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* [PATCH v8 00/26] APEI in_nmi() rework and SDEI wire-up
@ 2019-01-29 18:48 James Morse
  2019-01-29 18:48 ` [PATCH v8 01/26] ACPI / APEI: Don't wait to serialise with oops messages when panic()ing James Morse
                   ` (26 more replies)
  0 siblings, 27 replies; 36+ messages in thread
From: James Morse @ 2019-01-29 18:48 UTC (permalink / raw)
  To: linux-acpi
  Cc: Rafael Wysocki, Tony Luck, Xie XiuQi, Marc Zyngier,
	Catalin Marinas, Will Deacon, Christoffer Dall, Dongjiu Geng,
	linux-mm, Borislav Petkov, james.morse, Naoya Horiguchi, kvmarm,
	linux-arm-kernel, Len Brown

Changes since v7?
 * Removed the memory allocation in the task_work stuff.
 * More user-friendly and easier on the eye,
 * Switched the irq-mask testing in the arch code to be safe before&after
   Julien's GIC PMR series.
Specific changes are noted in each patch.


This series aims to wire-up arm64's fancy new software-NMI notifications
for firmware-first RAS. These need to use the estatus-queue, which is
also needed for notifications via emulated-SError. All of these
things take the 'in_nmi()' path through ghes_copy_tofrom_phys(), and
so will deadlock if they can interact, which they might.

To that end, this series removes the in_nmi() stuff from ghes.c.
Locks are pushed out to the notification helpers, and fixmap entries
are passed in to the code that needs them. This means the estatus-queue
users can interrupt each other however they like.

While doing this there is a fair amount of cleanup, which is (now) at the
beginning of the series. NMIlike notifications interrupting
ghes_probe() can go wrong for three different reasons. CPER record
blocks greater than PAGE_SIZE dont' work.
The estatus-pool allocation is simplified and the silent-flag/oops-begin
is removed.

Nothing in this series is intended as fixes, as its all cleanup or
never-worked.

----------%<----------
The earlier boiler-plate:

What's SDEI? Its ARM's "Software Delegated Exception Interface" [0]. It's
used by firmware to tell the OS about firmware-first RAS events.

These Software exceptions can interrupt anything, so I describe them as
NMI-like. They aren't the only NMI-like way to notify the OS about
firmware-first RAS events, the ACPI spec also defines 'NOTFIY_SEA' and
'NOTIFY_SEI'.

(Acronyms: SEA, Synchronous External Abort. The CPU requested some memory,
but the owner of that memory said no. These are always synchronous with the
instruction that caused them. SEI, System-Error Interrupt, commonly called
SError. This is an asynchronous external abort, the memory-owner didn't say no
at the right point. Collectively these things are called external-aborts
How is firmware involved? It traps these and re-injects them into the kernel
once its written the CPER records).

APEI's GHES code only expects one source of NMI. If a platform implements
more than one of these mechanisms, APEI needs to handle the interaction.
'SEA' and 'SEI' can interact as 'SEI' is asynchronous. SDEI can interact
with itself: its exceptions can be 'normal' or 'critical', and firmware
could use both types for RAS. (errors using normal, 'panic-now' using
critical).
----------%<----------

This series is base on v5.0-rc1, and can be retrieved from:
git://linux-arm.org/linux-jm.git -b apei_ioremap_rework/v8


Known issues:
 * ghes_copy_tofrom_phys() already takes a lock in NMI context, this
   series moves that around, and makes sure we never try to take the
   same lock from different NMIlike notifications. Since the switch to
   queued spinlocks it looks like the kernel can only be 4 context's
   deep in spinlock, which arm64 could exceed as it doesn't have a
   single architected NMI. This would be fixed by dropping back to
   test-and-set when the nesting gets too deep:
 lore.kernel.org/r/1548215351-18896-1-git-send-email-longman@redhat.com

* Taking an NMI from a KVM guest on arm64 with VHE leaves HCR_EL2.TGE
  clear, meaning AT and TLBI point at the guest, and PAN/UAO are squiffy.
  Only TLBI matters for APEI, and this is fixed by Julien's patch:
 http://lore.kernel.org/r/1548084825-8803-2-git-send-email-julien.thierry@arm.com

* Linux ignores the physical address mask, meaning it doesn't call
  memory_failure() on all the affected pages if firmware or hypervisor
  believe in a different page size. Easy to hit on arm64, (easy to fix too,
  it just conflicts with this series)


[v7] https://lore.kernel.org/linux-arm-kernel/20181203180613.228133-1-james.morse@arm.com/
[v6] https://www.spinics.net/lists/linux-acpi/msg84228.html
[v5] https://www.spinics.net/lists/linux-acpi/msg82993.html
[v4] https://www.spinics.net/lists/arm-kernel/msg653078.html
[v3] https://www.spinics.net/lists/arm-kernel/msg649230.html

[0] https://static.docs.arm.com/den0054/a/ARM_DEN0054A_Software_Delegated_Exception_Interface.pdf


James Morse (26):
  ACPI / APEI: Don't wait to serialise with oops messages when
    panic()ing
  ACPI / APEI: Remove silent flag from ghes_read_estatus()
  ACPI / APEI: Switch estatus pool to use vmalloc memory
  ACPI / APEI: Make hest.c manage the estatus memory pool
  ACPI / APEI: Make estatus pool allocation a static size
  ACPI / APEI: Don't store CPER records physical address in struct ghes
  ACPI / APEI: Remove spurious GHES_TO_CLEAR check
  ACPI / APEI: Don't update struct ghes' flags in read/clear estatus
  ACPI / APEI: Generalise the estatus queue's notify code
  ACPI / APEI: Don't allow ghes_ack_error() to mask earlier errors
  ACPI / APEI: Move NOTIFY_SEA between the estatus-queue and NOTIFY_NMI
  ACPI / APEI: Switch NOTIFY_SEA to use the estatus queue
  KVM: arm/arm64: Add kvm_ras.h to collect kvm specific RAS plumbing
  arm64: KVM/mm: Move SEA handling behind a single 'claim' interface
  ACPI / APEI: Move locking to the notification helper
  ACPI / APEI: Let the notification helper specify the fixmap slot
  ACPI / APEI: Pass ghes and estatus separately to avoid a later copy
  ACPI / APEI: Make GHES estatus header validation more user friendly
  ACPI / APEI: Split ghes_read_estatus() to allow a peek at the CPER
    length
  ACPI / APEI: Only use queued estatus entry during
    in_nmi_queue_one_entry()
  ACPI / APEI: Use separate fixmap pages for arm64 NMI-like
    notifications
  mm/memory-failure: Add memory_failure_queue_kick()
  ACPI / APEI: Kick the memory_failure() queue for synchronous errors
  arm64: acpi: Make apei_claim_sea() synchronise with APEI's irq work
  firmware: arm_sdei: Add ACPI GHES registration helper
  ACPI / APEI: Add support for the SDEI GHES Notification type

 arch/arm/include/asm/kvm_ras.h       |  14 +
 arch/arm/include/asm/system_misc.h   |   5 -
 arch/arm64/include/asm/acpi.h        |   4 +-
 arch/arm64/include/asm/daifflags.h   |   1 +
 arch/arm64/include/asm/fixmap.h      |   6 +-
 arch/arm64/include/asm/kvm_ras.h     |  25 +
 arch/arm64/include/asm/system_misc.h |   2 -
 arch/arm64/kernel/acpi.c             |  54 ++
 arch/arm64/mm/fault.c                |  25 +-
 drivers/acpi/apei/Kconfig            |  12 +-
 drivers/acpi/apei/ghes.c             | 725 ++++++++++++++++-----------
 drivers/acpi/apei/hest.c             |  10 +-
 drivers/firmware/arm_sdei.c          |  68 +++
 include/acpi/ghes.h                  |   7 +-
 include/linux/arm_sdei.h             |   9 +
 include/linux/mm.h                   |   1 +
 mm/memory-failure.c                  |  15 +-
 virt/kvm/arm/mmu.c                   |   4 +-
 18 files changed, 646 insertions(+), 341 deletions(-)
 create mode 100644 arch/arm/include/asm/kvm_ras.h
 create mode 100644 arch/arm64/include/asm/kvm_ras.h

-- 
2.20.1


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Thread overview: 36+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-01-29 18:48 [PATCH v8 00/26] APEI in_nmi() rework and SDEI wire-up James Morse
2019-01-29 18:48 ` [PATCH v8 01/26] ACPI / APEI: Don't wait to serialise with oops messages when panic()ing James Morse
2019-01-29 18:48 ` [PATCH v8 02/26] ACPI / APEI: Remove silent flag from ghes_read_estatus() James Morse
2019-01-29 18:48 ` [PATCH v8 03/26] ACPI / APEI: Switch estatus pool to use vmalloc memory James Morse
2019-01-29 18:48 ` [PATCH v8 04/26] ACPI / APEI: Make hest.c manage the estatus memory pool James Morse
2019-02-01 13:20   ` Borislav Petkov
2019-01-29 18:48 ` [PATCH v8 05/26] ACPI / APEI: Make estatus pool allocation a static size James Morse
2019-01-29 18:48 ` [PATCH v8 06/26] ACPI / APEI: Don't store CPER records physical address in struct ghes James Morse
2019-01-29 18:48 ` [PATCH v8 07/26] ACPI / APEI: Remove spurious GHES_TO_CLEAR check James Morse
2019-01-29 18:48 ` [PATCH v8 08/26] ACPI / APEI: Don't update struct ghes' flags in read/clear estatus James Morse
2019-01-29 18:48 ` [PATCH v8 09/26] ACPI / APEI: Generalise the estatus queue's notify code James Morse
2019-02-01 13:46   ` Borislav Petkov
2019-01-29 18:48 ` [PATCH v8 10/26] ACPI / APEI: Don't allow ghes_ack_error() to mask earlier errors James Morse
2019-01-29 18:48 ` [PATCH v8 11/26] ACPI / APEI: Move NOTIFY_SEA between the estatus-queue and NOTIFY_NMI James Morse
2019-01-29 18:48 ` [PATCH v8 12/26] ACPI / APEI: Switch NOTIFY_SEA to use the estatus queue James Morse
2019-01-29 18:48 ` [PATCH v8 13/26] KVM: arm/arm64: Add kvm_ras.h to collect kvm specific RAS plumbing James Morse
2019-01-29 18:48 ` [PATCH v8 14/26] arm64: KVM/mm: Move SEA handling behind a single 'claim' interface James Morse
2019-01-29 18:48 ` [PATCH v8 15/26] ACPI / APEI: Move locking to the notification helper James Morse
2019-01-29 18:48 ` [PATCH v8 16/26] ACPI / APEI: Let the notification helper specify the fixmap slot James Morse
2019-01-29 18:48 ` [PATCH v8 17/26] ACPI / APEI: Pass ghes and estatus separately to avoid a later copy James Morse
2019-01-29 18:48 ` [PATCH v8 18/26] ACPI / APEI: Make GHES estatus header validation more user friendly James Morse
2019-02-01 14:30   ` Borislav Petkov
2019-01-29 18:48 ` [PATCH v8 19/26] ACPI / APEI: Split ghes_read_estatus() to allow a peek at the CPER length James Morse
2019-01-29 18:48 ` [PATCH v8 20/26] ACPI / APEI: Only use queued estatus entry during in_nmi_queue_one_entry() James Morse
2019-01-29 18:48 ` [PATCH v8 21/26] ACPI / APEI: Use separate fixmap pages for arm64 NMI-like notifications James Morse
2019-01-29 18:48 ` [PATCH v8 22/26] mm/memory-failure: Add memory_failure_queue_kick() James Morse
2019-01-29 18:48 ` [PATCH v8 23/26] ACPI / APEI: Kick the memory_failure() queue for synchronous errors James Morse
2019-01-29 18:49 ` [PATCH v8 24/26] arm64: acpi: Make apei_claim_sea() synchronise with APEI's irq work James Morse
2019-01-30  8:56   ` Julien Thierry
2019-01-29 18:49 ` [PATCH v8 25/26] firmware: arm_sdei: Add ACPI GHES registration helper James Morse
2019-01-29 18:49 ` [PATCH v8 26/26] ACPI / APEI: Add support for the SDEI GHES Notification type James Morse
2019-02-08 11:40 ` [PATCH v8 00/26] APEI in_nmi() rework and SDEI wire-up Rafael J. Wysocki
2019-02-08 14:13   ` James Morse
2019-02-11 11:05     ` Rafael J. Wysocki
2019-02-11 18:35       ` James Morse
2019-02-12 22:14         ` Rafael J. Wysocki

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