Re: [qvm86-devel] Re: [Qemu-devel] Open source qemu x86 accelerator module.

[Paul Brook]

On Sunday 03 April 2005 19:58, Herbert Poetzl wrote:
> > qvm86 is still in the early stages of development, so I provide no
> > guarantees about its reliability. It almost certainly has bugs which
> > could crash your machine or cause data corruption. Any assistance
> > identifying and fixing these bugs is welcomed ;-)
>
> is an ioctl interface really the best choice here?
> what about a new syscall instead?
>
> I know that might need some changes to qemu too, but
> I guess it might increase performance ...
> (i.e. lower overhead)

I'm fairly sure a syscall is not the right way to do this.

I guess there are other ways of communicating between kernel and userspace. 
However I don't know what these are, or if they would be suitable for qvm86.

Most of the shared information (eg. the guest RAM) is mapped directly into 
kernel space, so the ioctl is mainly just used as a signalling machanism.
An ioctl is a fairly simple way of doing this, and I'd be surprised if the 
ioctl overhead was significant.

Paul