From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53917) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1e1veU-0002AU-PN for qemu-devel@nongnu.org; Tue, 10 Oct 2017 10:37:00 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1e1veQ-0007om-NT for qemu-devel@nongnu.org; Tue, 10 Oct 2017 10:36:58 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:39970) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1e1veQ-0007oF-Eh for qemu-devel@nongnu.org; Tue, 10 Oct 2017 10:36:54 -0400 Received: from pps.filterd (m0098393.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id v9AETVtX143940 for ; Tue, 10 Oct 2017 10:36:48 -0400 Received: from e06smtp10.uk.ibm.com (e06smtp10.uk.ibm.com [195.75.94.106]) by mx0a-001b2d01.pphosted.com with ESMTP id 2dgurrr8h3-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Tue, 10 Oct 2017 10:36:47 -0400 Received: from localhost by e06smtp10.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 10 Oct 2017 15:36:44 +0100 References: <20171004154144.88995-1-pasic@linux.vnet.ibm.com> <20171004154144.88995-4-pasic@linux.vnet.ibm.com> <20171010150733.444aa2fe.cohuck@redhat.com> From: Halil Pasic Date: Tue, 10 Oct 2017 16:36:41 +0200 MIME-Version: 1.0 In-Reply-To: <20171010150733.444aa2fe.cohuck@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Message-Id: Subject: Re: [Qemu-devel] [PATCH v2 3/8] s390x: improve error handling for SSCH and RSCH List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Cornelia Huck Cc: Dong Jia Shi , Thomas Huth , Pierre Morel , qemu-devel@nongnu.org On 10/10/2017 03:07 PM, Cornelia Huck wrote: > On Wed, 4 Oct 2017 17:41:39 +0200 > Halil Pasic wrote: > >> Simplify the error handling of the SSCH and RSCH handler avoiding >> arbitrary and cryptic error codes being used to tell how the instruction >> is supposed to end. Let the code detecting the condition tell how it's >> to be handled in a less ambiguous way. It's best to handle SSCH and RSCH >> in one go as the emulation of the two shares a lot of code. >> >> For passthrough this change isn't pure refactoring, but changes the >> way kernel reported EFAULT is handled. After clarifying the kernel >> interface we decided that EFAULT shall be mapped to unit exception. >> Same goes for unexpected error codes. >> >> Signed-off-by: Halil Pasic >> --- >> >> AFAIR we decided in the previous round to rather do transformation >> and fixing in one patch than touch stuff twice. Hence this patch >> ain't pure transformation any more. >> --- >> hw/s390x/css.c | 83 +++++++++++++-------------------------------- >> hw/s390x/s390-ccw.c | 11 +++--- >> hw/vfio/ccw.c | 30 ++++++++++++---- >> include/hw/s390x/css.h | 24 +++++++++---- >> include/hw/s390x/s390-ccw.h | 2 +- >> target/s390x/ioinst.c | 53 ++++------------------------- >> 6 files changed, 77 insertions(+), 126 deletions(-) > > After browsing through this patch, I think the change will work just as > well if you use e.g. #defines instead of the structure, won't it? > Sure. We just loose type safety. For example if someone ever should try to propagate a normal errno via return do_something() the compiler won't catch it we effectively use int for both.