10 Commits

Author SHA1 Message Date
Jithu Joseph
09265345cc platform/x86/intel/ifs: Add missing kernel-doc entry
Document the test_num member of struct ifs_data.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Jithu Joseph <jithu.joseph@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/lkml/774fd22a-aaee-758d-8195-77bac783ecbc@infradead.org/
2022-12-03 11:16:16 +01:00
Jithu Joseph
4fb858f3dc platform/x86/intel/ifs: Add current_batch sysfs entry
Initial implementation assumed a single IFS test image file with a
fixed name ff-mm-ss.scan. (where ff, mm, ss refers to family, model and
stepping of the core).

Subsequently, it became evident that supporting more than one test
image file is needed to provide more comprehensive test coverage. (Test
coverage in this scenario refers to testing more transistors in the core
to identify faults).

The other alternative of increasing the size of a single scan test image
file would not work as the  upper bound is limited by the size of memory
area reserved by BIOS for loading IFS test image.

Introduce "current_batch" file which accepts a number. Writing a
number to the current_batch file would load the test image file by
name ff-mm-ss-<xy>.scan, where <xy> is the number written to the
"current_batch" file in hex. Range check of the input is done to verify
it not greater than 0xff.

For e.g if the scan test image comprises of 6 files, they would be named:

  06-8f-06-01.scan
  06-8f-06-02.scan
  06-8f-06-03.scan
  06-8f-06-04.scan
  06-8f-06-05.scan
  06-8f-06-06.scan

And writing 3 to current_batch would result in loading 06-8f-06-03.scan
above. The file can also be read to know the currently loaded file.

And testing a system looks like:

  for each scan file
  do
  	load the IFS test image file (write to the batch file)
  	for each core
  	do
  		test the core with this set of tests
  	done
  done

Qualify few error messages with the test image file suffix to provide
better context.

  [ bp: Massage commit message. Add link to the discussion. ]

Signed-off-by: Jithu Joseph <jithu.joseph@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Sohil Mehta <sohil.mehta@intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20221107225323.2733518-13-jithu.joseph@intel.com
2022-11-19 11:29:00 +01:00
Jithu Joseph
48c6e7dc19 platform/x86/intel/ifs: Add metadata validation
The data portion of a IFS test image file contains a metadata region
containing possibly multiple metadata structures in addition to test
data and hashes.

    IFS Metadata layout
   +----------------------+  0
   |META_TYPE_IFS (=1)    |
   +----------------------+
   |meta_size             |
   +----------------------+
   |test type             |
   +----------------------+
   |fusa info             |
   +----------------------+
   |total images          |
   +----------------------+
   |current image#        |
   +----------------------+
   |total chunks          |
   +----------------------+
   |starting chunk        |
   +----------------------+
   |size per chunk        |
   +----------------------+
   |chunks per stride     |
   +----------------------+
   |Reserved[54]          |
   +----------------------+ 256
   |                      |
   |  Test Data/Chunks    |
   |                      |
   +----------------------+  meta_size
   |   META_TYPE_END (=0) |
   +----------------------+  meta_size + 4
   |   size of end (=8)   |
   +----------------------+  meta_size + 8

Introduce the layout of this meta_data structure and validate
the sanity of certain fields of the new image before loading.

Tweak references to IFS test image chunks to reflect the updated
layout of the test image.

  [ bp: Massage commit message. ]

Signed-off-by: Jithu Joseph <jithu.joseph@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Sohil Mehta <sohil.mehta@intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20221117230408.30331-1-jithu.joseph@intel.com
2022-11-19 11:22:29 +01:00
Jithu Joseph
cb5eceee81 platform/x86/intel/ifs: Remove memory allocation from load path
IFS requires tests to be authenticated once for each CPU socket on a
system.

scan_chunks_sanity_check() was dynamically allocating memory to store
the state of whether tests have been authenticated on each socket for
every load operation.

Move the memory allocation to init path and store the pointer in
ifs_data struct.

Also rearrange the adjacent error checking in init for a more simplified
and natural flow.

Suggested-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Jithu Joseph <jithu.joseph@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20221117195957.28225-1-jithu.joseph@intel.com
2022-11-18 21:43:18 +01:00
Jithu Joseph
a4c30fa4ea platform/x86/intel/ifs: Remove image loading during init
IFS test image is unnecessarily loaded during driver initialization.
Drop image loading during ifs_init() and improve module load time. With
this change, user has to load one when starting the tests.

As a consequence, make ifs_sem static as it is only used within sysfs.c

Suggested-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Jithu Joseph <jithu.joseph@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Sohil Mehta <sohil.mehta@intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20221117035935.4136738-4-jithu.joseph@intel.com
2022-11-18 21:37:04 +01:00
Tony Luck
34604d2891 Documentation: In-Field Scan
Add documentation for In-Field Scan (IFS). This documentation
describes the basics of IFS, the loading IFS image, chunk
authentication, running scan and how to check result via sysfs.

The CORE_CAPABILITIES MSR enumerates whether IFS is supported.

The full  github location for distributing the IFS images is
still being decided. So just a placeholder included for now
in the documentation.

Future CPUs will support more than one type of test. Plan for
that now by using a "_0" suffix on the ABI directory names.
Additional test types will use "_1", etc.

Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20220506225410.1652287-13-tony.luck@intel.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
2022-05-12 15:35:29 +02:00
Jithu Joseph
6f33a92b92 platform/x86/intel/ifs: Add IFS sysfs interface
Implement sysfs interface to trigger ifs test for a specific cpu.
Additional interfaces related to checking the status of the
scan test and seeing the version of the loaded IFS binary
are also added.

The basic usage is as below.
   - To start test, for example on cpu5:
       echo 5 > /sys/devices/platform/intel_ifs/run_test
   - To see the status of the last test
       cat /sys/devices/platform/intel_ifs/status
   - To see the version of the loaded scan binary
       cat /sys/devices/platform/intel_ifs/image_version

Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jithu Joseph <jithu.joseph@intel.com>
Co-developed-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20220506225410.1652287-10-tony.luck@intel.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
2022-05-12 15:35:29 +02:00
Jithu Joseph
2b40e654b7 platform/x86/intel/ifs: Add scan test support
In a core, the scan engine is shared between sibling cpus.

When a Scan test (for a particular core) is triggered by the user,
the scan chunks are executed on all the threads on the core using
stop_core_cpuslocked.

Scan may be aborted by some reasons. Scan test will be aborted in certain
circumstances such as when interrupt occurred or cpu does not have enough
power budget for scan. In this case, the kernel restart scan from the chunk
where it stopped. Scan will also be aborted when the test is failed. In
this case, the test is immediately stopped without retry.

Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jithu Joseph <jithu.joseph@intel.com>
Co-developed-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20220506225410.1652287-9-tony.luck@intel.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
2022-05-12 15:35:29 +02:00
Jithu Joseph
684ec21570 platform/x86/intel/ifs: Authenticate and copy to secured memory
The IFS image contains hashes that will be used to authenticate the ifs
test chunks. First, use WRMSR to copy the hashes and enumerate the number
of test chunks, chunk size and the maximum number of cores that can run
scan test simultaneously.

Next, use WRMSR to authenticate each and every scan test chunk which is
stored in the IFS image. The CPU will check if the test chunks match
the hashes, otherwise failure is indicated to system software. If the test
chunk is authenticated, it is automatically copied to secured memory.

Use schedule_work_on() to perform the hash copy and authentication. Note
this needs only be done on the first logical cpu of each socket.

Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jithu Joseph <jithu.joseph@intel.com>
Co-developed-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20220506225410.1652287-8-tony.luck@intel.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
2022-05-12 15:35:29 +02:00
Jithu Joseph
fb57fc785e platform/x86/intel/ifs: Read IFS firmware image
Driver probe routine allocates structure to communicate status
and parameters between functions in the driver. Also call
load_ifs_binary() to load the scan image file.

There is a separate scan image file for each processor family,
model, stepping combination. This is read from the static path:

  /lib/firmware/intel/ifs/{ff-mm-ss}.scan

Step 1 in loading is to generate the correct path and use
request_firmware_direct() to load into memory.

Subsequent patches will use the IFS MSR interfaces to copy
the image to BIOS reserved memory and validate the SHA256
checksums.

Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jithu Joseph <jithu.joseph@intel.com>
Co-developed-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20220506225410.1652287-6-tony.luck@intel.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
2022-05-12 15:35:29 +02:00