On Thu, Feb 16, 2023 at 08:14:50PM -0400, Jason Gunthorpe wrote:

On Tue, Feb 07, 2023 at 08:08:43PM +0800, Nanyong Sun wrote:

quoted

From: Rong Wang <redacted>

Once enable iommu domain for one device, the MSI
translation tables have to be there for software-managed MSI.
Otherwise, platform with software-managed MSI without an
irq bypass function, can not get a correct memory write event
from pcie, will not get irqs.
The solution is to obtain the MSI phy base address from
iommu reserved region, and set it to iommu MSI cookie,
then translation tables will be created while request irq.

Probably not what anyone wants to hear, but I would prefer we not add
more uses of this stuff. It looks like we have to get rid of
iommu_get_msi_cookie() :\

I'd like it if vdpa could move to iommufd not keep copying stuff from
it..

Absolutely but when is that happening?

Also the iommu_group_has_isolated_msi() check is missing on the vdpa
path, and it is missing the iommu ownership mechanism.

Also which in-tree VDPA driver that uses the iommu runs on ARM? Please
don't propose core changes for unmerged drivers. :(

Jason