Re: [libvirt] OVMF exposure in libvirt
On Mon, Jul 14, 2014 at 04:12:14PM +0200, Paolo Bonzini wrote:
Il 14/07/2014 11:27, Daniel P. Berrange ha scritto:
> -drive file=img_1,if=pflash,format=raw,readonly \
> -drive file=img_2,if=pflash,format=raw
It's safer to add ",unit=0" and ",unit=1" too.
Is there any compelling reason to make the unit numbers user
configurable. Are they guest ABI sensitive for example ?
If so, we're kind of screwed with <loader> because we can't
add a <address> sub-element to it as we do for ABI addressing
elsewhere.
>We already use <loader/> for specifying alternative BIOS
blobs for
>the QEMU -bios arg. Since you say this obsoletes the -bios arg, I
>think it makes sense to use <loader/> for the read-only firmware
>image.
It obsoletes the -bios argument, but it is not the same thing:
1) on some machines you can use "-drive if=pflash" for the nvram, but not
for the firmware
2) on some older versions of QEMU, "-drive if=pflash" will work only on TCG
or will not work at all so you cannot blindly replace it.
What about:
<loader readonly='on|off' type='rom|flash'>...</loader>
<nvram>...</nvram>
where the mapping from <nvram> to -drive if=flash is partly
machine-dependent. On x86, for example, <nvram> adds the ",unit=1"
sub-option and fails if the <loader> element is absent; it also fails if
<loader> has type='rom'.
That sounds reasonable to me.
>For the variable storage, I'd probably suggest <nvram/> as the
>element name, since IIUC that's a fairly commonly used term for
>this concept.
I like this.
Regards,
Daniel
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