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From: Matt Fleming <matt@codeblueprint.co.uk>
To: Ingo Molnar <mingo@kernel.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	"H . Peter Anvin" <hpa@zytor.com>
Cc: Toshi Kani <toshi.kani@hp.com>,
	Matt Fleming <matt@codeblueprint.co.uk>,
	linux-kernel@vger.kernel.org, linux-efi@vger.kernel.org,
	Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Dave Jones <davej@codemonkey.org.uk>,
	Andrew Morton <akpm@linux-foundation.org>,
	Andy Lutomirski <luto@kernel.org>,
	Denys Vlasenko <dvlasenk@redhat.com>,
	Stephen Smalley <sds@tycho.nsa.gov>, Borislav Petkov <bp@suse.de>
Subject: [PATCH v4 6/6] Documentation/x86: Update EFI memory region description
Date: Fri, 27 Nov 2015 21:09:35 +0000
Message-ID: <1448658575-17029-7-git-send-email-matt@codeblueprint.co.uk> (raw)
In-Reply-To: <1448658575-17029-1-git-send-email-matt@codeblueprint.co.uk>

Make it clear that the EFI page tables are only available during EFI
runtime calls since that subject has come up a fair numbers of times
in the past.

Additionally, add the EFI region start and end addresses to the table
so that it's possible to see at a glance where they fall in relation
to other regions.

Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Dave Jones <davej@codemonkey.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Denys Vlasenko <dvlasenk@redhat.com>,
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
---
 Documentation/x86/x86_64/mm.txt | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/Documentation/x86/x86_64/mm.txt b/Documentation/x86/x86_64/mm.txt
index 05712ac83e38..c518dce7da4d 100644
--- a/Documentation/x86/x86_64/mm.txt
+++ b/Documentation/x86/x86_64/mm.txt
@@ -16,6 +16,8 @@ ffffec0000000000 - fffffc0000000000 (=44 bits) kasan shadow memory (16TB)
 ... unused hole ...
 ffffff0000000000 - ffffff7fffffffff (=39 bits) %esp fixup stacks
 ... unused hole ...
+ffffffef00000000 - ffffffff00000000 (=64 GB) EFI region mapping space
+... unused hole ...
 ffffffff80000000 - ffffffffa0000000 (=512 MB)  kernel text mapping, from phys 0
 ffffffffa0000000 - ffffffffff5fffff (=1525 MB) module mapping space
 ffffffffff600000 - ffffffffffdfffff (=8 MB) vsyscalls
@@ -32,11 +34,9 @@ reference.
 Current X86-64 implementations only support 40 bits of address space,
 but we support up to 46 bits. This expands into MBZ space in the page tables.
 
-->trampoline_pgd:
-
-We map EFI runtime services in the aforementioned PGD in the virtual
-range of 64Gb (arbitrarily set, can be raised if needed)
-
-0xffffffef00000000 - 0xffffffff00000000
+We map EFI runtime services in the 'efi_pgd' PGD in a 64Gb large virtual
+memory window (this size is arbitrary, it can be raised later if needed).
+The mappings are not part of any other kernel PGD and are only available
+during EFI runtime calls.
 
 -Andi Kleen, Jul 2004
-- 
2.6.2

  parent reply index

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-11-27 21:09 [GIT PULL v4 0/6] EFI page table isolation Matt Fleming
2015-11-27 21:09 ` [PATCH v4 1/6] x86: Page align _end to avoid pfn conversion bugs Matt Fleming
2015-11-27 21:09 ` [PATCH v4 2/6] x86/mm/pageattr: Ensure cpa->pfn only contains page frame numbers Matt Fleming
     [not found] ` <1448658575-17029-1-git-send-email-matt-mF/unelCI9GS6iBeEJttW/XRex20P6io@public.gmane.org>
2015-11-27 21:09   ` [PATCH v4 3/6] x86/efi: Map RAM into the identity page table for mixed mode Matt Fleming
2015-11-27 21:09   ` [PATCH v4 4/6] x86/efi: Hoist page table switching code into efi_call_virt() Matt Fleming
2015-11-27 21:09 ` [PATCH v4 5/6] x86/efi: Build our own page table structures Matt Fleming
2015-11-27 21:09 ` Matt Fleming [this message]
2015-11-29  8:18 ` [GIT PULL v4 0/6] EFI page table isolation Ingo Molnar

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