On Fri, Feb 03, 2023 at 09:33:44AM +0800, Baolu Lu wrote: > External email: Use caution opening links or attachments > > > On 2023/2/3 3:14, Nicolin Chen wrote: > > On Thu, Feb 02, 2023 at 06:21:20PM +0800, Baolu Lu wrote: > > > External email: Use caution opening links or attachments > > > > > > > > > On 2023/2/2 15:05, Nicolin Chen wrote: > > > > +/** > > > > + * iommu_group_replace_domain - replace the domain that a group is attached to > > > > + * @new_domain: new IOMMU domain to replace with > > > > + * @group: IOMMU group that will be attached to the new domain > > > > + * > > > > + * This API allows the group to switch domains without being forced to go to > > > > + * the blocking domain in-between. > > > > + * > > > > + * If the attached domain is a core domain (e.g. a default_domain), it will act > > > > + * just like the iommu_attach_group(). > > > I am not following above two lines. Why and how could iommufd set a > > > core domain to an iommu_group? > > Perhaps this isn't the best narrative. What it's supposed to say > > is that this function acts as an iommu_attach_group() call if the > > device is "detached", yet we have changed the semantics about the > > word "detach". So, what should the correct way to write such a > > note? > > How could this interface be used as detaching a domain from a group? > Even it could be used, doesn't it act as an iommu_detach_group()? No. I didn't say that. It doesn't act as detach(), but attach() when a device is already "detached". The original statement is saying, "if the attached domain is a core domain", i.e. the device is detach()-ed, "it will act just like the iommu_attach_group()". Thanks Nic
