From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:57256) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1R9XkH-0007Nz-3V for qemu-devel@nongnu.org; Fri, 30 Sep 2011 03:42:57 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1R9XkF-0005Ee-HR for qemu-devel@nongnu.org; Fri, 30 Sep 2011 03:42:57 -0400 Received: from mx1.redhat.com ([209.132.183.28]:47279) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1R9XkF-0005EN-AP for qemu-devel@nongnu.org; Fri, 30 Sep 2011 03:42:55 -0400 Received: from int-mx02.intmail.prod.int.phx2.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id p8U7gr0H006532 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Fri, 30 Sep 2011 03:42:53 -0400 Received: from localhost (vpn1-6-177.ams2.redhat.com [10.36.6.177]) by int-mx02.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id p8U7gq5W022743 for ; Fri, 30 Sep 2011 03:42:53 -0400 Date: Fri, 30 Sep 2011 08:42:51 +0100 From: "Richard W.M. Jones" Message-ID: <20110930074251.GA3972@amd.home.annexia.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Subject: [Qemu-devel] How to capture guest %rip from a qemu process without monitor? List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org I've finally managed to reproduce a very infrequent kernel boot hang by forcing TCG (so it runs slower, bug seems to be timing sensitive) and running a boot test in a loop thousands of times. I'd like to find out where in the guest kernel this is looping. Unfortunately I don't have access to the monitor so "info registers" won't work, but I can attach to the qemu process with gdb. Which TCG struct contains %rip, other registers? What other useful information can be captured using only gdb? Rich. https://bugzilla.redhat.com/show_bug.cgi?id=723822 Command line: qemu-kvm -machine pc,accel=tcg -drive file=/dev/null,if=virtio -nodefconfig -nodefaults -nographic -m 500 -no-reboot -no-hpet -device virtio-serial -serial stdio -chardev socket,path=/home/rjones/d/libguestfs/libguestfsoFRvo0/guestfsd.sock,id=channel0 -device virtserialport,chardev=channel0,name=org.libguestfs.channel.0 -kernel /home/rjones/d/libguestfs/.guestfs-500/kernel.27140 -initrd /home/rjones/d/libguestfs/.guestfs-500/initrd.27140 -append 'panic=1 console=ttyS0 udevtimeout=300 no_timer_check acpi=off printk.time=1 cgroup_disable=memory selinux=0 guestfs_verbose=1 TERM=xterm' -drive file=/home/rjones/d/libguestfs/.guestfs-500/root.27140,snapshot=on,if=virtio,cache=unsafe -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones New in Fedora 11: Fedora Windows cross-compiler. Compile Windows programs, test, and build Windows installers. Over 70 libraries supprt'd http://fedoraproject.org/wiki/MinGW http://www.annexia.org/fedora_mingw