[Qemu-devel] How to capture guest %rip from a qemu process without monitor?

[Richard W.M. Jones]

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