On Tue, Sep 14, 2010 at 05:46:55PM +0200, Bernhard Kohl wrote:
> This patch was motivated by the following use case: In our system
> the VMs usually have 4 NICs, any combination of virtio-net-pci and
> pci-assign NIC devices. The VMs boot via gPXE preferably over the
> pci-assign devices.
>
> There is no way to make this working with a combination of the
> current options -net -pcidevice -device -optionrom -boot.
>
> With the parameter boot=off it is possible to avoid loading
> and using gPXE option ROMs either for old style "-net nic" or
> for "-device" NIC devices. So we can select which NIC is used
> for booting.
>
> A side effect of the boot=off parameter is that unneeded ROMs
> which might waste memory are not longer loaded. E.g. if you have
> 2 virtio-net-pci and 2 pci-assign NICs in sum 4 option ROMs are
> loaded and the virtio ROMs take precedence over the pci-assign
> ROMs. The BIOS uses the first gPXE ROM which it finds and only
> needs one of them even if there are more NICs of the same type.
>
> Without using the boot=on|off parameter the current behaviour
> does not change.
>
> Signed-off-by: Thomas Ostler<address@hidden>
> Signed-off-by: Bernhard Kohl<address@hidden>
I think this is useful, however:
- We have bit properties which handle parsing on/off
and other formats automatically. Please don't use string.
- boot is not a great property name for PCI: what
you actually do is disable option rom.
So maybe call it 'rom' or something like that?