Re: [Qemu-devel] [PATCH 07/29] framebuffer: check memory_region_is_logging

[Paolo Bonzini <pbonzini@redhat.com>]

On 26/05/2015 10:02, Fam Zheng wrote:
> On Mon, 04/27 18:28, Paolo Bonzini wrote:
>> framebuffer.c expects DIRTY_MEMORY_VGA logging to be always on, but that
>> will not be the case soon.  Because framebuffer.c computes the memory
>> region on the fly for every update (with memory_region_find), it cannot
>> enable/disable logging by itself.
>>
>> Instead, always treat updates as invalidations if dirty logging is
>> not enabled, assuming that the board will enable logging on the
>> RAM region that includes the framebuffer.
>>
>> To simplify the code, replace memory_region_get_dirty with
>> memory_region_test_and_clear_dirty.  Then memory_region_reset_dirty
>> is only needed in the invalidate case.
> 
> The commit message seems out-of-date, but I think it's better to keep the v1
> hunks which skip memory_region_get_dirty if invalidate == true, otherwise use
> memory_region_test_and_clear_dirty.

Unfortunately that is wrong.  See the first paragraph of the commit
message: "because framebuffer.c computes the memory region on the fly
for every update (with memory_region_find), it cannot enable/disable
logging by itself".

Only the last paragraph of the commit message is out-of-date, and I will
remove it.

Paolo