Subject: Re: remplacing page mappings behind uvm
To: None <>
From: YAMAMOTO Takashi <>
List: tech-kern
Date: 11/30/2007 21:08:39
> On Fri, Nov 30, 2007 at 12:31:06PM +0900, YAMAMOTO Takashi wrote:
> > > Although it'a gross hack, it works for Xeni386. It also works on Xenamd64,
> > > up to process exit: it triggers an assersion in pmap_destroy() because
> > > pmap_remove() is not called on the hacked memory ranges.
> > 
> > how about tweaking device pager instead of maintaining these hacks?
> I did look at this when I implemented these ioctls. It's not so easy.
> mmap() on devices will use offsets, but the physical pages are not contigous,
> yet xen wants them mapped as a contigous VM area. It can be done but would
> mean a driver more complex than the simple ioctl I have now,

isn't an array enough to convert offset -> machine address?

i'm not sure if it's a good idea to make vm deal with it
in order to simplify this very uncommon driver.

> and to maintain
> changes in qemu-dm too (or other hardware emulators when they show up in
> Xen). 

does qemu-dm work without modifications currently?