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

[Janosch Frank <frankja@linux.ibm.com>]

[-- 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 --]