From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50134) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dn5yh-0007Fk-8C for qemu-devel@nongnu.org; Wed, 30 Aug 2017 12:36:32 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dn5ye-0006Gv-5F for qemu-devel@nongnu.org; Wed, 30 Aug 2017 12:36:31 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:59494 helo=mx0a-001b2d01.pphosted.com) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dn5yd-0006Gn-VL for qemu-devel@nongnu.org; Wed, 30 Aug 2017 12:36:28 -0400 Received: from pps.filterd (m0098414.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id v7UGWMlh123925 for ; Wed, 30 Aug 2017 12:36:27 -0400 Received: from e06smtp11.uk.ibm.com (e06smtp11.uk.ibm.com [195.75.94.107]) by mx0b-001b2d01.pphosted.com with ESMTP id 2cnx1vp5je-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Wed, 30 Aug 2017 12:36:27 -0400 Received: from localhost by e06smtp11.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 30 Aug 2017 17:36:25 +0100 From: Halil Pasic Date: Wed, 30 Aug 2017 18:36:02 +0200 In-Reply-To: <20170830163609.50260-1-pasic@linux.vnet.ibm.com> References: <20170830163609.50260-1-pasic@linux.vnet.ibm.com> Message-Id: <20170830163609.50260-3-pasic@linux.vnet.ibm.com> Subject: [Qemu-devel] [PATCH 2/9] s390x: fix invalid use of cc 1 for SSCH List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Cornelia Huck Cc: Dong Jia Shi , Pierre Morel , qemu-devel@nongnu.org, Halil Pasic According to the POP a start subchannel instruction (SSCH) returning with cc 1 implies that the subchannel was status pending when SSCH executed. Due to a somewhat confusing error handling, where error codes are mapped to cc value, sane looking error codes result in non AR compliant behavior. Let's fix this! Instead of cc 1 we use cc 3 which means device not operational, and is much closer to the truth in the given cases. Signed-off-by: Halil Pasic Acked-by: Pierre Morel --- This patch turned out quite controversial. We did not reach a consensus during the internal review. The most of the discussion revolved around the ORB flag which architecturally must be supported, but are currently not supported by vfio-ccw (not yet, or can't be). The idea showing the most promise for consensus was to handle this via device status (along the lines better a strange acting device than a non-conform machine) but since it's a radical change we decided to first discuss upstream and then do whatever needs to be done. --- hw/s390x/css.c | 15 ++++++--------- hw/s390x/s390-ccw.c | 2 +- 2 files changed, 7 insertions(+), 10 deletions(-) diff --git a/hw/s390x/css.c b/hw/s390x/css.c index a50fb0727e..0822538cde 100644 --- a/hw/s390x/css.c +++ b/hw/s390x/css.c @@ -1034,7 +1034,7 @@ static int sch_handle_start_func_passthrough(SubchDev *sch) */ if (!(orb->ctrl0 & ORB_CTRL0_MASK_PFCH) || !(orb->ctrl0 & ORB_CTRL0_MASK_C64)) { - return -EINVAL; + return -ENODEV; } ret = s390_ccw_cmd_request(orb, s, sch->driver_data); @@ -1046,16 +1046,13 @@ static int sch_handle_start_func_passthrough(SubchDev *sch) break; case -ENODEV: break; + case -EFAULT: + break; case -EACCES: /* Let's reflect an inaccessible host device by cc 3. */ - ret = -ENODEV; - break; default: - /* - * All other return codes will trigger a program check, - * or set cc to 1. - */ - break; + /* Let's make all other return codes map to cc 3. */ + ret = -ENODEV; }; return ret; @@ -1115,7 +1112,7 @@ static int do_subchannel_work(SubchDev *sch) if (sch->do_subchannel_work) { return sch->do_subchannel_work(sch); } else { - return -EINVAL; + return -ENODEV; } } diff --git a/hw/s390x/s390-ccw.c b/hw/s390x/s390-ccw.c index 8614dda6f8..2b0741741c 100644 --- a/hw/s390x/s390-ccw.c +++ b/hw/s390x/s390-ccw.c @@ -25,7 +25,7 @@ int s390_ccw_cmd_request(ORB *orb, SCSW *scsw, void *data) if (cdc->handle_request) { return cdc->handle_request(orb, scsw, data); } else { - return -ENOSYS; + return -ENODEV; } } -- 2.13.5