From: "Lendacky, Thomas" <Thomas.Lendacky@amd.com>
To: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"x86@kernel.org" <x86@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
Dave Hansen <dave.hansen@linux.intel.com>,
Andy Lutomirski <luto@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Lianbo Jiang <lijiang@redhat.com>, Baoquan He <bhe@redhat.com>
Subject: [PATCH v3 0/2] x86: SME: Kexec/kdump memory loading fix
Date: Wed, 19 Jun 2019 18:40:55 +0000 [thread overview]
Message-ID: <cover.1560969363.git.thomas.lendacky@amd.com> (raw)
This series addresses an issue related to kexec/kdump when SME is active.
The SME support uses a workarea located after the end of the kernel to
perform "in-place" encryption of the kernel. When kexec/kdump is used, it
is possible that some other data used by kexec/kdump could be in this area
of memory which would cause the kexec/kdump of the kernel to fail.
Create a workarea section for use by SME in vmlinux.lds.S that is
positioned after "_end", so that the memory it occupies will be reclaimed
after its use during boot. Since it is part of the kernel image, there is
no worry now that kexec/kdump will place data in the SME workarea when
installing the kexec/kdump kernel. As part of this fix, clarify what
occupied kernel memory is reserved and what parts of the kernel memory are
discarded.
The following patches are included:
- Identify and document what parts of the kernel image are reserved
(saved) and what is discarded.
- Create a new section that lives outside of the kernel proper, so that it
will be reclaimed as available memory during boot, thus allowing it to
be used as a workarea by SME for kernel in-place encryption during early
boot..
This patch series is based on tip/master.
---
Changes from v2:
- Grammar fixes
- A more generic naming of the scratch/workarea section to indicate it
is not restricted to SME usage
Changes from v1:
- Clarify how and where the kernel sections/memory is reserved.
- Add an explicit symbol, __end_of_kernel_reserve, for reserving the
kernel memory rather than using __bss_stop.
Tom Lendacky (2):
x86/mm: Identify the end of the kernel area to be reserved
x86/mm: Create a workarea in the kernel for SME early encryption
arch/x86/include/asm/sections.h | 2 ++
arch/x86/kernel/setup.c | 8 ++++++-
arch/x86/kernel/vmlinux.lds.S | 34 +++++++++++++++++++++++++++++-
arch/x86/mm/mem_encrypt_identity.c | 22 +++++++++++++++++--
4 files changed, 62 insertions(+), 4 deletions(-)
--
2.17.1
next reply other threads:[~2019-06-19 18:41 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-19 18:40 Lendacky, Thomas [this message]
2019-06-19 18:40 ` [PATCH v3 1/2] x86/mm: Identify the end of the kernel area to be reserved Lendacky, Thomas
2019-06-20 9:58 ` [tip:x86/kdump] " tip-bot for Thomas Lendacky
2019-07-13 14:59 ` [PATCH v3 1/2] " Mike Lothian
2019-07-14 10:16 ` Thomas Gleixner
2019-07-14 10:27 ` Mike Lothian
2019-07-15 8:12 ` Thomas Gleixner
[not found] ` <CAHbf0-F9yUDJ=DKug+MZqsjW+zPgwWaLUC40BLOsr5+t4kYOLQ@mail.gmail.com>
2019-07-15 9:25 ` Thomas Gleixner
2019-07-15 10:35 ` Thomas Gleixner
2019-07-15 20:16 ` H.J. Lu
2019-07-23 13:05 ` Greg KH
2019-07-23 13:31 ` Thomas Gleixner
2019-07-23 13:44 ` Greg KH
2019-07-24 15:34 ` Greg KH
2019-07-24 15:49 ` Thomas Gleixner
2019-07-24 15:57 ` Greg KH
2019-07-24 16:03 ` Thomas Gleixner
2019-07-24 16:16 ` Greg KH
2019-07-24 20:02 ` Thomas Gleixner
2019-07-24 20:20 ` Thomas Gleixner
2019-07-25 6:24 ` Greg KH
2019-08-14 11:09 ` Mike Lothian
2019-08-19 12:53 ` Mike Lothian
2019-08-19 13:08 ` Thomas Gleixner
2019-08-19 13:21 ` Mike Lothian
2019-08-19 13:31 ` Thomas Gleixner
2019-08-20 12:46 ` Mike Lothian
2019-07-24 16:22 ` Peter Zijlstra
2019-07-24 16:01 ` Thomas Gleixner
2019-07-23 13:43 ` Greg KH
2019-06-19 18:40 ` [PATCH v3 2/2] x86/mm: Create a workarea in the kernel for SME early encryption Lendacky, Thomas
2019-06-20 9:58 ` [tip:x86/kdump] " tip-bot for Thomas Lendacky
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