From mboxrd@z Thu Jan 1 00:00:00 1970 From: Srivatsa Vaddagiri Subject: Re: [PATCH 5/5] virtio: Add bounce DMA ops Date: Wed, 29 Apr 2020 16:04:40 +0530 Message-ID: <20200429103438.GF5097@quicinc.com> References: <20200428174952.GA5097@quicinc.com> <20200428163448-mutt-send-email-mst@kernel.org> <275eba4b-dd35-aa95-b2e3-9c5cbf7c6d71@linux.intel.com> <20200429004531-mutt-send-email-mst@kernel.org> <20200429023842-mutt-send-email-mst@kernel.org> <20200429094410.GD5097@quicinc.com> <20200429055125-mutt-send-email-mst@kernel.org> <20200429100953.GE5097@quicinc.com> <20200429061621-mutt-send-email-mst@kernel.org> Reply-To: Srivatsa Vaddagiri Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Return-path: Content-Disposition: inline In-Reply-To: <20200429061621-mutt-send-email-mst@kernel.org> Sender: linux-kernel-owner@vger.kernel.org To: "Michael S. Tsirkin" Cc: Lu Baolu , tsoni@codeaurora.org, virtio-dev@lists.oasis-open.org, konrad.wilk@oracle.com, jan.kiszka@siemens.com, jasowang@redhat.com, christoffer.dall@arm.com, virtualization@lists.linux-foundation.org, alex.bennee@linaro.org, iommu@lists.linux-foundation.org, stefano.stabellini@xilinx.com, will@kernel.org, linux-kernel@vger.kernel.org, pratikp@codeaurora.org List-Id: virtualization@lists.linuxfoundation.org * Michael S. Tsirkin [2020-04-29 06:20:48]: > On Wed, Apr 29, 2020 at 03:39:53PM +0530, Srivatsa Vaddagiri wrote: > > That would still not work I think where swiotlb is used for pass-thr devices > > (when private memory is fine) as well as virtio devices (when shared memory is > > required). > > So that is a separate question. When there are multiple untrusted > devices, at the moment it looks like a single bounce buffer is used. > > Which to me seems like a security problem, I think we should protect > untrusted devices from each other. I think as first step, let me see if we can make swiotlb driver accept a target memory segment as its working area. That may suffice our needs I think. A subsequent step could be to make swiotlb driver recognize multiple pools. -- QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation