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b=AG12x7tgg25+b9BGhXiSz/ofPJ4/nOOi9uaGp8uGSrgkfC6bThURnEzl370xiLQpC 6muAHtivbUfevoV3luEzApxkC8XXfAHuDlJqLtaVtu1OONXVixuRtjn5c1UD9JIbh5 byWnONieIPW8PfllGp8EESZ/SwNwqh+z+bUeOFhSUE0oNulQ0zcu+Pv5pPKNy1VA/v PXcbV0RACErEMoyZsiEx6uq7lKwa1pq0Kc38NlHNoFAHt2wIyJj2a0fiHRBcgHX0Jt UBIZMH7O7j5NDtS3xfVZrECjEHi7M1FxaeHxqmkQ+XBWSr9qt2j43IsF7RzChgfKCz qsCOafVsbDhNA== Date: Thu, 5 Nov 2026 14:53:04 +0200 From: Mike Rapoport To: George Guo Cc: pasha.tatashin@soleen.com, pratyush@kernel.org, chenhuacai@kernel.org, ardb@kernel.org, shuah@kernel.org, ilias.apalodimas@linaro.org, akpm@linux-foundation.org, baoquan.he@linux.dev, ruirui.yang@linux.dev, guodongtai@kylinos.cn, kernel@xen0n.name, graf@amazon.com, liukexin@kylinos.cn, loongarch@lists.linux.dev, linux-kernel@vger.kernel.org, kexec@lists.infradead.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org, linux-efi@vger.kernel.org Subject: Re: [PATCH v6 4/8] kho: Add kho_disable() Message-ID: References: <20261029172956.20791-1-dongtai.guo@linux.dev> <20261029172956.20791-5-dongtai.guo@linux.dev> X-Archived-By: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20261029172956.20791-5-dongtai.guo@linux.dev> X-Stat-Signature: f6jy3isjx75914o3uqmbeembto8guhrc X-Rspamd-Queue-Id: 8BC5E4000C X-Rspam-User: X-Rspamd-Server: rspam08 X-Spam-Status: No, score=-15.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_PASS, SPF_PASS autolearn=unavailable autolearn_force=no version=4.0.1 X-HE-Tag: 1793883195-753090 X-HE-Meta: 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 8uvXSTOg N2tIGJBFwep5v4sAHHEystn5QMKPsjehH+OaPkr4JyMEDEYFUtEHPSrb30QEjcK6U9w/6BLERmHRj1gyIToaxDkgeg8u7uEuZ3BNi24pbqCeqRkBF79MM9ZRItkuP1BbPhuwZjb9yINBumz5Oe9fRgQ36uWmcZ3eQaJkBVl+jfelMg/dpWhi1GLyDZdB2moxgtgEUk1oxpJ0JY9q7aaFTyRVk3VklvQgBZT4lzjQnOsp/QYsBnvrAZGKEH9utGc/gtdNhCBHuGH9JehD51ZgmeX8+qj+T/LgNxKC7BZzxJOIgOQCULiFihIk+9Q== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 Hi George, On Fri, Oct 30, 2026 at 02:29:51AM +0900, George Guo wrote: > From: George Guo > > On LoongArch, KHO state is passed to the next kernel only through an EFI > configuration table. Only the EFI stub installs this table, during a cold > boot. > > A kernel entered through kexec does not run the EFI stub, so it cannot > create the table if the previous kernel did not provide one. Without > the table, it cannot pass KHO state to the next kernel on a subsequent > kexec. The idea behind KHO and liveupdate is that the system uses kexec + KHO for reboots after the cold boot unless a new cold reboot is a must. Doing one yes, one no, breaks that assumption. > Add kho_disable() so architecture code can turn KHO off when the EFI > configuration table is missing. I don't like a global kho_disable() API. It's ambiguous and fragile. > Signed-off-by: George Guo > --- > include/linux/kexec_handover.h | 3 +++ > kernel/liveupdate/kexec_handover.c | 9 +++++++++ > 2 files changed, 12 insertions(+) -- Sincerely yours, Mike.