Message-ID: <CAJZ5v0jJgqtScVa7855X=e5sE++af3AiZ+C33ooA5WsQs_UV5A@mail.gmail.com>
Date:   Wed, 22 Dec 2021 18:16:00 +0100
From:   "Rafael J. Wysocki" <rafael@...nel.org>
To:     Chen Yu <yu.c.chen@...el.com>
Cc:     ACPI Devel Maling List <linux-acpi@...r.kernel.org>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        "Rafael J. Wysocki" <rafael@...nel.org>,
        Ard Biesheuvel <ardb@...nel.org>, Len Brown <lenb@...nel.org>,
        Ashok Raj <ashok.raj@...el.com>,
        Andy Shevchenko <andriy.shevchenko@...el.com>,
        Mike Rapoport <rppt@...nel.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v13 0/4] Introduce Platform Firmware Runtime Update and
 Telemetry drivers

On Wed, Dec 22, 2021 at 5:27 AM Chen Yu <yu.c.chen@...el.com> wrote:
>
> The PFRUT(Platform Firmware Runtime Update and Telemetry) kernel interface
> is designed to interact with the platform firmware interface defined in the
> `Management Mode Firmware Runtime Update
> <https://uefi.org/sites/default/files/resources/Intel_MM_OS_Interface_Spec_Rev100.pdf>`
> specification. The primary function of PFRUT is to carry out runtime
> updates of the platform firmware, which doesn't require the system to
> be restarted. It also allows telemetry data to be retrieved from the
> platform firmware.
>
> =============
> - Change from v12 to v13:
>   - Print the _DSM failure result if invalid EFI capsule is provided.
>     (Hongyu Ning)
> - Change from v11 to v12:
>   - Rename the driver from pfru_update to pfr_update, and the
>     telemetry part to pfr_telementry for symmetry.
>     (Rafael J. Wysocki)
>   - Rename the "capsule file" to "EFI capsule".
>     (Rafael J. Wysocki)
>   - Revise the commit log. (Rafael J. Wysocki)
>   - Add the reason in the commit log that explains why it is
>     a good idea to add this driver to the kernel.
>     (Rafael J. Wysocki)
>   - Rename pfru.h to pfrut.h (Rafael J. Wysocki)
>   - Rename the CONFIG_ACPI_PFRU to CONFIG_ACPI_PFRUT
>     (Rafael J. Wysocki)
>   - Rename the Kconfig name to "ACPI Platform Firmware Runtime
>     Update and Telemetry"
>     (Rafael J. Wysocki)
>   - Revise the Kconfig help message (Rafael J. Wysocki)
>   - Describe what the driver is for briefly in the beginning of
>     the source code file.
>     (Rafael J. Wysocki)
>   - Add a comment pointing to the definitions of the GUIDs and
>     explain briefly what they are for.
>     (Rafael J. Wysocki)
>   - Reduce redundant memory updates by doing all of the checks
>     upfront. (Rafael J. Wysocki)
>   - Rename valid_version() to applicable_image(), and revise the
>     comment.(Rafael J. Wysocki)
>   - Remove Redundant else in applicable_image().(Rafael J. Wysocki)
>   - Rename dump_update_result() to print_ipdate_debug_info().
>     (Rafael J. Wysocki)
>   - Rename start_acpi_update() to start_update()(Rafael J. Wysocki)
>     Add a blank line before each "case xxx:"(Rafael J. Wysocki)
>   - Move status check into query_capability() and returns -EBUSY if
>     fails(Rafael J. Wysocki)
>   - Rename the device node name from "acpi_pfru%d" to "acpi_pfr_update%d"
>     (Rafael J. Wysocki)
>   - Rename the drive name from "pfru_update" to "pfr_update"
>     (Rafael J. Wysocki)
>   - Rename PFRU_MAGIC_FOR_IOCTL to PFRUT_IOCTL_MAGIC(Rafael J. Wysocki)
>     Fix grammar errors in the comments.(Rafael J. Wysocki)
> - Change from v10 to v11:
>   - Revise the commit log to explain why version check is introduced
>     in kernel rather than letting Management Mode to do it.
>     (Rafael J. Wysocki)
>   - Revise the commit log to better describe the pack attribute.
>     (Rafael J. Wysocki)
>   - Refine the comment for hw_ins and capsule_support.
>     (Rafael J. Wysocki)
> - Change from v9 to v10:
>   - Remove the explicit assignment of the last item of enum.
>     (Andy Shevchenko)
> - Change from v8 to v9:
>   - Use GUID_INIT() instead of guid_parse() during boot up.
>     (Andy Shevchenko)
>   - Drop uuid, code_uuid, drv_uuid in struct pfru_device as they
>     are not needed. (Andy Shevchenko)
>   - Drop type casting from void * in valid_version().
>     (Andy Shevchenko)
>   - Use kfree() instead of ACPI_FREE() in non-ACPICA usage.
>     (Andy Shevchenko)
>   - Use sizeof(rev) instead of sizeof(u32) in copy_from_user().
>     (Andy Shevchenko)
>   - Generate physical address from MSB part to LSB.
>     (Andy Shevchenko)
>   - Use devm_add_action_or_reset() to add ida release into dev resource
>     management. (Andy Shevchenko)
>   - Use devm_kasprintf() instead of kasprintf() to format the
>     pfru_dev name.(Andy Shevchenko)
>   - Remove redundant 0 in acpi_pfru_ids. (Andy Shevchenko)
>   - Adjust the order of included headers in pfru.h.
>     (Andy Shevchenko)
>   - Replace PFRU_MAGIC with PFRU_MAGIC_FOR_IOCTL in uapi file.
>     (Andy Shevchenko)
>     Use devm_kasprintf() instead of kasprintf() to format the
>     pfru_log_dev name.(Andy Shevchenko)
>     Remove redundant 0 in acpi_pfru_log_ids. (Andy Shevchenko)
> - Change from v7 to v8:
>   - Remove the variable-length array in struct pfru_update_cap_info, and
>     copy the non-variable-length struct pfru_update_cap_info to userspace
>     directly. (Greg Kroah-Hartman)
>   - Use efi_guid_t instead of guid_t when parsing capsule file.
>     (Andy Shevchenko)
>   - Change the type of rev_id from int to u32, because this data will
>     be copied between kernel and userspace. (Greg Kroah-Hartman)
>   - Add a prefix for dev in struct pfru_device to parent_dev, so as
>     to indicate that this filed is the parent of the created miscdev.
>     (Greg Kroah-Hartman)
>   - Use blank lines between different macro sections. (Greg Kroah-Hartman)
>     Illusatrate the possible errno for each ioctl interface.
>     (Greg Kroah-Hartman)
>   - Remove pfru_valid_revid() from uapi header to avoid poluting the global
>     namespace.(Greg Kroah-Hartman)
>   - Assign the value to the enum type explicitly.(Greg Kroah-Hartman)
>   - Change the guid_t to efi_guid_t when parsing image header in get_image_type()
>     (Greg Kroah-Hartman)
>   - Remove the void * to other type casting in valid_version(). (Andy Shevchenko)
>   - Combined the assignment of variables with definitions. (Andy Shevchenko)
>   - Define this magic for revision ID. (Andy Shevchenko)
>   - Make the labeling consistent for error handling. (Andy Shevchenko)
>   - Replace the UUID_SIZE in uapi with 16 directly. (Andy Shevchenko)
>   - Add blank line between generic include header and uapi header.
>     (Andy Shevchenko)
>   - Arrange the order between devm_kzalloc() and normal allocation in
>     acpi_pfru_probe() that, the former should always be ahead of the
>     latter. (Andy Shevchenko)
> - Change from v6 to v7:
>   - Use __packed instead of pragma pack(1).
>     (Greg Kroah-Hartman, Ard Biesheuve)
>   - Use ida_alloc() to allocate a ID, and release the ID when
>     device is removed. (Greg Kroah-Hartman)
>   - Check the _DSM method at early stage, before allocate or parse
>     anything in acpi_pfru_[log_]probe(). (Greg Kroah-Hartman)
>   - Set the parent of the misc device. (Greg Kroah-Hartman)
>   - Use module_platform_driver() instead of platform_driver_register()
>     in module_init(). Separate pfru driver and pfru_telemetry driver
>     to two files. (Greg Kroah-Hartman)
> - Change from v5 to v6:
>   - Use Link: tag to add the specification download address.
>     (Andy Shevchenko)
>   - Drop comma for each terminator entry in the enum structure.
>     (Andy Shevchenko)
>   - Remove redundant 'else' in get_image_type().
>     (Andy Shevchenko)
>   - Directly return results from the switch cases in adjust_efi_size()
>     and pfru_ioctl().(Andy Shevchenko)
>   - Keep comment style consistency by removing the period for
>     one line comment.
>     (Andy Shevchenko)
>   - Remove devm_kfree() if .probe() failed.
>     (Andy Shevchenko)
>   - Remove linux/uuid.h and use raw buffers to contain uuid.
>     (Andy Shevchenko)
>   - Include types.h in pfru.h. (Andy Shevchenko)
>   - Use __u8[16] instead of uuid_t. (Andy Shevchenko)
>   - Replace enum in pfru.h with __u32 as enum size is not the
>     same size on all possible architectures.
>     (Andy Shevchenko)
>   - Simplify the userspace tool to use while loop for getopt_long().
>     (Andy Shevchenko)
> - Change from v4 to v5:
>   - Remove Documentation/ABI/pfru, and move the content to kernel doc
>     in include/uapi/linux/pfru.h (Greg Kroah-Hartman)
>   - Shrink the range of ioctl numbers declared in
>     Documentation/userspace-api/ioctl/ioctl-number.rst
>     from 16 to 8. (Greg Kroah-Hartman)
>   - Change global variable struct pfru_device *pfru_dev to
>     per PFRU device. (Greg Kroah-Hartman)
>   - Unregister the misc device in acpi_pfru_remove().
>     (Greg Kroah-Hartman)
>   - Convert the kzalloc() to devm_kzalloc() in the driver so
>     as to avoid freeing the memory. (Greg Kroah-Hartman)
>   - Fix the compile warning by declaring the pfru_log_ioctl() as
>     static. (kernel test robot LKP)
>   - Change to global variable misc_device to per PFRU device.
>     (Greg Kroah-Hartman)
>   - Remove the telemetry output in commit log. (Greg Kroah-Hartman)
>   - Add link for corresponding userspace tool in the commit log.
>     (Greg Kroah-Hartman)
>   - Replace the telemetry .read() with .mmap() so that the userspace
>     could mmap once, and read multiple times. (Greg Kroah-Hartman)
> - Change from v3 to v4:
>   - Add Documentation/ABI/testing/pfru to document the ABI and
>     remove Documentation/x86/pfru.rst (Rafael J. Wysocki)
>   - Replace all pr_err() with dev_dbg() (Greg Kroah-Hartman,
>     Rafael J. Wysocki)
>   - returns ENOTTY rather than ENOIOCTLCMD if invalid ioctl command
>     is provided. (Greg Kroah-Hartman)
>   - Remove compat ioctl. (Greg Kroah-Hartman)
>   - Rename /dev/pfru/pfru_update to /dev/acpi_pfru (Greg Kroah-Hartman)
>   - Simplify the check for element of the package in query_capability()
>     (Rafael J. Wysocki)
>   - Remove the loop in query_capability(), query_buffer() and query
>     the package elemenet directly. (Rafael J. Wysocki)
>   - Check the number of elements in case the number of package
>     elements is too small. (Rafael J. Wysocki)
>   - Doing the assignment as initialization in get_image_type().
>     Meanwhile, returns the type or a negative error code in
>     get_image_type(). (Rafael J. Wysocki)
>   - Put the comments inside the function. (Rafael J. Wysocki)
>   - Returns the size or a negative error code in adjust_efi_size()
>     (Rafael J. Wysocki)
>   - Fix the return value from EFAULT to EINVAL if pfru_valid_revid()
>     does not pass. (Rafael J. Wysocki)
>   - Change the write() to be the code injection/update, the read() to
>     be telemetry retrieval and all of the rest to be ioctl()s under
>     one special device file.(Rafael J. Wysocki)
>   - Remove redundant parens. (Rafael J. Wysocki)
>   - Putting empty code lines after an if () statement that is not
>     followed by a block. (Rafael J. Wysocki)
>   - Remove "goto" tags to make the code more readable. (Rafael J. Wysocki)
> - Change from v2 to v3:
>   - Use valid types for structures that cross the user/kernel boundary
>     in the uapi header. (Greg Kroah-Hartman)
>   - Rename the structure in uapi to start with a prefix pfru so as
>     to avoid confusing in the global namespace. (Greg Kroah-Hartman)
> - Change from v1 to v2:
>   - Add a spot in index.rst so it becomes part of the docs build
>     (Jonathan Corbet).
>   - Sticking to the 80-column limit(Jonathan Corbet).
>   - Underline lengths should match the title text(Jonathan Corbet).
>   - Use literal blocks for the code samples(Jonathan Corbet).
>   - Add sanity check for duplicated instance of ACPI device.
>   - Update the driver to work with allocated pfru_device objects.
>     (Mike Rapoport)
>   - For each switch case pair, get rid of the magic case numbers
>     and add a default clause with the error handling.(Mike Rapoport)
>   - Move the obj->type checks outside the switch to reduce redundancy.
>     (Mike Rapoport)
>   - Parse the code_inj_id and drv_update_id at driver initialization time
>     to reduce the re-parsing at runtime. (Mike Rapoport)
>   - Explain in detail how the size needs to be adjusted when doing
>     version check. (Mike Rapoport)
>   - Rename parse_update_result() to dump_update_result()
>     (Mike Rapoport)
>   - Remove redundant return.(Mike Rapoport)
>   - Do not expose struct capsulate_buf_info to uapi, since it is
>     not needed in userspace. (Mike Rapoport)
>   - Do not allow non-root user to run this test.(Shuah Khan)
>   - Test runs on platform without pfru_telemetry should skip
>     instead of reporting failure/error.(Shuah Khan)
>   - Reuse uapi/linux/pfru.h instead of copying it into the test
>     directory. (Mike Rapoport)
>
> Chen Yu (4):
>   efi: Introduce EFI_FIRMWARE_MANAGEMENT_CAPSULE_HEADER and
>     corresponding structures
>   drivers/acpi: Introduce Platform Firmware Runtime Update device driver
>   drivers/acpi: Introduce Platform Firmware Runtime Telemetry
>   tools: Introduce power/acpi/tools/pfrut
>
>  .../userspace-api/ioctl/ioctl-number.rst      |   1 +
>  drivers/acpi/Kconfig                          |  22 +
>  drivers/acpi/Makefile                         |   1 +
>  drivers/acpi/pfr_telemetry.c                  | 434 +++++++++++++
>  drivers/acpi/pfr_update.c                     | 575 ++++++++++++++++++
>  include/linux/efi.h                           |  46 ++
>  include/uapi/linux/pfrut.h                    | 262 ++++++++
>  tools/power/acpi/.gitignore                   |   1 +
>  tools/power/acpi/Makefile                     |  16 +-
>  tools/power/acpi/Makefile.rules               |   2 +-
>  tools/power/acpi/man/pfrut.8                  | 137 +++++
>  tools/power/acpi/tools/pfrut/Makefile         |  23 +
>  tools/power/acpi/tools/pfrut/pfrut.c          | 424 +++++++++++++
>  13 files changed, 1935 insertions(+), 9 deletions(-)
>  create mode 100644 drivers/acpi/pfr_telemetry.c
>  create mode 100644 drivers/acpi/pfr_update.c
>  create mode 100644 include/uapi/linux/pfrut.h
>  create mode 100644 tools/power/acpi/man/pfrut.8
>  create mode 100644 tools/power/acpi/tools/pfrut/Makefile
>  create mode 100644 tools/power/acpi/tools/pfrut/pfrut.c
>
> --

I have one comment regarding the second patch (I'll send it
separately), but generally I'm inclined to pick up the patches in
their current form, barring any objections from Greg.

Thanks!

Powered by blists - more mailing lists