On 08/20/2014 05:46 AM, Michal Privoznik wrote:
On 19.08.2014 22:11, Giuseppe Scrivano wrote:
Generate the qemu command line option:
-device 'usb-mtp,root=$SRC,desc=$TARGET'
from the definition XML:
<filesystem type='mount'> <source dir='$SRC'/> <target dir='$TARGET'/> <model type='mtp'/> </filesystem>
Closes: https://bugzilla.redhat.com/show_bug.cgi?id=1121781
Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com> ---
+ virBufferAddLit(&opt, "usb-mtp"); + virBufferAsprintf(&opt, ",root=%s,desc=%s", fs->src, fs->dst);
Reading qemu sources the root property is called 'x-root'. And indeed domain fails to start:
Ouch. Qemu has explicitly documented that anything starting with x- is unstable, and may change. We probably should NOT be targetting this in libvirt API just yet, in case qemu changes their mind. It's nice that you've done the patch as a proof of concept, but I don't think we want it in the tree yet :(
usb: mtp: tag root property as experimental
Reason: we don't want commit to that interface yet. Possibly the implementation will be switched over to use fsdev.
Suggested-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
diff --git a/hw/usb/dev-mtp.c b/hw/usb/dev-mtp.c index 1b51a90..384d4a5 100644 --- a/hw/usb/dev-mtp.c +++ b/hw/usb/dev-mtp.c @@ -1090,7 +1090,7 @@ static const VMStateDescription vmstate_usb_mtp = { };
static Property mtp_properties[] = { - DEFINE_PROP_STRING("root", MTPState, root), + DEFINE_PROP_STRING("x-root", MTPState, root), DEFINE_PROP_STRING("desc", MTPState, desc), DEFINE_PROP_END_OF_LIST(), };
Question that pops up immediately: do we want to commit to something that even qemu developers don't believe yet? What will happen when qemu decides to switch to 'root' attribute again? Libvirt will have to adapt which won't work with older qemus supporting 'x-root' only.
Yep - anything in qemu with x- is not a candidate for libvirt support (for the longest time, we refused to support RDMA migration because it still had an x- prefix). -- Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org