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