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>
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>
Cloud Service Providers that operate fleets of servers have reported
[1] occasions where they can detect that a CPU has gone bad due to
effects like electromigration, or isolated manufacturing defects.
However, that detection method is A/B testing seemingly random
application failures looking for a pattern. In-Field Scan (IFS) is
a driver for a platform capability to load a crafted 'scan image'
to run targeted low level diagnostics outside of the CPU's architectural
error detection capabilities.
Stub version of driver just does initial part of check for the IFS
feature. MSR_IA32_CORE_CAPS must enumerate the presence of the
MSR_INTEGRITY_CAPS MSR.
[1]: https://www.youtube.com/watch?v=QMF3rqhjYuM
Reviewed-by: Dan Williams <dan.j.williams@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/20220506225410.1652287-5-tony.luck@intel.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
