On Fri, 21 Sep 2018 18:14:43 +0100,
Jeffrey Hugo <jh...@codeaurora.org> wrote:
>
> On 9/21/2018 10:32 AM, Ard Biesheuvel wrote:
> > Add support for persistent memory reservations across kexec reboot on EFI
> > systems by introducing a Linux-specific UEFI configuration table that points
> > to a linked list in memory that can be augmented by each successive kexec
> > kernel to describe regions in memory that the subsequent kernel should treat
> > as reserved.
> >
> > The specific use case for this feature is GICv3 ARM systems that are not
> > able to disable DMA access to LPI tables, meaning we have to reserve them
> > and make the next kernel reuse the existing tables rather than allocating
> > them from scratch.
>
> As far as I recall, Shanker Donthineni attempted to address a similar
> (the same?) issue. I think we would be very interested, if that is
> the case.
Shanker's patches didn't solve the story of preserving the allocated
memory across kexec, and were just expecting to get similar mappings.
Ard's patches allow us to track the allocation, and to reuse those if
it is safe to do so.
> Is there another series that depends on these changes? If not, can
> you describe the plan for this?
I have a series which does exactly that[1], and that rely on Ard's
patches. I'm about to post these patches now the dependency is public.
Thanks,
M.
[1]
https://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms.git/log/?h=irq/gicv3-kdump
--
Jazz is not dead, it just smell funny.
