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AJvYcCV3lG0KuglsWPAaTVT199noK1VCJ2Q3d7FRzp/i11uYAAorwpVU+axDcDSDnBzPfMVscawtGp/xgg==@kvack.org X-Gm-Message-State: AOJu0Yy9/fAMND8JpEtihb5XqvlDMvH/3gQUbk1lbQwVoajS0tlYILuc Qkz/ryREaiPs0af1OhXTcHZI+siZPGW98NaKl25FiKVfV5W8jlOwlFhj6WYnNR0a/ZMVuoSA3zf yNAEqFYQ6Dmt1pL/2hXBXonYSmv5HfNRGr/39etzeFw== X-Gm-Gg: ASbGncsaO9p7KsY9PvKAJIsgm/qgbmlaXUy1RK2sBLW8/zTrOnOlmdoCyAI+PBUnok5 JR8XjpQSEf/FtgcrhBce8BxsRzsGHH/SUYjo/+ETHOYB/tiXAR+wMtIQx5Ud13RWX5oKfEYss6/ tE8U2GfUptWzJejDXsTdtwQ8qqbZd4dlJ+3YVDkTw3ZsKGXzjO4DP/kXYWbRgYh6eFP4ZTFonjV 3pUqIAgud+Ut2JtHhmxf7CfmZUXsH1t5IRFvMGJXzoqkarrxPTrredR+4ULDVH49QeD X-Google-Smtp-Source: AGHT+IGY+tZRbaslLz2kOHg+aNV3t0hpe7oMeZfcGmL5vq41YDW/o61wTpChY/KiKQIFV5hvmww+CFYOhBuLb1d6YYI= X-Received: by 2002:a05:6402:2106:b0:640:f481:984 with SMTP id 4fb4d7f45d1cf-6431a395d5cmr5583802a12.2.1763042203396; Thu, 13 Nov 2025 05:56:43 -0800 (PST) MIME-Version: 1.0 References: <20251107210526.257742-1-pasha.tatashin@soleen.com> <20251107210526.257742-2-pasha.tatashin@soleen.com> In-Reply-To: From: Pasha Tatashin Date: Thu, 13 Nov 2025 08:56:06 -0500 X-Gm-Features: AWmQ_bmd0HSccxoETOjnPXP7LM0Avf6TAjDFvEucAEYN_rSyfWXxN426kJbKdTA Message-ID: Subject: Re: [PATCH v5 01/22] liveupdate: luo_core: luo_ioctl: Live Update Orchestrator To: Mike Rapoport Cc: pratyush@kernel.org, jasonmiu@google.com, graf@amazon.com, dmatlack@google.com, rientjes@google.com, corbet@lwn.net, rdunlap@infradead.org, ilpo.jarvinen@linux.intel.com, kanie@linux.alibaba.com, ojeda@kernel.org, aliceryhl@google.com, masahiroy@kernel.org, akpm@linux-foundation.org, tj@kernel.org, yoann.congal@smile.fr, mmaurer@google.com, roman.gushchin@linux.dev, chenridong@huawei.com, axboe@kernel.dk, mark.rutland@arm.com, jannh@google.com, vincent.guittot@linaro.org, hannes@cmpxchg.org, dan.j.williams@intel.com, david@redhat.com, joel.granados@kernel.org, rostedt@goodmis.org, anna.schumaker@oracle.com, song@kernel.org, zhangguopeng@kylinos.cn, linux@weissschuh.net, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, gregkh@linuxfoundation.org, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com, rafael@kernel.org, dakr@kernel.org, bartosz.golaszewski@linaro.org, cw00.choi@samsung.com, myungjoo.ham@samsung.com, yesanishhere@gmail.com, Jonathan.Cameron@huawei.com, quic_zijuhu@quicinc.com, aleksander.lobakin@intel.com, ira.weiny@intel.com, andriy.shevchenko@linux.intel.com, leon@kernel.org, lukas@wunner.de, bhelgaas@google.com, wagi@kernel.org, djeffery@redhat.com, stuart.w.hayes@gmail.com, ptyadav@amazon.de, lennart@poettering.net, brauner@kernel.org, linux-api@vger.kernel.org, linux-fsdevel@vger.kernel.org, saeedm@nvidia.com, ajayachandra@nvidia.com, jgg@nvidia.com, parav@nvidia.com, leonro@nvidia.com, witu@nvidia.com, hughd@google.com, skhawaja@google.com, chrisl@kernel.org Content-Type: text/plain; charset="UTF-8" X-Rspamd-Server: rspam12 X-Rspam-User: X-Rspamd-Queue-Id: 0EE1D1C0007 X-Stat-Signature: 5s6jn8kk8epubrkhofdeske7i65jyayc X-HE-Tag: 1763042205-873782 X-HE-Meta: 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 mrt2B5Lv hh2TBX0Z6SZpzBjrCoy/c3nqUW7Lj7R5fmyx3TVGdjy3iP3yFp/As7qmrwZ1hqHeoPnMIh1KhMYU16NY5SEGRnwOAcjUN+EYSvKkCVu30YRAqsS0adJr+Nubq1pACWOIFVT5/RTJ8thR6yiMINvwmrbFs4TD0d7WtnY0DYyULF7dVsumET24DF4e8eoe6FMx5muhTH7YSbXCjfA95Q6orPjWWmmgEEQocXgkuoJ2YSO9ljRUmL/YK4WK4yAU5/kJAMTJ/P3aPTU6RK3ZS+KBawsq/YxB0AKS0QP/Ww/3xQUQRyrLnXyzNp2zPYV2kr8l8gXTUWIfBsLWGwwbEMITKzZIcRg94khynhYoYOokFvqfe3dWDyflALBQNX7K/clmXhZA0sYNp0VcR3ywSxShKrGBOpQ== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: > > +/** > > + * DOC: General ioctl format > > + * > > It seems it's not linked from Documentation/.../liveupdate.rst It is linked: Here is uAPI: https://docs.kernel.org/next/userspace-api/liveupdate.html And also from the main Doc: https://docs.kernel.org/next/core-api/liveupdate.html There is a link in "Sea Also" section: Live Update uAPI > > + * The ioctl interface follows a general format to allow for extensibility. Each > > + * ioctl is passed in a structure pointer as the argument providing the size of > > + * the structure in the first u32. The kernel checks that any structure space > > + * beyond what it understands is 0. This allows userspace to use the backward > > + * compatible portion while consistently using the newer, larger, structures. > > + * > > + * ioctls use a standard meaning for common errnos: > > + * > > + * - ENOTTY: The IOCTL number itself is not supported at all > > + * - E2BIG: The IOCTL number is supported, but the provided structure has > > + * non-zero in a part the kernel does not understand. > > + * - EOPNOTSUPP: The IOCTL number is supported, and the structure is > > + * understood, however a known field has a value the kernel does not > > + * understand or support. > > + * - EINVAL: Everything about the IOCTL was understood, but a field is not > > + * correct. > > + * - ENOENT: A provided token does not exist. > > + * - ENOMEM: Out of memory. > > + * - EOVERFLOW: Mathematics overflowed. > > + * > > + * As well as additional errnos, within specific ioctls. > > ... > > > --- a/kernel/liveupdate/Kconfig > > +++ b/kernel/liveupdate/Kconfig > > @@ -1,7 +1,34 @@ > > # SPDX-License-Identifier: GPL-2.0-only > > +# > > +# Copyright (c) 2025, Google LLC. > > +# Pasha Tatashin > > +# > > +# Live Update Orchestrator > > +# > > > > menu "Live Update and Kexec HandOver" > > > > +config LIVEUPDATE > > + bool "Live Update Orchestrator" > > + depends on KEXEC_HANDOVER > > + help > > + Enable the Live Update Orchestrator. Live Update is a mechanism, > > + typically based on kexec, that allows the kernel to be updated > > + while keeping selected devices operational across the transition. > > + These devices are intended to be reclaimed by the new kernel and > > + re-attached to their original workload without requiring a device > > + reset. > > + > > + Ability to handover a device from current to the next kernel depends > > + on specific support within device drivers and related kernel > > + subsystems. > > + > > + This feature primarily targets virtual machine hosts to quickly update > > + the kernel hypervisor with minimal disruption to the running virtual > > + machines. > > + > > + If unsure, say N. > > + > > Not a big deal, but since LIVEUPDATE depends on KEXEC_HANDOVER, shouldn't > it go after KEXEC_HANDOVER? Sure, I'll move them to the end of the file. Thanks, Pasha