From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 122952E403 for ; Fri, 2 May 2025 00:44:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746146645; cv=none; b=df/0WkZFA8TA5nV0r4CTFVFqUf1v0WltZSih1vqbF5dRVhhCMeJwe7ElKlCoC2YljPoUgIAmN7DbBuQODdG1RQJznf5P3tIOwOI3ltw5WaQk4rJs7K4zykS5Bo60WLa7E96HKadGmW6sUq3KF8Zf2UiSDYoHXvTOCHFH6VNZ8fA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746146645; c=relaxed/simple; bh=j/8dPFe95OUPTCulv459NecYOynhnqCJQdB2NdiIJYE=; h=Date:To:From:Subject:Message-Id; b=mItqA5mqrN5Mpw8EaoF5JIgU4KZGcN22poGWIEVtgP4xxgs//4LK20hc5f8/0PhpDeDM5EFbJeCD9+nQbgVIMRgYPe8G1GUJJuangKVBDkTWGGbmserkQrwgJnNnrZ6q/RAad/lTU8m10sFEj1ccV3lQC5NKKeY2r3YFzmPlYEQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=HiocB7/F; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="HiocB7/F" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 71DF5C4CEE3; Fri, 2 May 2025 00:44:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1746146644; bh=j/8dPFe95OUPTCulv459NecYOynhnqCJQdB2NdiIJYE=; h=Date:To:From:Subject:From; b=HiocB7/FPCW+irFE5JmVQWR3hVvQORnrgDeuAtJHbyFv+H0tIuEcJ2+8kHhAOzaCy OZNNhHT/N3arQAF2An3Eq0oG+O3Y/0CG3zq5G6nupdwyIbGv0PN9VpMygkip8R9U0S XYCKK435ZmOFADrDSoR+zf5ev8jMlXz0DOCr/UAA= Date: Thu, 01 May 2025 17:44:03 -0700 To: mm-commits@vger.kernel.org,graf@amazon.com,changyuanl@google.com,rppt@kernel.org,akpm@linux-foundation.org From: Andrew Morton Subject: + documentation-kho-add-memblock-bindings.patch added to mm-unstable branch Message-Id: <20250502004404.71DF5C4CEE3@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: Documentation: KHO: add memblock bindings has been added to the -mm mm-unstable branch. Its filename is documentation-kho-add-memblock-bindings.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/documentation-kho-add-memblock-bindings.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: "Mike Rapoport (Microsoft)" Subject: Documentation: KHO: add memblock bindings Date: Thu, 1 May 2025 15:54:25 -0700 We introduced KHO into Linux: A framework that allows Linux to pass metadata and memory across kexec from Linux to Linux. KHO reuses fdt as file format and shares a lot of the same properties of firmware-to- Linux boot formats: It needs a stable, documented ABI that allows for forward and backward compatibility as well as versioning. As first user of KHO, we introduced memblock which can now preserve memory ranges reserved with reserve_mem command line options contents across kexec, so you can use the post-kexec kernel to read traces from the pre-kexec kernel. This patch adds memblock schemas similar to "device" device tree ones to a new kho bindings directory. This allows us to force contributors to document the data that moves across KHO kexecs and catch breaking change during review. Link: https://lkml.kernel.org/r/20250501225425.635167-19-changyuanl@google.com Co-developed-by: Alexander Graf Signed-off-by: Alexander Graf Signed-off-by: Mike Rapoport (Microsoft) Signed-off-by: Changyuan Lyu Signed-off-by: Andrew Morton --- Documentation/core-api/kho/bindings/memblock/memblock.yaml | 39 +++++++++ Documentation/core-api/kho/bindings/memblock/reserve-mem.yaml | 40 ++++++++++ MAINTAINERS | 1 3 files changed, 80 insertions(+) diff --git a/Documentation/core-api/kho/bindings/memblock/memblock.yaml a/Documentation/core-api/kho/bindings/memblock/memblock.yaml new file mode 100644 --- /dev/null +++ a/Documentation/core-api/kho/bindings/memblock/memblock.yaml @@ -0,0 +1,39 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +%YAML 1.2 +--- +title: Memblock reserved memory + +maintainers: + - Mike Rapoport + +description: | + Memblock can serialize its current memory reservations created with + reserve_mem command line option across kexec through KHO. + The post-KHO kernel can then consume these reservations and they are + guaranteed to have the same physical address. + +properties: + compatible: + enum: + - reserve-mem-v1 + +patternProperties: + "$[0-9a-f_]+^": + $ref: reserve-mem.yaml# + description: reserved memory regions + +required: + - compatible + +additionalProperties: false + +examples: + - | + memblock { + compatible = "memblock-v1"; + n1 { + compatible = "reserve-mem-v1"; + start = <0xc06b 0x4000000>; + size = <0x04 0x00>; + }; + }; diff --git a/Documentation/core-api/kho/bindings/memblock/reserve-mem.yaml a/Documentation/core-api/kho/bindings/memblock/reserve-mem.yaml new file mode 100644 --- /dev/null +++ a/Documentation/core-api/kho/bindings/memblock/reserve-mem.yaml @@ -0,0 +1,40 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +%YAML 1.2 +--- +title: Memblock reserved memory regions + +maintainers: + - Mike Rapoport + +description: | + Memblock can serialize its current memory reservations created with + reserve_mem command line option across kexec through KHO. + This object describes each such region. + +properties: + compatible: + enum: + - reserve-mem-v1 + + start: + description: | + physical address (u64) of the reserved memory region. + + size: + description: | + size (u64) of the reserved memory region. + +required: + - compatible + - start + - size + +additionalProperties: false + +examples: + - | + n1 { + compatible = "reserve-mem-v1"; + start = <0xc06b 0x4000000>; + size = <0x04 0x00>; + }; --- a/MAINTAINERS~documentation-kho-add-memblock-bindings +++ a/MAINTAINERS @@ -15433,6 +15433,7 @@ M: Mike Rapoport L: linux-mm@kvack.org S: Maintained F: Documentation/core-api/boot-time-mm.rst +F: Documentation/core-api/kho/bindings/memblock/* F: include/linux/memblock.h F: mm/memblock.c F: mm/mm_init.c _ Patches currently in -mm which might be from rppt@kernel.org are memblock-add-memblock_rsrv_kern-flag.patch memblock-introduce-memmap_init_kho_scratch.patch kexec-enable-kho-support-for-memory-preservation.patch x86-setup-use-memblock_reserve_kern-for-memory-used-by-kernel.patch documentation-kho-add-memblock-bindings.patch execmem-enforce-allocation-size-aligment-to-page_size.patch