On 1/3/25 11:32, Jason Gunthorpe wrote:
On Thu, Feb 27, 2025 at 11:33:31AM +1100, Alexey Kardashevskiy wrote:
On 27/2/25 00:12, Jason Gunthorpe wrote:
On Wed, Feb 26, 2025 at 06:49:18PM +0800, Xu Yilun wrote:
E.g. I don't think VFIO driver would expect its MMIO access suddenly
failed without knowing what happened.
What do people expect to happen here anyhow? Do you still intend to
mmap any of the MMIO into the hypervisor? No, right? It is all locked
down?
This patchset expects it to be mmap'able as this is how MMIO gets mapped in
the NPT and SEV-SNP still works with that (and updates the RMPs on top), the
host os is not expected to access these though. TDX will handle this somehow
different. Thanks,
I'm expecting you'll wrap that in a FD,
A KVM memslot from VFIO's fd similar to gmemfd's fd, and skip VMA?
Doable but 1) creates a KVM->VFIO dependency to do gpa->hpa translation
2) is not necessary in the AMD case (although host-mmap of
guest-assigned private BAR is way too easy way of shooting yourself in
the foot).
> since iommufd will not be accessing MMIO through mmaps.
here I do not follow, why would iommufd care about MMIO? or it is about
p2p DMA? Thanks,
Jason
--
Alexey
