linux/arch/x86/kernel/cpu
Thomas Gleixner 885f82bfbc x86/process: Allow runtime control of Speculative Store Bypass
The Speculative Store Bypass vulnerability can be mitigated with the
Reduced Data Speculation (RDS) feature. To allow finer grained control of
this eventually expensive mitigation a per task mitigation control is
required.

Add a new TIF_RDS flag and put it into the group of TIF flags which are
evaluated for mismatch in switch_to(). If these bits differ in the previous
and the next task, then the slow path function __switch_to_xtra() is
invoked. Implement the TIF_RDS dependent mitigation control in the slow
path.

If the prctl for controlling Speculative Store Bypass is disabled or no
task uses the prctl then there is no overhead in the switch_to() fast
path.

Update the KVM related speculation control functions to take TID_RDS into
account as well.

Based on a patch from Tim Chen. Completely rewritten.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2018-05-03 13:55:50 +02:00
..
mcheck Merge branch 'x86-timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-04-02 16:18:31 -07:00
microcode x86/microcode: Do not exit early from __reload_late() 2018-04-24 09:48:22 +02:00
mtrr x86/cpu: Rename cpu_data.x86_mask to cpu_data.x86_stepping 2018-02-15 01:15:52 +01:00
.gitignore
amd.c x86/speculation: Create spec-ctrl.h to avoid include hell 2018-05-03 13:55:50 +02:00
aperfmperf.c x86 / CPU: Always show current CPU frequency in /proc/cpuinfo 2017-11-15 19:46:50 +01:00
bugs.c x86/process: Allow runtime control of Speculative Store Bypass 2018-05-03 13:55:50 +02:00
centaur.c Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-02-14 17:02:15 -08:00
common.c x86/bugs/AMD: Add support to disable RDS on Fam[15,16,17]h if requested 2018-05-03 13:55:49 +02:00
cpu.h x86/bugs/intel: Set proper CPU features and setup RDS 2018-05-03 13:55:48 +02:00
cpuid-deps.c x86/cpuid: Switch to 'static const' specifier 2018-03-08 12:23:42 +01:00
cyrix.c x86/cpu: Rename cpu_data.x86_mask to cpu_data.x86_stepping 2018-02-15 01:15:52 +01:00
hypervisor.c x86/jailhouse: Add infrastructure for running in non-root cell 2018-01-14 21:11:54 +01:00
intel_cacheinfo.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
intel_pconfig.c x86/pconfig: Detect PCONFIG targets 2018-03-12 12:10:54 +01:00
intel_rdt_ctrlmondata.c x86/intel_rdt: Fix a silent failure when writing zero value schemata 2017-11-12 09:01:40 +01:00
intel_rdt_monitor.c x86/intel_rdt/cqm: Make integer rmid_limbo_count static 2017-10-05 13:20:32 +02:00
intel_rdt_rdtgroup.c x86/intel_rdt: Fix incorrect returned value when creating rdgroup sub-directory in resctrl file system 2018-02-23 08:03:21 +01:00
intel_rdt.c Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-02-14 17:02:15 -08:00
intel_rdt.h x86/intel_rdt: Enable L2 CDP in MSR IA32_L2_QOS_CFG 2018-01-18 09:33:31 +01:00
intel.c x86/bugs/intel: Set proper CPU features and setup RDS 2018-05-03 13:55:48 +02:00
Makefile x86/pconfig: Detect PCONFIG targets 2018-03-12 12:10:54 +01:00
match.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mkcapflags.sh License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mshyperv.c ARM: 2018-04-09 11:42:31 -07:00
perfctr-watchdog.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
powerflags.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
proc.c x86/cpu: Change type of x86_cache_size variable to unsigned int 2018-02-15 01:15:53 +01:00
rdrand.c
scattered.c Merge branch 'x86/hyperv' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-02-01 15:04:17 +01:00
topology.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
transmeta.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
umc.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
vmware.c x86/virt: Add enum for hypervisors to replace x86_hyper 2017-11-10 10:03:12 +01:00