Several recent exploits have used direct calls to the native_write_cr4()
function to disable SMEP and SMAP before then continuing their exploits
using userspace memory access.
Direct calls of this form can be mitigate by pinning bits of CR4 so that
they cannot be changed through a common function. This is not intended to
be a general ROP protection (which would require CFI to defend against
properly), but rather a way to avoid trivial direct function calling (or
CFI bypasses via a matching function prototype) as seen in:
https://googleprojectzero.blogspot.com/2017/05/exploiting-linux-kernel-via-packet.html
(https://github.com/xairy/kernel-exploits/tree/master/CVE-2017-7308)
The goals of this change:
- Pin specific bits (SMEP, SMAP, and UMIP) when writing CR4.
- Avoid setting the bits too early (they must become pinned only after
CPU feature detection and selection has finished).
- Pinning mask needs to be read-only during normal runtime.
- Pinning needs to be checked after write to validate the cr4 state
Using __ro_after_init on the mask is done so it can't be first disabled
with a malicious write.
Since these bits are global state (once established by the boot CPU and
kernel boot parameters), they are safe to write to secondary CPUs before
those CPUs have finished feature detection. As such, the bits are set at
the first cr4 write, so that cr4 write bugs can be detected (instead of
silently papered over). This uses a few bytes less storage of a location we
don't have: read-only per-CPU data.
A check is performed after the register write because an attack could just
skip directly to the register write. Such a direct jump is possible because
of how this function may be built by the compiler (especially due to the
removal of frame pointers) where it doesn't add a stack frame (function
exit may only be a retq without pops) which is sufficient for trivial
exploitation like in the timer overwrites mentioned above).
The asm argument constraints gain the "+" modifier to convince the compiler
that it shouldn't make ordering assumptions about the arguments or memory,
and treat them as changed.
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: kernel-hardening@lists.openwall.com
Link: https://lkml.kernel.org/r/20190618045503.39105-3-keescook@chromium.org
The kernel needs to explicitly enable FSGSBASE. So, the application needs
to know if it can safely use these instructions. Just looking at the CPUID
bit is not enough because it may be running in a kernel that does not
enable the instructions.
One way for the application would be to just try and catch the SIGILL.
But that is difficult to do in libraries which may not want to overwrite
the signal handlers of the main application.
Enumerate the enabled FSGSBASE capability in bit 1 of AT_HWCAP2 in the ELF
aux vector. AT_HWCAP2 is already used by PPC for similar purposes.
The application can access it open coded or by using the getauxval()
function in newer versions of glibc.
[ tglx: Massaged changelog ]
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Ravi Shankar <ravi.v.shankar@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Link: https://lkml.kernel.org/r/1557309753-24073-18-git-send-email-chang.seok.bae@intel.com
Add cpu feature conditional FSGSBASE access to the relevant helper
functions. That allows to accelerate certain FS/GS base operations in
subsequent changes.
Note, that while possible, the user space entry/exit GSBASE operations are
not going to use the new FSGSBASE instructions. The reason is that it would
require additional storage for the user space value which adds more
complexity to the low level code and experiments have shown marginal
benefit. This may be revisited later but for now the SWAPGS based handling
in the entry code is preserved except for the paranoid entry/exit code.
To preserve the SWAPGS entry mechanism introduce __[rd|wr]gsbase_inactive()
helpers. Note, for Xen PV, paravirt hooks can be added later as they might
allow a very efficient but different implementation.
[ tglx: Massaged changelog ]
Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ravi Shankar <ravi.v.shankar@intel.com>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Link: https://lkml.kernel.org/r/1557309753-24073-7-git-send-email-chang.seok.bae@intel.com
Pull still more SPDX updates from Greg KH:
"Another round of SPDX updates for 5.2-rc6
Here is what I am guessing is going to be the last "big" SPDX update
for 5.2. It contains all of the remaining GPLv2 and GPLv2+ updates
that were "easy" to determine by pattern matching. The ones after this
are going to be a bit more difficult and the people on the spdx list
will be discussing them on a case-by-case basis now.
Another 5000+ files are fixed up, so our overall totals are:
Files checked: 64545
Files with SPDX: 45529
Compared to the 5.1 kernel which was:
Files checked: 63848
Files with SPDX: 22576
This is a huge improvement.
Also, we deleted another 20000 lines of boilerplate license crud,
always nice to see in a diffstat"
* tag 'spdx-5.2-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/spdx: (65 commits)
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 507
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 506
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 505
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 504
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 503
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 502
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 501
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 499
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 498
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 497
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 496
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 495
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 491
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 490
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 489
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 488
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 487
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 486
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 485
...
This cleanly handles arches who do not yet define clone3.
clone3() was initially placed under __ARCH_WANT_SYS_CLONE under the
assumption that this would cleanly handle all architectures. It does
not.
Architectures such as nios2 or h8300 simply take the asm-generic syscall
definitions and generate their syscall table from it. Since they don't
define __ARCH_WANT_SYS_CLONE the build would fail complaining about
sys_clone3 missing. The reason this doesn't happen for legacy clone is
that nios2 and h8300 provide assembly stubs for sys_clone. This seems to
be done for architectural reasons.
The build failures for nios2 and h8300 were caught int -next luckily.
The solution is to define __ARCH_WANT_SYS_CLONE3 that architectures can
add. Additionally, we need a cond_syscall(clone3) for architectures such
as nios2 or h8300 that generate their syscall table in the way I
explained above.
Fixes: 8f3220a806 ("arch: wire-up clone3() syscall")
Signed-off-by: Christian Brauner <christian@brauner.io>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Kees Cook <keescook@chromium.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Adrian Reber <adrian@lisas.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: linux-api@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: x86@kernel.org
Pull kvm fixes from Paolo Bonzini:
"Fixes for ARM and x86, plus selftest patches and nicer structs for
nested state save/restore"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: nVMX: reorganize initial steps of vmx_set_nested_state
KVM: arm/arm64: Fix emulated ptimer irq injection
tests: kvm: Check for a kernel warning
kvm: tests: Sort tests in the Makefile alphabetically
KVM: x86/mmu: Allocate PAE root array when using SVM's 32-bit NPT
KVM: x86: Modify struct kvm_nested_state to have explicit fields for data
KVM: fix typo in documentation
KVM: nVMX: use correct clean fields when copying from eVMCS
KVM: arm/arm64: vgic: Fix kvm_device leak in vgic_its_destroy
KVM: arm64: Filter out invalid core register IDs in KVM_GET_REG_LIST
KVM: arm64: Implement vq_present() as a macro
Based on 2 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation #
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 4122 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Improve the KVM_{GET,SET}_NESTED_STATE structs by detailing the format
of VMX nested state data in a struct.
In order to avoid changing the ioctl values of
KVM_{GET,SET}_NESTED_STATE, there is a need to preserve
sizeof(struct kvm_nested_state). This is done by defining the data
struct as "data.vmx[0]". It was the most elegant way I found to
preserve struct size while still keeping struct readable and easy to
maintain. It does have a misfortunate side-effect that now it has to be
accessed as "data.vmx[0]" rather than just "data.vmx".
Because we are already modifying these structs, I also modified the
following:
* Define the "format" field values as macros.
* Rename vmcs_pa to vmcs12_pa for better readability.
Signed-off-by: Liran Alon <liran.alon@oracle.com>
[Remove SVM stubs, add KVM_STATE_NESTED_VMX_VMCS12_SIZE. - Paolo]
Reviewed-by: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Per commit 1b6269db3f ("KVM: VMX: Handle NMIs before enabling
interrupts and preemption"), NMIs are handled directly in vmx_vcpu_run()
to "make sure we handle NMI on the current cpu, and that we don't
service maskable interrupts before non-maskable ones". The other
exceptions handled by complete_atomic_exit(), e.g. async #PF and #MC,
have similar requirements, and are located there to avoid extra VMREADs
since VMX bins hardware exceptions and NMIs into a single exit reason.
Clean up the code and eliminate the vaguely named complete_atomic_exit()
by moving the interrupts-disabled exception and NMI handling into the
existing handle_external_intrs() callback, and rename the callback to
a more appropriate name. Rename VMexit handlers throughout so that the
atomic and non-atomic counterparts have similar names.
In addition to improving code readability, this also ensures the NMI
handler is run with the host's debug registers loaded in the unlikely
event that the user is debugging NMIs. Accuracy of the last_guest_tsc
field is also improved when handling NMIs (and #MCs) as the handler
will run after updating said field.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
[Naming cleanups. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Make it available to AMD hosts as well, just in case someone is trying
to use an Intel processor's CPUID setup.
Suggested-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add an MSRs which allows the guest to disable
host polling (specifically the cpuidle-haltpoll,
when performing polling in the guest, disables
host side polling).
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Nadav reported that since the this_cpu_*() ops got asm-volatile
constraints on, code generation suffered for do_IRQ(), but since this
is all with IRQs disabled we can use __this_cpu_*().
smp_x86_platform_ipi 234 222 -12,+0
smp_kvm_posted_intr_ipi 74 66 -8,+0
smp_kvm_posted_intr_wakeup_ipi 86 78 -8,+0
smp_apic_timer_interrupt 292 284 -8,+0
smp_kvm_posted_intr_nested_ipi 74 66 -8,+0
do_IRQ 195 187 -8,+0
Reported-by: Nadav Amit <nadav.amit@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Recent probing at the Linux Kernel Memory Model uncovered a
'surprise'. Strongly ordered architectures where the atomic RmW
primitive implies full memory ordering and
smp_mb__{before,after}_atomic() are a simple barrier() (such as x86)
fail for:
*x = 1;
atomic_inc(u);
smp_mb__after_atomic();
r0 = *y;
Because, while the atomic_inc() implies memory order, it
(surprisingly) does not provide a compiler barrier. This then allows
the compiler to re-order like so:
atomic_inc(u);
*x = 1;
smp_mb__after_atomic();
r0 = *y;
Which the CPU is then allowed to re-order (under TSO rules) like:
atomic_inc(u);
r0 = *y;
*x = 1;
And this very much was not intended. Therefore strengthen the atomic
RmW ops to include a compiler barrier.
NOTE: atomic_{or,and,xor} and the bitops already had the compiler
barrier.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Currently, the jump label of a static key is transformed via the arch
specific function:
void arch_jump_label_transform(struct jump_entry *entry,
enum jump_label_type type)
The new approach (batch mode) uses two arch functions, the first has the
same arguments of the arch_jump_label_transform(), and is the function:
bool arch_jump_label_transform_queue(struct jump_entry *entry,
enum jump_label_type type)
Rather than transforming the code, it adds the jump_entry in a queue of
entries to be updated. This functions returns true in the case of a
successful enqueue of an entry. If it returns false, the caller must to
apply the queue and then try to queue again, for instance, because the
queue is full.
This function expects the caller to sort the entries by the address before
enqueueuing then. This is already done by the arch independent code, though.
After queuing all jump_entries, the function:
void arch_jump_label_transform_apply(void)
Applies the changes in the queue.
Signed-off-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Chris von Recklinghausen <crecklin@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Scott Wood <swood@redhat.com>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/57b4caa654bad7e3b066301c9a9ae233dea065b5.1560325897.git.bristot@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Currently, the patch of an address is done in three steps:
-- Pseudo-code #1 - Current implementation ---
1) add an int3 trap to the address that will be patched
sync cores (send IPI to all other CPUs)
2) update all but the first byte of the patched range
sync cores (send IPI to all other CPUs)
3) replace the first byte (int3) by the first byte of replacing opcode
sync cores (send IPI to all other CPUs)
-- Pseudo-code #1 ---
When a static key has more than one entry, these steps are called once for
each entry. The number of IPIs then is linear with regard to the number 'n' of
entries of a key: O(n*3), which is O(n).
This algorithm works fine for the update of a single key. But we think
it is possible to optimize the case in which a static key has more than
one entry. For instance, the sched_schedstats jump label has 56 entries
in my (updated) fedora kernel, resulting in 168 IPIs for each CPU in
which the thread that is enabling the key is _not_ running.
With this patch, rather than receiving a single patch to be processed, a vector
of patches is passed, enabling the rewrite of the pseudo-code #1 in this
way:
-- Pseudo-code #2 - This patch ---
1) for each patch in the vector:
add an int3 trap to the address that will be patched
sync cores (send IPI to all other CPUs)
2) for each patch in the vector:
update all but the first byte of the patched range
sync cores (send IPI to all other CPUs)
3) for each patch in the vector:
replace the first byte (int3) by the first byte of replacing opcode
sync cores (send IPI to all other CPUs)
-- Pseudo-code #2 - This patch ---
Doing the update in this way, the number of IPI becomes O(3) with regard
to the number of keys, which is O(1).
The batch mode is done with the function text_poke_bp_batch(), that receives
two arguments: a vector of "struct text_to_poke", and the number of entries
in the vector.
The vector must be sorted by the addr field of the text_to_poke structure,
enabling the binary search of a handler in the poke_int3_handler function
(a fast path).
Signed-off-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Chris von Recklinghausen <crecklin@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Scott Wood <swood@redhat.com>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/ca506ed52584c80f64de23f6f55ca288e5d079de.1560325897.git.bristot@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull x86 fixes from Thomas Gleixner:
"The accumulated fixes from this and last week:
- Fix vmalloc TLB flush and map range calculations which lead to
stale TLBs, spurious faults and other hard to diagnose issues.
- Use fault_in_pages_writable() for prefaulting the user stack in the
FPU code as it's less fragile than the current solution
- Use the PF_KTHREAD flag when checking for a kernel thread instead
of current->mm as the latter can give the wrong answer due to
use_mm()
- Compute the vmemmap size correctly for KASLR and 5-Level paging.
Otherwise this can end up with a way too small vmemmap area.
- Make KASAN and 5-level paging work again by making sure that all
invalid bits are masked out when computing the P4D offset. This
worked before but got broken recently when the LDT remap area was
moved.
- Prevent a NULL pointer dereference in the resource control code
which can be triggered with certain mount options when the
requested resource is not available.
- Enforce ordering of microcode loading vs. perf initialization on
secondary CPUs. Otherwise perf tries to access a non-existing MSR
as the boot CPU marked it as available.
- Don't stop the resource control group walk early otherwise the
control bitmaps are not updated correctly and become inconsistent.
- Unbreak kgdb by returning 0 on success from
kgdb_arch_set_breakpoint() instead of an error code.
- Add more Icelake CPU model defines so depending changes can be
queued in other trees"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/microcode, cpuhotplug: Add a microcode loader CPU hotplug callback
x86/kasan: Fix boot with 5-level paging and KASAN
x86/fpu: Don't use current->mm to check for a kthread
x86/kgdb: Return 0 from kgdb_arch_set_breakpoint()
x86/resctrl: Prevent NULL pointer dereference when local MBM is disabled
x86/resctrl: Don't stop walking closids when a locksetup group is found
x86/fpu: Update kernel's FPU state before using for the fsave header
x86/mm/KASLR: Compute the size of the vmemmap section properly
x86/fpu: Use fault_in_pages_writeable() for pre-faulting
x86/CPU: Add more Icelake model numbers
mm/vmalloc: Avoid rare case of flushing TLB with weird arguments
mm/vmalloc: Fix calculation of direct map addr range
Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation version 2 of the license
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 315 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Armijn Hemel <armijn@tjaldur.nl>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190531190115.503150771@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms and conditions of the gnu general public license
version 2 as published by the free software foundation this program
is distributed in the hope it will be useful but without any
warranty without even the implied warranty of merchantability or
fitness for a particular purpose see the gnu general public license
for more details you should have received a copy of the gnu general
public license along with this program if not write to the free
software foundation inc 51 franklin st fifth floor boston ma 02110
1301 usa
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 111 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190530000436.567572064@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation this program is
distributed in the hope that it will be useful but without any
warranty without even the implied warranty of merchantability or
fitness for a particular purpose see the gnu general public license
for more details you should have received a copy of the gnu general
public license along with this program if not write to the free
software foundation inc 59 temple place suite 330 boston ma 02111
1307 usa
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 136 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190530000436.384967451@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms and conditions of the gnu general public license
version 2 as published by the free software foundation this program
is distributed in the hope it will be useful but without any
warranty without even the implied warranty of merchantability or
fitness for a particular purpose see the gnu general public license
for more details you should have received a copy of the gnu general
public license along with this program if not write to the free
software foundation inc 59 temple place suite 330 boston ma 02111
1307 usa
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 33 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190530000435.254582722@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms and conditions of the gnu general public license
version 2 as published by the free software foundation this program
is distributed in the hope it will be useful but without any
warranty without even the implied warranty of merchantability or
fitness for a particular purpose see the gnu general public license
for more details
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 263 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190529141901.208660670@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
MSR IA32_MISC_ENABLE bit 18, according to SDM:
| When this bit is set to 0, the MONITOR feature flag is not set (CPUID.01H:ECX[bit 3] = 0).
| This indicates that MONITOR/MWAIT are not supported.
|
| Software attempts to execute MONITOR/MWAIT will cause #UD when this bit is 0.
|
| When this bit is set to 1 (default), MONITOR/MWAIT are supported (CPUID.01H:ECX[bit 3] = 1).
The CPUID.01H:ECX[bit 3] ought to mirror the value of the MSR bit,
CPUID.01H:ECX[bit 3] is a better guard than kvm_mwait_in_guest().
kvm_mwait_in_guest() affects the behavior of MONITOR/MWAIT, not its
guest visibility.
This patch implements toggling of the CPUID bit based on guest writes
to the MSR.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Liran Alon <liran.alon@oracle.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
[Fixes for backwards compatibility - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
1. Using X86_FEATURE_ARCH_CAPABILITIES to enumerate the existence of
MSR_IA32_ARCH_CAPABILITIES to avoid using rdmsrl_safe().
2. Since kvm_get_arch_capabilities() is only used in this file, making
it static.
Signed-off-by: Xiaoyao Li <xiaoyao.li@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
