[libvirt] [PATCH v5 02/16] qemu: Introduce qemuDomainDeviceDefValidateControllerAttributes

John Ferlan jferlan at redhat.com
Mon Jan 29 17:43:14 UTC 2018

On 01/29/2018 04:18 AM, Ján Tomko wrote:
> On Fri, Jan 05, 2018 at 06:47:25PM -0500, John Ferlan wrote:
>> Move the checks that various attributes are not set on any controller
>> other than SCSI controller using virtio-scsi model into the common
>> controller validate checks.
>> Need to also add a qemuDomainResetSCSIControllerModel call in order
>> to ensure we get the "right" SCSI model if it's not set by default
>> since it wouldn't be set during post parse processing.
> So we should set it in post-parse processing once instead of adding this
> second call.
> Jan

This is a point you raised in v3:


to which I responded:


and even carried into my v4:


So, now that we're here again - the question becomes, do we really want
post parse processing to set a default model if it's not set? Should
that be part of this series? Should it be a followup? Should be
something done before this one and then rework this one?

Are there drawbacks to doing so?  One drawback that I kept coming back
to is that LSI becomes the default qemu model instead of VIRTIO-SCSI
(it's the order of setting *model in qemuDomainSetSCSIControllerModel).
That drawback caused problems when setting the model if we create a new
SCSI controller during something like hotplug because we had already
filled the current controller or when adding one VIRTIO-SCSI controller
but more than 7 disks (or hostdevs) that end up using that controller.
Although I think that's at least partially resolved by other changes
I've already made.

Tks -


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