Re: [PATCH v11 17/17]add two new ioctls for mp device.

Michael S. Tsirkin
2010-09-28T13:09:28Z

On Mon, Sep 27, 2010 at 10:36:15PM +0100, Ben Hutchings wrote:
> On Sat, 2010-09-25 at 12:27 +0800, xiaohui.xin@intel.com wrote:
> > From: Xin Xiaohui <xiaohui.xin@intel.com>
> >
> > The patch add two ioctls for mp device.
> > One is for userspace to query how much memory locked to make mp device
> > run smoothly. Another one is for userspace to set how much meory locked
> > it really wants.
> [...]
> > diff --git a/include/linux/mpassthru.h b/include/linux/mpassthru.h
> > index ba8f320..083e9f7 100644
> > --- a/include/linux/mpassthru.h
> > +++ b/include/linux/mpassthru.h
> > @@ -7,6 +7,8 @@
> > /* ioctl defines */
> > #define MPASSTHRU_BINDDEV _IOW('M', 213, int)
> > #define MPASSTHRU_UNBINDDEV _IO('M', 214)
> > +#define MPASSTHRU_SET_MEM_LOCKED _IOW('M', 215, unsigned long)
> > +#define MPASSTHRU_GET_MEM_LOCKED_NEED _IOR('M', 216, unsigned long)
> [...]
>
> These will need compat handling. You can avoid that by defining them to
> use a parameter type of u32 or u64.
>
> Ben.

No need to introduce compat mess unless we have to. I guess int is
sufficient: locking >= 2G just for guest networking is insane.

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MST