148a1b232SPasha Tatashin# SPDX-License-Identifier: GPL-2.0-only 248a1b232SPasha Tatashin 348a1b232SPasha Tatashinmenu "Live Update and Kexec HandOver" 448a1b232SPasha Tatashin depends on !DEFERRED_STRUCT_PAGE_INIT 548a1b232SPasha Tatashin 648a1b232SPasha Tatashinconfig KEXEC_HANDOVER 748a1b232SPasha Tatashin bool "kexec handover" 848a1b232SPasha Tatashin depends on ARCH_SUPPORTS_KEXEC_HANDOVER && ARCH_SUPPORTS_KEXEC_FILE 948a1b232SPasha Tatashin depends on !DEFERRED_STRUCT_PAGE_INIT 1048a1b232SPasha Tatashin select MEMBLOCK_KHO_SCRATCH 1148a1b232SPasha Tatashin select KEXEC_FILE 1248a1b232SPasha Tatashin select LIBFDT 1348a1b232SPasha Tatashin select CMA 1448a1b232SPasha Tatashin help 1548a1b232SPasha Tatashin Allow kexec to hand over state across kernels by generating and 1648a1b232SPasha Tatashin passing additional metadata to the target kernel. This is useful 1748a1b232SPasha Tatashin to keep data or state alive across the kexec. For this to work, 1848a1b232SPasha Tatashin both source and target kernels need to have this option enabled. 1948a1b232SPasha Tatashin 2048a1b232SPasha Tatashinconfig KEXEC_HANDOVER_DEBUG 2148a1b232SPasha Tatashin bool "Enable Kexec Handover debug checks" 2248a1b232SPasha Tatashin depends on KEXEC_HANDOVER 2348a1b232SPasha Tatashin help 2448a1b232SPasha Tatashin This option enables extra sanity checks for the Kexec Handover 2548a1b232SPasha Tatashin subsystem. Since, KHO performance is crucial in live update 2648a1b232SPasha Tatashin scenarios and the extra code might be adding overhead it is 2748a1b232SPasha Tatashin only optionally enabled. 2848a1b232SPasha Tatashin 2948a1b232SPasha Tatashinconfig KEXEC_HANDOVER_DEBUGFS 3048a1b232SPasha Tatashin bool "kexec handover debugfs interface" 3148a1b232SPasha Tatashin default KEXEC_HANDOVER 3248a1b232SPasha Tatashin depends on KEXEC_HANDOVER 3348a1b232SPasha Tatashin select DEBUG_FS 3448a1b232SPasha Tatashin help 3548a1b232SPasha Tatashin Allow to control kexec handover device tree via debugfs 3648a1b232SPasha Tatashin interface, i.e. finalize the state or aborting the finalization. 3748a1b232SPasha Tatashin Also, enables inspecting the KHO fdt trees with the debugfs binary 3848a1b232SPasha Tatashin blobs. 3948a1b232SPasha Tatashin 407bd3643fSPasha Tatashinconfig KEXEC_HANDOVER_ENABLE_DEFAULT 417bd3643fSPasha Tatashin bool "Enable kexec handover by default" 427bd3643fSPasha Tatashin depends on KEXEC_HANDOVER 437bd3643fSPasha Tatashin help 447bd3643fSPasha Tatashin Enable Kexec Handover by default. This avoids the need to 457bd3643fSPasha Tatashin explicitly pass 'kho=on' on the kernel command line. 467bd3643fSPasha Tatashin 477bd3643fSPasha Tatashin This is useful for systems where KHO is a prerequisite for other 487bd3643fSPasha Tatashin features, such as Live Update, ensuring the mechanism is always 497bd3643fSPasha Tatashin active. 507bd3643fSPasha Tatashin 517bd3643fSPasha Tatashin The default behavior can still be overridden at boot time by 527bd3643fSPasha Tatashin passing 'kho=off'. 537bd3643fSPasha Tatashin 549e2fd062SPasha Tatashinconfig LIVEUPDATE 559e2fd062SPasha Tatashin bool "Live Update Orchestrator" 569e2fd062SPasha Tatashin depends on KEXEC_HANDOVER 579e2fd062SPasha Tatashin help 589e2fd062SPasha Tatashin Enable the Live Update Orchestrator. Live Update is a mechanism, 599e2fd062SPasha Tatashin typically based on kexec, that allows the kernel to be updated 609e2fd062SPasha Tatashin while keeping selected devices operational across the transition. 619e2fd062SPasha Tatashin These devices are intended to be reclaimed by the new kernel and 629e2fd062SPasha Tatashin re-attached to their original workload without requiring a device 639e2fd062SPasha Tatashin reset. 649e2fd062SPasha Tatashin 659e2fd062SPasha Tatashin Ability to handover a device from current to the next kernel depends 669e2fd062SPasha Tatashin on specific support within device drivers and related kernel 679e2fd062SPasha Tatashin subsystems. 689e2fd062SPasha Tatashin 699e2fd062SPasha Tatashin This feature primarily targets virtual machine hosts to quickly update 709e2fd062SPasha Tatashin the kernel hypervisor with minimal disruption to the running virtual 719e2fd062SPasha Tatashin machines. 729e2fd062SPasha Tatashin 739e2fd062SPasha Tatashin If unsure, say N. 749e2fd062SPasha Tatashin 75*998be0a4SPasha Tatashinconfig LIVEUPDATE_MEMFD 76*998be0a4SPasha Tatashin bool "Live update support for memfd" 77*998be0a4SPasha Tatashin depends on LIVEUPDATE 78*998be0a4SPasha Tatashin depends on MEMFD_CREATE 79*998be0a4SPasha Tatashin depends on SHMEM 80*998be0a4SPasha Tatashin default LIVEUPDATE 81*998be0a4SPasha Tatashin help 82*998be0a4SPasha Tatashin Enable live update support for memfd regions. This allows preserving 83*998be0a4SPasha Tatashin memfd-backed memory across kernel live updates. 84*998be0a4SPasha Tatashin 85*998be0a4SPasha Tatashin This can be used to back VM memory with memfds, allowing the guest 86*998be0a4SPasha Tatashin memory to persist, or for other user workloads needing to preserve 87*998be0a4SPasha Tatashin pages. 88*998be0a4SPasha Tatashin 89*998be0a4SPasha Tatashin If unsure, say N. 90*998be0a4SPasha Tatashin 9148a1b232SPasha Tatashinendmenu 92