From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: virtio-dev-return-5481-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 066CC9860BA for ; Thu, 21 Feb 2019 09:59:09 +0000 (UTC) Date: Thu, 21 Feb 2019 10:59:02 +0100 From: Gerd Hoffmann Message-ID: <20190221095902.mfa54mu7b4q5524p@sirius.home.kraxel.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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190221092455.GB2605@work-vm> Subject: Re: [virtio-dev] Memory sharing device To: "Dr. David Alan Gilbert" Cc: Frank Yang , "Michael S. Tsirkin" , Roman Kiryanov , Stefan Hajnoczi , virtio-dev@lists.oasis-open.org List-ID: 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 --------------------------------------------------------------------- To unsubscribe, e-mail: virtio-dev-unsubscribe@lists.oasis-open.org For additional commands, e-mail: virtio-dev-help@lists.oasis-open.org