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(c-73-239-240-195.hsd1.wa.comcast.net [73.239.240.195]) by linux.microsoft.com (Postfix) with ESMTPSA id 8634120B3CC1; Tue, 2 Jan 2024 12:18:47 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 8634120B3CC1 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1704226728; bh=JFUj3C7F4v1llVh0SHjV/UZr4Y8Q5mWVzW88656cZ4c=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=jBZq+QImwExtqzfSMUaFBx5SqLCBQZlhbdMiNYB9OQZDuVtBKnZllTeupWgAKu58t 4yOsU39+h82ZiQ2rxDh7b264mytw7f1GFBNGYW+/MioPPM90R/n2xElpJXMoDcvHCU nesWzuBT96S1hmpCoXyzFXlJiuFt3xFbHxdqt+iM= Date: Sun, 31 Dec 2023 19:55:18 -0800 From: Stanislav Kinsburskii To: Alexander Graf Cc: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-mm@kvack.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kexec@lists.infradead.org, linux-doc@vger.kernel.org, x86@kernel.org, Eric Biederman , "H. Peter Anvin" , Andy Lutomirski , Peter Zijlstra , Rob Herring , Steven Rostedt , Andrew Morton , Mark Rutland , Tom Lendacky , Ashish Kalra , James Gowans , arnd@arndb.de, pbonzini@redhat.com, madvenka@linux.microsoft.com, Anthony Yznaga , Usama Arif , David Woodhouse , Benjamin Herrenschmidt Subject: Re: [PATCH v2 07/17] kexec: Add documentation for KHO Message-ID: <20240101035518.GA804@skinsburskii.> References: <20231222193607.15474-1-graf@amazon.com> <20231222193607.15474-8-graf@amazon.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20231222193607.15474-8-graf@amazon.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240102_121849_671908_7E7B1D0F X-CRM114-Status: GOOD ( 20.74 ) X-BeenThere: kexec@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "kexec" Errors-To: kexec-bounces+kexec=archiver.kernel.org@lists.infradead.org On Fri, Dec 22, 2023 at 07:35:57PM +0000, Alexander Graf wrote: > diff --git a/Documentation/kho/concepts.rst b/Documentation/kho/concepts.rst > new file mode 100644 > index 000000000000..8e4fe8c57865 > --- /dev/null > +++ b/Documentation/kho/concepts.rst > @@ -0,0 +1,88 @@ > +.. SPDX-License-Identifier: GPL-2.0-or-later > + > +======================= > +Kexec Handover Concepts > +======================= > + > +Kexec HandOver (KHO) is a mechanism that allows Linux to preserve state - > +arbitrary properties as well as memory locations - across kexec. > + > +It introduces multiple concepts: > + > +KHO Device Tree > +--------------- > + > +Every KHO kexec carries a KHO specific flattened device tree blob that > +describes the state of the system. Device drivers can register to KHO to > +serialize their state before kexec. After KHO, device drivers can read > +the device tree and extract previous state. > + > +KHO only uses the fdt container format and libfdt library, but does not > +adhere to the same property semantics that normal device trees do: Properties > +are passed in native endianness and standardized properties like ``regs`` and > +``ranges`` do not exist, hence there are no ``#...-cells`` properties. > + > +KHO introduces a new concept to its device tree: ``mem`` properties. A > +``mem`` property can inside any subnode in the device tree. When present, Should it be "property can be" ? ... > diff --git a/Documentation/kho/usage.rst b/Documentation/kho/usage.rst > new file mode 100644 > index 000000000000..5efa2a58f9c3 > --- /dev/null > +++ b/Documentation/kho/usage.rst > @@ -0,0 +1,57 @@ > +.. SPDX-License-Identifier: GPL-2.0-or-later > + > +==================== > +Kexec Handover Usage > +==================== > + > +Kexec HandOver (KHO) is a mechanism that allows Linux to preserve state - > +arbitrary properties as well as memory locations - across kexec. > + > +This document expects that you are familiar with the base KHO > +:ref:`Documentation/kho/concepts.rst `. If you have not read > +them yet, please do so now. > + > +Prerequisites > +------------- > + > +KHO is available when the ``CONFIG_KEXEC_KHO`` config option is set to y > +at compile team. Every KHO producer has its own config option that you Should it be "at compile time."? _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec