Re: [kvm-devel] [RFC] Stable kvm userspace interface

[Avi Kivity]

Jeff Garzik wrote:
> Arnd Bergmann wrote:
> > On Tuesday 09 January 2007 14:47, Jeff Garzik wrote:
> > > Can we please avoid adding a ton of new ioctls?  ioctls inevitably 
> > > require 64-bit compat code for certain architectures, whereas 
> > > sysfs/procfs does not.
> >
> > For performance reasons, an ascii string based interface is not
> > desireable here, some of these calls should be optimized to
> > the point of counting cycles.
>
> sysfs does not require ASCII...

The main kvm ioctl switches the execution mode to guest mode.  Just like 
a syscall enters kernel mode, ioctl(vcpu_fd, KVM_VCPU_RUN) enters the 
guest address space and begins executing guest code.

I don't see how to model that with sysfs.

There are other objections as well. sysfs is a public interface, whereas 
kvm is a process private attribute.  These objections don't apply to 
/proc though.


--
error compiling committee.c: too many arguments to function

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/