Anthony Liguori wrote:
Sebastian Herbszt wrote:
Anthony Liguori wrote:
Michael S. Tsirkin wrote:
Further, we should error out when device is added.
Doing this during boot is way too late, management
won't be able to understand such errors and
won't be able to recover.
I don't quite understand this.
In 0.11, we never loaded option roms unless a user specified -boot
n. If a user specified -boot n and used more than one nic type, I'm
fairly certain it would error out during start up because it would
run out of option rom space. Maybe it required three types of nics,
but the point still remains.
I think it used to be possible to have two different nic types and
only load
one rom, e.g. -net nic,model=pcnet -net nic,model=e1000 -option-rom
e1000.rom
Then use the boot menu to select the e1000 nic.
That's a super hack :-) The fact that works is pure luck.
Super hack? Maybe. Pure luck - no. Even if, it's still a regression if that's no
longer possible.
In 0.12, we always load the option rom for a PCI device. An easy
solution here would be to just gracefully handle the case where we
ran out of option rom space and (silently) stop loading additional
roms. With respect to -boot n, it makes the behavior buggy (you
cannot boot from the second nic) but my original point is that that
is not a regression from 0.11.
Even if i repeat myself [1] i suggest putting an option-rom loading
flag to the -net option:
-net nic,model=e1000,rom=[on,off,e1000.bin]
Well it ought to be a qdev property and it ought to be applicable to
every PCI device.
And ISA too.
For 0.13, we should probably allow a user to suppress option rom
loading for a given PCI device. The limited space is a pretty good
justification for that.
The default behaviour should be not loading option-roms; users should
request those.
I disagree. A user should not have to decide whether they want PXE boot
or not when they create a VM. The less decisions a user has to make up
front the easier qemu is to use.
If i want PXE boot on my computer, i have to enter the BIOS and enable it.
If qemu starts to automagically enable stuff people might want to use, some
people will end up with long command lines just to disable it again.
- Sebastian
