linux_dsm_epyc7002/Documentation
Linus Torvalds eb094f0696 Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 TSX Async Abort and iTLB Multihit mitigations from Thomas Gleixner:
 "The performance deterioration departement is not proud at all of
  presenting the seventh installment of speculation mitigations and
  hardware misfeature workarounds:

   1) TSX Async Abort (TAA) - 'The Annoying Affair'

      TAA is a hardware vulnerability that allows unprivileged
      speculative access to data which is available in various CPU
      internal buffers by using asynchronous aborts within an Intel TSX
      transactional region.

      The mitigation depends on a microcode update providing a new MSR
      which allows to disable TSX in the CPU. CPUs which have no
      microcode update can be mitigated by disabling TSX in the BIOS if
      the BIOS provides a tunable.

      Newer CPUs will have a bit set which indicates that the CPU is not
      vulnerable, but the MSR to disable TSX will be available
      nevertheless as it is an architected MSR. That means the kernel
      provides the ability to disable TSX on the kernel command line,
      which is useful as TSX is a truly useful mechanism to accelerate
      side channel attacks of all sorts.

   2) iITLB Multihit (NX) - 'No eXcuses'

      iTLB Multihit is an erratum where some Intel processors may incur
      a machine check error, possibly resulting in an unrecoverable CPU
      lockup, when an instruction fetch hits multiple entries in the
      instruction TLB. This can occur when the page size is changed
      along with either the physical address or cache type. A malicious
      guest running on a virtualized system can exploit this erratum to
      perform a denial of service attack.

      The workaround is that KVM marks huge pages in the extended page
      tables as not executable (NX). If the guest attempts to execute in
      such a page, the page is broken down into 4k pages which are
      marked executable. The workaround comes with a mechanism to
      recover these shattered huge pages over time.

  Both issues come with full documentation in the hardware
  vulnerabilities section of the Linux kernel user's and administrator's
  guide.

  Thanks to all patch authors and reviewers who had the extraordinary
  priviledge to be exposed to this nuisance.

  Special thanks to Borislav Petkov for polishing the final TAA patch
  set and to Paolo Bonzini for shepherding the KVM iTLB workarounds and
  providing also the backports to stable kernels for those!"

* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/speculation/taa: Fix printing of TAA_MSG_SMT on IBRS_ALL CPUs
  Documentation: Add ITLB_MULTIHIT documentation
  kvm: x86: mmu: Recovery of shattered NX large pages
  kvm: Add helper function for creating VM worker threads
  kvm: mmu: ITLB_MULTIHIT mitigation
  cpu/speculation: Uninline and export CPU mitigations helpers
  x86/cpu: Add Tremont to the cpu vulnerability whitelist
  x86/bugs: Add ITLB_MULTIHIT bug infrastructure
  x86/tsx: Add config options to set tsx=on|off|auto
  x86/speculation/taa: Add documentation for TSX Async Abort
  x86/tsx: Add "auto" option to the tsx= cmdline parameter
  kvm/x86: Export MDS_NO=0 to guests when TSX is enabled
  x86/speculation/taa: Add sysfs reporting for TSX Async Abort
  x86/speculation/taa: Add mitigation for TSX Async Abort
  x86/cpu: Add a "tsx=" cmdline option with TSX disabled by default
  x86/cpu: Add a helper function x86_read_arch_cap_msr()
  x86/msr: Add the IA32_TSX_CTRL MSR
2019-11-12 10:53:24 -08:00
..
ABI x86/bugs: Add ITLB_MULTIHIT bug infrastructure 2019-11-04 12:22:01 +01:00
accounting
admin-guide Documentation: Add ITLB_MULTIHIT documentation 2019-11-04 20:26:00 +01:00
arm
arm64 arm64: apply ARM64_ERRATUM_843419 workaround for Brahma-B53 core 2019-11-01 10:47:37 +00:00
block
bpf
cdrom
core-api Modules fixes for v5.4-rc3 2019-10-11 10:19:24 -07:00
cpu-freq
crypto
dev-tools mm, page_owner: decouple freeing stack trace from debug_pagealloc 2019-10-14 15:04:00 -07:00
devicetree ARM: SoC fixes 2019-10-25 16:00:47 -04:00
doc-guide
driver-api
EDID
fault-injection
fb
features
filesystems add virtio-fs 2019-09-27 15:54:24 -07:00
firmware_class
firmware-guide
fpga
gpu
hid
hwmon hwmon: docs: Extend inspur-ipsps1 title underline 2019-10-07 05:56:57 -07:00
i2c
ia64
ide
iio
infiniband
input
ioctl
isdn
kbuild Modules fixes for v5.4-rc3 2019-10-11 10:19:24 -07:00
kernel-hacking
leds
livepatch
locking
m68k
maintainer
media
mic
mips Main MIPS changes for v5.4: 2019-09-22 09:30:30 -07:00
misc-devices
netlabel
networking Documentation: TLS: Add missing counter description 2019-11-05 18:34:06 -08:00
nios2
openrisc
parisc
PCI
pcmcia
power
powerpc
process Documentation/process: Add fallthrough pseudo-keyword 2019-10-11 09:26:05 -07:00
RCU
riscv
s390
scheduler
scsi
security Merge branch 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity 2019-09-27 19:37:27 -07:00
sh
sound
sparc
sphinx
sphinx-static
spi
target
timers
trace
translations
usb USB: rio500: Remove Rio 500 kernel driver 2019-10-04 10:53:36 +02:00
userspace-api
virt KVM/Hyper-V: Add new KVM capability KVM_CAP_HYPERV_DIRECT_TLBFLUSH 2019-09-24 13:37:13 +02:00
virtual
vm mm: treewide: clarify pgtable_page_{ctor,dtor}() naming 2019-09-26 10:10:44 -07:00
w1
watchdog linux-watchdog 5.4-rc1 tag 2019-09-27 11:17:38 -07:00
x86 x86/speculation/taa: Add documentation for TSX Async Abort 2019-10-28 08:37:00 +01:00
xtensa
.gitignore
atomic_bitops.txt
atomic_t.txt
bus-virt-phys-mapping.txt
Changes
CodingStyle
conf.py
COPYING-logo
crc32.txt
debugging-modules.txt
debugging-via-ohci1394.txt
digsig.txt
DMA-API-HOWTO.txt
DMA-API.txt
DMA-attributes.txt
DMA-ISA-LPC.txt
docutils.conf
dontdiff
futex-requeue-pi.txt
hwspinlock.txt
index.rst Main MIPS changes for v5.4: 2019-09-22 09:30:30 -07:00
io_ordering.txt
io-mapping.txt
IPMI.txt
IRQ-affinity.txt
IRQ-domain.txt
IRQ.txt
irqflags-tracing.txt
Kconfig
kobject.txt
kprobes.txt
kref.txt
logo.gif
lzo.txt
mailbox.txt
Makefile
memory-barriers.txt
nommu-mmap.txt
padata.txt
percpu-rw-semaphore.txt
pi-futex.txt
preempt-locking.txt
rbtree.txt
remoteproc.txt
robust-futex-ABI.txt
robust-futexes.txt
rpmsg.txt
speculation.txt
static-keys.txt
SubmittingPatches
tee.txt
this_cpu_ops.txt
unaligned-memory-access.txt
xz.txt