Re: [Qemu-devel] [RFC PATCH] vfio: VFIO Driver core framework

[Alex Williamson <alex.williamson@redhat.com>]

On Mon, 2011-11-14 at 13:54 -0700, Alex Williamson wrote:
> On Fri, 2011-11-11 at 18:14 -0600, Scott Wood wrote:
> > On 11/03/2011 03:12 PM, Alex Williamson wrote:
> > > +	int			(*get)(void *);
> > > +	void			(*put)(void *);
> > > +	ssize_t			(*read)(void *, char __user *,
> > > +					size_t, loff_t *);
> > > +	ssize_t			(*write)(void *, const char __user *,
> > > +					 size_t, loff_t *);
> > > +	long			(*ioctl)(void *, unsigned int, unsigned long);
> > > +	int			(*mmap)(void *, struct vm_area_struct *);
> > > +};
> > 
> > When defining an API, please do not omit parameter names.
> 
> ok
> 
> > Should specify what the driver is supposed to do with get/put -- I guess
> > not try to unbind when the count is nonzero?  Races could still lead the
> > unbinder to be blocked, but I guess it lets the driver know when it's
> > likely to succeed.
> 
> Right, for the pci bus driver, it's mainly for reference counting,
> including the module_get to prevent vfio-pci from being unloaded.  On
> the first get for a device, we also do a pci_enable() and pci_disable()
> on last put.  I'll try to clarify in the docs.

Looking at these again, I should just rename them to open/release.  That
matches the points when they're called.  I suspect I started with just
reference counting and it grew to more of a full blown open/release.
Thanks,

Alex