[pve-devel] [PATCH qemu-server 02/14] blockdev: cmdline: convert drive to blockdev syntax

[DERUMIER, Alexandre]

-------- Message initial --------
De: Fiona Ebner <f.ebner at proxmox.com>
À: "DERUMIER, Alexandre" <alexandre.derumier at groupe-cyllene.com>, pve-
devel at lists.proxmox.com <pve-devel at lists.proxmox.com>
Objet: Re: [pve-devel] [PATCH qemu-server 02/14] blockdev: cmdline:
convert drive to blockdev syntax
Date: 08/05/2025 13:21:06

Am 06.05.25 um 17:40 schrieb DERUMIER, Alexandre:
> > > Do we need to handle old client (for example, a pve8 doing a live
> > > migrate + lcoal storage migration  sending a nbd:// uri to a pve9
> > > with
> > > blockdev support ) ?
> 
> Thinking about this, maybe this is a good reason for version guard
> too.
> (so don't change from drive to blockdev during a live migration)
> 
> I don't have tested, but I don't think that efi disk can mirrored &&
> reattached from drive to blockdev, it's seem quite different and I'm
> pretty sure that it could have border effects.

>>The EFI disk is not attached via -drive, but via -pflash. I don't
>>think
>>we should change that, just keep attaching via -pflash. Or does
>>blockdev-mirror not work there? If we really need to change away from
>>-pflash, then yes, we'll need to version guard.

mmmm, from what is see, , efidisk && ovmf  , are currently attached
with -drive if=pflash

- drive 'if=pflash,unit=0,format=raw,readonly=on,file=/usr/share/pve-
edk2-firmware//OVMF_CODE.fd' \
-drive 'if=pflash,unit=1,id=drive-
efidisk0,format=raw,file=/var/lib/vz/images/100/vm-disk-100-
0.raw,size=131072' \


the blockdev part, are attached to -machine pflash0 && pflash1.


+  -blockdev '{"cache":{"direct":true,"no-
flush":false},"driver":"raw","file":{"cache":{"direct":true,"no-
flush":false},"discard":"ignore","driver":"file","filename":"/usr/share
/pve-edk2-firmware//OVMF_CODE.fd","node-name":"e-
WxbgqVgkl6KMmuyWKSKESesSKws"},"node-name":"f-
WxbgqVgkl6KMmuyWKSKESesSKws","read-only":true}' \
+  -blockdev '{"driver":"throttle","file":{"cache":{"direct":true,"no-
flush":false},"driver":"raw","file":{"cache":{"direct":true,"no-
flush":false},"discard":"ignore","driver":"file","filename":"/var/lib/v
z/images/100/vm-disk-100-0.raw","node-name":"e-
2lc6uRlbPUs6Si4A2GQOg0qicCW"},"node-name":"f-
2lc6uRlbPUs6Si4A2GQOg0qicCW","read-only":false},"node-name":"drive-
efidisk0","throttle-group":"throttle-drive-efidisk0"}' \
+  -machine 'pflash0=f-WxbgqVgkl6KMmuyWKSKESesSKws,pflash1=drive-
efidisk0,type=pc+pve1'


So, I think it's quite different internally.

(for example, they are an "size" option on drive not existing on
blockdev for example, I have wrote details on the patch 3/14.)