[Qemu-devel] bug reports and suggestions

[Don Kitchen]

First some suggestions for what they're worth...



$ qemu-img info someimage
image: someimage
file format: qcow
virtual size: 75G (80026361856 bytes)
disk size: 304K

For files with a backing file, has anyone thought about having it print out
the name of the backing file? Particularly this would be helpful to edit in
the case the backing file is relocated. I'm afraid I have been unable to
locate the correct code for this.

Next, it seems the *one* thing QEMU lacks that you-know-who does correctly
is networking, specifically bridged mode. I know about creating a tap device
and sticking it into a bridge (really hasn't worked for me, but that's the
subject for a different day.) I realize that it's a complicated issue
requiring kernel modules, etc, and exponentially more complicated with
cross platform, but I wonder if anyone has considered trying to tie into
the vmware-player's kernel modules and use them? There has to be some sort
of de-facto API for interaction between the modules and the player. Too
rife with IP problems?

And let me express my appreciation both to Fabrice and everyone else who
contributes. In many other emulators it seems like everything is like, Gee,
I wish this had the features that <loud voice> VMWARE </loud> has, but with
QEMU it seems like for everything but network it's Gee, I wish vmware did
that like QEMU. I read the stuff people contribute, stuff like fixing for
cdrom to be moved around, null block writes auto ignored, all great and
welcome stuff, not to mention a built-in vnc server out of the blue, wow.





Now on to the bug reports...Sorry it's in only one email, I thought best
not to blitz many different emails.





If I am starting QEMU on a second X server on another VT using this:
xinit qemu ... -full-screen -- :1
(In this case I am booting windows 2000) and I switch back to :0 *before*
Windoze switches from the splash screen to the light blue background (ie
still booting) X server :1 crashes with the following error:
BadValue (integer parameter out of range for operation)

Could someone else test this? I suspect that Qemu is involved somehow since
it depends on what is happening inside the guest machine. I have not had an
opportunity to test this on any hosts but FC3. Oh yeah, did I mention too
bad VMWARE is all but useless this way?


Next, relating to Image size:

I am creating a large image (320G):
qemu-img create -f raw big.img 312571224

but it's only recognized as being 137 GB. By my calculation there are
exactly 37 significant bits. Is this a limitation of the BIOS or qemu?
The only stuff I've found is about an old 2 GB limit. 

What it should be: 

Disk /dev/hda: 320.0 GB, 320072933376 bytes
255 heads, 63 sectors/track, 38913 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/hda1   *           1        1200     9638968+  83  Linux
/dev/hda2            1201        1260      481950   82  Linux swap / Solaris
/dev/hda3            1261       38913   302447722+  83  Linux


What it is: 

Disk /dev/hda: 137.4 GB, 137438953472 bytes
255 heads, 63 sectors/track, 16709 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/hda1   *           1        1200     9638968+  83  Linux
/dev/hda2            1201        1260      481950   82  Linux swap / Solaris
/dev/hda3            1261       38913   302447722+  83  Linux



Next, relating to the "invisible wall" problem. Sorry I didn't get around to
writing this report earlier, but I have a Mar 25 CVS compile which does not
have this problem and an Apr 21 compile which does. I remember talk about
the tablet stuff about that time but hope this adds a little data to the
issue.


Thanks all for reading.