The PR KVM implementation of the PAPR HPT hypercalls (H_ENTER etc.)
access an image of the HPT in userspace memory using copy_from_user
and copy_to_user.  Recently, the declarations of those functions were
annotated to indicate that the return value must be checked.  Since
this code doesn't currently check the return value, this causes
compile warnings like the ones shown below, and since on PPC the
default is to compile arch/powerpc with -Werror, this causes the
build to fail.

To fix this, we check the return values, and if non-zero, fail the
hypercall being processed with a H_FUNCTION error return value.
There is really no good error return value to use since PAPR didn't
envisage the possibility that the hypervisor may not be able to access
the guest's HPT, and H_FUNCTION (function not supported) seems as
good as any.

The typical compile warnings look like this:

  CC      arch/powerpc/kvm/book3s_pr_papr.o
/home/paulus/kernel/kvm/arch/powerpc/kvm/book3s_pr_papr.c: In function ‘kvmppc_h_pr_enter’:
/home/paulus/kernel/kvm/arch/powerpc/kvm/book3s_pr_papr.c:53:2: error: ignoring return value of ‘copy_from_user’, declared with attribute warn_unused_result [-Werror=unused-result]
  copy_from_user(pteg, (void __user *)pteg_addr, sizeof(pteg));
  ^
/home/paulus/kernel/kvm/arch/powerpc/kvm/book3s_pr_papr.c:74:2: error: ignoring return value of ‘copy_to_user’, declared with attribute warn_unused_result [-Werror=unused-result]
  copy_to_user((void __user *)pteg_addr, hpte, HPTE_SIZE);
  ^

... etc.
Signed-off-by: NPaul Mackerras <paulus@ozlabs.org>

POWER9 running a radix guest will take some hypervisor interrupts
without going to real mode (turning off the MMU).  This means that
early hypercall handlers may now be called in virtual mode.  Most of
the handlers work just fine in both modes, but there are some that
can crash the host if called in virtual mode, notably the TCE (IOMMU)
hypercalls H_PUT_TCE, H_STUFF_TCE and H_PUT_TCE_INDIRECT.  These
already have both a real-mode and a virtual-mode version, so we
arrange for the real-mode version to return H_TOO_HARD for radix
guests, which will result in the virtual-mode version being called.

The other hypercall which is sensitive to the MMU mode is H_RANDOM.
It doesn't have a virtual-mode version, so this adds code to enable
it to be called in either mode.

An alternative solution was considered which would refuse to call any
of the early hypercall handlers when doing a virtual-mode exit from a
radix guest.  However, the XICS-on-XIVE code depends on the XICS
hypercalls being handled early even for virtual-mode exits, because
the handlers need to be called before the XIVE vCPU state has been
pulled off the hardware.  Therefore that solution would have become
quite invasive and complicated, and was rejected in favour of the
simpler, though less elegant, solution presented here.
Reviewed-by: NDavid Gibson <david@gibson.dropbear.id.au>
Tested-by: NDavid Gibson <david@gibson.dropbear.id.au>
Signed-off-by: NPaul Mackerras <paulus@ozlabs.org>

Merge tag 'kvm-arm-for-v4.12-round2' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

Second round of KVM/ARM Changes for v4.12.

Changes include:
 - A fix related to the 32-bit idmap stub
 - A fix to the bitmask used to deode the operands of an AArch32 CP
   instruction
 - We have moved the files shared between arch/arm/kvm and
   arch/arm64/kvm to virt/kvm/arm
 - We add support for saving/restoring the virtual ITS state to
   userspace

When failing to restore the ITT for a DTE, we should remove the failed
device entry from the list and free the object.

We slightly refactor vgic_its_destroy to be able to reuse the now
separate vgic_its_free_dte() function.
Signed-off-by: NChristoffer Dall <cdall@linaro.org>
Reviewed-by: NEric Auger <eric.auger@redhat.com>

The only reason we called kvm_vgic_map_resources() when restoring the
ITS tables was because we wanted to have the KVM iodevs registered in
the KVM IO bus framework at the time when the ITS was restored such that
a restored and active device can inject MSIs prior to otherwise calling
kvm_vgic_map_resources() from the first run of a VCPU.

Since we now register the KVM iodevs for the redestributors and ITS as
soon as possible (when setting the base addresses), we no longer need
this call and kvm_vgic_map_resources() is again called only when first
running a VCPU.
Signed-off-by: NChristoffer Dall <cdall@linaro.org>
Reviewed-by: NEric Auger <eric.auger@redhat.com>

We have to register the ITS iodevice before running the VM, because in
migration scenarios, we may be restoring a live device that wishes to
inject MSIs before the VCPUs have started.

All we need to register the ITS io device is the base address of the
ITS, so we can simply register that when the base address of the ITS is
set.

  [ Code to fix concurrency issues when setting the ITS base address and
    to fix the undef base address check written by Marc Zyngier ]
Signed-off-by: NChristoffer Dall <cdall@linaro.org>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Reviewed-by: NEric Auger <eric.auger@redhat.com>

The its->initialized doesn't bring much to the table, and creates
unnecessary ordering between setting the address and initializing it
(which amounts to exactly nothing).

Let's kill it altogether, making KVM_DEV_ARM_VGIC_CTRL_INIT the no-op
it deserves to be.
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NChristoffer Dall <cdall@linaro.org>
Reviewed-by: NEric Auger <eric.auger@redhat.com>

Instead of waiting with registering KVM iodevs until the first VCPU is
run, we can actually create the iodevs when the redist base address is
set.  The only downside is that we must now also check if we need to do
this for VCPUs which are created after creating the VGIC, because there
is no enforced ordering between creating the VGIC (and setting its base
addresses) and creating the VCPUs.
Signed-off-by: NChristoffer Dall <cdall@linaro.org>
Reviewed-by: NEric Auger <eric.auger@redhat.com>

As we are about to handle setting the address for the redistributor base
region separately from some of the other base addresses, let's rework
this function to leave a little more room for being flexible in what
each type of base address does.
Signed-off-by: NChristoffer Dall <cdall@linaro.org>
Reviewed-by: NEric Auger <eric.auger@redhat.com>

As we are about to fiddle with the IO device registration mechanism,
let's be a little more careful when setting base addresses as early as
possible.  When setting a base address, we can check that there's
address space enough for its scope and when the last of the two
base addresses (dist and redist) get set, we can also check if the
regions overlap at that time.

This allows us to provide error messages to the user at time when trying
to set the base address, as opposed to later when trying to run the VM.

To do this,  we make vgic_v3_check_base available in the core vgic-v3
code as well as in the other parts of the GICv3 code, namely the MMIO
config code.

We also return true for undefined base addresses so that the function
can be used before all base addresses are set; all callers already check
for uninitialized addresses before calling this function.
Signed-off-by: NChristoffer Dall <cdall@linaro.org>
Reviewed-by: NEric Auger <eric.auger@redhat.com>

Split out the function to register all the redistributor iodevs into a
function that handles a single redistributor at a time in preparation
for being able to call this per VCPU as these get created.
Signed-off-by: NChristoffer Dall <cdall@linaro.org>
Reviewed-by: NEric Auger <eric.auger@redhat.com>

There are occasional needs to use the index of vcpu in the kvm->vcpus
array to map something related to a VCPU.  For example, unlike the
vcpu->vcpu_id, the vcpu index is guaranteed to not be sparse across all
vcpus which is useful when allocating a memory area for each vcpu.
Signed-off-by: NChristoffer Dall <cdall@linaro.org>
Reviewed-by: NEric Auger <eric.auger@redhat.com>

Advertise the PML bit in vmcs12 but don't try to enable
it in hardware when running L2 since L0 is emulating it. Also,
preserve L0's settings for PML since it may still
want to log writes.
Signed-off-by: NBandan Das <bsd@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

With EPT A/D enabled, processor access to L2 guest
paging structures will result in a write violation.
When this happens, write the GUEST_PHYSICAL_ADDRESS
to the pml buffer provided by L1 if the access is
write and the dirty bit is being set.

This patch also adds necessary checks during VMEntry if L1
has enabled PML. If the PML index overflows, we change the
exit reason and run L1 to simulate a PML full event.
Signed-off-by: NBandan Das <bsd@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

When KVM updates accessed/dirty bits, this hook can be used
to invoke an arch specific function that implements/emulates
dirty logging such as PML.
Signed-off-by: NBandan Das <bsd@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

According to the SDM, the CR3-target count must not be greater than
4. Future processors may support a different number of CR3-target
values. Software should read the VMX capability MSR IA32_VMX_MISC to
determine the number of values supported.
Signed-off-by: NJim Mattson <jmattson@google.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Merge branch 'kvm-ppc-next' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc into HEAD

The main thing here is a new implementation of the in-kernel
XICS interrupt controller emulation for POWER9 machines, from Ben
Herrenschmidt.

POWER9 has a new interrupt controller called XIVE (eXternal Interrupt
Virtualization Engine) which is able to deliver interrupts directly
to guest virtual CPUs in hardware without hypervisor intervention.
With this new code, the guest still sees the old XICS interface but
performance is better because the XICS emulation in the host uses the
XIVE directly rather than going through a XICS emulation in firmware.

Conflicts:
	arch/powerpc/kernel/cpu_setup_power.S [cherry-picked fix]
	arch/powerpc/kvm/book3s_xive.c [include asm/debugfs.h]

In vm_stat_get_per_vm_fops and vcpu_stat_get_per_vm_fops, since we
use nonseekable_open() to open, we should use no_llseek() to seek,
not generic_file_llseek().
Signed-off-by: NGeliang Tang <geliangtang@gmail.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

This function really doesn't init anything, it enables the CPU
interface, so name it as such, which gives us the name to use for actual
init work later on.
Signed-off-by: NChristoffer Dall <cdall@linaro.org>
Reviewed-by: NEric Auger <eric.auger@redhat.com>

Clarify what is meant by the save/restore ABI only supporting virtual
physical interrupts.

Relax the requirement of the order that the collection entries are
written in and be clear that there is no particular ordering enforced.

Some cosmetic changes in the capitalization of ID names to align with
the GICv3 manual and remove the empty line in the bottom of the patch.
Signed-off-by: NChristoffer Dall <cdall@linaro.org>
Reviewed-by: NEric Auger <eric.auger@redhat.com>

Merge tag 'linux-kselftest-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

Pull kselftest updates from Shuah Khan:
 "This update consists of:

   - important fixes for build failures and clean target related
     warnings to address regressions introduced in commit 88baa78d
     ("selftests: remove duplicated all and clean target")

   - several minor spelling fixes in and log messages and comment
     blocks.

   - Enabling configs for better test coverage in ftrace, vm, and
     cpufreq tests.

   - .gitignore changes"

* tag 'linux-kselftest-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest: (26 commits)
  selftests: x86: add missing executables to .gitignore
  selftests: watchdog: accept multiple params on command line
  selftests: create cpufreq kconfig fragments
  selftests: x86: override clean in lib.mk to fix warnings
  selftests: sync: override clean in lib.mk to fix warnings
  selftests: splice: override clean in lib.mk to fix warnings
  selftests: gpio: fix clean target to remove all generated files and dirs
  selftests: add gpio generated files to .gitignore
  selftests: powerpc: override clean in lib.mk to fix warnings
  selftests: gpio: override clean in lib.mk to fix warnings
  selftests: futex: override clean in lib.mk to fix warnings
  selftests: lib.mk: define CLEAN macro to allow Makefiles to override clean
  selftests: splice: fix clean target to not remove default_file_splice_read.sh
  selftests: gpio: add config fragment for gpio-mockup
  selftests: breakpoints: allow to cross-compile for aarch64/arm64
  selftests/Makefile: Add missed PHONY targets
  selftests/vm/run_vmtests: Fix wrong comment
  selftests/Makefile: Add missed closing `"` in comment
  selftests/vm/run_vmtests: Polish output text
  selftests/timers: fix spelling mistake: "Asynchronous"
  ...

Pull more tracing updates from Steven Rostedt:
 "These are three simple changes.

  The first one is just a switch from using strcpy() to strlcpy().
  Someone thought that it may cause an overflow bug, but since it only
  copies comms into a pre-allocated array of TASK_COMM_LEN, and no comm
  should ever be bigger than that, nor not end with a nul character,
  this change is more of a safety precaution than fixing anything that
  is actually broken.

  The other two changes are simply cleaning and optimizing some code"

* tag 'trace-v4.12-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  ftrace: Simplify ftrace_match_record() even more
  ftrace: Remove an unneeded condition
  tracing: Use strlcpy() instead of strcpy() in __trace_find_cmdline()

Merge tags 'for-linus' and 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma

Pull more rdma updates from Doug Ledford:
 "As mentioned in my first pull request, this is the subsequent pull
  requests I had. This is all I have, and in fact this cleans out the
  RDMA subsystem's entire patchworks queue of kernel changes that are
  ready to go (well, it did for the weekend anyway, a few new patches
  are in, but they'll be coming during the -rc cycle).

  The first tag contains a single patch that would have conflicted if
  taken from my tree or DaveM's tree as it needed our trees merged to
  come cleanly.

  The second tag contains the patch series from Intel plus three other
  stragllers that came in late last week. I took them because it allowed
  me to legitimately claim that the RDMA patchworks queue was, for a
  short time, 100% cleared of all waiting kernel patches, woohoo! :-).

  I have it under my for-next tag, so it did get 0day and linux- next
  over the end of last week, and linux-next did show one minor conflict.

  Summary:

  'for-linus' tag:
   - mlx5/IPoIB fixup patch

  'for-next' tag:
   - the hfi1 15 patch set that landed late
   - IPoIB get_link_ksettings which landed late because I asked for a
     respin
   - one late rxe change
   - one -rc worthy fix that's in early"

* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma:
  IB/mlx5: Enable IPoIB acceleration

* tag 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma:
  rxe: expose num_possible_cpus() cnum_comp_vectors
  IB/rxe: Update caller's CRC for RXE_MEM_TYPE_DMA memory type
  IB/hfi1: Clean up on context initialization failure
  IB/hfi1: Fix an assign/ordering issue with shared context IDs
  IB/hfi1: Clean up context initialization
  IB/hfi1: Correctly clear the pkey
  IB/hfi1: Search shared contexts on the opened device, not all devices
  IB/hfi1: Remove atomic operations for SDMA_REQ_HAVE_AHG bit
  IB/hfi1: Use filedata rather than filepointer
  IB/hfi1: Name function prototype parameters
  IB/hfi1: Fix a subcontext memory leak
  IB/hfi1: Return an error on memory allocation failure
  IB/hfi1: Adjust default eager_buffer_size to 8MB
  IB/hfi1: Get rid of divide when setting the tx request header
  IB/hfi1: Fix yield logic in send engine
  IB/hfi1, IB/rdmavt: Move r_adefered to r_lock cache line
  IB/hfi1: Fix checks for Offline transient state
  IB/ipoib: add get_link_ksettings in ethtool

Pull PCI updates from Bjorn Helgaas:

 - add framework for supporting PCIe devices in Endpoint mode (Kishon
   Vijay Abraham I)

 - use non-postable PCI config space mappings when possible (Lorenzo
   Pieralisi)

 - clean up and unify mmap of PCI BARs (David Woodhouse)

 - export and unify Function Level Reset support (Christoph Hellwig)

 - avoid FLR for Intel 82579 NICs (Sasha Neftin)

 - add pci_request_irq() and pci_free_irq() helpers (Christoph Hellwig)

 - short-circuit config access failures for disconnected devices (Keith
   Busch)

 - remove D3 sleep delay when possible (Adrian Hunter)

 - freeze PME scan before suspending devices (Lukas Wunner)

 - stop disabling MSI/MSI-X in pci_device_shutdown() (Prarit Bhargava)

 - disable boot interrupt quirk for ASUS M2N-LR (Stefan Assmann)

 - add arch-specific alignment control to improve device passthrough by
   avoiding multiple BARs in a page (Yongji Xie)

 - add sysfs sriov_drivers_autoprobe to control VF driver binding
   (Bodong Wang)

 - allow slots below PCI-to-PCIe "reverse bridges" (Bjorn Helgaas)

 - fix crashes when unbinding host controllers that don't support
   removal (Brian Norris)

 - add driver for MicroSemi Switchtec management interface (Logan
   Gunthorpe)

 - add driver for Faraday Technology FTPCI100 host bridge (Linus
   Walleij)

 - add i.MX7D support (Andrey Smirnov)

 - use generic MSI support for Aardvark (Thomas Petazzoni)

 - make Rockchip driver modular (Brian Norris)

 - advertise 128-byte Read Completion Boundary support for Rockchip
   (Shawn Lin)

 - advertise PCI_EXP_LNKSTA_SLC for Rockchip root port (Shawn Lin)

 - convert atomic_t to refcount_t in HV driver (Elena Reshetova)

 - add CPU IRQ affinity in HV driver (K. Y. Srinivasan)

 - fix PCI bus removal in HV driver (Long Li)

 - add support for ThunderX2 DMA alias topology (Jayachandran C)

 - add ThunderX pass2.x 2nd node MCFG quirk (Tomasz Nowicki)

 - add ITE 8893 bridge DMA alias quirk (Jarod Wilson)

 - restrict Cavium ACS quirk only to CN81xx/CN83xx/CN88xx devices
   (Manish Jaggi)

* tag 'pci-v4.12-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (146 commits)
  PCI: Don't allow unbinding host controllers that aren't prepared
  ARM: DRA7: clockdomain: Change the CLKTRCTRL of CM_PCIE_CLKSTCTRL to SW_WKUP
  MAINTAINERS: Add PCI Endpoint maintainer
  Documentation: PCI: Add userguide for PCI endpoint test function
  tools: PCI: Add sample test script to invoke pcitest
  tools: PCI: Add a userspace tool to test PCI endpoint
  Documentation: misc-devices: Add Documentation for pci-endpoint-test driver
  misc: Add host side PCI driver for PCI test function device
  PCI: Add device IDs for DRA74x and DRA72x
  dt-bindings: PCI: dra7xx: Add DT bindings to enable unaligned access
  PCI: dwc: dra7xx: Workaround for errata id i870
  dt-bindings: PCI: dra7xx: Add DT bindings for PCI dra7xx EP mode
  PCI: dwc: dra7xx: Add EP mode support
  PCI: dwc: dra7xx: Facilitate wrapper and MSI interrupts to be enabled independently
  dt-bindings: PCI: Add DT bindings for PCI designware EP mode
  PCI: dwc: designware: Add EP mode support
  Documentation: PCI: Add binding documentation for pci-test endpoint function
  ixgbe: Use pcie_flr() instead of duplicating it
  IB/hfi1: Use pcie_flr() instead of duplicating it
  PCI: imx6: Fix spelling mistake: "contol" -> "control"
  ...

Pull tty/serial updates from Greg KH:
 "Here is the "big" TTY/Serial patch updates for 4.12-rc1

  Not a lot of new things here, the normal number of serial driver
  updates and additions, tiny bugs fixed, and some core files split up
  to make future changes a bit easier for Nicolas's "tiny-tty" work.

  All of these have been in linux-next for a while"

* tag 'tty-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (62 commits)
  serial: small Makefile reordering
  tty: split job control support into a file of its own
  tty: move baudrate handling code to a file of its own
  console: move console_init() out of tty_io.c
  serial: 8250_early: Add earlycon support for Palmchip UART
  tty: pl011: use "qdf2400_e44" as the earlycon name for QDF2400 E44
  vt: make mouse selection of non-ASCII consistent
  vt: set mouse selection word-chars to gpm's default
  imx-serial: Reduce RX DMA startup latency when opening for reading
  serial: omap: suspend device on probe errors
  serial: omap: fix runtime-pm handling on unbind
  tty: serial: omap: add UPF_BOOT_AUTOCONF flag for DT init
  serial: samsung: Remove useless spinlock
  serial: samsung: Add missing checks for dma_map_single failure
  serial: samsung: Use right device for DMA-mapping calls
  serial: imx: setup DCEDTE early and ensure DCD and RI irqs to be off
  tty: fix comment typo s/repsonsible/responsible/
  tty: amba-pl011: Fix spurious TX interrupts
  serial: xuartps: Enable clocks in the pm disable case also
  serial: core: Re-use struct uart_port {name} field
  ...

Merge more updates from Andrew Morton:

 - the rest of MM

 - various misc things

 - procfs updates

 - lib/ updates

 - checkpatch updates

 - kdump/kexec updates

 - add kvmalloc helpers, use them

 - time helper updates for Y2038 issues. We're almost ready to remove
   current_fs_time() but that awaits a btrfs merge.

 - add tracepoints to DAX

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (114 commits)
  drivers/staging/ccree/ssi_hash.c: fix build with gcc-4.4.4
  selftests/vm: add a test for virtual address range mapping
  dax: add tracepoint to dax_insert_mapping()
  dax: add tracepoint to dax_writeback_one()
  dax: add tracepoints to dax_writeback_mapping_range()
  dax: add tracepoints to dax_load_hole()
  dax: add tracepoints to dax_pfn_mkwrite()
  dax: add tracepoints to dax_iomap_pte_fault()
  mtd: nand: nandsim: convert to memalloc_noreclaim_*()
  treewide: convert PF_MEMALLOC manipulations to new helpers
  mm: introduce memalloc_noreclaim_{save,restore}
  mm: prevent potential recursive reclaim due to clearing PF_MEMALLOC
  mm/huge_memory.c: deposit a pgtable for DAX PMD faults when required
  mm/huge_memory.c: use zap_deposited_table() more
  time: delete CURRENT_TIME_SEC and CURRENT_TIME
  gfs2: replace CURRENT_TIME with current_time
  apparmorfs: replace CURRENT_TIME with current_time()
  lustre: replace CURRENT_TIME macro
  fs: ubifs: replace CURRENT_TIME_SEC with current_time
  fs: ufs: use ktime_get_real_ts64() for birthtime
  ...

  drivers/staging/ccree/ssi_hash.c:1990: error: unknown field 'template_ahash' specified in initializer
  drivers/staging/ccree/ssi_hash.c:1991: error: unknown field 'init' specified in initializer
  drivers/staging/ccree/ssi_hash.c:1991: warning: missing braces around initializer
  drivers/staging/ccree/ssi_hash.c:1991: warning: (near initialization for 'driver_hash[0].<anonymous>.template_ahash')
  drivers/staging/ccree/ssi_hash.c:1992: error: unknown field 'update' specified in initializer
  drivers/staging/ccree/ssi_hash.c:1992: warning: excess elements in union initializer
  drivers/staging/ccree/ssi_hash.c:1992: warning: (near initialization for 'driver_hash[0].<anonymous>')
  drivers/staging/ccree/ssi_hash.c:1993: error: unknown field 'final' specified in initializer
  drivers/staging/ccree/ssi_hash.c:1993: warning: excess elements in union initializer
  drivers/staging/ccree/ssi_hash.c:1993: warning: (near initialization for 'driver_hash[0].<anonymous>')
  ...

gcc-4.4.4 has issues with anon union initializers.  Work around this.

Cc: Gilad Ben-Yossef <gilad@benyossef.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This verifies virtual address mapping below and above the 128TB range
and makes sure that address returned are within the expected range
depending upon the hint passed from the user space.

Link: http://lkml.kernel.org/r/20170418095252.20533-1-khandual@linux.vnet.ibm.comSigned-off-by: NAnshuman Khandual <khandual@linux.vnet.ibm.com>
Cc: Michal Suchanek <msuchanek@suse.de>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add a tracepoint to dax_insert_mapping(), following the same logging
conventions as the rest of DAX.  This tracepoint, along with the one in
dax_load_hole(), lets us know how a DAX PTE fault was serviced.

Here is an example DAX fault that inserts a PTE mapping:

  small-1126  [007] ....
   145.451604: dax_pte_fault: dev 259:0 ino 0x1003 shared WRITE|ALLOW_RETRY|KILLABLE|USER address 0x10420000 pgoff 0x220

  small-1126  [007] ....
   145.452317: dax_insert_mapping: dev 259:0 ino 0x1003 shared write address 0x10420000 radix_entry 0x100006

  small-1126  [007] ....
   145.452399: dax_pte_fault_done: dev 259:0 ino 0x1003 shared WRITE|ALLOW_RETRY|KILLABLE|USER address 0x10420000 pgoff 0x220 MAJOR|NOPAGE

Link: http://lkml.kernel.org/r/20170221195116.13278-7-ross.zwisler@linux.intel.comSigned-off-by: NRoss Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: NJan Kara <jack@suse.cz>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add a tracepoint to dax_writeback_one(), following the same logging
conventions as the rest of DAX.

Here is an example range writeback which ends up flushing one PMD and
one PTE:

  test-1265  [003] ....
   496.615250: dax_writeback_range: dev 259:0 ino 0x1003 pgoff 0x0-0x7ffffffffffff

  test-1265  [003] ....
   496.616263: dax_writeback_one: dev 259:0 ino 0x1003 pgoff 0x0 pglen 0x200

  test-1265  [003] ....
   496.616270: dax_writeback_one: dev 259:0 ino 0x1003 pgoff 0x305 pglen 0x1

  test-1265  [003] ....
   496.616272: dax_writeback_range_done: dev 259:0 ino 0x1003 pgoff 0x0-0x7ffffffffffff

[akpm@linux-foundation.org: struct blk_dax_ctl has disappeared]
Link: http://lkml.kernel.org/r/20170221195116.13278-6-ross.zwisler@linux.intel.comSigned-off-by: NRoss Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: NJan Kara <jack@suse.cz>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add tracepoints to dax_writeback_mapping_range(), following the same
logging conventions as the rest of DAX.

Here is an example writeback call:

  msync-1085  [006] ....
   200.902565: dax_writeback_range: dev 259:0 ino 0x1003 pgoff 0x200-0x2ff

  msync-1085  [006] ....
   200.902579: dax_writeback_range_done: dev 259:0 ino 0x1003 pgoff 0x200-0x2ff

[ross.zwisler@linux.intel.com: fix regression in dax_writeback_mapping_range()]
  Link: http://lkml.kernel.org/r/20170314215358.31451-1-ross.zwisler@linux.intel.com
Link: http://lkml.kernel.org/r/20170221195116.13278-5-ross.zwisler@linux.intel.comSigned-off-by: NRoss Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: NJan Kara <jack@suse.cz>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add tracepoints to dax_load_hole(), following the same logging conventions
as the rest of DAX.

Here is the logging generated by a PTE read from a hole:

  read-1075  [002] ....
    62.362108: dax_pte_fault: dev 259:0 ino 0x1003 shared ALLOW_RETRY|KILLABLE|USER address 0x10480000 pgoff 0x280

  read-1075  [002] ....
    62.362140: dax_load_hole: dev 259:0 ino 0x1003 shared ALLOW_RETRY|KILLABLE|USER address 0x10480000 pgoff 0x280 NOPAGE

  read-1075  [002] ....
    62.362141: dax_pte_fault_done: dev 259:0 ino 0x1003 shared ALLOW_RETRY|KILLABLE|USER address 0x10480000 pgoff 0x280 NOPAGE

Link: http://lkml.kernel.org/r/20170221195116.13278-4-ross.zwisler@linux.intel.comSigned-off-by: NRoss Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: NJan Kara <jack@suse.cz>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add tracepoints to dax_pfn_mkwrite(), following the same logging
conventions as the rest of DAX.

Here is an example PTE fault followed by a pfn_mkwrite:

  small_aligned-1094  [002] ....
   374.084998: dax_pte_fault: dev 259:0 ino 0x1003 shared WRITE|ALLOW_RETRY|KILLABLE|USER address 0x10400000 pgoff 0x200

  small_aligned-1094  [002] ....
   374.085145: dax_pte_fault_done: dev 259:0 ino 0x1003 shared WRITE|ALLOW_RETRY|KILLABLE|USER address 0x10400000 pgoff 0x200 MAJOR|NOPAGE

  small_aligned-1094  [002] ....
   374.085165: dax_pfn_mkwrite: dev 259:0 ino 0x1003 shared WRITE|MKWRITE|ALLOW_RETRY|KILLABLE|USER address 0x10400000 pgoff 0x200 NOPAGE

Link: http://lkml.kernel.org/r/20170221195116.13278-3-ross.zwisler@linux.intel.comSigned-off-by: NRoss Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: NJan Kara <jack@suse.cz>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Patch series "second round of tracepoints for DAX".

This second round of DAX tracepoint patches adds tracing to the PTE
fault path (dax_iomap_pte_fault(), dax_pfn_mkwrite(), dax_load_hole(),
dax_insert_mapping()) and to the writeback path
(dax_writeback_mapping_range(), dax_writeback_one()).

The purpose of this tracing is to give us a high level view of what DAX
is doing, whether faults are being serviced by PMDs or PTEs, and by real
storage or by zero pages covering holes.

I do have some patches nearly ready which also add tracing to
grab_mapping_entry() and dax_insert_mapping_entry().  These are more
targeted at logging how we are interacting with the radix tree, how we
use empty entries for locking, whether we "downgrade" huge zero pages to
4k PTE sized allocations, etc.  In the end it seemed to me that this
might be too detailed to have as constantly present tracepoints, but if
anyone sees value in having tracepoints like this in the DAX code
permanently (Jan?), please let me know and I'll add those last two
patches.

All these tracepoints were done to be consistent with the style of the
XFS tracepoints and with the existing DAX PMD tracepoints.

This patch (of 6):

Add tracepoints to dax_iomap_pte_fault(), following the same logging
conventions as the rest of DAX.

Here is an example fault that initially tries to be serviced by the PMD
fault handler but which falls back to PTEs because the VMA isn't large
enough to hold a PMD:

  small-1086  [005] ....
   71.140014: xfs_filemap_huge_fault: dev 259:0 ino 0x1003

  small-1086  [005] ....
    71.140027: dax_pmd_fault: dev 259:0 ino 0x1003 shared WRITE|ALLOW_RETRY|KILLABLE|USER address 0x10420000 vm_start 0x10200000 vm_end 0x10500000 pgoff 0x220 max_pgoff 0x1400

  small-1086  [005] ....
    71.140028: dax_pmd_fault_done: dev 259:0 ino 0x1003 shared WRITE|ALLOW_RETRY|KILLABLE|USER address 0x10420000 vm_start 0x10200000 vm_end 0x10500000 pgoff 0x220 max_pgoff 0x1400 FALLBACK

  small-1086  [005] ....
    71.140035: dax_pte_fault: dev 259:0 ino 0x1003 shared WRITE|ALLOW_RETRY|KILLABLE|USER address 0x10420000 pgoff 0x220

  small-1086  [005] ....
    71.140396: dax_pte_fault_done: dev 259:0 ino 0x1003 shared WRITE|ALLOW_RETRY|KILLABLE|USER address 0x10420000 pgoff 0x220 MAJOR|NOPAGE

Link: http://lkml.kernel.org/r/20170221195116.13278-2-ross.zwisler@linux.intel.comSigned-off-by: NRoss Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: NJan Kara <jack@suse.cz>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Nandsim has own functions set_memalloc() and clear_memalloc() for robust
setting and clearing of PF_MEMALLOC.  Replace them by the new generic
helpers.  No functional change.

Link: http://lkml.kernel.org/r/20170405074700.29871-5-vbabka@suse.czSigned-off-by: NVlastimil Babka <vbabka@suse.cz>
Cc: Boris Brezillon <boris.brezillon@free-electrons.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Chris Leech <cleech@redhat.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Josef Bacik <jbacik@fb.com>
Cc: Lee Duncan <lduncan@suse.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We now have memalloc_noreclaim_{save,restore} helpers for robust setting
and clearing of PF_MEMALLOC.  Let's convert the code which was using the
generic tsk_restore_flags().  No functional change.

[vbabka@suse.cz: in net/core/sock.c the hunk is missing]
Link: http://lkml.kernel.org/r/20170405074700.29871-4-vbabka@suse.czSigned-off-by: NVlastimil Babka <vbabka@suse.cz>
Acked-by: NMichal Hocko <mhocko@suse.com>
Cc: Josef Bacik <jbacik@fb.com>
Cc: Lee Duncan <lduncan@suse.com>
Cc: Chris Leech <cleech@redhat.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Boris Brezillon <boris.brezillon@free-electrons.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Wouter Verhelst <w@uter.be>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The previous patch ("mm: prevent potential recursive reclaim due to
clearing PF_MEMALLOC") has shown that simply setting and clearing
PF_MEMALLOC in current->flags can result in wrongly clearing a
pre-existing PF_MEMALLOC flag and potentially lead to recursive reclaim.
Let's introduce helpers that support proper nesting by saving the
previous stat of the flag, similar to the existing memalloc_noio_* and
memalloc_nofs_* helpers.  Convert existing setting/clearing of
PF_MEMALLOC within mm to the new helpers.

There are no known issues with the converted code, but the change makes
it more robust.

Link: http://lkml.kernel.org/r/20170405074700.29871-3-vbabka@suse.czSigned-off-by: NVlastimil Babka <vbabka@suse.cz>
Suggested-by: NMichal Hocko <mhocko@suse.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Acked-by: NHillf Danton <hillf.zj@alibaba-inc.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Boris Brezillon <boris.brezillon@free-electrons.com>
Cc: Chris Leech <cleech@redhat.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Josef Bacik <jbacik@fb.com>
Cc: Lee Duncan <lduncan@suse.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Richard Weinberger <richard@nod.at>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Patch series "more robust PF_MEMALLOC handling"

This series aims to unify the setting and clearing of PF_MEMALLOC, which
prevents recursive reclaim.  There are some places that clear the flag
unconditionally from current->flags, which may result in clearing a
pre-existing flag.  This already resulted in a bug report that Patch 1
fixes (without the new helpers, to make backporting easier).  Patch 2
introduces the new helpers, modelled after existing memalloc_noio_* and
memalloc_nofs_* helpers, and converts mm core to use them.  Patches 3
and 4 convert non-mm code.

This patch (of 4):

__alloc_pages_direct_compact() sets PF_MEMALLOC to prevent deadlock
during page migration by lock_page() (see the comment in
__unmap_and_move()).  Then it unconditionally clears the flag, which can
clear a pre-existing PF_MEMALLOC flag and result in recursive reclaim.
This was not a problem until commit a8161d1e ("mm, page_alloc:
restructure direct compaction handling in slowpath"), because direct
compation was called only after direct reclaim, which was skipped when
PF_MEMALLOC flag was set.

Even now it's only a theoretical issue, as the new callsite of
__alloc_pages_direct_compact() is reached only for costly orders and
when gfp_pfmemalloc_allowed() is true, which means either
__GFP_NOMEMALLOC is in gfp_flags or in_interrupt() is true.  There is no
such known context, but let's play it safe and make
__alloc_pages_direct_compact() robust for cases where PF_MEMALLOC is
already set.

Fixes: a8161d1e ("mm, page_alloc: restructure direct compaction handling in slowpath")
Link: http://lkml.kernel.org/r/20170405074700.29871-2-vbabka@suse.czSigned-off-by: NVlastimil Babka <vbabka@suse.cz>
Reported-by: NAndrey Ryabinin <aryabinin@virtuozzo.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Acked-by: NHillf Danton <hillf.zj@alibaba-inc.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Boris Brezillon <boris.brezillon@free-electrons.com>
Cc: Chris Leech <cleech@redhat.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Josef Bacik <jbacik@fb.com>
Cc: Lee Duncan <lduncan@suse.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Although all architectures use a deposited page table for THP on
anonymous VMAs, some architectures (s390 and powerpc) require the
deposited storage even for file backed VMAs due to quirks of their MMUs.

This patch adds support for depositing a table in DAX PMD fault handling
path for archs that require it.  Other architectures should see no
functional changes.

Link: http://lkml.kernel.org/r/20170411174233.21902-3-oohall@gmail.comSigned-off-by: NOliver O'Halloran <oohall@gmail.com>
Cc: Reza Arbab <arbab@linux.vnet.ibm.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: linux-nvdimm@ml01.01.org
Cc: Oliver O'Halloran <oohall@gmail.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Depending on the flags of the PMD being zapped there may or may not be a
deposited pgtable to be freed.  In two of the three cases this is open
coded while the third uses the zap_deposited_table() helper.  This patch
converts the others to use the helper to clean things up a bit.

Link: http://lkml.kernel.org/r/20170411174233.21902-2-oohall@gmail.com
Cc: Reza Arbab <arbab@linux.vnet.ibm.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: linux-nvdimm@ml01.01.org
Cc: Oliver O'Halloran <oohall@gmail.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>