Re: [PATCH 1/3] proc/vmcore: Do not map unaccepted memory

[David Hildenbrand]

On 11.09.23 10:41, Kirill A. Shutemov wrote:
> On Mon, Sep 11, 2023 at 10:03:36AM +0200, David Hildenbrand wrote:
> > On 06.09.23 09:39, Adrian Hunter wrote:
> > > Support for unaccepted memory was added recently, refer commit
> > > dcdfdd40fa82 ("mm: Add support for unaccepted memory"), whereby
> > > a virtual machine may need to accept memory before it can be used.
> > >
> > > Do not map unaccepted memory because it can cause the guest to fail.
> > >
> > > For /proc/vmcore, which is read-only, this means a read or mmap of
> > > unaccepted memory will return zeros.
> >
> > Does a second (kdump) kernel that exposes /proc/vmcore reliably get access
> > to the information whether memory of the first kernel is unaccepted (IOW,
> > not its memory, but the memory of the first kernel it is supposed to expose
> > via /proc/vmcore)?
>
> There are few patches in my queue to few related issue, but generally,
> yes, the information is available to the target kernel via EFI
> configuration table.

I assume that table provided by the first kernel, and not read directly 
from HW, correct?

--
Cheers,

David / dhildenb