On Fri, Aug 03, 2018 at 10:58:36AM -0500, Benjamin Herrenschmidt wrote:
On Fri, 2018-08-03 at 00:05 -0700, Christoph Hellwig wrote:
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2- Make virtio use the DMA API with our custom platform-provided
swiotlb callbacks when needed, that is when not using IOMMU *and*
running on a secure VM in our case.
And total NAK the customer platform-provided part of this. We need
a flag passed in from the hypervisor that the device needs all bus
specific dma api treatment, and then just use the normal plaform
dma mapping setup.
Christoph, as I have explained already, we do NOT have a way to provide
such a flag as neither the hypervisor nor qemu knows anything about
this when the VM is created.
Well, if your setup is so fucked up I see no way to support it in Linux.
Let's end the discussion right now then.