[Qemu-devel] Re: [COMMIT ff24bd5] qemu/virtio: virtio save/load bindings

[Kevin Wolf <kwolf@redhat.com>]

Anthony Liguori schrieb:
> From: Michael S. Tsirkin <mst@redhat.com>
> 
> Implement bindings for virtio save/load. Use them in virtio pci.
> 
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

This patch causes segfaults during savevm:

Program received signal SIGSEGV, Segmentation fault.
0x0000003d1d0842a2 in memcpy () from /lib64/libc.so.6
(gdb) bt
#0  0x0000003d1d0842a2 in memcpy () from /lib64/libc.so.6
#1  0x00000000004a65bf in qemu_put_buffer (f=0xd4f220, buf=0x0, size=48)
at savevm.c:478
#2  0x0000000000419133 in msix_save (dev=0xc93410, f=0xd4f220) at
/home/kwolf/source/qemu/hw/msix.c:289
#3  0x0000000000555424 in virtio_pci_save_config (opaque=0xc93410,
f=0xd4f220) at /home/kwolf/source/qemu/hw/virtio-pci.c:112
#4  0x00000000005545b3 in virtio_save (vdev=0xc93ad0, f=0xd4f220) at
/home/kwolf/source/qemu/hw/virtio.c:620
#5  0x0000000000419eaf in virtio_balloon_save (f=0xd4f220,
opaque=0xc93ad0) at /home/kwolf/source/qemu/hw/virtio-balloon.c:151
#6  0x00000000004a6756 in qemu_savevm_state_complete (f=0xd4f220) at
savevm.c:811
#7  0x00000000004a68dd in qemu_savevm_state (f=0xd4f220) at savevm.c:842
#8  0x00000000004a6a4b in do_savevm (mon=0xcd87b0, name=<value optimized
out>) at savevm.c:1134
#9  0x00000000004138f4 in monitor_handle_command (mon=0xcd87b0,
cmdline=<value optimized out>) at /home/kwolf/source/qemu/monitor.c:2697
#10 0x00000000004139ba in monitor_command_cb (mon=0xcd87b0, cmdline=0x0,
opaque=0x30) at /home/kwolf/source/qemu/monitor.c:2964
#11 0x000000000047cc74 in readline_handle_byte (rs=0xcb7aa0, ch=<value
optimized out>) at readline.c:369
#12 0x0000000000413a24 in monitor_read (opaque=<value optimized out>,
buf=0x7fffffffc6b0 "\r����\177", size=1)
    at /home/kwolf/source/qemu/monitor.c:2950
#13 0x00000000004a33e3 in qemu_chr_read (len=<value optimized out>,
buf=<value optimized out>, s=<value optimized out>) at qemu-char.c:168
#14 fd_chr_read (opaque=<value optimized out>) at qemu-char.c:571
#15 0x0000000000409d92 in main_loop_wait (timeout=<value optimized out>)
at /home/kwolf/source/qemu/vl.c:4273
#16 0x000000000040dbdd in main_loop () at /home/kwolf/source/qemu/vl.c:4499
#17 main (argc=6, argv=0x7fffffffe178, envp=<value optimized out>) at
/home/kwolf/source/qemu/vl.c:6252

I guess it's easy to reproduce with any setup, just for completeness
here is what I did:

$ ./qemu-img create -f qcow2 images/tmp.qcow2 1M
$ x86_64-softmmu/qemu-system-x86_64 -L pc-bios/ images/tmp.qcow2
-monitor stdio <<< savevm test

Kevin