Scrubbing pages on initial balloon down can take some time, especially
in nested virtualization case (nested EPT is slow). When HVM/PVH guest is
started with memory= significantly lower than maxmem=, all the extra
pages will be scrubbed before returning to Xen. But since most of them
weren't used at all at that point, Xen needs to populate them first
(from populate-on-demand pool). In nested virt case (Xen inside KVM)
this slows down the guest boot by 15-30s with just 1.5GB needed to be
returned to Xen.

Add runtime parameter to enable/disable it, to allow initially disabling
scrubbing, then enable it back during boot (for example in initramfs).
Such usage relies on assumption that a) most pages ballooned out during
initial boot weren't used at all, and b) even if they were, very few
secrets are in the guest at that time (before any serious userspace
kicks in).
Convert CONFIG_XEN_SCRUB_PAGES to CONFIG_XEN_SCRUB_PAGES_DEFAULT (also
enabled by default), controlling default value for the new runtime
switch.

Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>

Pull random driver fix from Ted Ts'o:
 "Fix things so the choice of whether or not to trust RDRAND to
  initialize the CRNG is configurable via the boot option
  random.trust_cpu={on,off}"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random:
  random: make CPU trust a boot parameter

Instead of forcing a distro or other system builder to choose
at build time whether the CPU is trusted for CRNG seeding via
CONFIG_RANDOM_TRUST_CPU, provide a boot-time parameter for end users to
control the choice. The CONFIG will set the default state instead.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

Pull IOMMU updates from Joerg Roedel:

 - PASID table handling updates for the Intel VT-d driver. It implements
   a global PASID space now so that applications usings multiple devices
   will just have one PASID.

 - A new config option to make iommu passthroug mode the default.

 - New sysfs attribute for iommu groups to export the type of the
   default domain.

 - A debugfs interface (for debug only) usable by IOMMU drivers to
   export internals to user-space.

 - R-Car Gen3 SoCs support for the ipmmu-vmsa driver

 - The ARM-SMMU now aborts transactions from unknown devices and devices
   not attached to any domain.

 - Various cleanups and smaller fixes all over the place.

* tag 'iommu-updates-v4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: (42 commits)
  iommu/omap: Fix cache flushes on L2 table entries
  iommu: Remove the ->map_sg indirection
  iommu/arm-smmu-v3: Abort all transactions if SMMU is enabled in kdump kernel
  iommu/arm-smmu-v3: Prevent any devices access to memory without registration
  iommu/ipmmu-vmsa: Don't register as BUS IOMMU if machine doesn't have IPMMU-VMSA
  iommu/ipmmu-vmsa: Clarify supported platforms
  iommu/ipmmu-vmsa: Fix allocation in atomic context
  iommu: Add config option to set passthrough as default
  iommu: Add sysfs attribyte for domain type
  iommu/arm-smmu-v3: sync the OVACKFLG to PRIQ consumer register
  iommu/arm-smmu: Error out only if not enough context interrupts
  iommu/io-pgtable-arm-v7s: Abort allocation when table address overflows the PTE
  iommu/io-pgtable-arm: Fix pgtable allocation in selftest
  iommu/vt-d: Remove the obsolete per iommu pasid tables
  iommu/vt-d: Apply per pci device pasid table in SVA
  iommu/vt-d: Allocate and free pasid table
  iommu/vt-d: Per PCI device pasid table interfaces
  iommu/vt-d: Add for_each_device_domain() helper
  iommu/vt-d: Move device_domain_info to header
  iommu/vt-d: Apply global PASID in SVA
  ...

The Kconfig text for CONFIG_PAGE_POISONING doesn't mention that it has to
be enabled explicitly.  This updates the documentation for that and adds a
note about CONFIG_PAGE_POISONING to the "page_poison" command line docs.
While here, change description of CONFIG_PAGE_POISONING_ZERO too, as it's
not "random" data, but rather the fixed debugging value that would be used
when not zeroing.  Additionally removes a stray "bool" in the Kconfig.

Link: http://lkml.kernel.org/r/20180725223832.GA43733@beast
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Laura Abbott <labbott@redhat.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull driver core updates from Greg KH:
 "Here are all of the driver core and related patches for 4.19-rc1.

  Nothing huge here, just a number of small cleanups and the ability to
  now stop the deferred probing after init happens.

  All of these have been in linux-next for a while with only a merge
  issue reported"

* tag 'driver-core-4.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (21 commits)
  base: core: Remove WARN_ON from link dependencies check
  drivers/base: stop new probing during shutdown
  drivers: core: Remove glue dirs from sysfs earlier
  driver core: remove unnecessary function extern declare
  sysfs.h: fix non-kernel-doc comment
  PM / Domains: Stop deferring probe at the end of initcall
  iommu: Remove IOMMU_OF_DECLARE
  iommu: Stop deferring probe at end of initcalls
  pinctrl: Support stopping deferred probe after initcalls
  dt-bindings: pinctrl: add a 'pinctrl-use-default' property
  driver core: allow stopping deferred probe after init
  driver core: add a debugfs entry to show deferred devices
  sysfs: Fix internal_create_group() for named group updates
  base: fix order of OF initialization
  linux/device.h: fix kernel-doc notation warning
  Documentation: update firmware loader fallback reference
  kobject: Replace strncpy with memcpy
  drivers: base: cacheinfo: use OF property_read_u32 instead of get_property,read_number
  kernfs: Replace strncpy with memcpy
  device: Add #define dev_fmt similar to #define pr_fmt
  ...

Pull powerpc updates from Michael Ellerman:
 "Notable changes:

   - A fix for a bug in our page table fragment allocator, where a page
     table page could be freed and reallocated for something else while
     still in use, leading to memory corruption etc. The fix reuses
     pt_mm in struct page (x86 only) for a powerpc only refcount.

   - Fixes to our pkey support. Several are user-visible changes, but
     bring us in to line with x86 behaviour and/or fix outright bugs.
     Thanks to Florian Weimer for reporting many of these.

   - A series to improve the hvc driver & related OPAL console code,
     which have been seen to cause hardlockups at times. The hvc driver
     changes in particular have been in linux-next for ~month.

   - Increase our MAX_PHYSMEM_BITS to 128TB when SPARSEMEM_VMEMMAP=y.

   - Remove Power8 DD1 and Power9 DD1 support, neither chip should be in
     use anywhere other than as a paper weight.

   - An optimised memcmp implementation using Power7-or-later VMX
     instructions

   - Support for barrier_nospec on some NXP CPUs.

   - Support for flushing the count cache on context switch on some IBM
     CPUs (controlled by firmware), as a Spectre v2 mitigation.

   - A series to enhance the information we print on unhandled signals
     to bring it into line with other arches, including showing the
     offending VMA and dumping the instructions around the fault.

  Thanks to: Aaro Koskinen, Akshay Adiga, Alastair D'Silva, Alexey
  Kardashevskiy, Alexey Spirkov, Alistair Popple, Andrew Donnellan,
  Aneesh Kumar K.V, Anju T Sudhakar, Arnd Bergmann, Bartosz Golaszewski,
  Benjamin Herrenschmidt, Bharat Bhushan, Bjoern Noetel, Boqun Feng,
  Breno Leitao, Bryant G. Ly, Camelia Groza, Christophe Leroy, Christoph
  Hellwig, Cyril Bur, Dan Carpenter, Daniel Klamt, Darren Stevens, Dave
  Young, David Gibson, Diana Craciun, Finn Thain, Florian Weimer,
  Frederic Barrat, Gautham R. Shenoy, Geert Uytterhoeven, Geoff Levand,
  Guenter Roeck, Gustavo Romero, Haren Myneni, Hari Bathini, Joel
  Stanley, Jonathan Neuschäfer, Kees Cook, Madhavan Srinivasan, Mahesh
  Salgaonkar, Markus Elfring, Mathieu Malaterre, Mauro S. M. Rodrigues,
  Michael Hanselmann, Michael Neuling, Michael Schmitz, Mukesh Ojha,
  Murilo Opsfelder Araujo, Nicholas Piggin, Parth Y Shah, Paul
  Mackerras, Paul Menzel, Ram Pai, Randy Dunlap, Rashmica Gupta, Reza
  Arbab, Rodrigo R. Galvao, Russell Currey, Sam Bobroff, Scott Wood,
  Shilpasri G Bhat, Simon Guo, Souptick Joarder, Stan Johnson, Thiago
  Jung Bauermann, Tyrel Datwyler, Vaibhav Jain, Vasant Hegde, Venkat
  Rao, zhong jiang"

* tag 'powerpc-4.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (234 commits)
  powerpc/mm/book3s/radix: Add mapping statistics
  powerpc/uaccess: Enable get_user(u64, *p) on 32-bit
  powerpc/mm/hash: Remove unnecessary do { } while(0) loop
  powerpc/64s: move machine check SLB flushing to mm/slb.c
  powerpc/powernv/idle: Fix build error
  powerpc/mm/tlbflush: update the mmu_gather page size while iterating address range
  powerpc/mm: remove warning about ‘type’ being set
  powerpc/32: Include setup.h header file to fix warnings
  powerpc: Move `path` variable inside DEBUG_PROM
  powerpc/powermac: Make some functions static
  powerpc/powermac: Remove variable x that's never read
  cxl: remove a dead branch
  powerpc/powermac: Add missing include of header pmac.h
  powerpc/kexec: Use common error handling code in setup_new_fdt()
  powerpc/xmon: Add address lookup for percpu symbols
  powerpc/mm: remove huge_pte_offset_and_shift() prototype
  powerpc/lib: Use patch_site to patch copy_32 functions once cache is enabled
  powerpc/pseries: Fix endianness while restoring of r3 in MCE handler.
  powerpc/fadump: merge adjacent memory ranges to reduce PT_LOAD segements
  powerpc/fadump: handle crash memory ranges array index overflow
  ...

Pull pci updates from Bjorn Helgaas:

 - Decode AER errors with names similar to "lspci" (Tyler Baicar)

 - Expose AER statistics in sysfs (Rajat Jain)

 - Clear AER status bits selectively based on the type of recovery (Oza
   Pawandeep)

 - Honor "pcie_ports=native" even if HEST sets FIRMWARE_FIRST (Alexandru
   Gagniuc)

 - Don't clear AER status bits if we're using the "Firmware-First"
   strategy where firmware owns the registers (Alexandru Gagniuc)

 - Use sysfs_match_string() to simplify ASPM sysfs parsing (Andy
   Shevchenko)

 - Remove unnecessary includes of <linux/pci-aspm.h> (Bjorn Helgaas)

 - Defer DPC event handling to work queue (Keith Busch)

 - Use threaded IRQ for DPC bottom half (Keith Busch)

 - Print AER status while handling DPC events (Keith Busch)

 - Work around IDT switch ACS Source Validation erratum (James
   Puthukattukaran)

 - Emit diagnostics for all cases of PCIe Link downtraining (Links
   operating slower than they're capable of) (Alexandru Gagniuc)

 - Skip VFs when configuring Max Payload Size (Myron Stowe)

 - Reduce Root Port Max Payload Size if necessary when hot-adding a
   device below it (Myron Stowe)

 - Simplify SHPC existence/permission checks (Bjorn Helgaas)

 - Remove hotplug sample skeleton driver (Lukas Wunner)

 - Convert pciehp to threaded IRQ handling (Lukas Wunner)

 - Improve pciehp tolerance of missed events and initially unstable
   links (Lukas Wunner)

 - Clear spurious pciehp events on resume (Lukas Wunner)

 - Add pciehp runtime PM support, including for Thunderbolt controllers
   (Lukas Wunner)

 - Support interrupts from pciehp bridges in D3hot (Lukas Wunner)

 - Mark fall-through switch cases before enabling -Wimplicit-fallthrough
   (Gustavo A. R. Silva)

 - Move DMA-debug PCI init from arch code to PCI core (Christoph
   Hellwig)

 - Fix pci_request_irq() usage of IRQF_ONESHOT when no handler is
   supplied (Heiner Kallweit)

 - Unify PCI and DMA direction #defines (Shunyong Yang)

 - Add PCI_DEVICE_DATA() macro (Andy Shevchenko)

 - Check for VPD completion before checking for timeout (Bert Kenward)

 - Limit Netronome NFP5000 config space size to work around erratum
   (Jakub Kicinski)

 - Set IRQCHIP_ONESHOT_SAFE for PCI MSI irqchips (Heiner Kallweit)

 - Document ACPI description of PCI host bridges (Bjorn Helgaas)

 - Add "pci=disable_acs_redir=" parameter to disable ACS redirection for
   peer-to-peer DMA support (we don't have the peer-to-peer support yet;
   this is just one piece) (Logan Gunthorpe)

 - Clean up devm_of_pci_get_host_bridge_resources() resource allocation
   (Jan Kiszka)

 - Fixup resizable BARs after suspend/resume (Christian König)

 - Make "pci=earlydump" generic (Sinan Kaya)

 - Fix ROM BAR access routines to stay in bounds and check for signature
   correctly (Rex Zhu)

 - Add DMA alias quirk for Microsemi Switchtec NTB (Doug Meyer)

 - Expand documentation for pci_add_dma_alias() (Logan Gunthorpe)

 - To avoid bus errors, enable PASID only if entire path supports
   End-End TLP prefixes (Sinan Kaya)

 - Unify slot and bus reset functions and remove hotplug knowledge from
   callers (Sinan Kaya)

 - Add Function-Level Reset quirks for Intel and Samsung NVMe devices to
   fix guest reboot issues (Alex Williamson)

 - Add function 1 DMA alias quirk for Marvell 88SS9183 PCIe SSD
   Controller (Bjorn Helgaas)

 - Remove Xilinx AXI-PCIe host bridge arch dependency (Palmer Dabbelt)

 - Remove Aardvark outbound window configuration (Evan Wang)

 - Fix Aardvark bridge window sizing issue (Zachary Zhang)

 - Convert Aardvark to use pci_host_probe() to reduce code duplication
   (Thomas Petazzoni)

 - Correct the Cadence cdns_pcie_writel() signature (Alan Douglas)

 - Add Cadence support for optional generic PHYs (Alan Douglas)

 - Add Cadence power management ops (Alan Douglas)

 - Remove redundant variable from Cadence driver (Colin Ian King)

 - Add Kirin MSI support (Xiaowei Song)

 - Drop unnecessary root_bus_nr setting from exynos, imx6, keystone,
   armada8k, artpec6, designware-plat, histb, qcom, spear13xx (Shawn
   Guo)

 - Move link notification settings from DesignWare core to individual
   drivers (Gustavo Pimentel)

 - Add endpoint library MSI-X interfaces (Gustavo Pimentel)

 - Correct signature of endpoint library IRQ interfaces (Gustavo
   Pimentel)

 - Add DesignWare endpoint library MSI-X callbacks (Gustavo Pimentel)

 - Add endpoint library MSI-X test support (Gustavo Pimentel)

 - Remove unnecessary GFP_ATOMIC from Hyper-V "new child" allocation
   (Jia-Ju Bai)

 - Add more devices to Broadcom PAXC quirk (Ray Jui)

 - Work around corrupted Broadcom PAXC config space to enable SMMU and
   GICv3 ITS (Ray Jui)

 - Disable MSI parsing to work around broken Broadcom PAXC logic in some
   devices (Ray Jui)

 - Hide unconfigured functions to work around a Broadcom PAXC defect
   (Ray Jui)

 - Lower iproc log level to reduce console output during boot (Ray Jui)

 - Fix mobiveil iomem/phys_addr_t type usage (Lorenzo Pieralisi)

 - Fix mobiveil missing include file (Lorenzo Pieralisi)

 - Add mobiveil Kconfig/Makefile support (Lorenzo Pieralisi)

 - Fix mvebu I/O space remapping issues (Thomas Petazzoni)

 - Use generic pci_host_bridge in mvebu instead of ARM-specific API
   (Thomas Petazzoni)

 - Whitelist VMD devices with fast interrupt handlers to avoid sharing
   vectors with slow handlers (Keith Busch)

* tag 'pci-v4.19-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (153 commits)
  PCI/AER: Don't clear AER bits if error handling is Firmware-First
  PCI: Limit config space size for Netronome NFP5000
  PCI/MSI: Set IRQCHIP_ONESHOT_SAFE for PCI-MSI irqchips
  PCI/VPD: Check for VPD access completion before checking for timeout
  PCI: Add PCI_DEVICE_DATA() macro to fully describe device ID entry
  PCI: Match Root Port's MPS to endpoint's MPSS as necessary
  PCI: Skip MPS logic for Virtual Functions (VFs)
  PCI: Add function 1 DMA alias quirk for Marvell 88SS9183
  PCI: Check for PCIe Link downtraining
  PCI: Add ACS Redirect disable quirk for Intel Sunrise Point
  PCI: Add device-specific ACS Redirect disable infrastructure
  PCI: Convert device-specific ACS quirks from NULL termination to ARRAY_SIZE
  PCI: Add "pci=disable_acs_redir=" parameter for peer-to-peer support
  PCI: Allow specifying devices using a base bus and path of devfns
  PCI: Make specifying PCI devices in kernel parameters reusable
  PCI: Hide ACS quirk declarations inside PCI core
  PCI: Delay after FLR of Intel DC P3700 NVMe
  PCI: Disable Samsung SM961/PM961 NVMe before FLR
  PCI: Export pcie_has_flr()
  PCI: mvebu: Drop bogus comment above mvebu_pcie_map_registers()
  ...

Pull random updates from Ted Ts'o:
 "Some changes to trust cpu-based hwrng (such as RDRAND) for
  initializing hashed pointers and (optionally, controlled by a config
  option) to initialize the CRNG to avoid boot hangs"

* tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random:
  random: Make crng state queryable
  random: remove preempt disabled region
  random: add a config option to trust the CPU's hwrng
  vsprintf: Add command line option debug_boot_weak_hash
  vsprintf: Use hw RNG for ptr_key
  random: Return nbytes filled from hw RNG
  random: Fix whitespace pre random-bytes work

  - Clean up devm_of_pci_get_host_bridge_resources() resource allocation
    (Jan Kiszka)

  - Fixup resizable BARs after suspend/resume (Christian König)

  - Make "pci=earlydump" generic (Sinan Kaya)

  - Fix ROM BAR access routines to stay in bounds and check for signature
    correctly (Rex Zhu)

* pci/resource:
  PCI: Make pci_get_rom_size() static
  PCI: Add check code for last image indicator not set
  PCI: Avoid accessing memory outside the ROM BAR
  PCI: Make early dump functionality generic
  PCI: Cleanup PCI_REBAR_CTRL_BAR_SHIFT handling
  PCI: Restore resized BAR state on resume
  PCI: Clean up resource allocation in devm_of_pci_get_host_bridge_resources()

# Conflicts:
#	Documentation/admin-guide/kernel-parameters.txt