When software changes D bit (either from 1 to 0, or 0 to 1), the
corresponding TLB entity in the hardware won't be updated immediately. We
should flush it to guarantee the consistence of D bit between TLB and
MMU page table in memory.  This is especially important when clearing
the D bit, since it may cause false negatives in reporting dirtiness.

Sanity test was done on my machine with Intel processor.
Signed-off-by: Kai Huang <kai.huang@linux.intel.com>
[Check A bit too. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Emulation does not utilize the feature.
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Adds a function kvm_vcpu_set_pending_timer instead of calling
kvm_make_request in lapic.c.
Signed-off-by: Nicholas Krause <xerofoify@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

When access to descriptor in LDT/GDT wraparound outside long-mode, the address
of the descriptor should be truncated to 32-bit.  Citing Intel SDM 2.1.1.1
"Global and Local Descriptor Tables in IA-32e Mode": "GDTR and LDTR registers
are expanded to 64-bits wide in both IA-32e sub-modes (64-bit mode and
compatibility mode)."

So in other cases, we need to truncate. Creating new function to return a
pointer to descriptor table to avoid too much code duplication.
Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
[Wrap 64-bit check with #ifdef CONFIG_X86_64, to avoid a "right shift count
 >= width of type" warning and consequent undefined behavior. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

When segment is loaded, the segment access bit is set unconditionally.  In
fact, it should be set conditionally, based on whether the segment had the
accessed bit set before. In addition, it can improve performance.
Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

According to Intel SDM: "If the ESP register is used as a base register for
addressing a destination operand in memory, the POP instruction computes the
effective address of the operand after it increments the ESP register."

The current emulation does not behave so. The fix required to waste another
of the precious instruction flags and to check the flag in decode_modrm.
Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Currently, if em_call_far fails it returns success instead of the resulting
error-code. Fix it.
Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

The KVM emulator does not emulate JMP and CALL that target a call gate or a
task gate.  This patch does not try to implement these scenario as they are
presumably rare; yet it returns X86EMUL_UNHANDLEABLE error in such cases
instead of generating an exception.
Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Since the operand size of fnstcw and fnstsw is updated during the execution,
the emulation may cause spurious exceptions as it reads the memory beforehand.

Marking these instructions as Mov (since the previous value is ignored) and
DstMem16 to simplify the setting of operand size.
Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Although pop sreg updates RSP according to the operand size, only 2 bytes are
read.  The current behavior may result in incorrect #GP or #PF exceptions.
Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

This makes the direction of the conditions consistent with code that
is already using WARN_ON.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Because ASSERT is just a printk, these would oops right away.
The assertion thus hardly adds anything.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

The initialization function in mmu.c can always use walk_mmu, which
is known to be vcpu->arch.mmu.  Only init_kvm_nested_mmu is used to
initialize vcpu->arch.nested_mmu.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

This is, pedantically, not valid C.  It also looks weird.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Add tracepoint to wait_lapic_expire.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
[Remind reader if early or late. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

For the hrtimer which emulates the tscdeadline timer in the guest,
add an option to advance expiration, and busy spin on VM-entry waiting
for the actual expiration time to elapse.

This allows achieving low latencies in cyclictest (or any scenario
which requires strict timing regarding timer expiration).

Reduces average cyclictest latency from 12us to 8us
on Core i5 desktop.

Note: this option requires tuning to find the appropriate value
for a particular hardware/guest combination. One method is to measure the
average delay between apic_timer_fn and VM-entry.
Another method is to start with 1000ns, and increase the value
in say 500ns increments until avg cyclictest numbers stop decreasing.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

kvm_x86_ops->test_posted_interrupt() returns true/false depending
whether 'vector' is set.

Next patch makes use of this interface.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

In most cases calling hwapic_isr_update(), we always check if
kvm_apic_vid_enabled() == 1, but actually,
kvm_apic_vid_enabled()
    -> kvm_x86_ops->vm_has_apicv()
        -> vmx_vm_has_apicv() or '0' in svm case
            -> return enable_apicv && irqchip_in_kernel(kvm)

So its a little cost to recall vmx_vm_has_apicv() inside
hwapic_isr_update(), here just NULL out hwapic_isr_update() in
case of !enable_apicv inside hardware_setup() then make all
related stuffs follow this. Note we don't check this under that
condition of irqchip_in_kernel() since we should make sure
definitely any caller don't work  without in-kernel irqchip.
Signed-off-by: Tiejun Chen <tiejun.chen@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Remove FIXME comments about needing fault addresses to be returned.  These
are propaagated from walk_addr_generic to gva_to_gpa and from there to
ops->read_std and ops->write_std.
Signed-off-by: Nicholas Krause <xerofoify@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

When generating #PF VM-exit, check equality:
(PFEC & PFEC_MASK) == PFEC_MATCH
If there is equality, the 14 bit of exception bitmap is used to take decision
about generating #PF VM-exit. If there is inequality, inverted 14 bit is used.
Signed-off-by: Eugene Korenevsky <ekorenevsky@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

This patch improve checks required by Intel Software Developer Manual.
 - SMM MSRs are not allowed.
 - microcode MSRs are not allowed.
 - check x2apic MSRs only when LAPIC is in x2apic mode.
 - MSR switch areas must be aligned to 16 bytes.
 - address of first and last byte in MSR switch areas should not set any bits
   beyond the processor's physical-address width.

Also it adds warning messages on failures during MSR switch. These messages
are useful for people who debug their VMMs in nVMX.
Signed-off-by: Eugene Korenevsky <ekorenevsky@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Several hypervisors need MSR auto load/restore feature.
We read MSRs from VM-entry MSR load area which specified by L1,
and load them via kvm_set_msr in the nested entry.
When nested exit occurs, we get MSRs via kvm_get_msr, writing
them to L1`s MSR store area. After this, we read MSRs from VM-exit
MSR load area, and load them via kvm_set_msr.
Signed-off-by: Wincy Van <fanwenyi0529@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Pull powerpc fixes from Michael Ellerman:

 - Wire up sys_execveat(). Tested on 32 & 64 bit.

 - Fix for kdump on LE systems with cpus hot unplugged.

 - Revert Anton's fix for "kernel BUG at kernel/smpboot.c:134!", this
   broke other platforms, we'll do a proper fix for 3.20.

* tag 'powerpc-3.19-3' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux:
  Revert "powerpc: Secondary CPUs must set cpu_callin_map after setting active and online"
  powerpc/kdump: Ignore failure in enabling big endian exception during crash
  powerpc: Wire up sys_execveat() syscall

Pull ia64 fixlet from Tony Luck:
 "Add execveat syscall"

* tag 'please-pull-syscall' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux:
  [IA64] Enable execveat syscall for ia64

See commit 51f39a1f
    syscalls: implement execveat() system call
Signed-off-by: Tony Luck <tony.luck@intel.com>

Pull UML fixes from Richard Weinberger:
 "Two fixes for UML regressions. Nothing exciting"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml:
  x86, um: actually mark system call tables readonly
  um: Skip futex_atomic_cmpxchg_inatomic() test

Commit 9fc2105a ("ARM: 7830/1: delay: don't bother reporting
bogomips in /proc/cpuinfo") breaks audio in python, and probably
elsewhere, with message

  FATAL: cannot locate cpu MHz in /proc/cpuinfo

I'm not the first one to hit it, see for example

  https://theredblacktree.wordpress.com/2014/08/10/fatal-cannot-locate-cpu-mhz-in-proccpuinfo/
  https://devtalk.nvidia.com/default/topic/765800/workaround-for-fatal-cannot-locate-cpu-mhz-in-proc-cpuinf/?offset=1

Reading original changelog, I have to say "Stop breaking working setups.
You know who you are!".
Signed-off-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Commit a074335a ("x86, um: Mark system call tables readonly") was
supposed to mark the sys_call_table in UML as RO by adding the const,
but it doesn't have the desired effect as it's nevertheless being placed
into the data section since __cacheline_aligned enforces sys_call_table
being placed into .data..cacheline_aligned instead. We need to use
the ____cacheline_aligned version instead to fix this issue.

Before:

$ nm -v arch/x86/um/sys_call_table_64.o | grep -1 "sys_call_table"
                 U sys_writev
0000000000000000 D sys_call_table
0000000000000000 D syscall_table_size

After:

$ nm -v arch/x86/um/sys_call_table_64.o | grep -1 "sys_call_table"
                 U sys_writev
0000000000000000 R sys_call_table
0000000000000000 D syscall_table_size

Fixes: a074335a ("x86, um: Mark system call tables readonly")
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

futex_atomic_cmpxchg_inatomic() does not work on UML because
it triggers a copy_from_user() in kernel context.
On UML copy_from_user() can only be used if the kernel was called
by a real user space process such that UML can use ptrace()
to fetch the value.
Reported-by: Miklos Szeredi <miklos@szeredi.hu>
Suggested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Richard Weinberger <richard@nod.at>
Tested-by: Daniel Walter <d.walter@0x90.at>

Pull SCSI fixes from James Bottomley:
 "This is a set of three fixes: one to correct an abort path thinko
  causing failures (and a panic) in USB on device misbehaviour, One to
  fix an out of order issue in the fnic driver and one to match discard
  expectations to qemu which otherwise cause Linux to behave badly as a
  guest"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  SCSI: fix regression in scsi_send_eh_cmnd()
  fnic: IOMMU Fault occurs when IO and abort IO is out of order
  sd: tweak discard heuristics to work around QEMU SCSI issue

Pull sound fixes from Takashi Iwai:
 "Nothing too exciting as a new year's start here: most of fixes are for
  ASoC, a boot crash fix on OMAP for deferred probe, a few driver
  specific fixes (Intel, dwc, rockchip, rt5677), in addition to typo
  fixes in kerneldoc comments for PCM"

* tag 'sound-3.19-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: pcm: Fix kerneldoc for params_*() functions
  ASoC: rockchip: i2s: fix maxburst of dma data to 4
  ASoC: rockchip: i2s: fix error defination of transmit data level
  ASoC: Intel: correct the fixed free block allocation
  ASoC: rt5677: fixed rt5677_dsp_vad_put rt5677_dsp_vad_get panic
  ASoC: Intel: Fix BYTCR machine driver MODULE_ALIAS
  ASoC: Intel: Fix BYTCR firmware name
  ASoC: dwc: Iterate over all channels
  ASoC: dwc: Ensure FIFOs are flushed to prevent channel swap
  ASoC: Intel: Add I2C dependency to two new machines
  ASoC: dapm: Remove snd_soc_of_parse_audio_routing() due to deferred probe

Pull vhost cleanup and virtio bugfix
 "There's a single change here, fixing a vhost bug where vhost
  initialization fails due to used ring alignment check being too
  strict"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  vhost: relax used address alignment
  virtio_ring: document alignment requirements

Pull audit fix from Paul Moore:
 "One audit patch to resolve a panic/oops when recording filenames in
  the audit log, see the mail archive link below.

  The fix isn't as nice as I would like, as it involves an allocate/copy
  of the filename, but it solves the problem and the overhead should
  only affect users who have configured audit rules involving file
  names.

  We'll revisit this issue with future kernels in an attempt to make
  this suck less, but in the meantime I think this fix should go into
  the next release of v3.19-rcX.

  [ https://marc.info/?t=141986927600001&r=1&w=2 ]"

* 'upstream' of git://git.infradead.org/users/pcmoore/audit:
  audit: create private file name copies when auditing inodes

This reverts commit 9d469d03.

It breaks the Chromebook Pixel touchpad (and touchscreen).
Reported-by: Dirk Hohndel <dirk@hohndel.org>
Bisected-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nick Dyer <nick.dyer@itdev.co.uk>
Cc: Benson Leung <bleung@chromium.org>
Cc: Yufeng Shen <miletus@chromium.org>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: stable@vger.kernel.org  # v3.16+
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull arch/nios2 fixes from Ley Foon Tan:

 - fix compilation error when enable CONFIG_PREEMPT

 - initialize cpuinfo.mmu variable supplied by the device tree

* tag 'nios2-fixes-v3.19-rc3' of git://git.rocketboards.org/linux-socfpga-next:
  nios2: Use preempt_schedule_irq
  nios2: Initialize cpuinfo.mmu

Pull crypto fix from Herbert Xu:
 "Fix a use-after-free crash in the user-space crypto API"

* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  crypto: af_alg - fix backlog handling

Follow aa0d5326 ("ia64: Use preempt_schedule_irq") and use
preempt_schedule_irq instead of enabling/disabling interrupts and
messing around with PREEMPT_ACTIVE in the nios2 low-level preemption
code ourselves. Also get rid of the now needless re-check for
TIF_NEED_RESCHED, preempt_schedule_irq will already take care of
rescheduling.

This also fixes the following build error when building with
CONFIG_PREEMPT:

arch/nios2/kernel/built-in.o: In function `need_resched':
arch/nios2/kernel/entry.S:374: undefined reference to `PREEMPT_ACTIVE'

Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Acked-by: Ley Foon Tan <lftan@altera.com>

This patch initializes the mmu field of the cpuinfo structure to the
value supplied by the devicetree.
Signed-off-by: Walter Goossens <waltergoossens@home.nl>
Acked-by: Ley Foon Tan <lftan@altera.com>

Pull ARM SoC fixes from Arnd Bergmann:
 "A very small set of fixes for 3.19, as everyone was out.

  The clocksource patch was something I missed for the merge window
  after the change that broke arm64 was merged through arm-soc.  The
  other two patches are a fix for an undetected merge problem in mvebu
  and a defconfig change to make some exynos boards work with the normal
  multi_v7_defconfig"

* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
  Add USB_EHCI_EXYNOS to multi_v7_defconfig
  ARM: mvebu: Fix pinctrl configuration for Armada 370 DB
  clocksource: arch_timer: Only use the virtual counter (CNTVCT) on arm64