Re: [RFC PATCH 08/12] vfio/pci: Create host unaccessible dma-buf for private device

From: Jason Gunthorpe
Date: Wed Jan 08 2025 - 08:30:41 EST


On Tue, Jan 07, 2025 at 10:27:15PM +0800, Xu Yilun wrote:
> Add a flag for ioctl(VFIO_DEVICE_BIND_IOMMUFD) to mark a device as
> for private assignment. For these private assigned devices, disallow
> host accessing their MMIO resources.

Why? Shouldn't the VMM simply not call mmap? Why does the kernel have
to enforce this?

Jason