Re: [Qemu-devel] [RFC][PATCH] File-backed memory maps

[Anthony Liguori <anthony@codemonkey.ws>]

Nathan Baum wrote:
> I'm mainly interested in the idea of moving the VNC server into its own
> process. It would listen for connections as usual and then send
> framebuffer updates from the file. Doing that also requires a
> side-channel for communicating graphics mode updates and peripheral
> input between QEMU and the VNC server. (Something like "-mouse
> <char-dev-spec> -keyboard <char-dev-spec>", perhaps?)
>   

I think the preferred way to do this would be to introduce a shared 
memory encoding to VNC.  You could then implement or whatever as a VNC 
client that used this shared memory transport.

You can't always share VGA remote because sometimes it's in planar 
mode.  However, in the cases where memory is proper ram, you could 
potentially share that memory directly resulting in zero copies.

I think the ideal thing to do would be to share a file descriptor that 
was mmap()'able.  Sharing sys v IPC keys is also a possibility and would 
better integrate with XShmImage.

Regards,

Anthony Liguori