From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:38686) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1duLdF-0005tb-24 for qemu-devel@nongnu.org; Tue, 19 Sep 2017 12:44:26 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1duLdE-0002di-66 for qemu-devel@nongnu.org; Tue, 19 Sep 2017 12:44:21 -0400 Received: from mx1.redhat.com ([209.132.183.28]:43358) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1duLdE-0002cL-1L for qemu-devel@nongnu.org; Tue, 19 Sep 2017 12:44:20 -0400 From: Cornelia Huck Date: Tue, 19 Sep 2017 18:43:06 +0200 Message-Id: <20170919164337.18555-8-cohuck@redhat.com> In-Reply-To: <20170919164337.18555-1-cohuck@redhat.com> References: <20170919164337.18555-1-cohuck@redhat.com> Subject: [Qemu-devel] [PULL v2 07/38] s390x/css: drop data-check in interpretation List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: peter.maydell@linaro.org Cc: qemu-devel@nongnu.org, rth@twiddle.net, agraf@suse.de, thuth@redhat.com, borntraeger@de.ibm.com, david@redhat.com, Halil Pasic , Cornelia Huck From: Halil Pasic The architecture says that channel-data check is indicating that an uncorrected storage (memory) error has been detected in regard to the data residing in main storage (memory) that is currently used for an I/O operation. The described detection is done using the CBC technology. The ccw interpretation code is however generating a channel-data check effectively when the (device specific) ccw_cb returns -EFAULT. In case of virtio-ccw devices this happens when mapping memory fails, or when a NULL pointer is encountered. So this behavior is not architecture conform. Furthermore the best fit for these situations (null pointer, mapping a piece of guest memory fails) from architectural perspective the condition described as the channel subsystem refers to a location that is not available, which when encountered shall result in a channel-program check. To fix this, all we have to do is to get rid of the switch case matching -EFAULT: the default is generating a channel-program check. Signed-off-by: Halil Pasic Message-Id: <20170908152446.14606-2-pasic@linux.vnet.ibm.com> Signed-off-by: Cornelia Huck --- hw/s390x/css.c | 9 --------- 1 file changed, 9 deletions(-) diff --git a/hw/s390x/css.c b/hw/s390x/css.c index 5d3de71c4c..bab78fc79a 100644 --- a/hw/s390x/css.c +++ b/hw/s390x/css.c @@ -980,15 +980,6 @@ static void sch_handle_start_func_virtual(SubchDev *sch) SCSW_STCTL_ALERT | SCSW_STCTL_STATUS_PEND; s->cpa = sch->channel_prog + 8; break; - case -EFAULT: - /* memory problem, generate channel data check */ - s->ctrl &= ~SCSW_ACTL_START_PEND; - s->cstat = SCSW_CSTAT_DATA_CHECK; - s->ctrl &= ~SCSW_CTRL_MASK_STCTL; - s->ctrl |= SCSW_STCTL_PRIMARY | SCSW_STCTL_SECONDARY | - SCSW_STCTL_ALERT | SCSW_STCTL_STATUS_PEND; - s->cpa = sch->channel_prog + 8; - break; case -EBUSY: /* subchannel busy, generate deferred cc 1 */ s->flags &= ~SCSW_FLAGS_MASK_CC; -- 2.13.5