From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx0b-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id AF6092BE042; Fri, 15 Aug 2025 21:36:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=148.163.158.5 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755293800; cv=none; b=DEVGjS/oNKbBMkTh5+SlSp5frrWnJYmMRc6kL+YUSON/hjlyiNBWu2T3At99nnTH4K2pdtnQ7luMcPUfBcyV27wyi/0LtEjf16Ki6G4Oyhc/SPuiO6GIuP0TZVt7rWO6BzDkX0F8kYFImqimVsHmSoXtYJipnggj3bGc/hILNdc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755293800; c=relaxed/simple; bh=B/twj5r3juH/ifMdr1BYMzMd10c1Lu7QAWhOIBEVKYg=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=qNHHZDRZbBjuz3A9vgVS6I/f63vQ1kWV0R7KDKoCj+E6JO3pRxo3DsvBT5T6on9taU81soL2R0M+xxAxYMxY7W7VAIT8e64b/YMNfgsIx9j9nlZ44RDMJGyxKQZ3Z5Ixbzh8sd3clLkTGYX+xOEXKu778AiO92xtUYuZncPUBXA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.ibm.com; spf=pass smtp.mailfrom=linux.ibm.com; dkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com header.b=EfF7fv5J; arc=none smtp.client-ip=148.163.158.5 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.ibm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.ibm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com header.b="EfF7fv5J" Received: from pps.filterd (m0356516.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 57FGwQIX020189; Fri, 15 Aug 2025 21:36:31 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=cc :content-transfer-encoding:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to; s=pp1; bh=nufP6a Tmq5KxJFQkk20gGDjNqydT7/AukDK59rrdrF4=; b=EfF7fv5JqnTP5wcdz8c42G jjD0vfYOCWOXWqNMgvYSJ37iyuO2k58Nl75W5aYw+F5q3cHOUqsxhQsu2zgLTIh7 2jjajxqRS113QKlx8ekQxRL38QVxm6RzPXxS3nsPlf6nxl2BhTR9yK05edpyVsjR VlFRzlxCO6iBNKiUFB8dbZ4FRwecvuKe4OkouFgPYG+a8Wl46UiqTBzq6gPglmFw b7PXB9MssOxnQYHI9+AEovtSDdFFa+9byhF4xBVS34EJsV5cVKGLcy0OrB8t2dIV YTy5WcDLylwg0rydO0f17HymvHE3MbqxlowxLPxLYgYo3NJ4ZLUzYils0IUCfLbw == Received: from ppma21.wdc07v.mail.ibm.com (5b.69.3da9.ip4.static.sl-reverse.com [169.61.105.91]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 48duruscg7-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 15 Aug 2025 21:36:31 +0000 (GMT) Received: from pps.filterd (ppma21.wdc07v.mail.ibm.com [127.0.0.1]) by ppma21.wdc07v.mail.ibm.com (8.18.1.2/8.18.1.2) with ESMTP id 57FKjg8q020752; Fri, 15 Aug 2025 21:36:30 GMT Received: from smtprelay07.wdc07v.mail.ibm.com ([172.16.1.74]) by ppma21.wdc07v.mail.ibm.com (PPS) with ESMTPS id 48ehnqaqv2-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 15 Aug 2025 21:36:30 +0000 Received: from smtpav02.wdc07v.mail.ibm.com (smtpav02.wdc07v.mail.ibm.com [10.39.53.229]) by smtprelay07.wdc07v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 57FLaToq25232098 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 15 Aug 2025 21:36:29 GMT Received: from smtpav02.wdc07v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 4ACE85805C; Fri, 15 Aug 2025 21:36:29 +0000 (GMT) Received: from smtpav02.wdc07v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 8823F58058; Fri, 15 Aug 2025 21:36:28 +0000 (GMT) Received: from [9.61.255.132] (unknown [9.61.255.132]) by smtpav02.wdc07v.mail.ibm.com (Postfix) with ESMTP; Fri, 15 Aug 2025 21:36:28 +0000 (GMT) Message-ID: Date: Fri, 15 Aug 2025 14:36:26 -0700 Precedence: bulk X-Mailing-List: linux-s390@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v1 6/6] vfio: Allow error notification and recovery for ISM device To: Alex Williamson Cc: Bjorn Helgaas , linux-s390@vger.kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, schnelle@linux.ibm.com, mjrosato@linux.ibm.com References: <20250814204850.GA346571@bhelgaas> <60855b41-a1ad-4966-aa5e-325256692279@linux.ibm.com> <20250815144855.51f2ac24.alex.williamson@redhat.com> Content-Language: en-US From: Farhan Ali In-Reply-To: <20250815144855.51f2ac24.alex.williamson@redhat.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 X-Proofpoint-GUID: xUyHZzTahb3OF9DOSMsN1wJfwXWVoSv7 X-Proofpoint-Spam-Details-Enc: AW1haW4tMjUwODEyMDIyNCBTYWx0ZWRfX7hOa+R1ILWL5 63vK1jZFzLhCXX6Qax42tLoVJAAMSwWTJX33/m/DIzuswiYkE+6JAtiG7rUwBT+fLu2lpt3m2Wi sofHlQa2JvmDmz/JySzIkSv3Fb505HafAKKkATVuPSNFy/1ZKEbRqAh+RwTvjO3DprcD9nTu/dc DPZYmtKC7fKAZq8IUUCOMemcZdXeCIcnQCM0gEMd4rhktb9WUjnYMDmV4OucNqKadyeLYhA2KCa Omnpo/K156/RrKefkeke7BoOfcbrOkY1VMGXsVgD+8IFSLQuOg+I5/8dtP0e8VJevyHxtHPUR7c R3vNrq4sy6F02gVMRJTbrh7hUKtx8d1a4WNpdDGCT+YtVVe5ZXtMlyuH8+3tGH7OGLOlM6M2wBT lRVk7PfP X-Authority-Analysis: v=2.4 cv=QtNe3Uyd c=1 sm=1 tr=0 ts=689fa85f cx=c_pps a=GFwsV6G8L6GxiO2Y/PsHdQ==:117 a=GFwsV6G8L6GxiO2Y/PsHdQ==:17 a=IkcTkHD0fZMA:10 a=2OwXVqhp2XgA:10 a=VnNF1IyMAAAA:8 a=qcL1lsCXI_0MITy6uOMA:9 a=3ZKOabzyN94A:10 a=QEXdDO2ut3YA:10 X-Proofpoint-ORIG-GUID: xUyHZzTahb3OF9DOSMsN1wJfwXWVoSv7 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1099,Hydra:6.1.9,FMLib:17.12.80.40 definitions=2025-08-15_07,2025-08-14_01,2025-03-28_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 adultscore=0 priorityscore=1501 phishscore=0 clxscore=1015 malwarescore=0 spamscore=0 suspectscore=0 impostorscore=0 bulkscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.19.0-2507300000 definitions=main-2508120224 On 8/15/2025 1:48 PM, Alex Williamson wrote: > On Thu, 14 Aug 2025 14:02:05 -0700 > Farhan Ali wrote: > >> On 8/14/2025 1:48 PM, Bjorn Helgaas wrote: >>> On Wed, Aug 13, 2025 at 10:08:20AM -0700, Farhan Ali wrote: >>>> VFIO allows error recovery and notification for devices that >>>> are PCIe (and thus AER) capable. But for PCI devices on IBM >>>> s390 error recovery involves platform firmware and >>>> notification to operating system is done by architecture >>>> specific way. The Internal Shared Memory(ISM) device is a legacy >>>> PCI device (so not PCIe capable), but can still be recovered >>>> when notified of an error. >>> "PCIe (and thus AER) capable" reads as though AER is required for all >>> PCIe devices, but AER is optional. >>> >>> I don't know the details of VFIO and why it tests for PCIe instead of >>> AER. Maybe AER is not relevant here and you don't need to mention >>> AER above at all? >> The original change that introduced this commit dad9f89 "VFIO-AER: >> Vfio-pci driver changes for supporting AER" was adding the support for >> AER for vfio. My assumption is the author thought if the device is AER >> capable the pcie check should be sufficient? I can remove the AER >> references in commit message. Thanks Farhan > I've looked back through discussions when this went in and can't find > any specific reasoning about why we chose pci_is_pcie() here. Maybe > we were trying to avoid setting up an error signal on devices that > cannot have AER, but then why didn't we check specifically for AER. > Maybe some version used PCIe specific calls in the handler that we > didn't want to check runtime, but I don't spot such a dependency now. > > Possibly we should just remove the check. We're configuring the error > signaling on the vast majority of devices, it's extremely rare that it > fires anyway, reporting it on a device where it cannot trigger seems > relatively negligible and avoids extra ugly code. Thanks, > > Alex Okay will remove the check and re-word the commit message. Thanks Farhan