Re: [PATCH] xen: add gntdev

[Roger Pau Monné <roger.pau%citrix.com@localhost>]

On 28/11/12 14:19, Roger Pau Monne wrote:
> This is a basic (and experimental) gntdev implementation for NetBSD.
> 
> The gnt device allows usermode applications to map grant references in
> userspace. It is mainly used by Qemu to implement a Xen backend (that
> runs in userspace).
> 
> Due to the fact that qemu-upstream is not yet functional in NetBSD,
> the only way to try this gntdev is to use the old qemu
> (qemu-traditional).
> 
> Performance is not that bad (given that we are using qemu-traditional
> and running a backend in userspace), the throughput of write
> operations is 64.7 MB/s, while in the Dom0 it is 104.6 MB/s. Regarding
> read operations, the throughput inside the DomU is 76.0 MB/s, while on
> the Dom0 it is 108.8 MB/s.

Independently of what we end up doing as default for handling raw file
disks, could someone review this code?

It's the first time I've done a device, so someone with more experience
should review it.

Thanks, Roger.