qemu 1.5.0 has been released, featuring ssh support so you can access remote disks over ssh, including from libguestfs.
Here’s how to use this from guestfish:
$ export LIBGUESTFS_BACKEND=direct $ guestfish --ro -a ssh://onuma/mnt/scratch/winxp.img -i Welcome to guestfish, the guest filesystem shell for editing virtual machine filesystems and disk images. Type: 'help' for help on commands 'man' to read the manual 'quit' to quit the shell Operating system: Microsoft Windows XP /dev/sda1 mounted on / ><fs> ll / total 1573209 drwxrwxrwx 1 root root 4096 Apr 16 2012 . drwxr-xr-x 23 1000 1000 4096 May 20 19:47 .. -rwxrwxrwx 1 root root 0 Oct 11 2011 AUTOEXEC.BAT -rwxrwxrwx 1 root root 0 Oct 11 2011 CONFIG.SYS drwxrwxrwx 1 root root 4096 Oct 11 2011 Documents and Settings -rwxrwxrwx 1 root root 0 Oct 11 2011 IO.SYS -rwxrwxrwx 1 root root 0 Oct 11 2011 MSDOS.SYS -rwxrwxrwx 1 root root 47564 Apr 14 2008 NTDETECT.COM drwxrwxrwx 1 root root 4096 Oct 11 2011 Program Files drwxrwxrwx 1 root root 4096 Oct 11 2011 System Volume Information drwxrwxrwx 1 root root 28672 Oct 11 2011 WINDOWS -rwxrwxrwx 1 root root 211 Oct 11 2011 boot.ini -rwxrwxrwx 1 root root 250048 Apr 14 2008 ntldr -rwxrwxrwx 1 root root 1610612736 Oct 11 2011 pagefile.sys