[Hyper-V] PCI: hv: Fix 2 hang issues in hv_compose_msi_msg

[Joshua R. Poulson]

We've identified some issues in recent testing against upstream 4.15 SR-IOV and DPDK. The following commits are in Lorenzo's PCI tree on their way into 4.16 and stable:

Tree: https://git.kernel.org/pub/scm/linux/kernel/git/lpieralisi/pci.git/log/?h=pci/hv

PCI: hv: Only queue new work items in hv_pci_devices_present() if necessary
If there is pending work in hv_pci_devices_present() we just need to add
the new dr entry into the dr_list. Add a check to detect pending work
items and update the code to skip queuing work if pending work items
are detected.

https://git.kernel.org/pub/scm/linux/kernel/git/lpieralisi/pci.git/commit/?h=pci/hv&id=948373b3ed1bcf05a237c24675b84804315aff14

PCI: hv: Remove the bogus test in hv_eject_device_work()
When kernel is executing hv_eject_device_work(), hpdev->state value must
be hv_pcichild_ejecting; any other value would consist in a bug,
therefore replace the bogus check with an explicit WARN_ON() on the
condition failure detection.

https://git.kernel.org/pub/scm/linux/kernel/git/lpieralisi/pci.git/commit/?h=pci/hv&id=fca288c0153b2b97114b9081bc3c33c3735145b6

PCI: hv: Fix a comment typo in _hv_pcifront_read_config()
Comment in _hv_pcifront_read_config() contains a typo, fix it.

No functional change.

https://git.kernel.org/pub/scm/linux/kernel/git/lpieralisi/pci.git/commit/?h=pci/hv&id=df3f2159f4e4146d40b244725ce79ed921530b99

PCI: hv: Fix 2 hang issues in hv_compose_msi_msg()
1. With the patch "x86/vector/msi: Switch to global reservation mode",
the recent v4.15 and newer kernels always hang for 1-vCPU Hyper-V VM
with SR-IOV. This is because when we reach hv_compose_msi_msg() by
request_irq() -> request_threaded_irq() ->__setup_irq()->irq_startup()
-> __irq_startup() -> irq_domain_activate_irq() -> ... ->
msi_domain_activate() -> ... -> hv_compose_msi_msg(), local irq is
disabled in __setup_irq().

Note: when we reach hv_compose_msi_msg() by another code path:
pci_enable_msix_range() -> ... -> irq_domain_activate_irq() -> ... ->
hv_compose_msi_msg(), local irq is not disabled.

hv_compose_msi_msg() depends on an interrupt from the host.
With interrupts disabled, a UP VM always hangs in the busy loop in
the function, because the interrupt callback hv_pci_onchannelcallback()
can not be called.

We can do nothing but work it around by polling the channel. This
is ugly, but we don't have any other choice.

2. If the host is ejecting the VF device before we reach
hv_compose_msi_msg(), in a UP VM, we can hang in hv_compose_msi_msg()
forever, because at this time the host doesn't respond to the
CREATE_INTERRUPT request. This issue exists the first day the
pci-hyperv driver appears in the kernel.

Luckily, this can also by worked around by polling the channel
for the PCI_EJECT message and hpdev->state, and by checking the
PCI vendor ID.

Note: actually the above 2 issues also happen to a SMP VM, if
"hbus->hdev->channel->target_cpu == smp_processor_id()" is true.

https://git.kernel.org/pub/scm/linux/kernel/git/lpieralisi/pci.git/commit/?h=pci/hv&id=de0aa7b2f97d348ba7d1e17a00744c989baa0cb6

PCI: hv: Serialize the present and eject work items
When we hot-remove the device, we first receive a PCI_EJECT message and
then receive a PCI_BUS_RELATIONS message with bus_rel->device_count == 0.

The first message is offloaded to hv_eject_device_work(), and the second
is offloaded to pci_devices_present_work(). Both the paths can be running
list_del(&hpdev->list_entry), causing general protection fault, because
system_wq can run them concurrently.

The patch eliminates the race condition.

Since access to present/eject work items is serialized, we do not need the
hbus->enum_sem anymore, so remove it.

https://git.kernel.org/pub/scm/linux/kernel/git/lpieralisi/pci.git/commit/?h=pci/hv&id=021ad274d7dc31611d4f47f7dd4ac7a224526f30

All 4.15-based kernels need these fixes, or any kernels that picked up:
Fixes: 4900be83602b ("x86/vector/msi: Switch to global reservation mode")

The race condition fixed by the serialization patch applies to all kernels with PCI passthrough on Hyper-V:
Fixes: 4daace0d8ce8 ("PCI: hv: Add paravirtual PCI front-end for Microsoft Hyper-V VMs") (the catch-all for PCI passthrough)

[Launchpad Janitor (janitor)]

This bug was fixed in the package linux-azure-edge - 4.15.0-1005.5

---------------
linux-azure-edge (4.15.0-1005.5) xenial; urgency=medium

  * linux-azure-edge: 4.15.0-1005.5 -proposed tracker (LP: #1759923)

  * [Hyper-V] hv_netvsc: enable multicast if necessary (LP: #1759885)
    - hv_netvsc: fix filter flags
    - SAUCE: hv_netvsc: enable multicast if necessary

linux-azure-edge (4.15.0-1004.4) xenial; urgency=medium

  * linux-azure-edge: 4.15.0-1004.4 -proposed tracker (LP: #1759673)

  * [Hyper-V][linux-azure] Change config for MLX4 and MLX5 (LP: #1759656)
    - [Config] azure: CONFIG_MLX{4,5}_INFINIBAND=y

  * [Hyper-V] Improvements for UDP on SRIOV (LP: #1756414)
    - SAUCE: hv_netvsc: avoid retry on send during shutdown
    - SAUCE: hv_netvsc: only wake transmit queue if link is up
    - SAUCE: hv_netvsc: fix error unwind handling if vmbus_open fails
    - SAUCE: hv_netvsc: cancel subchannel setup before halting device
    - SAUCE: hv_netvsc: fix race in napi poll when rescheduling
    - SAUCE: hv_netvsc: use napi_schedule_irqoff
    - SAUCE: hv_netvsc: defer queue selection to VF
    - SAUCE: hv_netvsc: filter multicast/broadcast
    - SAUCE: hv_netvsc: propagate rx filters to VF

  * [Hyper-V] PCI: hv: Fix 2 hang issues in hv_compose_msi_msg (LP: #1758378)
    - SAUCE: PCI: hv: Serialize the present and eject work items
    - SAUCE: PCI: hv: Fix 2 hang issues in hv_compose_msi_msg()
    - SAUCE: PCI: hv: Fix a comment typo in _hv_pcifront_read_config()
    - SAUCE: PCI: hv: Remove the bogus test in hv_eject_device_work()
    - SAUCE: PCI: hv: Only queue new work items in hv_pci_devices_present() if
      necessary

linux-azure-edge (4.15.0-1003.3) xenial; urgency=medium

  * linux-azure-edge: 4.15.0-1003.3 -proposed tracker (LP: #1755769)

  * linux-azure: 4.15.0-1003.3 -proposed tracker (LP: #1757167)

  * Enable secure boot on linux-azure (LP: #1754042)
    - Revert "UBUNTU: [debian] azure: do not build uefi signed binary"

  * [Hyper-v] Set CONFIG_I2C_PIIX4 to "n" (LP: #1752999)
    - [Config] azure: CONFIG_I2C_PIIX4=n

  * [Hyper-V] set config: CONFIG_EDAC_DECODE_MCE=y (LP: #1751123)
    - [Config] azure: CONFIG_EDAC_DECODE_MCE=y

  * Miscellaneous Ubuntu changes
    - [Config] updateconfigs after rebase to Ubuntu-4.15.0-13.14
    - [Config] fix up retpoline abi files

  [ Ubuntu: 4.15.0-13.14 ]

  * linux: 4.15.0-13.14 -proposed tracker (LP: #1756408)
  * devpts: handle bind-mounts (LP: #1755857)
    - SAUCE: devpts: hoist out check for DEVPTS_SUPER_MAGIC
    - SAUCE: devpts: resolve devpts bind-mounts
    - SAUCE: devpts: comment devpts_mntget()
    - SAUCE: selftests: add devpts selftests
  * [bionic][arm64] d-i: add hisi_sas_v3_hw to scsi-modules (LP: #1756103)
    - d-i: add hisi_sas_v3_hw to scsi-modules
  * [Bionic][ARM64] enable ROCE and HNS3 driver support for hip08 SoC
    (LP: #1756097)
    - RDMA/hns: Refactor eq code for hip06
    - RDMA/hns: Add eq support of hip08
    - RDMA/hns: Add detailed comments for mb() call
    - RDMA/hns: Add rq inline data support for hip08 RoCE
    - RDMA/hns: Update the usage of sr_max and rr_max field
    - RDMA/hns: Set access flags of hip08 RoCE
    - RDMA/hns: Filter for zero l...

[David Coronel (davecore)]

@Marcelo, Josh requested that these patches be backported to the 4.13 azure kernel:

"[...]Since 4.13 needs to be the default until the 26th, could we get them added to the 4.13 kernel?"

[Marcelo Cerri (mhcerri)]

The patches apply cleanly to the 4.13 linux-azure kernel. I built a test kernel with them that is available at http://kernel.ubuntu.com/~mhcerri/azure/linux-azure-4.13.0-1014.17~lp1758378.1/

[Joshua R. Poulson (jrp)]

WE are testing the fixes for linux-azure on 16.04 now.

[Launchpad Janitor (janitor)]

This bug was fixed in the package linux-azure - 4.15.0-1004.4

---------------
linux-azure (4.15.0-1004.4) bionic; urgency=medium

  * linux-azure: 4.15.0-1004.4 -proposed tracker (LP: #1761181)

  * [Hyper-V] hv_netvsc: enable multicast if necessary (LP: #1759885)
    - hv_netvsc: fix filter flags
    - SAUCE: hv_netvsc: enable multicast if necessary

  * [Hyper-V][linux-azure] Change config for MLX4 and MLX5 (LP: #1759656)
    - [Config] azure: CONFIG_MLX{4,5}_INFINIBAND=y

  * [Hyper-V] Improvements for UDP on SRIOV (LP: #1756414)
    - SAUCE: hv_netvsc: avoid retry on send during shutdown
    - SAUCE: hv_netvsc: only wake transmit queue if link is up
    - SAUCE: hv_netvsc: fix error unwind handling if vmbus_open fails
    - SAUCE: hv_netvsc: cancel subchannel setup before halting device
    - SAUCE: hv_netvsc: fix race in napi poll when rescheduling
    - SAUCE: hv_netvsc: use napi_schedule_irqoff
    - SAUCE: hv_netvsc: defer queue selection to VF
    - SAUCE: hv_netvsc: filter multicast/broadcast
    - SAUCE: hv_netvsc: propagate rx filters to VF

  * [Hyper-V] PCI: hv: Fix 2 hang issues in hv_compose_msi_msg (LP: #1758378)
    - SAUCE: PCI: hv: Serialize the present and eject work items
    - SAUCE: PCI: hv: Fix 2 hang issues in hv_compose_msi_msg()
    - SAUCE: PCI: hv: Fix a comment typo in _hv_pcifront_read_config()
    - SAUCE: PCI: hv: Remove the bogus test in hv_eject_device_work()
    - SAUCE: PCI: hv: Only queue new work items in hv_pci_devices_present() if
      necessary

  * Miscellaneous Ubuntu changes
    - [Packaging] Only install cloud init files when do_tools_common=true

  [ Ubuntu: 4.15.0-15.16 ]

  * linux: 4.15.0-15.16 -proposed tracker (LP: #1761177)
  * FFe: Enable configuring resume offset via sysfs (LP: #1760106)
    - PM / hibernate: Make passing hibernate offsets more friendly
  * /dev/bcache/by-uuid links not created after reboot (LP: #1729145)
    - SAUCE: (no-up) bcache: decouple emitting a cached_dev CHANGE uevent
  * Ubuntu18.04:POWER9:DD2.2 - Unable to start a KVM guest with default machine
    type(pseries-bionic) complaining "KVM implementation does not support
    Transactional Memory, try cap-htm=off" (kvm) (LP: #1752026)
    - powerpc: Use feature bit for RTC presence rather than timebase presence
    - powerpc: Book E: Remove unused CPU_FTR_L2CSR bit
    - powerpc: Free up CPU feature bits on 64-bit machines
    - powerpc: Add CPU feature bits for TM bug workarounds on POWER9 v2.2
    - powerpc/powernv: Provide a way to force a core into SMT4 mode
    - KVM: PPC: Book3S HV: Work around transactional memory bugs in POWER9
    - KVM: PPC: Book3S HV: Work around XER[SO] bug in fake suspend mode
    - KVM: PPC: Book3S HV: Work around TEXASR bug in fake suspend state
  * Important Kernel fixes to be backported for Power9 (kvm) (LP: #1758910)
    - powerpc/mm: Fixup tlbie vs store ordering issue on POWER9
  * Ubuntu 18.04 - IO Hang on some namespaces when running HTX with 16
    namespaces (Bolt / NVMe) (LP: #1757497)
    - powerpc/64s: Fix lost pending interrupt due to race causing lost update to
      irq_happened
  * fwts-efi-runtime-dkms 18.03.00-0ubuntu1: fwts-efi-runtime-dkms kernel module
    fa...

[Launchpad Janitor (janitor)]

This bug was fixed in the package linux-azure - 4.13.0-1014.17

---------------
linux-azure (4.13.0-1014.17) xenial; urgency=medium

  * linux-azure: 4.13.0-1014.17 -proposed tracker (LP: #1761459)

  * retpoline hints: primary infrastructure and initial hints (LP: #1758856)
    - [Config] retpoline -- switch to new format

  * [Hyper-V] PCI: hv: Fix 2 hang issues in hv_compose_msi_msg (LP: #1758378)
    - SAUCE: PCI: hv: Serialize the present and eject work items
    - SAUCE: PCI: hv: Fix 2 hang issues in hv_compose_msi_msg()
    - SAUCE: PCI: hv: Fix a comment typo in _hv_pcifront_read_config()
    - SAUCE: PCI: hv: Remove the bogus test in hv_eject_device_work()
    - SAUCE: PCI: hv: Only queue new work items in hv_pci_devices_present() if
      necessary

  [ Ubuntu: 4.13.0-39.44 ]

  * linux: 4.13.0-39.44 -proposed tracker (LP: #1761456)
  * intel-microcode 3.20180312.0 causes lockup at login screen(w/ linux-
    image-4.13.0-37-generic) (LP: #1759920) // CVE-2017-5715 (Spectre v2
    Intel) // CVE-2017-5754
    - x86/mm: Reinitialize TLB state on hotplug and resume
  * intel-microcode 3.20180312.0 causes lockup at login screen(w/ linux-
    image-4.13.0-37-generic) (LP: #1759920) // CVE-2017-5715 (Spectre v2 Intel)
    - Revert "x86/mm: Only set IBPB when the new thread cannot ptrace current
      thread"
    - x86/speculation: Use Indirect Branch Prediction Barrier in context switch
  * DKMS driver builds fail with: Cannot use CONFIG_STACK_VALIDATION=y, please
    install libelf-dev, libelf-devel or elfutils-libelf-devel (LP: #1760876)
    - [Packaging] include the retpoline extractor in the headers
  * retpoline hints: primary infrastructure and initial hints (LP: #1758856)
    - [Packaging] retpoline-extract: flag *0xNNN(%reg) branches
    - x86/speculation, objtool: Annotate indirect calls/jumps for objtool
    - x86/speculation, objtool: Annotate indirect calls/jumps for objtool on 32bit
    - x86/paravirt, objtool: Annotate indirect calls
    - [Packaging] retpoline -- add safe usage hint support
    - [Packaging] retpoline-check -- only report additions
    - [Packaging] retpoline -- widen indirect call/jmp detection
    - [Packaging] retpoline -- elide %rip relative indirections
    - [Packaging] retpoline -- clear hint information from packages
    - KVM: x86: Make indirect calls in emulator speculation safe
    - KVM: VMX: Make indirect call speculation safe
    - x86/boot, objtool: Annotate indirect jump in secondary_startup_64()
    - SAUCE: early/late -- annotate indirect calls in early/late initialisation
      code
    - SAUCE: vga_set_mode -- avoid jump tables
    - [Config] retpoline -- switch to new format
    - [Packaging] retpoline hints -- handle missing files when RETPOLINE not
      enabled
    - [Packaging] final-checks -- remove check for empty retpoline files
  * retpoline: ignore %cs:0xNNN constant indirections (LP: #1752655)
    - [Packaging] retpoline -- elide %cs:0xNNNN constants on i386
  * zfs system process hung on container stop/delete (LP: #1754584)
    - SAUCE: Fix non-prefaulted page deadlock (LP: #1754584)
  * zfs-linux 0.6.5.11-1ubuntu5 ADT test failure with linux 4.15.0-1.2
    (LP: #1737761)
    ...

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is missing log files that will aid in diagnosing the problem. While running an Ubuntu kernel (not a mainline or third-party kernel) please enter the following command in a terminal window:

apport-collect 1758378

and then change the status of the bug to 'Confirmed'.

If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.

[Marcelo Cerri (mhcerri)]

https://lists.ubuntu.com/archives/kernel-team/2018-June/093239.html

[Brad Figg (brad-figg)]

This bug is awaiting verification that the kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed-bionic' to 'verification-done-bionic'. If the problem still exists, change the tag 'verification-needed-bionic' to 'verification-failed-bionic'.

If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed.

See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you!

[Launchpad Janitor (janitor)]

This bug was fixed in the package linux - 4.15.0-24.26

---------------
linux (4.15.0-24.26) bionic; urgency=medium

  * linux: 4.15.0-24.26 -proposed tracker (LP: #1776338)

  * Bionic update: upstream stable patchset 2018-06-06 (LP: #1775483)
    - drm: bridge: dw-hdmi: Fix overflow workaround for Amlogic Meson GX SoCs
    - i40e: Fix attach VF to VM issue
    - tpm: cmd_ready command can be issued only after granting locality
    - tpm: tpm-interface: fix tpm_transmit/_cmd kdoc
    - tpm: add retry logic
    - Revert "ath10k: send (re)assoc peer command when NSS changed"
    - bonding: do not set slave_dev npinfo before slave_enable_netpoll in
      bond_enslave
    - ipv6: add RTA_TABLE and RTA_PREFSRC to rtm_ipv6_policy
    - ipv6: sr: fix NULL pointer dereference in seg6_do_srh_encap()- v4 pkts
    - KEYS: DNS: limit the length of option strings
    - l2tp: check sockaddr length in pppol2tp_connect()
    - net: validate attribute sizes in neigh_dump_table()
    - llc: delete timers synchronously in llc_sk_free()
    - tcp: don't read out-of-bounds opsize
    - net: af_packet: fix race in PACKET_{R|T}X_RING
    - tcp: md5: reject TCP_MD5SIG or TCP_MD5SIG_EXT on established sockets
    - net: fix deadlock while clearing neighbor proxy table
    - team: avoid adding twice the same option to the event list
    - net/smc: fix shutdown in state SMC_LISTEN
    - team: fix netconsole setup over team
    - packet: fix bitfield update race
    - tipc: add policy for TIPC_NLA_NET_ADDR
    - pppoe: check sockaddr length in pppoe_connect()
    - vlan: Fix reading memory beyond skb->tail in skb_vlan_tagged_multi
    - amd-xgbe: Add pre/post auto-negotiation phy hooks
    - sctp: do not check port in sctp_inet6_cmp_addr
    - amd-xgbe: Improve KR auto-negotiation and training
    - strparser: Do not call mod_delayed_work with a timeout of LONG_MAX
    - amd-xgbe: Only use the SFP supported transceiver signals
    - strparser: Fix incorrect strp->need_bytes value.
    - net: sched: ife: signal not finding metaid
    - tcp: clear tp->packets_out when purging write queue
    - net: sched: ife: handle malformed tlv length
    - net: sched: ife: check on metadata length
    - llc: hold llc_sap before release_sock()
    - llc: fix NULL pointer deref for SOCK_ZAPPED
    - net: ethernet: ti: cpsw: fix tx vlan priority mapping
    - virtio_net: split out ctrl buffer
    - virtio_net: fix adding vids on big-endian
    - KVM: s390: force bp isolation for VSIE
    - s390: correct module section names for expoline code revert
    - microblaze: Setup dependencies for ASM optimized lib functions
    - commoncap: Handle memory allocation failure.
    - scsi: mptsas: Disable WRITE SAME
    - cdrom: information leak in cdrom_ioctl_media_changed()
    - m68k/mac: Don't remap SWIM MMIO region
    - block/swim: Check drive type
    - block/swim: Don't log an error message for an invalid ioctl
    - block/swim: Remove extra put_disk() call from error path
    - block/swim: Rename macros to avoid inconsistent inverted logic
    - block/swim: Select appropriate drive on device open
    - block/swim: Fix array bounds check
    - block/swim: Fix IO error at end of medium
    -...

[Launchpad Janitor (janitor)]

This bug was fixed in the package linux - 4.15.0-29.31

---------------
linux (4.15.0-29.31) bionic; urgency=medium

  * linux: 4.15.0-29.31 -proposed tracker (LP: #1782173)

  * [SRU Bionic][Cosmic] kernel panic in ipmi_ssif at msg_done_handler
    (LP: #1777716)
    - ipmi_ssif: Fix kernel panic at msg_done_handler

  * Update to ocxl driver for 18.04.1 (LP: #1775786)
    - misc: ocxl: use put_device() instead of device_unregister()
    - powerpc: Add TIDR CPU feature for POWER9
    - powerpc: Use TIDR CPU feature to control TIDR allocation
    - powerpc: use task_pid_nr() for TID allocation
    - ocxl: Rename pnv_ocxl_spa_remove_pe to clarify it's action
    - ocxl: Expose the thread_id needed for wait on POWER9
    - ocxl: Add an IOCTL so userspace knows what OCXL features are available
    - ocxl: Document new OCXL IOCTLs
    - ocxl: Fix missing unlock on error in afu_ioctl_enable_p9_wait()

  * Critical upstream bugfix missing in Ubuntu 18.04 - frequent Xorg crash after
    suspend (LP: #1776887)
    - ocxl: Document the OCXL_IOCTL_GET_METADATA IOCTL

  * Hard LOCKUP observed on stressing Ubuntu 18 04 (LP: #1777194)
    - powerpc: use NMI IPI for smp_send_stop
    - powerpc: Fix smp_send_stop NMI IPI handling

  * IPL: ppc64_cpu --frequency hang with INFO: rcu_sched detected stalls on
    CPUs/tasks on w34 and wsbmc016 with 920.1714.20170330n (LP: #1773964)
    - rtc: opal: Fix OPAL RTC driver OPAL_BUSY loops

  * [Regression] EXT4-fs error (device sda2): ext4_validate_block_bitmap:383:
    comm stress-ng: bg 4705: bad block bitmap checksum (LP: #1781709)
    - SAUCE: Revert "UBUNTU: SAUCE: ext4: fix ext4_validate_inode_bitmap: comm
      stress-ng: Corrupt inode bitmap"
    - SAUCE: ext4: check for allocation block validity with block group locked

linux (4.15.0-28.30) bionic; urgency=medium

  * linux: 4.15.0-28.30 -proposed tracker (LP: #1781433)

  * Cannot set MTU higher than 1500 in Xen instance (LP: #1781413)
    - xen-netfront: Fix mismatched rtnl_unlock
    - xen-netfront: Update features after registering netdev

linux (4.15.0-27.29) bionic; urgency=medium

  * linux: 4.15.0-27.29 -proposed tracker (LP: #1781062)

  * [Regression] EXT4-fs error (device sda1): ext4_validate_inode_bitmap:99:
    comm stress-ng: Corrupt inode bitmap (LP: #1780137)
    - SAUCE: ext4: fix ext4_validate_inode_bitmap: comm stress-ng: Corrupt inode
      bitmap

linux (4.15.0-26.28) bionic; urgency=medium

  * linux: 4.15.0-26.28 -proposed tracker (LP: #1780112)

  * failure to boot with linux-image-4.15.0-24-generic (LP: #1779827) // Cloud-
    init causes potentially huge boot delays with 4.15 kernels (LP: #1780062)
    - random: Make getrandom() ready earlier

linux (4.15.0-25.27) bionic; urgency=medium

  * linux: 4.15.0-25.27 -proposed tracker (LP: #1779354)

  * hisi_sas_v3_hw: internal task abort: timeout and not done. (LP: #1777736)
    - scsi: hisi_sas: Update a couple of register settings for v3 hw

  * hisi_sas: Add missing PHY spinlock init (LP: #1777734)
    - scsi: hisi_sas: Add missing PHY spinlock init

  * hisi_sas: improve read performance by pre-allocating slot DMA buffers
    (LP: #1777727)
    - scsi: hisi_sas: use dma_zalloc_cohe...