From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54762) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ermM1-0005cA-L2 for qemu-devel@nongnu.org; Fri, 02 Mar 2018 10:12:14 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ermLx-0002YJ-Kt for qemu-devel@nongnu.org; Fri, 02 Mar 2018 10:12:13 -0500 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:51898 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1ermLx-0002YE-FR for qemu-devel@nongnu.org; Fri, 02 Mar 2018 10:12:09 -0500 References: <1519900415-30314-1-git-send-email-yi.l.liu@linux.intel.com> <1519900415-30314-9-git-send-email-yi.l.liu@linux.intel.com> From: Paolo Bonzini Message-ID: Date: Fri, 2 Mar 2018 16:12:01 +0100 MIME-Version: 1.0 In-Reply-To: <1519900415-30314-9-git-send-email-yi.l.liu@linux.intel.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v3 08/12] hw/pci: introduce pci_device_notify_iommu() List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Liu, Yi L" , qemu-devel@nongnu.org, mst@redhat.com, david@gibson.dropbear.id.au Cc: alex.williamson@redhat.com, eric.auger.pro@gmail.com, yi.l.liu@intel.com, peterx@redhat.com, kevin.tian@intel.com, jasowang@redhat.com On 01/03/2018 11:33, Liu, Yi L wrote: > This patch adds pci_device_notify_iommu() for notify virtual IOMMU > emulator when assigned device is added. And adds a new notify_func > in PCIBus. vIOMMU emulator provides the instance of this notify_func. > > Reason: > When virtual IOMMU is exposed to guest, vIOMMU emulator needs to > programm host IOMMU to setup DMA mapping for assigned devices. This > is a per-device operation, to be efficient, vIOMMU emulator needs > to record the assigned devices. > > Example: devices assigned thru vfio, vfio_realize would call > pci_device_notify_iommu() to notify vIOMMU emulator to record necessary > info for assigned device. I think the notification should not be left to the individual device. Instead, the add notification should be done in pci_setup_sva_ops, and the delete notification should be done in pci_qdev_unrealize, before calling pc->exit, and only if dev->sva_ops is not NULL. In general I think it's better to change your names from "assigned_dev" to "sva_dev", because the point of the list is to only iterate over devices that might be interested in using SVA. Paolo