[kvm-devel] Feedback and errors

[nadim k. <na...@kh...>]

Hi, great work.

While playing with kvm-qemu I noticed a few points that might be of interrest:

1/ -loadvm and -snapshot don't work together. It works as if -loadvm wasn't 
passed as argument

2/ two instances of kvm can be passed the same -hda. There is no locking 
whatsoever. This messes up things seriously.

3/ trying to run 'savevm' in the qemu console when -usb is used results in

(qemu) savevm scite
(qemu) exception 13 (0)
rax 0000000000000000 rbx 0000000000000000 rcx 0000000000000010 rdx 
0000000000000000
...

This is documented but a warning in the console would be better than a crash

if the vm is stopped first, 'savevm' works but it still crashes on 'cont' 
instead

4/ if -vga-std is used when doing a 'savevm', 'loadvm' restores a black 
screen. Everything is there and with some gymnastic (moving a window around) 
the screen is like it should be.

5/ -usbdevice tablet is a must, 'ctl+alt' is just too painfull! is it possible 
to get the same effect (with another system) and still be able to 'savevm'?

6/ If you use -usbdevice tablet, keyboard is first handled by guest OS. In my 
case I have 'alt F4' close windows in the host OS. If I try to close a window 
in the guest OS with 'alt f4', it closes qemu altogether.

7/ On the other hand, mouse events are _not_ handled by the gues OS first, IE: 
alt click isn't handled by X but by windows (in this case)

8/ keyboard input lost when switching to full screen or back. fixed by 
using 'ctl+alt' twice

9/ IMHO, the way "versionning" with 'savevm' is done could feel more natural.

first run
    time ------------------------------> stop VM
                 ^                          |
                 |                          |
                 |                          v
           savevm state1    automatically save "HEAD" in -hda



second run
    time ------------------------------>stop VM
         ^                                 |
         |                                 |
         |                                 v
   loadvm state1           automatically save "HEAD" in -hda
                                           ^
                                           |
                                .----------'
                                |
       .-------------------------------------------------.
       | I believe most people want to save in 'state1'  |
       | or possibly in 'state2' but few want to         |
       | override "HEAD"                                 |
       '-------------------------------------------------'


automatically overriding 'state1' feels as wrong as overriding "HEAD". I 
believe that a -savevm to qemu would be a good idea. If nothing is passed as 
argument "HEAD" is used. That would preserve "HEAD" and allow saving to a 
user defined vm snapshot.

10/ subscription to the mailing list doesn't seem to work

Cheers, Nadim.

# what kvm version you are using. qemu 0.9.1

# the cpu, arch  and host kernel version: Linux 2.6.24 #9 SMP x86_64 Intel(R) 
Core(TM)2 Quad CPU @ 2.66GHz GenuineIntel GNU/Linux

# what guest you are using, including OS type Windows XP SP2 (32 I guess)

# the qemu command line you are using to start the guest
qemu-system-x86_64 -no-acpi -m 1536 -hda overlay.img -boot c -monitor 
stdio -usb -smp 2 -std-vga -smb /home/nadim/ -k
fr