lkml.org 
[lkml]   [2020]   [Feb]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [tip: x86/kdump] x86/kexec: Do not reserve EFI setup_data in the kexec e820 table
On 02/24/20 at 10:51am, tip-bot2 for Dave Young wrote:
> The following commit has been merged into the x86/kdump branch of tip:
>
> Commit-ID: 8efbc518b884e1db2dd6a6fce62d0112ab871dcf
> Gitweb: https://git.kernel.org/tip/8efbc518b884e1db2dd6a6fce62d0112ab871dcf
> Author: Dave Young <dyoung@redhat.com>
> AuthorDate: Wed, 12 Feb 2020 19:04:24 +08:00
> Committer: Borislav Petkov <bp@suse.de>
> CommitterDate: Mon, 24 Feb 2020 11:41:57 +01:00
>
> x86/kexec: Do not reserve EFI setup_data in the kexec e820 table
>
> The e820 table for the kexec kernel unconditionally marks setup_data as
> reserved because the second kernel can reuse setup_data passed by the
> 1st kernel's boot loader, for example SETUP_PCI marked regions like PCI
> BIOS, etc.
>
> SETUP_EFI types, however, are used by kexec itself to enable EFI in the
> 2nd kernel. Thus, it is pointless to add this type of setup_data to the
> kexec e820 table as reserved.
>
> IOW, what happens is this:
>
> - 1st physical boot: no SETUP_EFI.
>
> - kexec loads a new kernel and prepares a SETUP_EFI setup_data blob, then
> reboots the machine.
>
> - 2nd kernel sees SETUP_EFI, reserves it both in the e820 and in the
> kexec e820 table.
>
> - If another kexec load is executed, it prepares a new SETUP_EFI blob and
> then reboots the machine into the new kernel.
>
> 5. The 3rd kexec-ed kernel has two SETUP_EFI ranges reserved. And so on...
>
> Thus skip SETUP_EFI while reserving setup_data in the e820_table_kexec
> table because it is not needed.
>
> [ bp: Heavily massage commit message, shorten line and improve comment. ]

Boris, thanks for the amending and log massage.
I was hesitating to break the long line or not and then I choosed
leaving it as is. Both are not very good and either of them is fine to me.

Thanks
Dave

\
 
 \ /
  Last update: 2020-02-25 02:49    [W:0.104 / U:57.704 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site