From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([209.51.188.92]:40953) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hH4aD-0003oX-2p for qemu-devel@nongnu.org; Thu, 18 Apr 2019 06:48:00 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hH4a9-0003QT-Aa for qemu-devel@nongnu.org; Thu, 18 Apr 2019 06:47:55 -0400 Date: Thu, 18 Apr 2019 12:47:37 +0200 From: Kevin Wolf Message-ID: <20190418104737.GC5242@linux.fritz.box> References: <20190417115343.30527-1-pbonzini@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Subject: Re: [Qemu-devel] [Qemu-block] [PATCH] scsi-generic: prevent guest from exceeding SG_IO limits List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paolo Bonzini Cc: Stefan Hajnoczi , Stefan Hajnoczi , qemu-devel , qemu block , qemu-stable Am 18.04.2019 um 11:48 hat Paolo Bonzini geschrieben: > On 17/04/19 14:30, Stefan Hajnoczi wrote: > > On Wed, Apr 17, 2019 at 12:54 PM Paolo Bonzini wrote: > >> Linux places a limit of UIO_MAXIOV pages on SG_IO ioctls (and if the limit > >> is exceeded, a confusing ENOMEM error is returned[1]). Prevent the guest > >> from exceeding these limits, by capping the maximum transfer length to > >> that value in the block limits VPD page. > >> > >> [1] Oh well, at least it was easier to follow the kernel source knowing > >> it had to end as ENOMEM... > >> > >> Cc: qemu-stable@nongnu.org > >> Cc: qemu-block@nongnu.org > >> Cc: Stefan Hajnoczi > >> Signed-off-by: Paolo Bonzini > >> --- > >> hw/scsi/scsi-generic.c | 17 +++++++++++++---- > >> 1 file changed, 13 insertions(+), 4 deletions(-) > > > > Reviewed-by: Stefan Hajnoczi > > > > This is acually only an issue with kernels prior to 4.5, so it should be > fixed downstream instead. I don't think that upstream QEMU has kernels > 4.5 as an official requirement, though? We try to be compatible with quite old libs, so we should stay compatible with old kernels, too. Kevin From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.4 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id AD5E9C10F0E for ; Thu, 18 Apr 2019 10:49:01 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 7AD7E217D7 for ; Thu, 18 Apr 2019 10:49:01 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7AD7E217D7 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([127.0.0.1]:39314 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hH4bE-0004Hi-BL for qemu-devel@archiver.kernel.org; Thu, 18 Apr 2019 06:49:00 -0400 Received: from eggs.gnu.org ([209.51.188.92]:40953) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hH4aD-0003oX-2p for qemu-devel@nongnu.org; Thu, 18 Apr 2019 06:48:00 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hH4a9-0003QT-Aa for qemu-devel@nongnu.org; Thu, 18 Apr 2019 06:47:55 -0400 Received: from mx1.redhat.com ([209.132.183.28]:44590) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hH4a1-0003Kg-CX; Thu, 18 Apr 2019 06:47:45 -0400 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 354C3307B964; Thu, 18 Apr 2019 10:47:42 +0000 (UTC) Received: from linux.fritz.box (ovpn-116-132.ams2.redhat.com [10.36.116.132]) by smtp.corp.redhat.com (Postfix) with ESMTPS id BCDE560BEC; Thu, 18 Apr 2019 10:47:38 +0000 (UTC) Date: Thu, 18 Apr 2019 12:47:37 +0200 From: Kevin Wolf To: Paolo Bonzini Message-ID: <20190418104737.GC5242@linux.fritz.box> References: <20190417115343.30527-1-pbonzini@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.11.3 (2019-02-01) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.47]); Thu, 18 Apr 2019 10:47:43 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: Re: [Qemu-devel] [Qemu-block] [PATCH] scsi-generic: prevent guest from exceeding SG_IO limits X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Stefan Hajnoczi , qemu block , qemu-devel , Stefan Hajnoczi , qemu-stable Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Message-ID: <20190418104737.iyOaLOJtU9YNhG_eHTR7D9YRmyv-bER5eLfjEcNpOmU@z> Am 18.04.2019 um 11:48 hat Paolo Bonzini geschrieben: > On 17/04/19 14:30, Stefan Hajnoczi wrote: > > On Wed, Apr 17, 2019 at 12:54 PM Paolo Bonzini wrote: > >> Linux places a limit of UIO_MAXIOV pages on SG_IO ioctls (and if the limit > >> is exceeded, a confusing ENOMEM error is returned[1]). Prevent the guest > >> from exceeding these limits, by capping the maximum transfer length to > >> that value in the block limits VPD page. > >> > >> [1] Oh well, at least it was easier to follow the kernel source knowing > >> it had to end as ENOMEM... > >> > >> Cc: qemu-stable@nongnu.org > >> Cc: qemu-block@nongnu.org > >> Cc: Stefan Hajnoczi > >> Signed-off-by: Paolo Bonzini > >> --- > >> hw/scsi/scsi-generic.c | 17 +++++++++++++---- > >> 1 file changed, 13 insertions(+), 4 deletions(-) > > > > Reviewed-by: Stefan Hajnoczi > > > > This is acually only an issue with kernels prior to 4.5, so it should be > fixed downstream instead. I don't think that upstream QEMU has kernels > 4.5 as an official requirement, though? We try to be compatible with quite old libs, so we should stay compatible with old kernels, too. Kevin