On 2012-08-14 12:20, Avi Kivity wrote: > On 08/14/2012 11:44 AM, Markus Armbruster wrote: >> >> Next error: >> >> $ gdb --args qemu-system-x86_64 -nodefaults --enable-kvm -vnc :0 >> -monitor stdio -m 640k >> [...] >> Program received signal SIGSEGV, Segmentation fault. >> [...] >> (gdb) bt >> #0 0x0000003b0de884ac in __memcmp_sse2 () from /lib64/libc.so.6 >> #1 0x000000000063f1ad in patch_hypercalls (s=0x139b350) >> at /work/armbru/qemu/hw/i386/../kvmvapic.c:532 >> #2 0x000000000063f3fe in vapic_prepare (s=0x139b350) >> at /work/armbru/qemu/hw/i386/../kvmvapic.c:597 >> #3 0x000000000063f4ed in vapic_write (opaque=0x139b350, addr=0, >> data=32, size= >> 2) at /work/armbru/qemu/hw/i386/../kvmvapic.c:634 >> #4 0x0000000000677a44 in memory_region_write_accessor >> (opaque=0x139d670, addr= >> >> Happens when -m argument is a multiple of 4k in [648k..768k]. Only with >> --enable-kvm. With and without my CMOS fix applied. > > kvmvapic requires RAM to be present underneath the ROM. We could fix up > kvmvapic to allocate a 4k region and insert it as an overlay, but it's > sufficient IMO to require sub-1M users to disable it. It won't be of > any use to the anyway as Windows XP requires more than 1MB.
We can also easily automatically disable it when there is insufficient (<1MB) memory. Will post a patch. Jan -- Siemens AG, Corporate Technology, CT RTC ITP SDP-DE Corporate Competence Center Embedded Linux
