (PSW_MASK_EA | PSW_MASK_BA)
>
> #define PONG_CU_TYPE 0xc0ca
> +/* Channel Commands for PONG device */
> +#define PONG_WRITE 0x21 /* Write */
> +#define PONG_READ 0x22 /* Read buffer */
> +
> +#define BUFSZ 9
> +static char buffer[BUFSZ];
>
> struct lowcore *lowcore = (void *)0x0;
>
> @@ -262,6 +268,53 @@ unreg_cb:
> unregister_io_int_func(irq_io);
> }
>
> +static void test_ping(void)
> +{
> + int success, result;
> + int cnt = 0, max = 4;
> +
> + if (senseid.cu_type != PONG_CU) {
> + report_skip("No PONG, no ping-pong");

"Device is not a pong device."

> + return;
> + }
> +
> + result = register_io_int_func(irq_io);
> + if (result) {
> + report(0, "Could not register IRQ handler");
> + return;
> + }

I'm not sure if it's worth checking the return values or even having a
check in register_io_int_func() in the first place.

> +
> + while (cnt++ < max) {
> + snprintf(buffer, BUFSZ, "%08x\n", cnt);
> + success = start_subchannel(PONG_WRITE, buffer, BUFSZ);
> + if (!success) {
> + report(0, "start_subchannel failed");
> + goto unreg_cb;
> + }
> +
> + wfi(PSW_MASK_IO);
> +
> + success = start_subchannel(PONG_READ, buffer, BUFSZ);
> + if (!success) {
> + report(0, "start_subchannel failed");
> + goto unreg_cb;
> + }
> +
> + wfi(PSW_MASK_IO);
> +
> + result = atol(buffer);
> + if (result != (cnt + 1)) {
> + report(0, "Bad answer from pong: %08x - %08x",
> + cnt, result);
> + goto unreg_cb;
> + }
> + }
> + report(1, "ping-pong count 0x%08x", cnt);
> +
> +unreg_cb:
> + unregister_io_int_func(irq_io);
> +}
> +
> static struct {
> const char *name;
> void (*func)(void);
> @@ -269,6 +322,7 @@ static struct {
> { "enumerate (stsch)", test_enumerate },
> { "enable (msch)", test_enable },
> { "sense (ssch/tsch)", test_sense },
> + { "ping-pong (ssch/tsch)", test_ping },
> { NULL, NULL }
> };
>
>

[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 833 bytes --]