Re: [RFC] /dev/ioasid uAPI proposal

Paolo Bonzini
2021-06-09T13:24:23Z

On 09/06/21 14:47, Jason Gunthorpe wrote:
> On Wed, Jun 09, 2021 at 02:46:05PM +0200, Paolo Bonzini wrote:
>> On 09/06/21 13:57, Jason Gunthorpe wrote:
>>> On Wed, Jun 09, 2021 at 02:49:32AM +0000, Tian, Kevin wrote:
>>>
>>>> Last unclosed open. Jason, you dislike symbol_get in this contract per
>>>> earlier comment. As Alex explained, looks it's more about module
>>>> dependency which is orthogonal to how this contract is designed. What
>>>> is your opinion now?
>>>
>>> Generally when you see symbol_get like this it suggests something is
>>> wrong in the layering..
>>>
>>> Why shouldn't kvm have a normal module dependency on drivers/iommu?
>>
>> It allows KVM to load even if there's an "install /bin/false" for vfio
>> (typically used together with the blacklist directive) in modprobe.conf.
>> This rationale should apply to iommu as well.
>
> I can vaugely understand this rational for vfio, but not at all for
> the platform's iommu driver, sorry.

Sorry, should apply to ioasid, not iommu (assuming that /dev/ioasid
support would be modular).

Paolo