From mboxrd@z Thu Jan 1 00:00:00 1970 From: Don Fry Subject: qemu pcnet emulation problems. Date: Tue, 21 Mar 2006 17:02:35 -0800 Message-ID: <20060322010235.GA16108@us.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: xen-devel@lists.xensource.com List-Id: xen-devel@lists.xenproject.org There are/may be several other bugs with the qemu pcnet emulation. I do not know if there is any other serialization outside of this code, but if both a transmit and a receive operation were to be performed at the same time on different cpus, since the same buffer is used for both transmit and receive, that would also cause data corruption. Does anyone else know how this is prevented, or is this another source of corruption? Another thing I noticed, that will reduce throughput if corrected, is that the wrong bit is being examined in the receive path, to determine if mac level crc should be computed. Right now, the wrong bit is being checked and no mac level crc is being calculated. If the right bit were looked at, mac level crc would need to be computed, slowing down the transfers. However, since no driver cares about the crc right now, since neither Linux or XP complain, could the code to compute the crc be deleted? Maybe just comment that the crc should be computed. Any recommendations? -- Don Fry brazilnut@us.ibm.com