Skip to contentSkip to conversation

qemu-kvm: Unsolicited boot from net

DISCUSSION Jan Kiszka 4 participants 6 messages Nov 12, 2009 – Nov 13, 2009 KVM

lore
Share & tools
lore

Jan Kiszka

author
#0 lore raw

Hi Marcelo,

since merge 2fb0744e0d qemu-kvm always tries to boot from network first when using default options. Upstream does not show this behavior.

Jan

Signature · 2 lines
Siemens AG, Corporate Technology, CT SE 2
Corporate Competence Center Embedded Linux
#1 lore raw
Quoted 4 lines · Jan Kiszka

Hi Marcelo,

since merge 2fb0744e0d qemu-kvm always tries to boot from network first when using default options. Upstream does not show this behavior.

Did you install the updated roms after this commit?

commit ec9f735638b6380361387fb49060f6712cb27602

Author: Anthony Liguori <[email protected]>
Date:   Fri Oct 30 16:44:26 2009 -0500

Update gpxe roms to have BANNER_TIMEOUT=0

author
#2 lore raw
Quoted 8 lines · Marcelo Tosatti
Quoted 4 lines · Jan Kiszka

Hi Marcelo,

since merge 2fb0744e0d qemu-kvm always tries to boot from network first when using default options. Upstream does not show this behavior.

Did you install the updated roms after this commit?

Quoted 7 lines

commit ec9f735638b6380361387fb49060f6712cb27602

Author: Anthony Liguori <[email protected]>
Date:   Fri Oct 30 16:44:26 2009 -0500

Update gpxe roms to have BANNER_TIMEOUT=0

I ran a complete & fresh mkbuilddir-configure-make-install cycle to exclude this. Moreover, the above change is actually not related to triggering the netboot but to wait for potential input of the user.

Looking closer: It's actually still pcbios that is used by my installation - shouldn't this be Seabios now?

Jan

Signature · 2 lines
Siemens AG, Corporate Technology, CT SE 2
Corporate Competence Center Embedded Linux
#3 lore raw
Quoted 13 lines · Jan Kiszka
Quoted 12 lines · Marcelo Tosatti
Quoted 4 lines · Jan Kiszka

Hi Marcelo,

since merge 2fb0744e0d qemu-kvm always tries to boot from network first when using default options. Upstream does not show this behavior.

Did you install the updated roms after this commit?

commit ec9f735638b6380361387fb49060f6712cb27602

Author: Anthony Liguori <[email protected]>
Date:   Fri Oct 30 16:44:26 2009 -0500
Quoted 7 lines
Quoted 3 lines

Update gpxe roms to have BANNER_TIMEOUT=0

I ran a complete & fresh mkbuilddir-configure-make-install cycle to exclude this. Moreover, the above change is actually not related to triggering the netboot but to wait for potential input of the user.

Right.

Quoted 2 lines

Looking closer: It's actually still pcbios that is used by my installation - shouldn't this be Seabios now?

My understanding is that Seabios should get more testing with qemu-kvm (other than the cpu hotplug debate). Gleb/Avi would know for sure.

Now whether pcbios option rom supports gpxe properly i don't know, maybe that is the root cause for the problem (yes, qemu-kvm loads gpxe and attempts to boot from the network first, the above commit only removes the annoying multi-second delay).

CC'ing people with some clue.

#4 lore raw
Quoted 7 lines · Marcelo Tosatti
Quoted 3 lines

Looking closer: It's actually still pcbios that is used by my installation - shouldn't this be Seabios now?

My understanding is that Seabios should get more testing with qemu-kvm (other than the cpu hotplug debate). Gleb/Avi would know for sure.

Quoted 7 lines

Now whether pcbios option rom supports gpxe properly i don't know, maybe that is the root cause for the problem (yes, qemu-kvm loads gpxe and attempts to boot from the network first, the above commit only removes the annoying multi-second delay).

CC'ing people with some clue.

Yup, that's the problem. gPXE doesn't think PCBIOS is a PnP bios because it isn't. Therefore it doesn't enable BEV and uses int19 instead.

This isn't a problem with older QEMUs because we only loaded the option roms on demand. We now load them unconditionally. Of course, that meant -boot cdn never really worked correctly.

The only easy solution is moving to SeaBIOS. I'm surprised qemu-kvm hasn't already made the move to be honest.

Signature · 3 lines
Regards,

Anthony Liguori
#5 lore raw
In reply to Marcelo Tosatti
Quoted 22 lines · Marcelo Tosatti
Quoted 13 lines · Jan Kiszka
Quoted 12 lines · Marcelo Tosatti
Quoted 4 lines · Jan Kiszka

Hi Marcelo,

since merge 2fb0744e0d qemu-kvm always tries to boot from network first when using default options. Upstream does not show this behavior.

Did you install the updated roms after this commit?

commit ec9f735638b6380361387fb49060f6712cb27602

Author: Anthony Liguori <[email protected]>
Date:   Fri Oct 30 16:44:26 2009 -0500
Quoted 7 lines
Quoted 3 lines

Update gpxe roms to have BANNER_TIMEOUT=0

I ran a complete & fresh mkbuilddir-configure-make-install cycle to exclude this. Moreover, the above change is actually not related to triggering the netboot but to wait for potential input of the user.

Quoted 8 lines

Right.

Quoted 2 lines

Looking closer: It's actually still pcbios that is used by my installation - shouldn't this be Seabios now?

My understanding is that Seabios should get more testing with qemu-kvm (other than the cpu hotplug debate). Gleb/Avi would know for sure.

There a couple of problem found recently in seabios. They will be fixed. I don't think we should wait with seabios switch in qemu-kvm.

Quoted 6 lines

Now whether pcbios option rom supports gpxe properly i don't know, maybe that is the root cause for the problem (yes, qemu-kvm loads gpxe and attempts to boot from the network first, the above commit only removes the annoying multi-second delay).

CC'ing people with some clue.

--
Gleb.