[Qemu-devel] [BUG] Migration segfaults

[Pierre Riteau]

The commit 7e72abc382b700a72549e8147bdea413534eeedc (vmstate: port  
cirrus_vga device) appears to break migration for me.
I'm migrating a Debian Lenny with 128 MB of RAM, and it segfaults at  
the end of the migration.

The following backtrace was acquired with the current HEAD  
(b348113d2161a339780e2d9e0479b1f9a53c6cbc).

Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0xb79e06b0 (LWP 9106)]
0x081571b3 in subpage_register (mmio=0xabf32008, start=0, end=4095,  
memory=2089441, region_offset=0) at /mnt/qemu/exec.c:2862
2862                if (io_mem_read[memory][i]) {
(gdb) bt
#0  0x081571b3 in subpage_register (mmio=0xabf32008, start=0,  
end=4095, memory=2089441, region_offset=0) at /mnt/qemu/exec.c:2862
#1  0x081564c6 in cpu_register_physical_memory_offset  
(start_addr=655360, size=131072, phys_offset=16715534,  
region_offset=0) at /mnt/qemu/exec.c:2339
#2  0x080bc969 in cpu_register_physical_memory (start_addr=655360,  
size=131072, phys_offset=16715534) at /mnt/qemu/cpu-common.h:28
#3  0x080bc9ce in unmap_linear_vram (s=0xa0c4008) at /mnt/qemu/hw/ 
cirrus_vga.c:2623
#4  0x080bca72 in cirrus_update_memory_access (s=0xa0c4008) at /mnt/ 
qemu/hw/cirrus_vga.c:2648
#5  0x080bd190 in cirrus_post_load (opaque=0xa0c4008) at /mnt/qemu/hw/ 
cirrus_vga.c:2965
#6  0x08128f92 in vmstate_load_state (f=0xa134760, vmsd=0x81d3a60,  
opaque=0xa0c4008, version_id=2) at savevm.c:1087
#7  0x08129139 in vmstate_load (f=0xa134760, se=0xa0c1218,  
version_id=2) at savevm.c:1133
#8  0x0812985d in qemu_loadvm_state (f=0xa134760) at savevm.c:1371
#9  0x0811ba2e in tcp_accept_incoming_migration (opaque=0xd) at  
migration-tcp.c:158
#10 0x080521b6 in main_loop_wait (timeout=5000) at /mnt/qemu/vl.c:3871
#11 0x08052870 in main_loop () at /mnt/qemu/vl.c:4091
#12 0x08056431 in main (argc=13, argv=0xbfd6ddf4, envp=0xbfd6de2c) at / 
mnt/qemu/vl.c:5943

--
Pierre Riteau -- http://perso.univ-rennes1.fr/pierre.riteau/