Re: [RFC PATCH] qemu pci: pci_add_capability enhancement to prevent damaging config space

[Jan Kiszka <jan.kiszka@siemens.com>]

On 2012-06-08 16:56, Alex Williamson wrote:
> The difference between VFIO and kvm device assignment is that VFIO
> emulates a lot of config space for us, so most things are passed
> through.

That's not different from current device assignment, is it? I think the
major difference is that VFIO filters and potentially post-processes the
direct writes in kernel space.

>  MSI and MSIX are unique that we actually do want the qemu
> support for helping us to manage them.  So we're basically not telling
> qemu about anything other than these, and for the most part, that works
> since qemu never handles access to the other capabilities.  However, I
> think you're probably right, VFIO should just walk the capabilities
> list, registering each with qemu.  It's a little "unnecessary" overhead
> from the VFIO perspective, but it makes the VFIO device less unique.
> I'll work on adding this.  Thanks,

Great, thanks!
Jan

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