[Xen-devel] [PATCHv4 0/8] kexec: extend kexec hypercall for use with pv-ops kernels

[Daniel Kiper]

On Thu, Apr 18, 2013 at 06:38:39PM +0100, David Vrabel wrote:
> On 17/04/13 13:34, Daniel Kiper wrote:
> >
> > kexec -e still does not work. I see in my console:
> >
> > I'm in purgatory
> > sha256 digests do not match :(
>
> I have now fixed this.  Xen was not probably zeroing out trailing pages
> (only partial pages) when loading a default image (crash was fine).

Idea is quite good but how many pages in percent are zero?
Is it worth to do that? Additionally, I am afraid that this
way you are only masking bug in kexec-tools. I think it
is better to do bisect on it and find out which patch
introduces a bug.

> The kernel does this by allocating and clearing pages and then
> relocating these as normal but it's wasteful to allocate a bunch of
> empty pages so I added a IND_ZERO entry type for the indirection pages
> which gets the relocation code to zero the destination.
>
> See the kexec-v5 branch at:
>
> http://xenbits.xen.org/gitweb/?p=people/dvrabel/xen.git;a=summary
>
> I shall repost this series again once the 4.4 development window is open.

Do you think that at this stage we are not able to introduce this
kexec implementation into 4.3? I think that we should try.

Daniel