[PATCH v1 1/3] crashdump/x86: dump any kind of "System RAM"

[Dave Hansen]

On 3/23/21 3:01 AM, David Hildenbrand wrote:
> Traditionally, we had "System RAM" only on the top level of in the
> kernel resource tree (-> /proc/iomem). Nowadays, we can also have
> "System RAM" on lower levels of the tree -- driver-managed device memory
> that is always detected and added via drivers. Current examples are
> memory added via dax/kmem -- ("System RAM (kmem)") and virtio-mem ("System
> RAM (virtio_mem)"). Note that in some kernel versions "System RAM
> (kmem)" was exposed as "System RAM", but similarly, on lower levels of
> the resource tree.
> 
> Let's add anything that contains "System RAM" to the elf core header, so
> it will be dumped for kexec_load(). Handling kexec_file_load() in the
> kernel is similarly getting fixed [1].

Although I don't do a lot of hacking in the crashdump code, this seems
sane to me.  As the perpetrator of the "System RAM (kmem)" trick:

Acked-by: Dave Hansen <dave.hansen at linux.intel.com>