From owner-freebsd-xen@freebsd.org Wed Jan 25 11:21:09 2017 Return-Path: Delivered-To: freebsd-xen@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 4848ECC07C3 for ; Wed, 25 Jan 2017 11:21:09 +0000 (UTC) (envelope-from alexander.nusov@nfvexpress.com) Received: from sender163-mail.zoho.com (sender163-mail.zoho.com [74.201.84.163]) (using TLSv1 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 3199718C; Wed, 25 Jan 2017 11:21:08 +0000 (UTC) (envelope-from alexander.nusov@nfvexpress.com) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; t=1485343257; s=zoho; d=nfvexpress.com; i=alexander.nusov@nfvexpress.com; h=Date:From:To:Cc:Message-Id:In-Reply-To:References:Subject:MIME-Version:Content-Type; l=9752; bh=s48+k4XREdQTXViyqGZv3XM6H8lNz9deQe6wONMsI5o=; b=N0qSsLIWCW17LD2gVZBF3AJp0KM47UcbDrVZ10ubmEdZcalkzo2QPVTsXRS2fkR5 jJ71ma0xjYKRhsAsusxQ4OdUcF3aN30BVZkZSabHRtdu8h0cGyrYyMMi7swhxbkVuLo HKY8xKxbCRXKw48Acrz1jf7VEUZ+NbE5Q7Dj2NfY= Received: from mail.zoho.com by mx.zohomail.com with SMTP id 1485343255500721.9455538969542; Wed, 25 Jan 2017 03:20:55 -0800 (PST) Date: Wed, 25 Jan 2017 14:20:55 +0300 From: Alexander Nusov To: "Akshay Jaggi" Cc: =?UTF-8?Q?=22Roger_Pau_Monn=C3=A9=22?= , "FreeBSD-Xen" Message-Id: <159d55b6b65.dc9b3b1720453.5847395326743424395@nfvexpress.com> In-Reply-To: References: <20170124114444.xdl3qj35lwebkso7@dhcp-3-221.uk.xensource.com> <159d0f04b55.10bbf935114648.7927688075504705395@nfvexpress.com> <20170124165621.iidjypfoyp4ccysi@dhcp-3-221.uk.xensource.com> Subject: Re: Xen on FreeBSD 11: Cannot boot from QCOW2 properly (waiting for XENBUS, xenbusb_nop_confighook_cb) MIME-Version: 1.0 X-Priority: Medium User-Agent: Zoho Mail X-Mailer: Zoho Mail Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Content-Filtered-By: Mailman/MimeDel 2.1.23 X-BeenThere: freebsd-xen@freebsd.org X-Mailman-Version: 2.1.23 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: Wed, 25 Jan 2017 11:21:09 -0000 Got it, thanks. I found a workaround to avoid XENBUS delay in Linux DomUs by adding xen_pla= tform_pci =3D 0 to the configuration file. So FreeBSD 11.0 Dom0 can boot Linux guests and Windows Server (FreeBSD DomU= still stuck on xenbusb_nop_confighook_cb) from QCOW2 images (also works wi= th QCOW2 overlay images) Can you tell me please what is the disadvantage of not using /dev/xen/vbd d= evices and drivers in guests? like slow I/O?=20 May it lead to data corruption? -- Alex ---- On Wed, 25 Jan 2017 12:35:14 +0300 Akshay Jaggi <jaggi@freebsd.org&= gt; wrote ---- Hi Alex and Roger, Without the patch and FreeBSD 12, qcow2 doesn't actually work. We were thin= king of adding code to warn against this, but then thought gntdev implement= ation is in process anyway. With the patch, the crash needs to be investigated (because I did run one o= f the gntdev based image, most probably qcow2, iirc). Sadly, I'm still searching for housing in Dublin, and hence won't be able t= o look at this immediately. Two weeks, to find and then move in, if I'm luc= ky. Meanwhile, I'll start hunting for a development machine in office. Regards, Akshay On Jan 24, 2017 16:56, Roger Pau Monn=C3=A9 <roger.pau@citrix.com> wr= ote: On Tue, Jan 24, 2017 at 05:45:25PM +0300, Alexander Nusov wrote: > Yes, it was FreeBSD 11.0-STABLE Dom0 with xen-kernel/xen-tools built f= rom the ports tree (head) > > > > It seems there is an issue with xen pci devices, since booting from QC= OW2 images actually works (even on FreeBSD 11.0-RELEASE branch) except comm= unication with /xen/vbd devices from the guest. Yes, I'm seeing exactly the same. The QEMU process is killed with a segmentation fault. Akshay, here is the full debug output: Program terminated with signal 11, Segmentation fault. [...] #0 blk_handle_requests (blkdev=3D0x807463c00) at hw/block/xen_disk.c:862 862 rp =3D blkdev->rings.common.sring->req_prod; [New Thread 8087f9000 (LWP 100947/<unknown>)] [New Thread 807418800 (LWP 100945/<unknown>)] [New Thread 807418300 (LWP 100944/<unknown>)] [New Thread 807417e00 (LWP 100943/<unknown>)] [New Thread 807417900 (LWP 100942/<unknown>)] [New Thread 807417400 (LWP 100941/<unknown>)] [New Thread 807416a00 (LWP 100940/<unknown>)] [New Thread 807416500 (LWP 100939/<unknown>)] [New Thread 807416000 (LWP 100091/<unknown>)] (gdb) bt #0 blk_handle_requests (blkdev=3D0x807463c00) at hw/block/xen_disk.c:862 #1 0x00000000005f9dcd in blk_bh (opaque=3D0x807463c00) at hw/block/xen_dis= k.c:918 #2 0x000000000080ba69 in aio_bh_call (bh=3D0x80780d810) at async.c:87 #3 0x000000000080bb10 in aio_bh_poll (ctx=3D0x8074a0680) at async.c:115 #4 0x000000000081c099 in aio_dispatch (ctx=3D0x8074a0680) at aio-posix.c:3= 03 #5 0x000000000080c2cd in aio_ctx_dispatch (source=3D0x8074a0680, callback= =3D0, user_data=3D0x0) at async.c:254 #6 0x0000000802e3903b in g_main_context_dispatch () from /usr/local/lib/li= bglib-2.0.so.0 #7 0x000000000081a34c in glib_pollfds_poll () at main-loop.c:259 #8 0x0000000000819dc5 in os_host_main_loop_wait (timeout=3D0) at main-loop= .c:306 #9 0x0000000000819c29 in main_loop_wait (nonblocking=3D0) at main-loop.c:5= 56 #10 0x0000000000588ed7 in main_loop () at vl.c:1966 #11 0x0000000000583b59 in main (argc=3D38, argv=3D0x7fffffffe750, envp=3D0x= 7fffffffe888) at vl.c:4684 Current language: auto; currently minimal It seems like the device is not properly mapping the grants, and QEMU gets = a SEGFAULT when trying to access the ring page. Roger.