Re: [PATCH v5 7/8] hisi_acc_vfio_pci: Add support for VFIO live migration

[Jason Gunthorpe]

On Mon, Feb 21, 2022 at 11:40:42AM +0000, Shameer Kolothum wrote:

> +	/*
> +	 * ACC VF dev BAR2 region consists of both functional register space
> +	 * and migration control register space. For migration to work, we
> +	 * need access to both. Hence, we map the entire BAR2 region here.
> +	 * But from a security point of view, we restrict access to the
> +	 * migration control space from Guest(Please see mmap/ioctl/read/write
> +	 * override functions).
> +	 *
> +	 * Also the HiSilicon ACC VF devices supported by this driver on
> +	 * HiSilicon hardware platforms are integrated end point devices
> +	 * and has no capability to perform PCIe P2P.

If that is the case why not implement the RUNNING_P2P as well as a
NOP?

Alex expressed concerned about proliferation of non-P2P devices as it
complicates qemu to support mixes

Jason