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 08DEE35BDC1 for ; Fri, 14 Nov 2025 21:35:42 +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=1763156142; cv=none; b=P2X3RuojLNO8D3Ie9JZXlNwlophR0CpeaM6f5f0LdKJhDOchdl8sjsGSNUkHHh4yr8YsajW0IYLH0m6rZrg/ZLm4+/LzzJEtAzakU3EZZXyzq38g4dlt4xIvw7Ux8+i5foYyxV3/losuufdRHVq4T3k+gwHyMHdeRH/ocT2ahFc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763156142; c=relaxed/simple; bh=nyMVx9701p+WNx+69cqACB2jA8RS/0DlIfpjKuxRpBc=; h=Date:To:From:Subject:Message-Id; b=Lb0JIJx4g8oBfCgo3zPwCFtuJC1LBvJk9Cg8sdltw5I8ZklbS5a4k5jPwArrW6xGu7xLQh1Wwhbayjp46vzGLIlf5scaAc2U2jUkLHy6eHv3DEPkV7k/rMZ0JiIMtRc5pjz2cX93OSuCvOkuouJVNfLcJ0ZK84VGjYTGxbwTBSA= 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=ak93smio; 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="ak93smio" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CFCBBC4CEF8; Fri, 14 Nov 2025 21:35:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1763156141; bh=nyMVx9701p+WNx+69cqACB2jA8RS/0DlIfpjKuxRpBc=; h=Date:To:From:Subject:From; b=ak93smiojkYdAb8RXvIeJXSKLFHhxKHzsu3TxqCfD4KVlP8BbLaf0nsRAVtBFtrkb l/v748k5f2kZEtsGsfrJ/LJv6rRq22FTDkwTJqMNCIQJKy1bYOuIWmWGwGkFnlwUGN hSDfPqBdOlJKW/hGMQlecBLRZzXKLkTT/d/StOTU= Date: Fri, 14 Nov 2025 13:35:40 -0800 To: mm-commits@vger.kernel.org,rppt@kernel.org,pratyush@kernel.org,kees@kernel.org,graf@amazon.com,ebiggers@google.com,dave@vasilevsky.ca,coxu@redhat.com,bhe@redhat.com,arnd@arndb.de,pasha.tatashin@soleen.com,akpm@linux-foundation.org From: Andrew Morton Subject: + kho-add-kconfig-option-to-enable-kho-by-default.patch added to mm-nonmm-unstable branch Message-Id: <20251114213541.CFCBBC4CEF8@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: kho: add Kconfig option to enable KHO by default has been added to the -mm mm-nonmm-unstable branch. Its filename is kho-add-kconfig-option-to-enable-kho-by-default.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/kho-add-kconfig-option-to-enable-kho-by-default.patch This patch will later appear in the mm-nonmm-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: Pasha Tatashin Subject: kho: add Kconfig option to enable KHO by default Date: Fri, 14 Nov 2025 14:00:02 -0500 Currently, Kexec Handover must be explicitly enabled via the kernel command line parameter `kho=on`. For workloads that rely on KHO as a foundational requirement (such as the upcoming Live Update Orchestrator), requiring an explicit boot parameter adds redundant configuration steps. Introduce CONFIG_KEXEC_HANDOVER_ENABLE_DEFAULT. When selected, KHO defaults to enabled. This is equivalent to passing kho=on at boot. The behavior can still be disabled at runtime by passing kho=off. Link: https://lkml.kernel.org/r/20251114190002.3311679-14-pasha.tatashin@soleen.com Signed-off-by: Pasha Tatashin Reviewed-by: Mike Rapoport (Microsoft) Reviewed-by: Pratyush Yadav Cc: Alexander Graf Cc: Arnd Bergmann Cc: Baoquan He Cc: Coiby Xu Cc: Dave Vasilevsky Cc: Eric Biggers Cc: Kees Cook Signed-off-by: Andrew Morton --- kernel/liveupdate/Kconfig | 14 ++++++++++++++ kernel/liveupdate/kexec_handover.c | 2 +- 2 files changed, 15 insertions(+), 1 deletion(-) --- a/kernel/liveupdate/Kconfig~kho-add-kconfig-option-to-enable-kho-by-default +++ a/kernel/liveupdate/Kconfig @@ -37,4 +37,18 @@ config KEXEC_HANDOVER_DEBUGFS Also, enables inspecting the KHO fdt trees with the debugfs binary blobs. +config KEXEC_HANDOVER_ENABLE_DEFAULT + bool "Enable kexec handover by default" + depends on KEXEC_HANDOVER + help + Enable Kexec Handover by default. This avoids the need to + explicitly pass 'kho=on' on the kernel command line. + + This is useful for systems where KHO is a prerequisite for other + features, such as Live Update, ensuring the mechanism is always + active. + + The default behavior can still be overridden at boot time by + passing 'kho=off'. + endmenu --- a/kernel/liveupdate/kexec_handover.c~kho-add-kconfig-option-to-enable-kho-by-default +++ a/kernel/liveupdate/kexec_handover.c @@ -52,7 +52,7 @@ union kho_page_info { static_assert(sizeof(union kho_page_info) == sizeof(((struct page *)0)->private)); -static bool kho_enable __ro_after_init; +static bool kho_enable __ro_after_init = IS_ENABLED(CONFIG_KEXEC_HANDOVER_ENABLE_DEFAULT); bool kho_is_enabled(void) { _ Patches currently in -mm which might be from pasha.tatashin@soleen.com are lib-test_kho-check-if-kho-is-enabled.patch kho-make-debugfs-interface-optional.patch kho-add-interfaces-to-unpreserve-folios-page-ranges-and-vmalloc.patch memblock-unpreserve-memory-in-case-of-error.patch test_kho-unpreserve-memory-in-case-of-error.patch kho-dont-unpreserve-memory-during-abort.patch liveupdate-kho-move-to-kernel-liveupdate.patch liveupdate-kho-move-to-kernel-liveupdate-fix.patch maintainers-update-kho-maintainers.patch kho-fix-misleading-log-message-in-kho_populate.patch kho-convert-__kho_abort-to-return-void.patch kho-introduce-high-level-memory-allocation-api.patch kho-preserve-fdt-folio-only-once-during-initialization.patch kho-verify-deserialization-status-and-fix-fdt-alignment-access.patch kho-always-expose-output-fdt-in-debugfs.patch kho-simplify-serialization-and-remove-__kho_abort.patch kho-remove-global-preserved_mem_map-and-store-state-in-fdt.patch kho-remove-abort-functionality-and-support-state-refresh.patch kho-update-fdt-dynamically-for-subtree-addition-removal.patch kho-allow-kexec-load-before-kho-finalization.patch kho-allow-memory-preservation-state-updates-after-finalization.patch kho-add-kconfig-option-to-enable-kho-by-default.patch liveupdate-luo_core-luo_ioctl-live-update-orchestrator.patch liveupdate-luo_core-integrate-with-kho.patch reboot-call-liveupdate_reboot-before-kexec.patch liveupdate-luo_session-add-sessions-support.patch liveupdate-luo_ioctl-add-user-interface.patch liveupdate-luo_file-implement-file-systems-callbacks.patch liveupdate-luo_session-add-ioctls-for-file-preservation-and-state-management.patch liveupdate-luo_flb-introduce-file-lifecycle-bound-global-state.patch docs-add-luo-documentation.patch maintainers-add-liveupdate-entry.patch selftests-liveupdate-add-userspace-api-selftests.patch selftests-liveupdate-add-kexec-based-selftest-for-session-lifecycle.patch selftests-liveupdate-add-kexec-test-for-multiple-and-empty-sessions.patch tests-liveupdate-add-in-kernel-liveupdate-test.patch