linux-kernel - Re: [PATCH v2 7/7] xen: tolerate ACPI NVS memory overlapping with Xen allocated memory

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <45a43d3c-35a5-49cd-a677-67fde3e5b56b@suse.com>
Date: Tue, 20 Aug 2024 12:23:41 +0200
From: Jan Beulich <jbeulich@...e.com>
To: Juergen Gross <jgross@...e.com>
Cc: Boris Ostrovsky <boris.ostrovsky@...cle.com>,
 Thomas Gleixner <tglx@...utronix.de>, Ingo Molnar <mingo@...hat.com>,
 Borislav Petkov <bp@...en8.de>, Dave Hansen <dave.hansen@...ux.intel.com>,
 "H. Peter Anvin" <hpa@...or.com>, xen-devel@...ts.xenproject.org,
 Marek Marczykowski-Górecki
 <marmarek@...isiblethingslab.com>, linux-kernel@...r.kernel.org,
 x86@...nel.org
Subject: Re: [PATCH v2 7/7] xen: tolerate ACPI NVS memory overlapping with Xen
 allocated memory

On 20.08.2024 10:20, Juergen Gross wrote:
> In order to minimize required special handling for running as Xen PV
> dom0, the memory layout is modified to match that of the host. This
> requires to have only RAM at the locations where Xen allocated memory
> is living. Unfortunately there seem to be some machines, where ACPI
> NVS is located at 64 MB, resulting in a conflict with the loaded
> kernel or the initial page tables built by Xen.
> 
> As ACPI NVS needs to be accessed by the kernel only for saving and
> restoring it across suspend operations, it can be relocated in the
> dom0's memory map by swapping it with unused RAM (this is possible
> via modification of the dom0 P2M map).

Shouldn't this paragraph be amended / re-written, as this was what made
me ask for what is now patch 6?

Jan