> Also, something like this has to be added for amd64 for
> modular-xorg-server in hw/xfree86/os-support/bsd/i386_video.c:
> 
> --- hw/xfree86/os-support/bsd/i386_video.c.orig 2006-12-13 01:33:54.000000000
> -0
> 500
> +++ hw/xfree86/os-support/bsd/i386_video.c
> @@ -50,6 +50,11 @@
> #include <machine/mtrr.h>
> #include <machine/sysarch.h>
> #include <sys/queue.h>
> +#if defined(__NetBSD__) && defined(__amd64__)__
> +#define i386_set_mtrr x86_64_set_mtrr
> +#define i386_get_mtrr x86_64_get_mtrr
> +#define i386_iopl x86_64_iopl
> +#endif
> #endif

I will commit this upstream unless someone provides something different. 
(Sorry I didn't test on x86_64 per my comment below.)

> In addition, the xorgos (sp?) library needs to be linked with -lx86_64
> instead of -li386. 

That should already be fixed.

Last May, I committed to xserver/configure.ac: "On NetBSD, add -li386 for 
i386 and -lx86_64 for x86_64 to SYS_LIBS. (x86_64 on NetBSD not tested.)"

But that is not in xorg-server-1.1.1 source tarball. That tarball is too 
old! Many, many fixes have been done since then. Please use newer tarball 
from http://xorg.freedesktop.org/releases/individual/xserver/ or from 
http://xorg.freedesktop.org/archive/development/individual/xserver/

I was using xorg-server-1.1.99.3 with my last testing on my own via 
pkgsrc-wip.