RE: [patch 21/32] NTB/msi: Convert to msi_on_each_desc()

[Thomas Gleixner]

Kevin,

On Sun, Dec 12 2021 at 01:56, Kevin Tian wrote:
>> From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
>> All I can find is drivers/iommu/virtio-iommu.c but I can't find anything
>> vIR related there.
>
> Well, virtio-iommu is a para-virtualized vIOMMU implementations.
>
> In reality there are also fully emulated vIOMMU implementations (e.g.
> Qemu fully emulates Intel/AMD/ARM IOMMUs). In those configurations
> the IR logic in existing iommu drivers just apply:
>
> 	drivers/iommu/intel/irq_remapping.c
> 	drivers/iommu/amd/iommu.c

thanks for the explanation. So that's a full IOMMU emulation. I was more
expecting a paravirtualized lightweight one.

Thanks,

        tglx