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

[Michael S. Tsirkin]

On Wed, Jul 20, 2011 at 05:32:54PM +0300, Avi Kivity wrote:
> On 07/20/2011 04:57 PM, Jan Kiszka wrote:
> >Something around dirty logging is still seriously borken: when I boot
> >with standard or cirrus vga, the screen is not properly updated in
> >logged modes.
> >
> 
> I don't see this here, will retest.
> 
> >I bet the reason is lacking semantics of
> >cpu_register_physical_memory_log(..., true), ie. the chance to register
> >a memory region with logging enabled. We need to explicitly enable it
> >now via memory_region_set_log, right? Is there any ordering issue to
> >expect, ie. when can I first call memory_region_set_log (as it issues
> >the start/stop client callbacks)?
> 
> There should be no ordering issue at all.
> 
> 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.
I don't think there's actual need for device to enable/disable
logging. What devices seem to need, instead, is enable/disable a region
through a back channel.


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