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2025-11-28netfilter: ip6t_srh: fix UAPI kernel-doc comments formatRandy Dunlap1-20/+20
Fix the kernel-doc format for struct members to be "@member" instead of "@ member" to avoid kernel-doc warnings. Warning: ip6t_srh.h:60 struct member 'next_hdr' not described in 'ip6t_srh' Warning: ip6t_srh.h:60 struct member 'hdr_len' not described in 'ip6t_srh' Warning: ip6t_srh.h:60 struct member 'segs_left' not described in 'ip6t_srh' Warning: ip6t_srh.h:60 struct member 'last_entry' not described in 'ip6t_srh' Warning: ip6t_srh.h:60 struct member 'tag' not described in 'ip6t_srh' Warning: ip6t_srh.h:60 struct member 'mt_flags' not described in 'ip6t_srh' Warning: ip6t_srh.h:60 struct member 'mt_invflags' not described in 'ip6t_srh' Warning: ip6t_srh.h:93 struct member 'next_hdr' not described in 'ip6t_srh1' Warning: ip6t_srh.h:93 struct member 'hdr_len' not described in 'ip6t_srh1' Warning: ip6t_srh.h:93 struct member 'segs_left' not described in 'ip6t_srh1' Warning: ip6t_srh.h:93 struct member 'last_entry' not described in 'ip6t_srh1' Warning: ip6t_srh.h:93 struct member 'tag' not described in 'ip6t_srh1' Warning: ip6t_srh.h:93 struct member 'psid_addr' not described in 'ip6t_srh1' Warning: ip6t_srh.h:93 struct member 'nsid_addr' not described in 'ip6t_srh1' Warning: ip6t_srh.h:93 struct member 'lsid_addr' not described in 'ip6t_srh1' Warning: ip6t_srh.h:93 struct member 'psid_msk' not described in 'ip6t_srh1' Warning: ip6t_srh.h:93 struct member 'nsid_msk' not described in 'ip6t_srh1' Warning: ip6t_srh.h:93 struct member 'lsid_msk' not described in 'ip6t_srh1' Warning: ip6t_srh.h:93 struct member 'mt_flags' not described in 'ip6t_srh1' Warning: ip6t_srh.h:93 struct member 'mt_invflags' not described in 'ip6t_srh1' Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2025-11-28netfilter: nf_conncount: rework API to use sk_buff directlyFernando Fernandez Mancera1-9/+8
When using nf_conncount infrastructure for non-confirmed connections a duplicated track is possible due to an optimization introduced since commit d265929930e2 ("netfilter: nf_conncount: reduce unnecessary GC"). In order to fix this introduce a new conncount API that receives directly an sk_buff struct. It fetches the tuple and zone and the corresponding ct from it. It comes with both existing conncount variants nf_conncount_count_skb() and nf_conncount_add_skb(). In addition remove the old API and adjust all the users to use the new one. This way, for each sk_buff struct it is possible to check if there is a ct present and already confirmed. If so, skip the add operation. Fixes: d265929930e2 ("netfilter: nf_conncount: reduce unnecessary GC") Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2025-11-28netfilter: flowtable: Add IPIP rx sw accelerationLorenzo Bianconi2-0/+31
Introduce sw acceleration for rx path of IPIP tunnels relying on the netfilter flowtable infrastructure. Subsequent patches will add sw acceleration for IPIP tunnels tx path. This series introduces basic infrastructure to accelerate other tunnel types (e.g. IP6IP6). IPIP rx sw acceleration can be tested running the following scenario where the traffic is forwarded between two NICs (eth0 and eth1) and an IPIP tunnel is used to access a remote site (using eth1 as the underlay device): ETH0 -- TUN0 <==> ETH1 -- [IP network] -- TUN1 (192.168.100.2) $ip addr show 6: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000 link/ether 00:00:22:33:11:55 brd ff:ff:ff:ff:ff:ff inet 192.168.0.2/24 scope global eth0 valid_lft forever preferred_lft forever 7: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000 link/ether 00:11:22:33:11:55 brd ff:ff:ff:ff:ff:ff inet 192.168.1.1/24 scope global eth1 valid_lft forever preferred_lft forever 8: tun0@NONE: <POINTOPOINT,NOARP,UP,LOWER_UP> mtu 1480 qdisc noqueue state UNKNOWN group default qlen 1000 link/ipip 192.168.1.1 peer 192.168.1.2 inet 192.168.100.1/24 scope global tun0 valid_lft forever preferred_lft forever $ip route show default via 192.168.100.2 dev tun0 192.168.0.0/24 dev eth0 proto kernel scope link src 192.168.0.2 192.168.1.0/24 dev eth1 proto kernel scope link src 192.168.1.1 192.168.100.0/24 dev tun0 proto kernel scope link src 192.168.100.1 $nft list ruleset table inet filter { flowtable ft { hook ingress priority filter devices = { eth0, eth1 } } chain forward { type filter hook forward priority filter; policy accept; meta l4proto { tcp, udp } flow add @ft } } Reproducing the scenario described above using veths I got the following results: - TCP stream received from the IPIP tunnel: - net-next: (baseline) ~ 71Gbps - net-next + IPIP flowtbale support: ~101Gbps Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2025-11-28netfilter: flowtable: remove hw_ifidxPablo Neira Ayuso1-1/+0
hw_ifidx was originally introduced to store the real netdevice as a requirement for the hardware offload support in: 73f97025a972 ("netfilter: nft_flow_offload: use direct xmit if hardware offload is enabled") Since ("netfilter: flowtable: consolidate xmit path"), ifidx and hw_ifidx points to the real device in the xmit path, remove it. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2025-11-27netfilter: flowtable: consolidate xmit pathPablo Neira Ayuso1-0/+1
Use dev_queue_xmit() for the XMIT_NEIGH case. Store the interface index of the real device behind the vlan/pppoe device, this introduces an extra lookup for the real device in the xmit path because rt->dst.dev provides the vlan/pppoe device. XMIT_NEIGH now looks more similar to XMIT_DIRECT but the check for stale dst and the neighbour lookup still remain in place which is convenient to deal with network topology changes. Note that nft_flow_route() needs to relax the check for _XMIT_NEIGH so the existing basic xfrm offload (which only works in one direction) does not break. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2025-11-27netfilter: flowtable: move path discovery infrastructure to its own filePablo Neira Ayuso1-0/+6
This file contains the path discovery that is run from the forward chain for the packet offloading the flow into the flowtable. This consists of a series of calls to dev_fill_forward_path() for each device stack. More topologies may be supported in the future, so move this code to its own file to separate it from the nftables flow_offload expression. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2025-11-27vmcoreinfo: track and log recoverable hardware errorsBreno Leitao2-0/+17
Introduce a generic infrastructure for tracking recoverable hardware errors (HW errors that are visible to the OS but does not cause a panic) and record them for vmcore consumption. This aids post-mortem crash analysis tools by preserving a count and timestamp for the last occurrence of such errors. On the other side, correctable errors, which the OS typically remains unaware of because the underlying hardware handles them transparently, are less relevant for crash dump and therefore are NOT tracked in this infrastructure. Add centralized logging for sources of recoverable hardware errors based on the subsystem it has been notified. hwerror_data is write-only at kernel runtime, and it is meant to be read from vmcore using tools like crash/drgn. For example, this is how it looks like when opening the crashdump from drgn. >>> prog['hwerror_data'] (struct hwerror_info[1]){ { .count = (int)844, .timestamp = (time64_t)1752852018, }, ... This helps fleet operators quickly triage whether a crash may be influenced by hardware recoverable errors (which executes a uncommon code path in the kernel), especially when recoverable errors occurred shortly before a panic, such as the bug fixed by commit ee62ce7a1d90 ("page_pool: Track DMA-mapped pages and unmap them when destroying the pool") This is not intended to replace full hardware diagnostics but provides a fast way to correlate hardware events with kernel panics quickly. Rare machine check exceptions—like those indicated by mce_flags.p5 or mce_flags.winchip—are not accounted for in this method, as they fall outside the intended usage scope for this feature's user base. [leitao@debian.org: add hw-recoverable-errors to toctree] Link: https://lkml.kernel.org/r/20251127-vmcoreinfo_fix-v1-1-26f5b1c43da9@debian.org Link: https://lkml.kernel.org/r/20251010-vmcore_hw_error-v5-1-636ede3efe44@debian.org Signed-off-by: Breno Leitao <leitao@debian.org> Suggested-by: Tony Luck <tony.luck@intel.com> Suggested-by: Shuai Xue <xueshuai@linux.alibaba.com> Reviewed-by: Shuai Xue <xueshuai@linux.alibaba.com> Reviewed-by: Hanjun Guo <guohanjun@huawei.com> [APEI] Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Bob Moore <robert.moore@intel.com> Cc: Borislav Betkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Morse <james.morse@arm.com> Cc: Konrad Rzessutek Wilk <konrad.wilk@oracle.com> Cc: Len Brown <lenb@kernel.org> Cc: Mahesh Salgaonkar <mahesh@linux.ibm.com> Cc: Mauro Carvalho Chehab <mchehab@kernel.org> Cc: "Oliver O'Halloran" <oohall@gmail.com> Cc: Omar Sandoval <osandov@osandov.com> Cc: Thomas Gleinxer <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-27mm: memfd_luo: allow preserving memfdPratyush Yadav1-0/+77
The ability to preserve a memfd allows userspace to use KHO and LUO to transfer its memory contents to the next kernel. This is useful in many ways. For one, it can be used with IOMMUFD as the backing store for IOMMU page tables. Preserving IOMMUFD is essential for performing a hypervisor live update with passthrough devices. memfd support provides the first building block for making that possible. For another, applications with a large amount of memory that takes time to reconstruct, reboots to consume kernel upgrades can be very expensive. memfd with LUO gives those applications reboot-persistent memory that they can use to quickly save and reconstruct that state. While memfd is backed by either hugetlbfs or shmem, currently only support on shmem is added. To be more precise, support for anonymous shmem files is added. The handover to the next kernel is not transparent. All the properties of the file are not preserved; only its memory contents, position, and size. The recreated file gets the UID and GID of the task doing the restore, and the task's cgroup gets charged with the memory. Once preserved, the file cannot grow or shrink, and all its pages are pinned to avoid migrations and swapping. The file can still be read from or written to. Use vmalloc to get the buffer to hold the folios, and preserve it using kho_preserve_vmalloc(). This doesn't have the size limit. Link: https://lkml.kernel.org/r/20251125165850.3389713-15-pasha.tatashin@soleen.com Signed-off-by: Pratyush Yadav <ptyadav@amazon.de> Co-developed-by: Pasha Tatashin <pasha.tatashin@soleen.com> Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com> Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Tested-by: David Matlack <dmatlack@google.com> Cc: Aleksander Lobakin <aleksander.lobakin@intel.com> Cc: Alexander Graf <graf@amazon.com> Cc: Alice Ryhl <aliceryhl@google.com> Cc: Andriy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: anish kumar <yesanishhere@gmail.com> Cc: Anna Schumaker <anna.schumaker@oracle.com> Cc: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Borislav Betkov <bp@alien8.de> Cc: Chanwoo Choi <cw00.choi@samsung.com> Cc: Chen Ridong <chenridong@huawei.com> Cc: Chris Li <chrisl@kernel.org> Cc: Christian Brauner <brauner@kernel.org> Cc: Daniel Wagner <wagi@kernel.org> Cc: Danilo Krummrich <dakr@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Jeffery <djeffery@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guixin Liu <kanie@linux.alibaba.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Hugh Dickins <hughd@google.com> Cc: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jann Horn <jannh@google.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Joanthan Cameron <Jonathan.Cameron@huawei.com> Cc: Joel Granados <joel.granados@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Lennart Poettering <lennart@poettering.net> Cc: Leon Romanovsky <leon@kernel.org> Cc: Leon Romanovsky <leonro@nvidia.com> Cc: Lukas Wunner <lukas@wunner.de> Cc: Marc Rutland <mark.rutland@arm.com> Cc: Masahiro Yamada <masahiroy@kernel.org> Cc: Matthew Maurer <mmaurer@google.com> Cc: Miguel Ojeda <ojeda@kernel.org> Cc: Myugnjoo Ham <myungjoo.ham@samsung.com> Cc: Parav Pandit <parav@nvidia.com> Cc: Pratyush Yadav <pratyush@kernel.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Saeed Mahameed <saeedm@nvidia.com> Cc: Samiullah Khawaja <skhawaja@google.com> Cc: Song Liu <song@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Stuart Hayes <stuart.w.hayes@gmail.com> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: Thomas Weißschuh <linux@weissschuh.net> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: William Tu <witu@nvidia.com> Cc: Yoann Congal <yoann.congal@smile.fr> Cc: Zhu Yanjun <yanjun.zhu@linux.dev> Cc: Zijun Hu <quic_zijuhu@quicinc.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-27liveupdate: luo_file: add private argument to store runtime statePratyush Yadav1-0/+5
Currently file handlers only get the serialized_data field to store their state. This field has a pointer to the serialized state of the file, and it becomes a part of LUO file's serialized state. File handlers can also need some runtime state to track information that shouldn't make it in the serialized data. One such example is a vmalloc pointer. While kho_preserve_vmalloc() preserves the memory backing a vmalloc allocation, it does not store the original vmap pointer, since that has no use being passed to the next kernel. The pointer is needed to free the memory in case the file is unpreserved. Provide a private field in struct luo_file and pass it to all the callbacks. The field's can be set by preserve, and must be freed by unpreserve. Link: https://lkml.kernel.org/r/20251125165850.3389713-14-pasha.tatashin@soleen.com Signed-off-by: Pratyush Yadav <ptyadav@amazon.de> Co-developed-by: Pasha Tatashin <pasha.tatashin@soleen.com> Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com> Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Tested-by: David Matlack <dmatlack@google.com> Cc: Aleksander Lobakin <aleksander.lobakin@intel.com> Cc: Alexander Graf <graf@amazon.com> Cc: Alice Ryhl <aliceryhl@google.com> Cc: Andriy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: anish kumar <yesanishhere@gmail.com> Cc: Anna Schumaker <anna.schumaker@oracle.com> Cc: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Borislav Betkov <bp@alien8.de> Cc: Chanwoo Choi <cw00.choi@samsung.com> Cc: Chen Ridong <chenridong@huawei.com> Cc: Chris Li <chrisl@kernel.org> Cc: Christian Brauner <brauner@kernel.org> Cc: Daniel Wagner <wagi@kernel.org> Cc: Danilo Krummrich <dakr@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Jeffery <djeffery@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guixin Liu <kanie@linux.alibaba.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Hugh Dickins <hughd@google.com> Cc: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jann Horn <jannh@google.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Joanthan Cameron <Jonathan.Cameron@huawei.com> Cc: Joel Granados <joel.granados@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Lennart Poettering <lennart@poettering.net> Cc: Leon Romanovsky <leon@kernel.org> Cc: Leon Romanovsky <leonro@nvidia.com> Cc: Lukas Wunner <lukas@wunner.de> Cc: Marc Rutland <mark.rutland@arm.com> Cc: Masahiro Yamada <masahiroy@kernel.org> Cc: Matthew Maurer <mmaurer@google.com> Cc: Miguel Ojeda <ojeda@kernel.org> Cc: Myugnjoo Ham <myungjoo.ham@samsung.com> Cc: Parav Pandit <parav@nvidia.com> Cc: Pratyush Yadav <pratyush@kernel.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Saeed Mahameed <saeedm@nvidia.com> Cc: Samiullah Khawaja <skhawaja@google.com> Cc: Song Liu <song@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Stuart Hayes <stuart.w.hayes@gmail.com> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: Thomas Weißschuh <linux@weissschuh.net> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: William Tu <witu@nvidia.com> Cc: Yoann Congal <yoann.congal@smile.fr> Cc: Zhu Yanjun <yanjun.zhu@linux.dev> Cc: Zijun Hu <quic_zijuhu@quicinc.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-27mm: shmem: allow freezing inode mappingPratyush Yadav1-0/+17
To prepare a shmem inode for live update, its index -> folio mappings must be serialized. Once the mappings are serialized, they cannot change since it would cause the serialized data to become inconsistent. This can be done by pinning the folios to avoid migration, and by making sure no folios can be added to or removed from the inode. While mechanisms to pin folios already exist, the only way to stop folios being added or removed are the grow and shrink file seals. But file seals come with their own semantics, one of which is that they can't be removed. This doesn't work with liveupdate since it can be cancelled or error out, which would need the seals to be removed and the file's normal functionality to be restored. Introduce SHMEM_F_MAPPING_FROZEN to indicate this instead. It is internal to shmem and is not directly exposed to userspace. It functions similar to F_SEAL_GROW | F_SEAL_SHRINK, but additionally disallows hole punching, and can be removed. Link: https://lkml.kernel.org/r/20251125165850.3389713-12-pasha.tatashin@soleen.com Signed-off-by: Pratyush Yadav <ptyadav@amazon.de> Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com> Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Tested-by: David Matlack <dmatlack@google.com> Cc: Aleksander Lobakin <aleksander.lobakin@intel.com> Cc: Alexander Graf <graf@amazon.com> Cc: Alice Ryhl <aliceryhl@google.com> Cc: Andriy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: anish kumar <yesanishhere@gmail.com> Cc: Anna Schumaker <anna.schumaker@oracle.com> Cc: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Borislav Betkov <bp@alien8.de> Cc: Chanwoo Choi <cw00.choi@samsung.com> Cc: Chen Ridong <chenridong@huawei.com> Cc: Chris Li <chrisl@kernel.org> Cc: Christian Brauner <brauner@kernel.org> Cc: Daniel Wagner <wagi@kernel.org> Cc: Danilo Krummrich <dakr@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Jeffery <djeffery@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guixin Liu <kanie@linux.alibaba.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Hugh Dickins <hughd@google.com> Cc: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jann Horn <jannh@google.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Joanthan Cameron <Jonathan.Cameron@huawei.com> Cc: Joel Granados <joel.granados@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Lennart Poettering <lennart@poettering.net> Cc: Leon Romanovsky <leon@kernel.org> Cc: Leon Romanovsky <leonro@nvidia.com> Cc: Lukas Wunner <lukas@wunner.de> Cc: Marc Rutland <mark.rutland@arm.com> Cc: Masahiro Yamada <masahiroy@kernel.org> Cc: Matthew Maurer <mmaurer@google.com> Cc: Miguel Ojeda <ojeda@kernel.org> Cc: Myugnjoo Ham <myungjoo.ham@samsung.com> Cc: Parav Pandit <parav@nvidia.com> Cc: Pratyush Yadav <pratyush@kernel.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Saeed Mahameed <saeedm@nvidia.com> Cc: Samiullah Khawaja <skhawaja@google.com> Cc: Song Liu <song@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Stuart Hayes <stuart.w.hayes@gmail.com> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: Thomas Weißschuh <linux@weissschuh.net> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: William Tu <witu@nvidia.com> Cc: Yoann Congal <yoann.congal@smile.fr> Cc: Zhu Yanjun <yanjun.zhu@linux.dev> Cc: Zijun Hu <quic_zijuhu@quicinc.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-27mm: shmem: use SHMEM_F_* flags instead of VM_* flagsPratyush Yadav1-0/+6
shmem_inode_info::flags can have the VM flags VM_NORESERVE and VM_LOCKED. These are used to suppress pre-accounting or to lock the pages in the inode respectively. Using the VM flags directly makes it difficult to add shmem-specific flags that are unrelated to VM behavior since one would need to find a VM flag not used by shmem and re-purpose it. Introduce SHMEM_F_NORESERVE and SHMEM_F_LOCKED which represent the same information, but their bits are independent of the VM flags. Callers can still pass VM_NORESERVE to shmem_get_inode(), but it gets transformed to the shmem-specific flag internally. No functional changes intended. Link: https://lkml.kernel.org/r/20251125165850.3389713-11-pasha.tatashin@soleen.com Signed-off-by: Pratyush Yadav <ptyadav@amazon.de> Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com> Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Tested-by: David Matlack <dmatlack@google.com> Cc: Aleksander Lobakin <aleksander.lobakin@intel.com> Cc: Alexander Graf <graf@amazon.com> Cc: Alice Ryhl <aliceryhl@google.com> Cc: Andriy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: anish kumar <yesanishhere@gmail.com> Cc: Anna Schumaker <anna.schumaker@oracle.com> Cc: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Borislav Betkov <bp@alien8.de> Cc: Chanwoo Choi <cw00.choi@samsung.com> Cc: Chen Ridong <chenridong@huawei.com> Cc: Chris Li <chrisl@kernel.org> Cc: Christian Brauner <brauner@kernel.org> Cc: Daniel Wagner <wagi@kernel.org> Cc: Danilo Krummrich <dakr@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Jeffery <djeffery@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guixin Liu <kanie@linux.alibaba.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Hugh Dickins <hughd@google.com> Cc: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jann Horn <jannh@google.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Joanthan Cameron <Jonathan.Cameron@huawei.com> Cc: Joel Granados <joel.granados@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Lennart Poettering <lennart@poettering.net> Cc: Leon Romanovsky <leon@kernel.org> Cc: Leon Romanovsky <leonro@nvidia.com> Cc: Lukas Wunner <lukas@wunner.de> Cc: Marc Rutland <mark.rutland@arm.com> Cc: Masahiro Yamada <masahiroy@kernel.org> Cc: Matthew Maurer <mmaurer@google.com> Cc: Miguel Ojeda <ojeda@kernel.org> Cc: Myugnjoo Ham <myungjoo.ham@samsung.com> Cc: Parav Pandit <parav@nvidia.com> Cc: Pratyush Yadav <pratyush@kernel.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Saeed Mahameed <saeedm@nvidia.com> Cc: Samiullah Khawaja <skhawaja@google.com> Cc: Song Liu <song@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Stuart Hayes <stuart.w.hayes@gmail.com> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: Thomas Weißschuh <linux@weissschuh.net> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: William Tu <witu@nvidia.com> Cc: Yoann Congal <yoann.congal@smile.fr> Cc: Zhu Yanjun <yanjun.zhu@linux.dev> Cc: Zijun Hu <quic_zijuhu@quicinc.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-27liveupdate: luo_session: add ioctls for file preservationPasha Tatashin1-0/+103
Introducing the userspace interface and internal logic required to manage the lifecycle of file descriptors within a session. Previously, a session was merely a container; this change makes it a functional management unit. The following capabilities are added: A new set of ioctl commands are added, which operate on the file descriptor returned by CREATE_SESSION. This allows userspace to: - LIVEUPDATE_SESSION_PRESERVE_FD: Add a file descriptor to a session to be preserved across the live update. - LIVEUPDATE_SESSION_RETRIEVE_FD: Retrieve a preserved file in the new kernel using its unique token. - LIVEUPDATE_SESSION_FINISH: finish session The session's .release handler is enhanced to be state-aware. When a session's file descriptor is closed, it correctly unpreserves the session based on its current state before freeing all associated file resources. Link: https://lkml.kernel.org/r/20251125165850.3389713-8-pasha.tatashin@soleen.com Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com> Reviewed-by: Pratyush Yadav <pratyush@kernel.org> Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Tested-by: David Matlack <dmatlack@google.com> Cc: Aleksander Lobakin <aleksander.lobakin@intel.com> Cc: Alexander Graf <graf@amazon.com> Cc: Alice Ryhl <aliceryhl@google.com> Cc: Andriy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: anish kumar <yesanishhere@gmail.com> Cc: Anna Schumaker <anna.schumaker@oracle.com> Cc: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Borislav Betkov <bp@alien8.de> Cc: Chanwoo Choi <cw00.choi@samsung.com> Cc: Chen Ridong <chenridong@huawei.com> Cc: Chris Li <chrisl@kernel.org> Cc: Christian Brauner <brauner@kernel.org> Cc: Daniel Wagner <wagi@kernel.org> Cc: Danilo Krummrich <dakr@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Jeffery <djeffery@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guixin Liu <kanie@linux.alibaba.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Hugh Dickins <hughd@google.com> Cc: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jann Horn <jannh@google.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Joanthan Cameron <Jonathan.Cameron@huawei.com> Cc: Joel Granados <joel.granados@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Lennart Poettering <lennart@poettering.net> Cc: Leon Romanovsky <leon@kernel.org> Cc: Leon Romanovsky <leonro@nvidia.com> Cc: Lukas Wunner <lukas@wunner.de> Cc: Marc Rutland <mark.rutland@arm.com> Cc: Masahiro Yamada <masahiroy@kernel.org> Cc: Matthew Maurer <mmaurer@google.com> Cc: Miguel Ojeda <ojeda@kernel.org> Cc: Myugnjoo Ham <myungjoo.ham@samsung.com> Cc: Parav Pandit <parav@nvidia.com> Cc: Pratyush Yadav <ptyadav@amazon.de> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Saeed Mahameed <saeedm@nvidia.com> Cc: Samiullah Khawaja <skhawaja@google.com> Cc: Song Liu <song@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Stuart Hayes <stuart.w.hayes@gmail.com> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: Thomas Weißschuh <linux@weissschuh.net> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: William Tu <witu@nvidia.com> Cc: Yoann Congal <yoann.congal@smile.fr> Cc: Zhu Yanjun <yanjun.zhu@linux.dev> Cc: Zijun Hu <quic_zijuhu@quicinc.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-27liveupdate: luo_file: implement file systems callbacksPasha Tatashin2-1/+136
This patch implements the core mechanism for managing preserved files throughout the live update lifecycle. It provides the logic to invoke the file handler callbacks (preserve, unpreserve, freeze, unfreeze, retrieve, and finish) at the appropriate stages. During the reboot phase, luo_file_freeze() serializes the final metadata for each file (handler compatible string, token, and data handle) into a memory region preserved by KHO. In the new kernel, luo_file_deserialize() reconstructs the in-memory file list from this data, preparing the session for retrieval. Link: https://lkml.kernel.org/r/20251125165850.3389713-7-pasha.tatashin@soleen.com Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com> Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Reviewed-by: Pratyush Yadav <pratyush@kernel.org> Tested-by: David Matlack <dmatlack@google.com> Cc: Aleksander Lobakin <aleksander.lobakin@intel.com> Cc: Alexander Graf <graf@amazon.com> Cc: Alice Ryhl <aliceryhl@google.com> Cc: Andriy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: anish kumar <yesanishhere@gmail.com> Cc: Anna Schumaker <anna.schumaker@oracle.com> Cc: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Borislav Betkov <bp@alien8.de> Cc: Chanwoo Choi <cw00.choi@samsung.com> Cc: Chen Ridong <chenridong@huawei.com> Cc: Chris Li <chrisl@kernel.org> Cc: Christian Brauner <brauner@kernel.org> Cc: Daniel Wagner <wagi@kernel.org> Cc: Danilo Krummrich <dakr@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Jeffery <djeffery@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guixin Liu <kanie@linux.alibaba.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Hugh Dickins <hughd@google.com> Cc: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jann Horn <jannh@google.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Joanthan Cameron <Jonathan.Cameron@huawei.com> Cc: Joel Granados <joel.granados@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Lennart Poettering <lennart@poettering.net> Cc: Leon Romanovsky <leon@kernel.org> Cc: Leon Romanovsky <leonro@nvidia.com> Cc: Lukas Wunner <lukas@wunner.de> Cc: Marc Rutland <mark.rutland@arm.com> Cc: Masahiro Yamada <masahiroy@kernel.org> Cc: Matthew Maurer <mmaurer@google.com> Cc: Miguel Ojeda <ojeda@kernel.org> Cc: Myugnjoo Ham <myungjoo.ham@samsung.com> Cc: Parav Pandit <parav@nvidia.com> Cc: Pratyush Yadav <ptyadav@amazon.de> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Saeed Mahameed <saeedm@nvidia.com> Cc: Samiullah Khawaja <skhawaja@google.com> Cc: Song Liu <song@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Stuart Hayes <stuart.w.hayes@gmail.com> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: Thomas Weißschuh <linux@weissschuh.net> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: William Tu <witu@nvidia.com> Cc: Yoann Congal <yoann.congal@smile.fr> Cc: Zhu Yanjun <yanjun.zhu@linux.dev> Cc: Zijun Hu <quic_zijuhu@quicinc.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-27liveupdate: luo_core: add user interfacePasha Tatashin1-0/+64
Introduce the user-space interface for the Live Update Orchestrator via ioctl commands, enabling external control over the live update process and management of preserved resources. The idea is that there is going to be a single userspace agent driving the live update, therefore, only a single process can ever hold this device opened at a time. The following ioctl commands are introduced: LIVEUPDATE_IOCTL_CREATE_SESSION Provides a way for userspace to create a named session for grouping file descriptors that need to be preserved. It returns a new file descriptor representing the session. LIVEUPDATE_IOCTL_RETRIEVE_SESSION Allows the userspace agent in the new kernel to reclaim a preserved session by its name, receiving a new file descriptor to manage the restored resources. Link: https://lkml.kernel.org/r/20251125165850.3389713-6-pasha.tatashin@soleen.com Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com> Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Reviewed-by: Pratyush Yadav <pratyush@kernel.org> Tested-by: David Matlack <dmatlack@google.com> Cc: Aleksander Lobakin <aleksander.lobakin@intel.com> Cc: Alexander Graf <graf@amazon.com> Cc: Alice Ryhl <aliceryhl@google.com> Cc: Andriy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: anish kumar <yesanishhere@gmail.com> Cc: Anna Schumaker <anna.schumaker@oracle.com> Cc: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Borislav Betkov <bp@alien8.de> Cc: Chanwoo Choi <cw00.choi@samsung.com> Cc: Chen Ridong <chenridong@huawei.com> Cc: Chris Li <chrisl@kernel.org> Cc: Christian Brauner <brauner@kernel.org> Cc: Daniel Wagner <wagi@kernel.org> Cc: Danilo Krummrich <dakr@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Jeffery <djeffery@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guixin Liu <kanie@linux.alibaba.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Hugh Dickins <hughd@google.com> Cc: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jann Horn <jannh@google.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Joanthan Cameron <Jonathan.Cameron@huawei.com> Cc: Joel Granados <joel.granados@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Lennart Poettering <lennart@poettering.net> Cc: Leon Romanovsky <leon@kernel.org> Cc: Leon Romanovsky <leonro@nvidia.com> Cc: Lukas Wunner <lukas@wunner.de> Cc: Marc Rutland <mark.rutland@arm.com> Cc: Masahiro Yamada <masahiroy@kernel.org> Cc: Matthew Maurer <mmaurer@google.com> Cc: Miguel Ojeda <ojeda@kernel.org> Cc: Myugnjoo Ham <myungjoo.ham@samsung.com> Cc: Parav Pandit <parav@nvidia.com> Cc: Pratyush Yadav <ptyadav@amazon.de> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Saeed Mahameed <saeedm@nvidia.com> Cc: Samiullah Khawaja <skhawaja@google.com> Cc: Song Liu <song@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Stuart Hayes <stuart.w.hayes@gmail.com> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: Thomas Weißschuh <linux@weissschuh.net> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: William Tu <witu@nvidia.com> Cc: Yoann Congal <yoann.congal@smile.fr> Cc: Zhu Yanjun <yanjun.zhu@linux.dev> Cc: Zijun Hu <quic_zijuhu@quicinc.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-27liveupdate: luo_session: add sessions supportPasha Tatashin2-0/+74
Introduce concept of "Live Update Sessions" within the LUO framework. LUO sessions provide a mechanism to group and manage `struct file *` instances (representing file descriptors) that need to be preserved across a kexec-based live update. Each session is identified by a unique name and acts as a container for file objects whose state is critical to a userspace workload, such as a virtual machine or a high-performance database, aiming to maintain their functionality across a kernel transition. This groundwork establishes the framework for preserving file-backed state across kernel updates, with the actual file data preservation mechanisms to be implemented in subsequent patches. [dan.carpenter@linaro.org: fix use after free in luo_session_deserialize()] Link: https://lkml.kernel.org/r/c5dd637d7eed3a3be48c5e9fedb881596a3b1f5a.1764163896.git.dan.carpenter@linaro.org Link: https://lkml.kernel.org/r/20251125165850.3389713-5-pasha.tatashin@soleen.com Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com> Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org> Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Reviewed-by: Pratyush Yadav <pratyush@kernel.org> Tested-by: David Matlack <dmatlack@google.com> Cc: Aleksander Lobakin <aleksander.lobakin@intel.com> Cc: Alexander Graf <graf@amazon.com> Cc: Alice Ryhl <aliceryhl@google.com> Cc: Andriy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: anish kumar <yesanishhere@gmail.com> Cc: Anna Schumaker <anna.schumaker@oracle.com> Cc: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Borislav Betkov <bp@alien8.de> Cc: Chanwoo Choi <cw00.choi@samsung.com> Cc: Chen Ridong <chenridong@huawei.com> Cc: Chris Li <chrisl@kernel.org> Cc: Christian Brauner <brauner@kernel.org> Cc: Daniel Wagner <wagi@kernel.org> Cc: Danilo Krummrich <dakr@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Jeffery <djeffery@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guixin Liu <kanie@linux.alibaba.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Hugh Dickins <hughd@google.com> Cc: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jann Horn <jannh@google.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Joanthan Cameron <Jonathan.Cameron@huawei.com> Cc: Joel Granados <joel.granados@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Lennart Poettering <lennart@poettering.net> Cc: Leon Romanovsky <leon@kernel.org> Cc: Leon Romanovsky <leonro@nvidia.com> Cc: Lukas Wunner <lukas@wunner.de> Cc: Marc Rutland <mark.rutland@arm.com> Cc: Masahiro Yamada <masahiroy@kernel.org> Cc: Matthew Maurer <mmaurer@google.com> Cc: Miguel Ojeda <ojeda@kernel.org> Cc: Myugnjoo Ham <myungjoo.ham@samsung.com> Cc: Parav Pandit <parav@nvidia.com> Cc: Pratyush Yadav <ptyadav@amazon.de> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Saeed Mahameed <saeedm@nvidia.com> Cc: Samiullah Khawaja <skhawaja@google.com> Cc: Song Liu <song@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Stuart Hayes <stuart.w.hayes@gmail.com> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: Thomas Weißschuh <linux@weissschuh.net> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: William Tu <witu@nvidia.com> Cc: Yoann Congal <yoann.congal@smile.fr> Cc: Zhu Yanjun <yanjun.zhu@linux.dev> Cc: Zijun Hu <quic_zijuhu@quicinc.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-27liveupdate: luo_core: integrate with KHOPasha Tatashin1-0/+58
Integrate the LUO with the KHO framework to enable passing LUO state across a kexec reboot. This patch implements the lifecycle integration with KHO: 1. Incoming State: During early boot (`early_initcall`), LUO checks if KHO is active. If so, it retrieves the "LUO" subtree, verifies the "luo-v1" compatibility string, and reads the `liveupdate-number` to track the update count. 2. Outgoing State: During late initialization (`late_initcall`), LUO allocates a new FDT for the next kernel, populates it with the basic header (compatible string and incremented update number), and registers it with KHO (`kho_add_subtree`). 3. Finalization: The `liveupdate_reboot()` notifier is updated to invoke `kho_finalize()`. This ensures that all memory segments marked for preservation are properly serialized before the kexec jump. Link: https://lkml.kernel.org/r/20251125165850.3389713-3-pasha.tatashin@soleen.com Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com> Reviewed-by: Pratyush Yadav <pratyush@kernel.org> Tested-by: David Matlack <dmatlack@google.com> Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Aleksander Lobakin <aleksander.lobakin@intel.com> Cc: Alexander Graf <graf@amazon.com> Cc: Alice Ryhl <aliceryhl@google.com> Cc: Andriy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: anish kumar <yesanishhere@gmail.com> Cc: Anna Schumaker <anna.schumaker@oracle.com> Cc: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Borislav Betkov <bp@alien8.de> Cc: Chanwoo Choi <cw00.choi@samsung.com> Cc: Chen Ridong <chenridong@huawei.com> Cc: Chris Li <chrisl@kernel.org> Cc: Christian Brauner <brauner@kernel.org> Cc: Daniel Wagner <wagi@kernel.org> Cc: Danilo Krummrich <dakr@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Jeffery <djeffery@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guixin Liu <kanie@linux.alibaba.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Hugh Dickins <hughd@google.com> Cc: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jann Horn <jannh@google.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Joanthan Cameron <Jonathan.Cameron@huawei.com> Cc: Joel Granados <joel.granados@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Lennart Poettering <lennart@poettering.net> Cc: Leon Romanovsky <leon@kernel.org> Cc: Leon Romanovsky <leonro@nvidia.com> Cc: Lukas Wunner <lukas@wunner.de> Cc: Marc Rutland <mark.rutland@arm.com> Cc: Masahiro Yamada <masahiroy@kernel.org> Cc: Matthew Maurer <mmaurer@google.com> Cc: Miguel Ojeda <ojeda@kernel.org> Cc: Myugnjoo Ham <myungjoo.ham@samsung.com> Cc: Parav Pandit <parav@nvidia.com> Cc: Pratyush Yadav <ptyadav@amazon.de> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Saeed Mahameed <saeedm@nvidia.com> Cc: Samiullah Khawaja <skhawaja@google.com> Cc: Song Liu <song@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Stuart Hayes <stuart.w.hayes@gmail.com> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: Thomas Weißschuh <linux@weissschuh.net> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: William Tu <witu@nvidia.com> Cc: Yoann Congal <yoann.congal@smile.fr> Cc: Zhu Yanjun <yanjun.zhu@linux.dev> Cc: Zijun Hu <quic_zijuhu@quicinc.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-27liveupdate: luo_core: Live Update OrchestratorPasha Tatashin2-0/+81
Patch series "Live Update Orchestrator", v8. This series introduces the Live Update Orchestrator, a kernel subsystem designed to facilitate live kernel updates using a kexec-based reboot. This capability is critical for cloud environments, allowing hypervisors to be updated with minimal downtime for running virtual machines. LUO achieves this by preserving the state of selected resources, such as memory, devices and their dependencies, across the kernel transition. As a key feature, this series includes support for preserving memfd file descriptors, which allows critical in-memory data, such as guest RAM or any other large memory region, to be maintained in RAM across the kexec reboot. The other series that use LUO, are VFIO [1], IOMMU [2], and PCI [3] preservations. Github repo of this series [4]. The core of LUO is a framework for managing the lifecycle of preserved resources through a userspace-driven interface. Key features include: - Session Management Userspace agent (i.e. luod [5]) creates named sessions, each represented by a file descriptor (via centralized agent that controls /dev/liveupdate). The lifecycle of all preserved resources within a session is tied to this FD, ensuring automatic kernel cleanup if the controlling userspace agent crashes or exits unexpectedly. - File Preservation A handler-based framework allows specific file types (demonstrated here with memfd) to be preserved. Handlers manage the serialization, restoration, and lifecycle of their specific file types. - File-Lifecycle-Bound State A new mechanism for managing shared global state whose lifecycle is tied to the preservation of one or more files. This is crucial for subsystems like IOMMU or HugeTLB, where multiple file descriptors may depend on a single, shared underlying resource that must be preserved only once. - KHO Integration LUO drives the Kexec Handover framework programmatically to pass its serialized metadata to the next kernel. The LUO state is finalized and added to the kexec image just before the reboot is triggered. In the future this step will also be removed once stateless KHO is merged [6]. - Userspace Interface Control is provided via ioctl commands on /dev/liveupdate for creating and retrieving sessions, as well as on session file descriptors for managing individual files. - Testing The series includes a set of selftests, including userspace API validation, kexec-based lifecycle tests for various session and file scenarios, and a new in-kernel test module to validate the FLB logic. Introduce LUO, a mechanism intended to facilitate kernel updates while keeping designated devices operational across the transition (e.g., via kexec). The primary use case is updating hypervisors with minimal disruption to running virtual machines. For userspace side of hypervisor update we have copyless migration. LUO is for updating the kernel. This initial patch lays the groundwork for the LUO subsystem. Further functionality, including the implementation of state transition logic, integration with KHO, and hooks for subsystems and file descriptors, will be added in subsequent patches. Create a character device at /dev/liveupdate. A new uAPI header, <uapi/linux/liveupdate.h>, will define the necessary structures. The magic number for IOCTL is registered in Documentation/userspace-api/ioctl/ioctl-number.rst. Link: https://lkml.kernel.org/r/20251125165850.3389713-1-pasha.tatashin@soleen.com Link: https://lkml.kernel.org/r/20251125165850.3389713-2-pasha.tatashin@soleen.com Link: https://lore.kernel.org/all/20251018000713.677779-1-vipinsh@google.com/ [1] Link: https://lore.kernel.org/linux-iommu/20250928190624.3735830-1-skhawaja@google.com [2] Link: https://lore.kernel.org/linux-pci/20250916-luo-pci-v2-0-c494053c3c08@kernel.org [3] Link: https://github.com/googleprodkernel/linux-liveupdate/tree/luo/v8 [4] Link: https://tinyurl.com/luoddesign [5] Link: https://lore.kernel.org/all/20251020100306.2709352-1-jasonmiu@google.com [6] Link: https://lore.kernel.org/all/20251115233409.768044-1-pasha.tatashin@soleen.com [7] Link: https://github.com/soleen/linux/blob/luo/v8b03/diff.v7.v8 [8] Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com> Reviewed-by: Pratyush Yadav <pratyush@kernel.org> Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Tested-by: David Matlack <dmatlack@google.com> Cc: Aleksander Lobakin <aleksander.lobakin@intel.com> Cc: Alexander Graf <graf@amazon.com> Cc: Alice Ryhl <aliceryhl@google.com> Cc: Andriy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: anish kumar <yesanishhere@gmail.com> Cc: Anna Schumaker <anna.schumaker@oracle.com> Cc: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Borislav Betkov <bp@alien8.de> Cc: Chanwoo Choi <cw00.choi@samsung.com> Cc: Chen Ridong <chenridong@huawei.com> Cc: Chris Li <chrisl@kernel.org> Cc: Christian Brauner <brauner@kernel.org> Cc: Daniel Wagner <wagi@kernel.org> Cc: Danilo Krummrich <dakr@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Jeffery <djeffery@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guixin Liu <kanie@linux.alibaba.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Hugh Dickins <hughd@google.com> Cc: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jann Horn <jannh@google.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Joanthan Cameron <Jonathan.Cameron@huawei.com> Cc: Joel Granados <joel.granados@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Lennart Poettering <lennart@poettering.net> Cc: Leon Romanovsky <leon@kernel.org> Cc: Leon Romanovsky <leonro@nvidia.com> Cc: Lukas Wunner <lukas@wunner.de> Cc: Marc Rutland <mark.rutland@arm.com> Cc: Masahiro Yamada <masahiroy@kernel.org> Cc: Matthew Maurer <mmaurer@google.com> Cc: Miguel Ojeda <ojeda@kernel.org> Cc: Myugnjoo Ham <myungjoo.ham@samsung.com> Cc: Parav Pandit <parav@nvidia.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Saeed Mahameed <saeedm@nvidia.com> Cc: Samiullah Khawaja <skhawaja@google.com> Cc: Song Liu <song@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Stuart Hayes <stuart.w.hayes@gmail.com> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: Thomas Weißschuh <linux@weissschuh.net> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: William Tu <witu@nvidia.com> Cc: Yoann Congal <yoann.congal@smile.fr> Cc: Zijun Hu <quic_zijuhu@quicinc.com> Cc: Pratyush Yadav <ptyadav@amazon.de> Cc: Zhu Yanjun <yanjun.zhu@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-27kho: allow memory preservation state updates after finalizationPasha Tatashin1-15/+6
Currently, kho_preserve_* and kho_unpreserve_* return -EBUSY if KHO is finalized. This enforces a rigid "freeze" on the KHO memory state. With the introduction of re-entrant finalization, this restriction is no longer necessary. Users should be allowed to modify the preservation set (e.g., adding new pages or freeing old ones) even after an initial finalization. The intended workflow for updates is now: 1. Modify state (preserve/unpreserve). 2. Call kho_finalize() again to refresh the serialized metadata. Remove the kho_out.finalized checks to enable this dynamic behavior. This also allows to convert kho_unpreserve_* functions to void, as they do not return any erro