From mboxrd@z Thu Jan 1 00:00:00 1970 Received: by 10.25.208.211 with SMTP id h202csp275802lfg; Fri, 4 Mar 2016 00:03:28 -0800 (PST) X-Received: by 10.140.144.83 with SMTP id 80mr8821652qhq.102.1457078608762; Fri, 04 Mar 2016 00:03:28 -0800 (PST) Return-Path: Received: from lists.gnu.org (lists.gnu.org. [2001:4830:134:3::11]) by mx.google.com with ESMTPS id 96si2649839qkw.52.2016.03.04.00.03.28 for (version=TLS1 cipher=AES128-SHA bits=128/128); Fri, 04 Mar 2016 00:03:28 -0800 (PST) Received-SPF: pass (google.com: domain of qemu-arm-bounces+alex.bennee=linaro.org@nongnu.org designates 2001:4830:134:3::11 as permitted sender) client-ip=2001:4830:134:3::11; Authentication-Results: mx.google.com; spf=pass (google.com: domain of qemu-arm-bounces+alex.bennee=linaro.org@nongnu.org designates 2001:4830:134:3::11 as permitted sender) smtp.mailfrom=qemu-arm-bounces+alex.bennee=linaro.org@nongnu.org Received: from localhost ([::1]:39431 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1abkhs-0002dq-BB for alex.bennee@linaro.org; Fri, 04 Mar 2016 03:03:28 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:42857) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1abkhP-00024c-Pb for qemu-arm@nongnu.org; Fri, 04 Mar 2016 03:03:00 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1abkhM-0003ys-I5 for qemu-arm@nongnu.org; Fri, 04 Mar 2016 03:02:59 -0500 Received: from mx1.redhat.com ([209.132.183.28]:52014) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1abkhM-0003ym-DD; Fri, 04 Mar 2016 03:02:56 -0500 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) by mx1.redhat.com (Postfix) with ESMTPS id D0DADC0005D6; Fri, 4 Mar 2016 08:02:55 +0000 (UTC) Received: from nilsson.home.kraxel.org (ovpn-116-34.ams2.redhat.com [10.36.116.34]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u2482rY5025114; Fri, 4 Mar 2016 03:02:54 -0500 Received: by nilsson.home.kraxel.org (Postfix, from userid 500) id 6B847816A2; Fri, 4 Mar 2016 09:02:48 +0100 (CET) Message-ID: <1457078568.3574.67.camel@redhat.com> From: Gerd Hoffmann To: Peter Maydell Date: Fri, 04 Mar 2016 09:02:48 +0100 In-Reply-To: References: <1456787490-17112-1-git-send-email-Andrew.Baumann@microsoft.com> <1457021768.3574.58.camel@redhat.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Mime-Version: 1.0 X-Scanned-By: MIMEDefang 2.68 on 10.5.11.22 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 209.132.183.28 Cc: Stefan Weil , =?ISO-8859-1?Q?Gr=E9gory?= ESTRADE , QEMU Developers , Andrew Baumann , qemu-arm , Paolo Bonzini Subject: Re: [Qemu-arm] [Qemu-devel] [PATCH RFC] bcm2835_dma: add emulation of Raspberry Pi DMA controller X-BeenThere: qemu-arm@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-arm-bounces+alex.bennee=linaro.org@nongnu.org Sender: qemu-arm-bounces+alex.bennee=linaro.org@nongnu.org X-TUID: cFunAbh6VjMU Hi, > I guess a more general approach to the problem would be to have > a (hopefully easy) way to say "if this has been going on for too > long then arrange to defer continued processing of it til later, > and for now resume the guest". Doable today, by simply applying some limit and if we hit it schedule a timer to continue later. uhci emulation does this, but it's basically no extra work there as usb emulation is timer based _anyway_. > That's too big a can of worms for > this patch, though. (And for something that's only used in TCG > emulation we care much less about malicious guests than for devices > that can be used with KVM.) Agree, given the use case this isn't critical by any means. cheers, Gerd From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:42868) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1abkhR-00026l-Lh for qemu-devel@nongnu.org; Fri, 04 Mar 2016 03:03:02 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1abkhQ-000408-Pe for qemu-devel@nongnu.org; Fri, 04 Mar 2016 03:03:01 -0500 Message-ID: <1457078568.3574.67.camel@redhat.com> From: Gerd Hoffmann Date: Fri, 04 Mar 2016 09:02:48 +0100 In-Reply-To: References: <1456787490-17112-1-git-send-email-Andrew.Baumann@microsoft.com> <1457021768.3574.58.camel@redhat.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Mime-Version: 1.0 Subject: Re: [Qemu-devel] [PATCH RFC] bcm2835_dma: add emulation of Raspberry Pi DMA controller List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Peter Maydell Cc: Peter Crosthwaite , Stefan Weil , =?ISO-8859-1?Q?Gr=E9gory?= ESTRADE , QEMU Developers , Andrew Baumann , qemu-arm , Paolo Bonzini Hi, > I guess a more general approach to the problem would be to have > a (hopefully easy) way to say "if this has been going on for too > long then arrange to defer continued processing of it til later, > and for now resume the guest". Doable today, by simply applying some limit and if we hit it schedule a timer to continue later. uhci emulation does this, but it's basically no extra work there as usb emulation is timer based _anyway_. > That's too big a can of worms for > this patch, though. (And for something that's only used in TCG > emulation we care much less about malicious guests than for devices > that can be used with KVM.) Agree, given the use case this isn't critical by any means. cheers, Gerd