From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1NUFkl-0007hG-Bm for qemu-devel@nongnu.org; Mon, 11 Jan 2010 03:36:00 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1NUFkf-0007eR-Sy for qemu-devel@nongnu.org; Mon, 11 Jan 2010 03:35:58 -0500 Received: from [199.232.76.173] (port=41799 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1NUFkd-0007eB-OS for qemu-devel@nongnu.org; Mon, 11 Jan 2010 03:35:53 -0500 Received: from mx1.redhat.com ([209.132.183.28]:30897) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1NUFkd-0004hf-4A for qemu-devel@nongnu.org; Mon, 11 Jan 2010 03:35:51 -0500 Date: Mon, 11 Jan 2010 14:04:43 +0530 From: Amit Shah Subject: Re: [Qemu-devel] [PATCH 5/8] virtio-serial-bus: Add support for buffering guest output, throttling guests Message-ID: <20100111083443.GA6061@amit-x200.redhat.com> References: <1262849506-27132-6-git-send-email-amit.shah@redhat.com> <20100108011231.GA5011@shareable.org> <20100108050351.GB8999@amit-x200.redhat.com> <20100108133503.GA19328@shareable.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100108133503.GA19328@shareable.org> List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Jamie Lokier Cc: qemu-devel@nongnu.org On (Fri) Jan 08 2010 [13:35:03], Jamie Lokier wrote: > > Since VNC is clearly designed to work over TCP, and is written by > people who know this, I'm wondering why you think it needs to be > different for virtio-serial. For vnc putting stuff from a guest clipboard into vnc client clipboard using the ServerCutText command, the entire buffer has to be provided after sending the command and the 'length' values. In this case, if the data from guest arrives in multiple packets, we really don't want to call into the write function multiple times. A single clipboard entry has to be created in the client with the entire contents, so a single write operation has to be invoked. For this to happen, there has to be some indication from the guest as to how much data was written in one write() operation, which will let us make a single write operation to the vnc client. Amit