qemu-devel
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[Qemu-devel] Re: [kvm-devel] Feedback and errors


From: Avi Kivity
Subject: [Qemu-devel] Re: [kvm-devel] Feedback and errors
Date: Fri, 02 May 2008 13:52:18 +0300
User-agent: Thunderbird 2.0.0.12 (X11/20080226)

nadim khemir wrote:
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.


These two are upstream qemu problems. Copying qemu-devel.

I guess using file locking by default would improve the situation, and we can add a -drive ...,exclusive=no option for people playing with cluster filesystems.

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'?


-vmmouse will work with Linux, with Windows, you might need to install a driver.

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.

Try full screen mode (alt-ctrl-F).

If the host didn't handle Alt-F4 in non-capture mode, you'd have no way to close the qemu window.

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


What do you mean?

--
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.





reply via email to

[Prev in Thread] Current Thread [Next in Thread]