• Tom Lendacky's avatar
    x86/CPU/AMD: Clear RDRAND CPUID bit on AMD family 15h/16h · 4aa0f3b0
    Tom Lendacky authored
    commit c49a0a80 upstream.
    
    There have been reports of RDRAND issues after resuming from suspend on
    some AMD family 15h and family 16h systems. This issue stems from a BIOS
    not performing the proper steps during resume to ensure RDRAND continues
    to function properly.
    
    RDRAND support is indicated by CPUID Fn00000001_ECX[30]. This bit can be
    reset by clearing MSR C001_1004[62]. Any software that checks for RDRAND
    support using CPUID, including the kernel, will believe that RDRAND is
    not supported.
    
    Update the CPU initialization to clear the RDRAND CPUID bit for any family
    15h and 16h processor that supports RDRAND. If it is known that the family
    15h or family 16h system does not have an RDRAND resume issue or that the
    system will not be placed in suspend, the "rdrand=force" kernel parameter
    can be used to stop the clearing of the RDRAND CPUID bit.
    
    Additionally, update the suspend and resume path to save and restore the
    MSR C001_1004 value to ensure that the RDRAND CPUID setting remains in
    place after resuming from suspend.
    
    Note, that clearing the RDRAND CPUID bit does not prevent a processor
    that normally supports the RDRAND instruction from executing it. So any
    code that determined the support based on family and model won't #UD.
    Signed-off-by: default avatarTom Lendacky <thomas.lendacky@amd.com>
    Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
    Cc: Andrew Cooper <andrew.cooper3@citrix.com>
    Cc: Andrew Morton <akpm@linux-foundation.org>
    Cc: Chen Yu <yu.c.chen@intel.com>
    Cc: "H. Peter Anvin" <hpa@zytor.com>
    Cc: Ingo Molnar <mingo@redhat.com>
    Cc: Jonathan Corbet <corbet@lwn.net>
    Cc: Josh Poimboeuf <jpoimboe@redhat.com>
    Cc: Juergen Gross <jgross@suse.com>
    Cc: Kees Cook <keescook@chromium.org>
    Cc: "linux-doc@vger.kernel.org" <linux-doc@vger.kernel.org>
    Cc: "linux-pm@vger.kernel.org" <linux-pm@vger.kernel.org>
    Cc: Nathan Chancellor <natechancellor@gmail.com>
    Cc: Paolo Bonzini <pbonzini@redhat.com>
    Cc: Pavel Machek <pavel@ucw.cz>
    Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
    Cc: <stable@vger.kernel.org>
    Cc: Thomas Gleixner <tglx@linutronix.de>
    Cc: "x86@kernel.org" <x86@kernel.org>
    Link: https://lkml.kernel.org/r/7543af91666f491547bd86cebb1e17c66824ab9f.1566229943.git.thomas.lendacky@amd.comSigned-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
    4aa0f3b0
Name
Last commit
Last update
..
ABI Loading commit data...
EDID Loading commit data...
PCI Loading commit data...
RCU Loading commit data...
accelerators Loading commit data...
accounting Loading commit data...
acpi/dsd Loading commit data...
admin-guide Loading commit data...
aoe Loading commit data...
arm Loading commit data...
arm64 Loading commit data...
auxdisplay Loading commit data...
backlight Loading commit data...
block Loading commit data...
blockdev Loading commit data...
bpf Loading commit data...
bus-devices Loading commit data...
cdrom Loading commit data...
cgroup-v1 Loading commit data...
cma Loading commit data...
connector Loading commit data...
console Loading commit data...
core-api Loading commit data...
cpu-freq Loading commit data...
crypto Loading commit data...
dev-tools Loading commit data...
device-mapper Loading commit data...
devicetree Loading commit data...
doc-guide Loading commit data...
driver-api Loading commit data...
driver-model Loading commit data...
early-userspace Loading commit data...
extcon Loading commit data...
fault-injection Loading commit data...
fb Loading commit data...
features Loading commit data...
filesystems Loading commit data...
firmware-guide Loading commit data...
firmware_class Loading commit data...
fmc Loading commit data...
fpga Loading commit data...
gpio Loading commit data...
gpu Loading commit data...
hid Loading commit data...
hwmon Loading commit data...
i2c Loading commit data...
ia64 Loading commit data...
ide Loading commit data...
iio Loading commit data...
infiniband Loading commit data...
input Loading commit data...
interconnect Loading commit data...
ioctl Loading commit data...
isdn Loading commit data...
kbuild Loading commit data...
kdump Loading commit data...
kernel-hacking Loading commit data...
laptops Loading commit data...
leds Loading commit data...
lightnvm Loading commit data...
livepatch Loading commit data...
locking Loading commit data...
m68k Loading commit data...
maintainer Loading commit data...
md Loading commit data...
media Loading commit data...
memory-devices Loading commit data...
mic Loading commit data...
mips Loading commit data...
misc-devices Loading commit data...
mmc Loading commit data...
mtd Loading commit data...
namespaces Loading commit data...
netlabel Loading commit data...
networking Loading commit data...
nfc Loading commit data...
nios2 Loading commit data...
nvdimm Loading commit data...
nvmem Loading commit data...
openrisc Loading commit data...
parisc Loading commit data...
pcmcia Loading commit data...
perf Loading commit data...
phy Loading commit data...
platform Loading commit data...
power Loading commit data...
powerpc Loading commit data...
pps Loading commit data...
process Loading commit data...
pti Loading commit data...
ptp Loading commit data...
rapidio Loading commit data...
riscv Loading commit data...
s390 Loading commit data...
scheduler Loading commit data...
scsi Loading commit data...
security Loading commit data...
serial Loading commit data...
sh Loading commit data...
sound Loading commit data...
sparc Loading commit data...
sphinx Loading commit data...
sphinx-static Loading commit data...
spi Loading commit data...
sysctl Loading commit data...
target Loading commit data...
thermal Loading commit data...
timers Loading commit data...
trace Loading commit data...
translations Loading commit data...
usb Loading commit data...
userspace-api Loading commit data...
virtual Loading commit data...
vm Loading commit data...
w1 Loading commit data...
watchdog Loading commit data...
wimax Loading commit data...
x86 Loading commit data...
xilinx Loading commit data...
xtensa Loading commit data...
.gitignore Loading commit data...
Changes Loading commit data...
CodingStyle Loading commit data...
DMA-API-HOWTO.txt Loading commit data...
DMA-API.txt Loading commit data...
DMA-ISA-LPC.txt Loading commit data...
DMA-attributes.txt Loading commit data...
IPMI.txt Loading commit data...
IRQ-affinity.txt Loading commit data...
IRQ-domain.txt Loading commit data...
IRQ.txt Loading commit data...
Intel-IOMMU.txt Loading commit data...
Makefile Loading commit data...
SAK.txt Loading commit data...
SM501.txt Loading commit data...
SubmittingPatches Loading commit data...
atomic_bitops.txt Loading commit data...
atomic_t.txt Loading commit data...
bt8xxgpio.txt Loading commit data...
btmrvl.txt Loading commit data...
bus-virt-phys-mapping.txt Loading commit data...
clearing-warn-once.txt Loading commit data...
conf.py Loading commit data...
cpu-load.txt Loading commit data...
cputopology.txt Loading commit data...
crc32.txt Loading commit data...
dcdbas.txt Loading commit data...
debugging-modules.txt Loading commit data...
debugging-via-ohci1394.txt Loading commit data...
dell_rbu.txt Loading commit data...
digsig.txt Loading commit data...
docutils.conf Loading commit data...
dontdiff Loading commit data...
efi-stub.txt Loading commit data...
eisa.txt Loading commit data...
futex-requeue-pi.txt Loading commit data...
gcc-plugins.txt Loading commit data...
highuid.txt Loading commit data...
hw_random.txt Loading commit data...
hwspinlock.txt Loading commit data...
index.rst Loading commit data...
intel_txt.txt Loading commit data...
io-mapping.txt Loading commit data...
io_ordering.txt Loading commit data...
iostats.txt Loading commit data...
irqflags-tracing.txt Loading commit data...
isa.txt Loading commit data...
isapnp.txt Loading commit data...
kernel-per-CPU-kthreads.txt Loading commit data...
kobject.txt Loading commit data...
kprobes.txt Loading commit data...
kref.txt Loading commit data...
ldm.txt Loading commit data...
lockup-watchdogs.txt Loading commit data...
logo.gif Loading commit data...
logo.txt Loading commit data...
lsm.txt Loading commit data...
lzo.txt Loading commit data...
mailbox.txt Loading commit data...
memory-barriers.txt Loading commit data...
men-chameleon-bus.txt Loading commit data...
nommu-mmap.txt Loading commit data...
ntb.txt Loading commit data...
numastat.txt Loading commit data...
packing.txt Loading commit data...
padata.txt Loading commit data...
parport-lowlevel.txt Loading commit data...
percpu-rw-semaphore.txt Loading commit data...
phy.txt Loading commit data...
pi-futex.txt Loading commit data...
pnp.txt Loading commit data...
preempt-locking.txt Loading commit data...
pwm.txt Loading commit data...
rbtree.txt Loading commit data...
remoteproc.txt Loading commit data...
rfkill.txt Loading commit data...
robust-futex-ABI.txt Loading commit data...
robust-futexes.txt Loading commit data...
rpmsg.txt Loading commit data...
rtc.txt Loading commit data...
sgi-ioc4.txt Loading commit data...
siphash.txt Loading commit data...
smsc_ece1099.txt Loading commit data...
speculation.txt Loading commit data...
static-keys.txt Loading commit data...
svga.txt Loading commit data...
switchtec.txt Loading commit data...
sync_file.txt Loading commit data...
tee.txt Loading commit data...
this_cpu_ops.txt Loading commit data...
unaligned-memory-access.txt Loading commit data...
vfio-mediated-device.txt Loading commit data...
vfio.txt Loading commit data...
video-output.txt Loading commit data...
xillybus.txt Loading commit data...
xz.txt Loading commit data...
zorro.txt Loading commit data...