Send async page fault to a PV guest if it accesses swapped out memory.
Guest will choose another task to run upon receiving the fault.

Allow async page fault injection only when guest is in user mode since
otherwise guest may be in non-sleepable context and will not be able
to reschedule.

Vcpu will be halted if guest will fault on the same page again or if
vcpu executes kernel code.

Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

When async PF capability is detected hook up special page fault handler
that will handle async page fault events and bypass other page faults to
regular page fault handler. Also add async PF handling to nested SVM
emulation. Async PF always generates exit to L1 where vcpu thread will
be scheduled out until page is available.

Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

Enable async PF in a guest if async PF capability is discovered.

Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

Guest enables async PF vcpu functionality using this MSR.

Reviewed-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

Async PF also needs to hook into smp_prepare_boot_cpu so move the hook
into generic code.

Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

Keep track of memslots changes by keeping generation number in memslots
structure. Provide kvm_write_guest_cached() function that skips
gfn_to_hva() translation if memslots was not changed since previous
invocation.

Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

When page is swapped in it is mapped into guest memory only after guest
tries to access it again and generate another fault. To save this fault
we can map it immediately since we know that guest is going to access
the page. Do it only when tdp is enabled for now. Shadow paging case is
more complicated. CR[034] and EFER registers should be switched before
doing mapping and then switched back.

Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

If a guest accesses swapped out memory do not swap it in from vcpu thread
context. Schedule work to do swapping and put vcpu into halted state
instead.

Interrupts will still be delivered to the guest and if interrupt will
cause reschedule guest will continue to run another task.

[avi: remove call to get_user_pages_noio(), nacked by Linus; this
      makes everything synchrnous again]

Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

The only bit of EFER that affects the mmu is NX, and this is already
accounted for (LME only takes effect when changing cr0).

Based on a patch by Hillf Danton.

Signed-off-by: Avi Kivity <avi@redhat.com>

isr_ack is never initialized.  So, until the first PIC reset, interrupts
may fail to be injected.  This can cause Windows XP to fail to boot, as
reported in the fallout from the fix to
https://bugzilla.kernel.org/show_bug.cgi?id=21962

.

Reported-and-tested-by: Nicolas Prochazka <prochazka.nicolas@gmail.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

We use the physical address instead of the base gfn for the four
PAE page directories we use in unpaged mode.  When the guest accesses
an address above 1GB that is backed by a large host page, a BUG_ON()
in kvm_mmu_set_gfn() triggers.

Resolves: https://bugzilla.kernel.org/show_bug.cgi?id=21962


Reported-and-tested-by: Nicolas Prochazka <prochazka.nicolas@gmail.com>
KVM-Stable-Tag.
Signed-off-by: Avi Kivity <avi@redhat.com>

* git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile:
  arch/tile: handle rt_sigreturn() more cleanly
  arch/tile: handle CLONE_SETTLS in copy_thread(), not user space

* 'upstream' of git://git.linux-mips.org/pub/scm/upstream-linus:
  MIPS: Fix build errors in sc-mips.c

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6:
  x86: avoid high BIOS area when allocating address space
  x86: avoid E820 regions when allocating address space
  x86: avoid low BIOS area when allocating address space
  resources: add arch hook for preventing allocation in reserved areas
  Revert "resources: support allocating space within a region from the top down"
  Revert "PCI: allocate bus resources from the top down"
  Revert "x86/PCI: allocate space from the end of a region, not the beginning"
  Revert "x86: allocate space within a region top-down"
  Revert "PCI: fix pci_bus_alloc_resource() hang, prefer positive decode"
  PCI: Update MCP55 quirk to not affect non HyperTransport variants

The current tile rt_sigreturn() syscall pattern uses the common idiom
of loading up pt_regs with all the saved registers from the time of
the signal, then anticipating the fact that we will clobber the ABI
"return value" register (r0) as we return from the syscall by setting
the rt_sigreturn return value to whatever random value was in the pt_regs
for r0.

However, this breaks in our 64-bit kernel when running "compat" tasks,
since we always sign-extend the "return value" register to properly
handle returned pointers that are in the upper 2GB of the 32-bit compat
address space.  Doing this to the sigreturn path then causes occasional
random corruption of the 64-bit r0 register.

Instead, we stop doing the crazy "load the return-value register"
hack in sigreturn.  We already have some sigreturn-specific assembly
code that we use to pass the pt_regs pointer to C code.  We extend that
code to also set the link register to point to a spot a few instructions
after the usual syscall return address so we don't clobber the saved r0.
Now it no longer matters what the rt_sigreturn syscall returns, and the
pt_regs structure can be cleanly and completely reloaded.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>

Previously we were just setting up the "tp" register in the
new task as started by clone() in libc.  However, this is not
quite right, since in principle a signal might be delivered to
the new task before it had its TLS set up.  (Of course, this race
window still exists for resetting the libc getpid() cached value
in the new task, in principle.  But in any case, we are now doing
this exactly the way all other architectures do it.)

This change is important for 2.6.37 since the tile glibc we will
be submitting upstream will not set TLS in user space any more,
so it will only work on a kernel that has this fix.  It should
also be taken for 2.6.36.x in the stable tree if possible.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Cc: stable <stable@kernel.org>

Seen with malta_defconfig on Linus' tree:

  CC      arch/mips/mm/sc-mips.o
arch/mips/mm/sc-mips.c: In function 'mips_sc_is_activated':
arch/mips/mm/sc-mips.c:77: error: 'config2' undeclared (first use in this function)
arch/mips/mm/sc-mips.c:77: error: (Each undeclared identifier is reported only once
arch/mips/mm/sc-mips.c:77: error: for each function it appears in.)
arch/mips/mm/sc-mips.c:81: error: 'tmp' undeclared (first use in this function)
make[2]: *** [arch/mips/mm/sc-mips.o] Error 1
make[1]: *** [arch/mips/mm] Error 2
make: *** [arch/mips] Error 2

[Ralf: Cosmetic changes to minimize the number of arguments passed to
mips_sc_is_activated]

Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
Patchwork: https://patchwork.linux-mips.org/patch/1752/


Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

This prevents allocation of the last 2MB before 4GB.

The experiment described here shows Windows 7 ignoring the last 1MB:
https://bugzilla.kernel.org/show_bug.cgi?id=23542#c27



This patch ignores the top 2MB instead of just 1MB because H. Peter Anvin
says "There will be ROM at the top of the 32-bit address space; it's a fact
of the architecture, and on at least older systems it was common to have a
shadow 1 MiB below."

Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

When we allocate address space, e.g., to assign it to a PCI device, don't
allocate anything mentioned in the BIOS E820 memory map.

On recent machines (2008 and newer), we assign PCI resources from the
windows described by the ACPI PCI host bridge _CRS.  On many Dell
machines, these windows overlap some E820 reserved areas, e.g.,

    BIOS-e820: 00000000bfe4dc00 - 00000000c0000000 (reserved)
    pci_root PNP0A03:00: host bridge window [mem 0xbff00000-0xdfffffff]

If we put devices at 0xbff00000, they don't work, probably because
that's really RAM, not I/O memory.  This patch prevents that by removing
the 0xbfe4dc00-0xbfffffff area from the "available" resource.

I'm not very happy with this solution because Windows solves the problem
differently (it seems to ignore E820 reserved areas and it allocates
top-down instead of bottom-up; details at comment 45 of the bugzilla
below).  That means we're vulnerable to BIOS defects that Windows would not
trip over.  For example, if BIOS described a device in ACPI but didn't
mention it in E820, Windows would work fine but Linux would fail.

Reference: https://bugzilla.kernel.org/show_bug.cgi?id=16228


Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

This implements arch_remove_reservations() so allocate_resource() can
avoid any arch-specific reserved areas.  This currently just avoids the
BIOS area (the first 1MB), but could be used for E820 reserved areas if
that turns out to be necessary.

We previously avoided this area in pcibios_align_resource().  This patch
moves the test from that PCI-specific path to a generic path, so *all*
resource allocations will avoid this area.

Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

This adds arch_remove_reservations(), which an arch can implement if it
needs to protect part of the address space from allocation.

Sometimes that can be done by just putting a region in the resource tree,
but there are cases where that doesn't work well.  For example, x86 BIOS
E820 reservations are not related to devices, so they may overlap part of,
all of, or more than a device resource, so they may not end up at the
correct spot in the resource tree.

Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

This reverts commit e7f8567d

.

Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

This reverts commit b126b470

.

We're going back to the old behavior of allocating from bus resources
in _CRS order.

Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

This reverts commit dc9887dc

.

Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

This reverts commit 1af3c2e4

.

Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

This reverts commit 82e3e767

.

We're going back to considering bus resources in the order we found
them (in _CRS order, when we're using _CRS), so we don't need to
define any ordering.

Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

* 'for_linus' of git://github.com/at91linux/linux-2.6-at91:
  at91: Refactor Stamp9G20 and PControl G20 board file
  at91: Fix uhpck clock rate in upll case

* 'kvm-updates/2.6.37' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: Fix preemption counter leak in kvm_timer_init()
  KVM: enlarge number of possible CPUID leaves
  KVM: SVM: Do not report xsave in supported cpuid
  KVM: Fix OSXSAVE after migration

* 'pm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6:
  PM / Runtime: Fix pm_runtime_suspended()
  PM / Hibernate: Restore old swap signature to avoid user space breakage
  PM / Hibernate: Fix PM_POST_* notification with user-space suspend

* 'bkl_removal' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-2.6:
  [media] uvcvideo: Convert to unlocked_ioctl
  [media] uvcvideo: Lock stream mutex when accessing format-related information
  [media] uvcvideo: Move mmap() handler to uvc_queue.c
  [media] uvcvideo: Move mutex lock/unlock inside uvc_free_buffers
  [media] uvcvideo: Lock controls mutex when querying menus
  [media] v4l2-dev: fix race condition
  [media] V4L: improve the BKL replacement heuristic
  [media] v4l2-dev: use mutex_lock_interruptible instead of plain mutex_lock
  [media] cx18: convert to unlocked_ioctl
  [media] radio-timb: convert to unlocked_ioctl
  [media] sh_vou: convert to unlocked_ioctl
  [media] cafe_ccic: replace ioctl by unlocked_ioctl
  [media] et61x251_core: trivial conversion to unlocked_ioctl
  [media] sn9c102: convert to unlocked_ioctl
  [media] BKL: trivial ioctl -> unlocked_ioctl video driver conversions
  [media] typhoon: convert to unlocked_ioctl
  [media] si4713: convert to unlocked_ioctl
  [media] tea5764: convert to unlocked_ioctl
  [media] cadet: use unlocked_ioctl
  [media] BKL: trivial BKL removal from V4L2 radio drivers

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6:
  ALSA: hda - Fix conflict of Mic Boot controls
  ALSA: HDA: Enable subwoofer on Asus G73Jw
  ALSA: HDA: Fix auto-mute on Lenovo Edge 14
  ASoC: Fix bias power down of non-DAPM codec
  ASoC: WM8580: Fix R8 initial value
  ASoC: fix deemphasis control in wm8904/55/60 codecs

Due to the recent change for multiple mics assignment, we need to handle
the index of each Mic Boost control respectively.  Otherwise the driver
gets the control element conflicts, and gives the unsable state.

Reference: kernel bug 25002
	https://bugzilla.kernel.org/show_bug.cgi?id=25002



Reported-and-tested-by: Adam Williamson <awilliam@redhat.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

As PControl G20 is a carrier board for the Stamp9G20 SoM, some code can
be shared. Therefore board-stamp9g20.c is refactored to allow reusing the
SoM initialization and board-pcontrol-g20.c is modified to use it.

Signed-off-by: Christian Glindkamp <christian.glindkamp@taskit.de>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>

The uhpck clock should be divided from the utmi clock, not its parent
(main). This change is mostly cosmetic as the uhpck rate value is not
used anywhere except for the debugfs clock output.

Signed-off-by: Ryan Mallon <ryan@bluewatersys.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>

* 'for-linus' of git://git.infradead.org/users/eparis/notify:
  fanotify: fill in the metadata_len field on struct fanotify_event_metadata
  fanotify: split version into version and metadata_len
  fanotify: Dont try to open a file descriptor for the overflow event
  fanotify: Introduce FAN_NOFD
  fanotify: do not leak user reference on allocation failure
  inotify: stop kernel memory leak on file creation failure
  fanotify: on group destroy allow all waiters to bypass permission check
  fanotify: Dont allow a mask of 0 if setting or removing a mark
  fanotify: correct broken ref counting in case adding a mark failed
  fanotify: if set by user unset FMODE_NONOTIFY before fsnotify_perm() is called
  fanotify: remove packed from access response message
  fanotify: deny permissions when no event was sent

* 'upstream' of git://git.linux-mips.org/pub/scm/upstream-linus: (28 commits)
  MIPS: Add a CONFIG_FORCE_MAX_ZONEORDER Kconfig option.
  MIPS: LD/SD o32 macro GAS fix update
  MIPS: Alchemy: fix build with SERIAL_8250=n
  MIPS: Rename mips_dma_cache_sync back to dma_cache_sync
  MIPS: MT: Fix typo in comment.
  SSB: Fix nvram_get on BCM47xx platform
  MIPS: BCM47xx: Swap serial console if ttyS1 was specified.
  MIPS: BCM47xx: Use sscanf for parsing mac address
  MIPS: BCM47xx: Fill values for b43 into SSB sprom
  MIPS: BCM47xx: Do not read config from CFE
  MIPS: FDT size is a be32
  MIPS: Fix CP0 COUNTER clockevent race
  MIPS: Fix regression on BCM4710 processor detection
  MIPS: JZ4740: Fix pcm device name
  MIPS: Separate two consecutive loads in memset.S
  MIPS: Send proper signal and siginfo on FP emulator faults.
  MIPS: AR7: Fix loops per jiffies on TNETD7200 devices
  MIPS: AR7: Fix double ar7_gpio_init declaration
  MIPS: Rework GENERIC_HARDIRQS Kconfig.
  MIPS: Alchemy: Add return value check for strict_strtoul()
  ...

I wrote this quirk awhile ago to properly setup MCP55 chips on hypertransport
busses so that interrupts reached whatever cpu happend to boot the kdump kernel.
while that works well, it was recently shown to me that a a non-hypertransport
variant of the MCP55 exists, and on those system the register that this quirk
manipulates causes hangs if you write to it.  Since the quirk was only meant to
handle errors found on MCP55 chips that have a HT interface, this patch adds a
filter to make sure the chip is an HT capable before making the needed register
adjustment.  This lets the broken MCP55s work with kdump while not breaking the
non-HT variants.

Resolves https://bugzilla.kernel.org/show_bug.cgi?id=23952



Tested successfully by the reporter and myself.

Cc: stable@kernel.org
Reported-by: Mathieu Bérard <mathieu@mberard.eu>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

For huge page support with base page size of 16K or 32K, we have to
increase the MAX_ORDER so that huge pages can be allocated.

[Ralf: I don't think a user should have to configure obscure constants like
this but for the time being this will have to suffice.]

Signed-off-by: David Daney <ddaney@caviumnetworks.com>
To: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/1685/


Signed-off-by: Ralf Baechle <ralf@linux-mips.org>