Re: [PATCH] kexec_core: Accept unaccepted kexec destination addresses

[Yan Zhao <yan.y.zhao@intel.com>]

On Tue, Dec 03, 2024 at 06:30:36PM +0800, Baoquan He wrote:
> On 12/03/24 at 06:06pm, Yan Zhao wrote:
> > On Mon, Dec 02, 2024 at 10:17:16PM +0800, Baoquan He wrote:
> > > On 11/29/24 at 01:52pm, Yan Zhao wrote:
> > > > On Thu, Nov 28, 2024 at 11:19:20PM +0800, Baoquan He wrote:
...
> > > Oh, I just said the opposite. I meant we could search according to the
> > > current unaccepted->bitmap to make sure the destination area definitely
> > > have been accepted. This is the best if doable, while I know it's not
> > > easy.
> > Well, this sounds like introducing a new constraint in addition to the current
> > checking of !kimage_is_destination_range() in locate_mem_hole_top_down() or
> > locate_mem_hole_bottom_up(). (powerpc also has a different implementation).
> > 
> > This could make the success unpredictable, depending on how many pages have
> > been accepted by the 1st kernel and the layout of the accepted pages(e.g.,
> > whether they are physically contiguous). The 1st kernel would also have no
> > reliable way to ensure success except by accepting all the guest pages.
> 
> Yeah, when I finished reading accept_memory code, this is the first idea
> which come up into my mind. If it can be made, it's the most ideal. When
> I tried to make a draft change, it does introduce a lot of code change and
> add very much complication and I just gave up.
> 
> Maybe this can be added to cover-letter too to tell this possible path we
> explored.
Ok.