Re: [PATCH v5 7/9] acpi/ghes: Process CXL Component Events

From: Jonathan Cameron <Jonathan.Cameron@Huawei.com>
To: Ira Weiny <ira.weiny@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>,
	Smita Koralahalli <Smita.KoralahalliChannabasappa@amd.com>,
	Shiju Jose <shiju.jose@huawei.com>,
	Yazen Ghannam <yazen.ghannam@amd.com>,
	"Davidlohr Bueso" <dave@stgolabs.net>,
	Dave Jiang <dave.jiang@intel.com>,
	"Alison Schofield" <alison.schofield@intel.com>,
	Vishal Verma <vishal.l.verma@intel.com>,
	Ard Biesheuvel <ardb@kernel.org>, <linux-efi@vger.kernel.org>,
	<linux-kernel@vger.kernel.org>, <linux-cxl@vger.kernel.org>,
	"Rafael J. Wysocki" <rafael@kernel.org>
Subject: Re: [PATCH v5 7/9] acpi/ghes: Process CXL Component Events
Date: Mon, 8 Jan 2024 13:41:57 +0000	[thread overview]
Message-ID: <20240108134157.0000013c@Huawei.com> (raw)
In-Reply-To: <20231220-cxl-cper-v5-7-1bb8a4ca2c7a@intel.com>

On Wed, 20 Dec 2023 16:17:34 -0800
Ira Weiny <ira.weiny@intel.com> wrote:

> BIOS can configure memory devices as firmware first.  This will send CXL
> events to the firmware instead of the OS.  The firmware can then send
> these events to the OS via UEFI.
> 
> UEFI v2.10 section N.2.14 defines a Common Platform Error Record (CPER)
> format for CXL Component Events.  The format is mostly the same as the
> CXL Common Event Record Format.  The difference is the use of a GUID in
> the Section Type rather than a UUID as part of the event itself.
> 
> Add GHES support to detect CXL CPER records and call a registered
> callback with the event.
> 
> A notifier chain was considered for the callback but the complexity did
> not justify the use case as only the CXL subsystem requires this event.
> Enforce that only one callback can be registered at any time.
> 
> Cc: Ard Biesheuvel <ardb@kernel.org>
> Cc: "Rafael J. Wysocki" <rafael@kernel.org>
> Signed-off-by: Ira Weiny <ira.weiny@intel.com>
> 

Very annoying that CXL using UUIDS and UEFI GUIDs (so endian swapped).

Is it worth a general conversion function or just keep the data duplication?

Otherwise LGTM

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>