From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: virtio-dev-return-5494-cohuck=redhat.com@lists.oasis-open.org Sender: List-Post: List-Help: List-Unsubscribe: List-Subscribe: Received: from lists.oasis-open.org (oasis.ws5.connectedcommunity.org [10.110.1.242]) by lists.oasis-open.org (Postfix) with ESMTP id 2694C9860E5 for ; Fri, 22 Feb 2019 06:15:37 +0000 (UTC) Date: Fri, 22 Feb 2019 01:15:27 -0500 From: "Michael S. Tsirkin" Message-ID: <20190222010657-mutt-send-email-mst@kernel.org> References: <20190211092943-mutt-send-email-mst@kernel.org> <20190219071222.jjebzcbh55kwlspn@sirius.home.kraxel.org> <20190220070213.3uetjgzzlf5qojan@sirius.home.kraxel.org> <20190221072950.tcii5np5dsk4wvyd@sirius.home.kraxel.org> <20190221092455.GB2605@work-vm> <20190221095902.mfa54mu7b4q5524p@sirius.home.kraxel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190221095902.mfa54mu7b4q5524p@sirius.home.kraxel.org> Subject: Re: [virtio-dev] Memory sharing device To: Gerd Hoffmann Cc: "Dr. David Alan Gilbert" , Frank Yang , Roman Kiryanov , Stefan Hajnoczi , virtio-dev@lists.oasis-open.org List-ID: On Thu, Feb 21, 2019 at 10:59:02AM +0100, Gerd Hoffmann wrote: > Hi, > > > > Note: I think using a pci memory bar (aka host memory mapped into the > > > guest) as backing storage for dma-bufs isn't going to work. > > > > (Not knowing dma-bufs) but could you explain why? > > Many places in the linux kernel assume dma-bufs are built out of normal > ram pages (i.e. something backed by struct page). Which is not the case > for pci memory bars which are typically ioremapped() (completely or in > chunks) to access them. > > cheers, > Gerd Can't we register PCI memory as ZONE_DEVICE? --------------------------------------------------------------------- To unsubscribe, e-mail: virtio-dev-unsubscribe@lists.oasis-open.org For additional commands, e-mail: virtio-dev-help@lists.oasis-open.org