Re: [PATCH v5 00/10] EFI Specific Purpose Memory Support

[Jonathan Cameron]

On Fri, 6 Sep 2019 13:37:30 +0200
"Rafael J. Wysocki" <rafael.j.wysocki@xxxxxxxxx> wrote:

> On 9/5/2019 1:06 AM, Dan Williams wrote:
> > On Mon, Sep 2, 2019 at 4:09 AM Rafael J. Wysocki <rjw@xxxxxxxxxxxxx> wrote:  
> >> On Friday, August 30, 2019 3:52:18 AM CEST Dan Williams wrote:  
> >>> Changes since v4 [1]:
> >>> - Rename the facility from "Application Reserved" to "Soft Reserved" to
> >>>    better reflect how the memory is treated. While the spec talks about
> >>>    "specific / application purpose" memory the expected kernel behavior is
> >>>    to make a best effort at reserving the memory from general purpose
> >>>    allocations.
> >>>
> >>> - Add a new efi=nosoftreserve option to disable consideration of the
> >>>    EFI_MEMORY_SP attribute at boot time. This is also motivated by
> >>>    Christoph's initial feedback of allowing the kernel to opt-out of the
> >>>    policy whims of the platform BIOS implementation.
> >>>
> >>> - Update the KASLR implementation to exclude soft-reserved memory
> >>>    including the case where soft-reserved memory is specified via the
> >>>    efi_fake_mem= attribute-override command-line option.
> >>>
> >>> - Move the memregion allocator to its own object file. v4 had it in
> >>>    kernel/resource.c which caused compile errors on Sparc. I otherwise
> >>>    could not find an appropriate place to stash it.
> >>>
> >>> - Rebase on a merge of tip/master and rafael/linux-next since the series
> >>>    collides with changes in both those trees.
> >>>
> >>> [1]: https://lore.kernel.org/r/156140036490.2951909.1837804994781523185.stgit@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/
> >>>
> >>> ---
> >>>
> >>> Thomas, Rafael,
> >>>
> >>> This happens to collide with both your trees. I think the content
> >>> warrants going through the x86 tree, but would need to publish commit:
> >>>
> >>> 5c7ed4385424 HMAT: Skip publishing target info for nodes with no online memory
> >>>
> >>> ...in Rafael's tree as a stable id for -tip to pull in, but I'm also
> >>> open to other options. I've retained Dave's reviewed-by from v4.
> >>>
> >>> ---
> >>>
> >>> The EFI 2.8 Specification [2] introduces the EFI_MEMORY_SP ("specific
> >>> purpose") memory attribute. This attribute bit replaces the deprecated
> >>> ACPI HMAT "reservation hint" that was introduced in ACPI 6.2 and removed
> >>> in ACPI 6.3.
> >>>
> >>> Given the increasing diversity of memory types that might be advertised
> >>> to the operating system, there is a need for platform firmware to hint
> >>> which memory ranges are free for the OS to use as general purpose memory
> >>> and which ranges are intended for application specific usage. For
> >>> example, an application with prior knowledge of the platform may expect
> >>> to be able to exclusively allocate a precious / limited pool of high
> >>> bandwidth memory. Alternatively, for the general purpose case, the
> >>> operating system may want to make the memory available on a best effort
> >>> basis as a unique numa-node with performance properties by the new
> >>> CONFIG_HMEM_REPORTING [3] facility.
> >>>
> >>> In support of optionally allowing either application-exclusive and
> >>> core-kernel-mm managed access to differentiated memory, claim
> >>> EFI_MEMORY_SP ranges for exposure as "soft reserved" and assigned to a
> >>> device-dax instance by default. Such instances can be directly owned /
> >>> mapped by a platform-topology-aware application. Alternatively, with the
> >>> new kmem facility [4], the administrator has the option to instead
> >>> designate that those memory ranges be hot-added to the core-kernel-mm as
> >>> a unique memory numa-node. In short, allow for the decision about what
> >>> software agent manages soft-reserved memory to be made at runtime.
> >>>
> >>> The patches build on the new HMAT+HMEM_REPORTING facilities merged
> >>> for v5.2-rc1. The implementation is tested with qemu emulation of HMAT
> >>> [5] plus the efi_fake_mem facility for applying the EFI_MEMORY_SP
> >>> attribute. Specific details on reproducing the test configuration are in
> >>> patch 10.
> >>>
> >>> [2]: https://uefi.org/sites/default/files/resources/UEFI_Spec_2_8_final.pdf
> >>> [3]: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=e1cf33aafb84
> >>> [4]: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=c221c0b0308f
> >>> [5]: http://patchwork.ozlabs.org/cover/1096737/
> >>>
> >>> ---
> >>>
> >>> Dan Williams (10):
> >>>        acpi/numa: Establish a new drivers/acpi/numa/ directory
> >>>        efi: Enumerate EFI_MEMORY_SP
> >>>        x86, efi: Push EFI_MEMMAP check into leaf routines
> >>>        x86, efi: Reserve UEFI 2.8 Specific Purpose Memory for dax
> >>>        x86, efi: Add efi_fake_mem support for EFI_MEMORY_SP
> >>>        lib: Uplevel the pmem "region" ida to a global allocator
> >>>        dax: Fix alloc_dax_region() compile warning
> >>>        device-dax: Add a driver for "hmem" devices
> >>>        acpi/numa/hmat: Register HMAT at device_initcall level
> >>>        acpi/numa/hmat: Register "soft reserved" memory as an "hmem" device
> >>>
> >>>
> >>>   Documentation/admin-guide/kernel-parameters.txt |   19 +++
> >>>   arch/x86/Kconfig                                |   21 ++++
> >>>   arch/x86/boot/compressed/eboot.c                |    7 +
> >>>   arch/x86/boot/compressed/kaslr.c                |   50 +++++++-
> >>>   arch/x86/include/asm/e820/types.h               |    8 +
> >>>   arch/x86/include/asm/efi-stub.h                 |   11 ++
> >>>   arch/x86/include/asm/efi.h                      |   17 +++
> >>>   arch/x86/kernel/e820.c                          |   12 ++
> >>>   arch/x86/kernel/setup.c                         |   19 ++-
> >>>   arch/x86/platform/efi/efi.c                     |   56 +++++++++
> >>>   arch/x86/platform/efi/quirks.c                  |    3 +
> >>>   drivers/acpi/Kconfig                            |    9 --
> >>>   drivers/acpi/Makefile                           |    3 -
> >>>   drivers/acpi/hmat/Makefile                      |    2
> >>>   drivers/acpi/numa/Kconfig                       |    8 +
> >>>   drivers/acpi/numa/Makefile                      |    3 +
> >>>   drivers/acpi/numa/hmat.c                        |  138 +++++++++++++++++++++--
> >>>   drivers/acpi/numa/srat.c                        |    0
> >>>   drivers/dax/Kconfig                             |   27 ++++-
> >>>   drivers/dax/Makefile                            |    2
> >>>   drivers/dax/bus.c                               |    2
> >>>   drivers/dax/bus.h                               |    2
> >>>   drivers/dax/dax-private.h                       |    2
> >>>   drivers/dax/hmem.c                              |   57 ++++++++++
> >>>   drivers/firmware/efi/Makefile                   |    5 +
> >>>   drivers/firmware/efi/efi.c                      |    8 +
> >>>   drivers/firmware/efi/esrt.c                     |    3 +
> >>>   drivers/firmware/efi/fake_mem.c                 |   26 ++--
> >>>   drivers/firmware/efi/fake_mem.h                 |   10 ++
> >>>   drivers/firmware/efi/libstub/efi-stub-helper.c  |   12 ++
> >>>   drivers/firmware/efi/x86-fake_mem.c             |   69 ++++++++++++
> >>>   drivers/nvdimm/Kconfig                          |    1
> >>>   drivers/nvdimm/core.c                           |    1
> >>>   drivers/nvdimm/nd-core.h                        |    1
> >>>   drivers/nvdimm/region_devs.c                    |   13 +-
> >>>   include/linux/efi.h                             |    4 -
> >>>   include/linux/ioport.h                          |    1
> >>>   include/linux/memregion.h                       |   23 ++++
> >>>   lib/Kconfig                                     |    3 +
> >>>   lib/Makefile                                    |    1
> >>>   lib/memregion.c                                 |   18 +++
> >>>   41 files changed, 584 insertions(+), 93 deletions(-)
> >>>   create mode 100644 arch/x86/include/asm/efi-stub.h
> >>>   delete mode 100644 drivers/acpi/hmat/Makefile
> >>>   rename drivers/acpi/{hmat/Kconfig => numa/Kconfig} (70%)
> >>>   create mode 100644 drivers/acpi/numa/Makefile
> >>>   rename drivers/acpi/{hmat/hmat.c => numa/hmat.c} (85%)
> >>>   rename drivers/acpi/{numa.c => numa/srat.c} (100%)
> >>>   create mode 100644 drivers/dax/hmem.c
> >>>   create mode 100644 drivers/firmware/efi/fake_mem.h
> >>>   create mode 100644 drivers/firmware/efi/x86-fake_mem.c
> >>>   create mode 100644 include/linux/memregion.h
> >>>   create mode 100644 lib/memregion.c
> >>>  
> >> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
> >>
> >> for the ACPI-related changes in this series.  
> > Thanks Rafael, is commit 5c7ed4385424 on a stable branch that Thomas
> > could merge, or Thomas, is this all too late for v5.4?  
> 
> Yes, I've just exported the acpi-tables branch containing that commit as 
> a stable one in the linux-pm.git tree at kernel.org.
> 
> Cheers!
> 
Hi All,

Just wondering when this set might make progress? As Rafael observed,
the Generic Initiator set needs rebasing on top of it under the
reasonable assumption that this gets applied first.

Thanks,

Jonathan