Re: [Qemu-devel] [RFC v4 00/58] Memory API

[Michael S. Tsirkin]

On Wed, Jul 20, 2011 at 05:54:26PM +0300, Avi Kivity wrote:
> On 07/20/2011 05:37 PM, Michael S. Tsirkin wrote:
> >>
> >>  If you do a memory_region_set_log() immediately after
> >>  memory_region_init_ram(), then as soon as the framebuffer is added
> >>  to the memory hierarchy, it will have logging enabled (or any
> >>  aliases of the framebuffer).
> >
> >Still, I think we should specify logging on/off when region is created,
> >and avoid APIs that tweak dirty logging.
> 
> It's the same thing.
> 
> memory_region_init*();
> // we have a disconnected memory region
> memory_region_set_log();
> // still disconnected, now logged
> 
> I don't want memory_region_init() with 231 parameters.

Pass in a struct then?

> >I don't think there's actual need for device to enable/disable
> >logging.
> 
> Why not? migration does it,

Yes but that's not a device.

> and vga could do it if the vnc display
> is disconnected, or if the update rate is so high it can just assume
> all memory is dirty.

Yes, but it's not something *devices* should be doing.

> >What devices seem to need, instead, is enable/disable a region
> >through a back channel.
> 
> What do you mean?

At least for qxl, all it seems to do is enable/disable
logging when the region is enabled disabled.
I'm not sure I follow what does vmware do - something
similar only with a custom register instead of
the standard memory enable?


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