[Qemu-devel] [BUG] QEMU crashes when 64bit BAR is present

[Alexey Korolev]

Hi all,
I had qemu 1.2.0 crash when using ivshmem driver with 64bit PCI support 
enabled. The qemu process is terminated at a very early stage of
Linux boot up. Here is the qemu command line:

LC_ALL=C 
PATH=/usr/kerberos/sbin:/usr/kerberos/bin:/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin
 HOME=/home/user
USER=user LOGNAME=user QEMU_AUDIO_DRV=none /usr/bin/qemu -M pc-0.11 -enable-kvm 
-m 4096 -smp 1,sockets=1,cores=1,threads=1 -name Cent5 -uuid
59342423-be7a-0f83-b9ac-35a42e521d99 -nodefconfig -nodefaults -chardev
socket,id=charmonitor,path=/var/lib/libvirt/qemu/Cent5.monitor,server,nowait 
-mon chardev=charmonitor,id=monitor,mode=readline -rtc base=utc
-boot order=cd,menu=on -drive 
file=/home/akorolev/Cent54.img,if=none,id=drive-ide0-0-0,format=raw -device
ide-drive,bus=ide.0,unit=0,drive=drive-ide0-0-0,id=ide0-0-0 -drive 
if=none,media=cdrom,id=drive-ide0-1-0,readonly=on,format=raw -device
ide-drive,bus=ide.1,unit=0,drive=drive-ide0-1-0,id=ide0-1-0 -chardev 
file,id=charserial0,path=/home/akorolev/Cent5.5.log -device
isa-serial,chardev=charserial0,id=serial0 -usb -vnc 127.0.0.1:0 -k en-us -vga 
cirrus -device
ivshmem,size=128M,pci64=1,shm,bus=pci.0,multifunction=on,addr=0x5.0x0 -device
virtio-balloon-pci,id=balloon0,bus=pci.0,multifunction=on,addr=0x4.0x0

And qemu error output is:
qemu: /home/akorolev/qemu-kvm/exec.c:2255: register_subpage: Assertion 
`existing->mr->subpage || existing->mr == &io_mem_unassigned' failed.

Guest OS is Centos 5.5 and log is pretty boring, as qemu crashes before Linux 
can report an issue.

Note: The only tweak I've made to qemu is changing PCI bar flag to 
PCI_ADDRESS_MEM_TYPE_64 in ivshmem driver

I guess the issue is related to this: 
http://lists.gnu.org/archive/html/qemu-devel/2012-01/msg03189.html
At that time /it was found out that ivshmem bar is split by/ /the hpet region/

Could you please have a look at this?
I'm willing to provide additional info if you need it.

Thanks
Alexey