On Fri, 2013-02-15 at 11:19 +0400, Michael Tokarev wrote:
This patch is more than 2 years old and is applied to all more or less recent qemu versions.
RHEL 6.3?
I'm *not* seeing this bug with recent qemu versions.
This does not tell us why disabling kvm (with this patch applied!) makes a difference. So there must be another (maybe similar) bug somewhere...
Are you looking at the same patch I'm looking at? Before the patch, if KVM is enabled then the i440fx_update_memory_mappings() function just bails out without doing anything. As the commit message describes, it fails to remap the 0xf0000 memory from ROM to RAM, so subsequent writes to the F-segment actually modify the *ROM* content instead of the RAM copy as they should. (KVM doesn't write-protect the ROM). So on reset, it ends up running the *modified* copy of the BIOS.
That's an *exact* description of what Laszlo was seeing, surely?