From mboxrd@z Thu Jan 1 00:00:00 1970 From: Julien Grall Subject: Re: [PATCH v3 18/24] xen/passthrough: iommu_deassign_device_dt: By default reassign device to nobody Date: Tue, 20 Jan 2015 14:31:53 +0000 Message-ID: <54BE66D9.9050409@linaro.org> References: <1421159133-31526-1-git-send-email-julien.grall@linaro.org> <1421159133-31526-19-git-send-email-julien.grall@linaro.org> <54BE2C3F0200007800056D50@mail.emea.novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta14.messagelabs.com ([193.109.254.103]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1YDZqx-0004GF-BC for xen-devel@lists.xenproject.org; Tue, 20 Jan 2015 14:32:23 +0000 Received: by mail-wi0-f181.google.com with SMTP id fb4so11581807wid.2 for ; Tue, 20 Jan 2015 06:32:21 -0800 (PST) In-Reply-To: <54BE2C3F0200007800056D50@mail.emea.novell.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Jan Beulich Cc: xen-devel@lists.xenproject.org, stefano.stabellini@citrix.com, ian.campbell@citrix.com, tim@xen.org List-Id: xen-devel@lists.xenproject.org Hi Jan, On 20/01/15 09:21, Jan Beulich wrote: >>>> On 13.01.15 at 15:25, wrote: >> Currently, when the device is deassigned from a domain, we directly reassign >> to DOM0. >> >> As the device may not have been correctly reset, this may lead to corruption >> or >> expose some part of DOM0 memory. Also, we may have no way to reset some >> platform devices. >> >> If Xen reassigns the device to "nobody", it may receive some global/context >> fault because the transaction has failed (indeed the context has been >> marked invalid). Unfortunately there is no simple way to quiesce a buggy >> hardware. I think we could live with that for a first version of platform >> device passthrough. >> >> DOM0 will have to issue an hypercall to assign the device to itself if it >> wants to use it. >> >> Signed-off-by: Julien Grall >> Cc: Jan Beulich > > Looks like this is because of ... > >> xen/drivers/passthrough/device_tree.c | 9 +++------ > > ... this. Which I think is a mistake, as I wasn't involved in the addition > of that file. I'd appreciate an update to ./MAINTAINERS adding this > file to the ARM section. Ok. I will send a patch to add xen/drivers/passthrough/device_tree.c in the "ARM section". Regards, -- Julien Grall