Re: [PATCH v3 0/8] Arm Live Firmware Activation (LFA) support

[Michal Suchánek]

On Mon, Jul 13, 2026 at 06:02:35PM +0200, Michal Suchánek wrote:
> On Mon, Jul 06, 2026 at 03:44:40PM +0200, Andre Przywara wrote:
> > Hi all,
> > 
> > this is version 3 of the Live Firmware Activation kernel support. The
> > device part of the code now relies on Aneesh's SMCCC bus patches[1],
> > which solves some problems rather nicely. I also added the formerly
> > missing sysfs ABI documentation. Based on v7.2-rc1, plus the first
> > two patches from Aneesh's series. More detailed changelog below.
> > ==============================
> > 
> > This series implements the kernel side support of the Arm Live
> > Firmware Activation (LFA) specification [2]. LFA enables the activation
> > of updated firmware components without requiring a system reboot,
> > reducing downtime and allowing quicker deployment of critical bug fixes
> > in environments such as data centers and hyperscale systems.
> > It requires explicit firmware support, both via an agent running in EL3
> > (for instance in TF-A, already merged), but also in the firmware
> > component to be activated. TF-RMM recently merged support for this.
> > 
> > Unlike the usual firmware update process (which may use tools like
> > fwupd), LFA focuses solely on the activation of an already updated
> > firmware component, called "pending activation" in LFA lingo. This works
> > by signalling the LFA agent (part of the EL3 runtime firmware) via an
> > SMC call, which then does the heavy lifting of the live update, in
> > cooperation with the to-be-updated firmware component.
> > 
> > Key features of the driver:
> > * Detects LFA support in system firmware (EL3).
> > * Lists all firmware components that support live activation, identified
> >   by their GUID.
> > * Exposes component attributes (e.g., activation capability, and
> >   activation pending) via sysfs under /sys/firmware/lfa/<GUID>/.
> > * Provides interfaces to:
> >   - Trigger activation of an updated firmware component.
> >   - Cancel an ongoing activation if required.
> > A more detailed list of features can be found in patch 2/8.
> > Based on v7.2-rc1.
> > 
> > This work is conceptually similar to Intel’s Platform Firmware Runtime
> > Update and telemetry (PFRUT) [3] and TDX module updates [4], but
> > targets Arm platforms. The driver has been used to successfully activate
> > a Realm Management Monitor (RMM) firmware image in a controlled test
> > environment. RMM is analogous to Intel’s TDX module.
> > 
> > There is effort on similar work from the OCP [5]. Future work may
> > include integration with utilities like fwupd to automatically select
> > the appropriate driver, based on platform architecture, for Live/Runtime
> > firmware updates.
> > 
> > Please have a look, test and comment!
> 
> Hello,
> 
> booting a kernel with v2 of this patchset applied the module does not
> get autoloaded. Loading it manually I get
> 
> [ 1972.957282] [   T5195] Arm LFA: Live Firmware Activation: detected v1.0
> [ 1972.958620] [   T5195] Arm LFA: registered LFA ACPI notification
> 
> Is this expected?
> 
> I would expect the driver to load automatically.
> 
> I do not see anything in the v3 changelog obviously addressing
> autoloading but changing to using a bus might affect that.
> 
> I will try to update to v3 later.

Hello,

updating to v3 of the patchset resolves the problem.

The driver is now autoloaded.

Thanks

Michal