From owner-freebsd-xen@FreeBSD.ORG Fri Jun 10 03:26:30 2011 Return-Path: Delivered-To: freebsd-xen@freebsd.org Received: from mx2.freebsd.org (mx2.freebsd.org [IPv6:2001:4f8:fff6::35]) by hub.freebsd.org (Postfix) with ESMTP id CC10A106566C for ; Fri, 10 Jun 2011 03:26:30 +0000 (UTC) (envelope-from cperciva@freebsd.org) Received: from xps.daemonology.net (freefall.freebsd.org [IPv6:2001:4f8:fff6::28]) by mx2.freebsd.org (Postfix) with SMTP id 67E621567DF for ; Fri, 10 Jun 2011 03:26:30 +0000 (UTC) Received: (qmail 23272 invoked from network); 10 Jun 2011 03:26:30 -0000 Received: from unknown (HELO xps.daemonology.net) (127.0.0.1) by localhost with SMTP; 10 Jun 2011 03:26:29 -0000 Message-ID: <4DF18EE5.5090704@freebsd.org> Date: Thu, 09 Jun 2011 20:26:29 -0700 From: Colin Percival User-Agent: Mozilla/5.0 (X11; U; FreeBSD amd64; en-US; rv:1.9.1.16) Gecko/20101220 Thunderbird/3.0.11 MIME-Version: 1.0 To: "freebsd-xen@freebsd.org" X-Enigmail-Version: 1.0.1 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: breakage in blkfront with ring_pages > 1 X-BeenThere: freebsd-xen@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussion of the freebsd port to xen - implementation and usage List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 10 Jun 2011 03:26:30 -0000 Hi all, I'm seeing breakage with ring_pages > 1 on a blkfront; more precisely, request #32 has a garbage response (resulting in a panic) exactly as if the dom0 thinks we're only using a single page for the ring. Forcing ring_pages to 1 makes the problem go away. Has anyone seen anything like this? Is it possible that there's a bug in how our blkfront negotiates the request ring? Does anyone have ring_pages > 1 in use? -- Colin Percival Security Officer, FreeBSD | freebsd.org | The power to serve Founder / author, Tarsnap | tarsnap.com | Online backups for the truly paranoid