No description
Find a file
Benjamin Herrenschmidt 7ed23e1bae powerpc: Disable HFSCR[TM] if TM is not supported
On Power8 & Power9 the early CPU inititialisation in __init_HFSCR()
turns on HFSCR[TM] (Hypervisor Facility Status and Control Register
[Transactional Memory]), but that doesn't take into account that TM
might be disabled by CPU features, or disabled by the kernel being built
with CONFIG_PPC_TRANSACTIONAL_MEM=n.

So later in boot, when we have setup the CPU features, clear HSCR[TM] if
the TM CPU feature has been disabled. We use CPU_FTR_TM_COMP to account
for the CONFIG_PPC_TRANSACTIONAL_MEM=n case.

Without this a KVM guest might try use TM, even if told not to, and
cause an oops in the host kernel. Typically the oops is seen in
__kvmppc_vcore_entry() and may or may not be fatal to the host, but is
always bad news.

In practice all shipping CPU revisions do support TM, and all host
kernels we are aware of build with TM support enabled, so no one should
actually be able to hit this in the wild.

Fixes: 2a3563b023 ("powerpc: Setup in HFSCR for POWER8")
Cc: stable@vger.kernel.org # v3.10+
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Tested-by: Sam Bobroff <sam.bobroff@au1.ibm.com>
[mpe: Rewrite change log with input from Sam, add Fixes/stable]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-03-28 19:52:37 +11:00
arch powerpc: Disable HFSCR[TM] if TM is not supported 2017-03-28 19:52:37 +11:00
block
certs
crypto
Documentation gcc-plugins: update architecture list in documentation 2017-03-21 22:20:05 +11:00
drivers cxl: Route eeh events to all slices for pci_channel_io_perm_failure state 2017-03-20 20:19:36 +11:00
firmware
fs NFS client fixes for 4.11 2017-03-17 14:16:22 -07:00
include Merge git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending 2017-03-19 18:06:31 -07:00
init
ipc
kernel Merge branch 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-03-18 08:33:44 -07:00
lib
mm mm/swap: don't BUG_ON() due to uninitialized swap slot cache 2017-03-19 19:00:47 -07:00
net NFS client fixes for 4.11 2017-03-17 14:16:22 -07:00
samples
scripts
security
sound
tools selftests/powerpc: Fix standalone powerpc build 2017-03-27 15:11:44 +11:00
usr
virt
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore
.mailmap
COPYING
CREDITS
Kbuild
Kconfig
MAINTAINERS
Makefile Linux 4.11-rc3 2017-03-19 19:09:39 -07:00
README

Linux kernel
============

This file was moved to Documentation/admin-guide/README.rst

Please notice that there are several guides for kernel developers and users.
These guides can be rendered in a number of formats, like HTML and PDF.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.