Messages in this thread |  | | Date | Wed, 30 Sep 2020 19:38:57 -0300 | From | Jason Gunthorpe <> | Subject | Re: [PATCH v3 05/18] dmaengine: idxd: add IMS support in base driver |
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On Wed, Sep 30, 2020 at 02:49:41PM -0700, Raj, Ashok wrote:
> One of the parameters it has is the "supported system page-sizes" which is > usually there in the SRIOV properties. So it needed a place holder for > that.
No idea why this would be a PCI cap. It is certainly not something so universal it needs standardizing. There are many ways a device can manage a BAR to match a required protection granularity.
> When we provision an entire PCI device that is IMS capable. The guest > driver does know it can update the IMS entries directly without going to > the host. But in order to do remapping we need something like how we manage > PASID allocation from guest, so an IRTE entry can be allocated and the host > driver can write the proper values for IMS.
Look at the architecture we ended up with.
You need to make pci_subdevice_msi_create_irq_domain() fail if the platform can't provide the functionality.
Working around that with PCI caps is pretty gross.
Jason
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