AMD64 qemu completely broken?

[Nate Eldredge]

On Thu, 4 Dec 2008, Juergen Lock wrote:

> I forgot to say the qemu-devel port (as well as the later snapshots I
> posted about on -emulation) also support -curses, which shows the emulated
> vga text(!)console on qemu's tty.  This works quite well with FreeBSD guests
> (even the isos) if you extend your xterm/whatever by one line (the default
> vga textconsole is 80x25 instead of 80x24.)

As long as we're sharing tips about qemu:

I've recently been working with qemu on amd64 and have set up a Debian 
etch i386 guest which is working well.  I am using the qemu-devel and 
kqemu-kmod-devel ports.  I am not using -kernel-kqemu at the moment; I 
thought I would get things working before trying to speed up.

Using qemu I've finally achieved my goal of being able to use flash on 
FreeBSD/amd64 (in some sense :-O).

savevm and loadvm don't work due to a security patch.  Since my guest 
system is trusted I reverted the patch.  I filed a PR as ports/129417 .

I found that '-net user' is horribly broken on amd64 (qemu segfaults). 
It uses some ancient [*] BSD TCP/IP code (via slirp) which assumes that 
pointers are 32 bits and doesn't hesitate to shove them into random 32-bit 
corners of externally defined structures if it's convenient.  Looks like a 
pain to clean up.  '-net tap' works fine, but requires root privileges and 
is more work to set up.

[*] Out of curiosity, I looked at some Unix Archive stuff and found the 
identical code in BSD's Net2, circa 1991.  It is identified in a comment 
as a "quick hack" and adorned with several /* XXX */.  Naturally the code 
and the comments survive intact, 17 years later. :-(

-- 

Nate Eldredge
neldredge at math.ucsd.edu