First, there should normally be few reasons for the user to want to copy files from VMs to Dom0, as Dom0 only acts as a "thin trusted terminal", and no user applications run there. However, one exception to this is if we want to copy a desktop wallpaper, that we normally have in one of the AppVMs (e.g. in the 'personal' AppVM where we got it from our camera, or downloaded from the Internet). While it's a well justified reason, one should remember, however, that copying untrusted files to Dom0 might be a fatal security problem. Imagine what would happen if the wallpaper (e.g. a JPEG file) was somehow malformed and was in fact attempting to exploit a hypothetical JPEG parser bug in Dom0 code (e.g. in the Dom0's Xorg/KDE component that parses the wallpaper and displays it).
For this reason we intentionally do not provide a convenient tool for copying files between VMs and Dom0 (while we provide a tool for copying files between VMs). However, if you're determined to copy some files to Dom0 anyway, you can use the following method (run this command from Dom0's console):
BTW, you can use the same method to copy files from Dom0 to VMs, e.g. logs (although in Qubes 1.0 this won't be needed, as we will provide a convenient one-click solution for copying logs to Qubes global clipboard):
