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I've been playing with this to allow for moderately flexible usage of
the get_unused_fd_flags() + create file + fd_install() pattern that's
used quite extensively.
How callers allocate files is really heterogenous so it's not really
convenient to fold them into a single class. It's possibe to split them
into subclasses like for anon inodes. I think that's not necessarily
nice as well.
My take is to add two primites:
(1) FD_ADD() the simple cases a file is installed:
fd = FD_ADD(O_CLOEXEC, open_file(some, args)));
if (fd >= 0)
kvm_get_kvm(vcpu->kvm);
return fd;
(2) FD_PREPARE() that captures all the cases where access to fd or file
or additional work before publishing the fd is needed:
FD_PREPARE(fdf, open_flag, file_open_handle(&path, open_flag));
if (fdf.err)
return fdf.err;
if (copy_to_user(/* something something */))
return -EFAULT;
return fd_publish(fdf);
I've converted all of the easy cases over to it and it gets rid of an
aweful lot of convoluted cleanup logic.
It's centered around struct fd_prepare. FD_PREPARE() encapsulates all of
allocation and cleanup logic and must be followed by a call to
fd_publish() which associates the fd with the file and installs it into
the callers fdtable. If fd_publish() isn't called both are deallocated.
It mandates a specific order namely that first we allocate the fd and
then instantiate the file. But that shouldn't be a problem nearly
everyone I've converted uses this exact pattern anyway.
There's a bunch of additional cases where it would be easy to convert
them to this pattern. For example, the whole sync file stuff in dma
currently retains the containing structure of the file instead of the
file itself even though it's only used to allocate files. Changing that
would make it fall into the FD_PREPARE() pattern easily. I've not done
that work yet.
There's room for extending this in a way that wed'd have subclasses for
some particularly often use patterns but as I said I'm not even sure
that's worth it.
Link: https://patch.msgid.link/20251123-work-fd-prepare-v4-1-b6efa1706cfd@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Some devices, namely Lenovo Legion devices, have an "extreme" mode where
power draw is at the maximum limit of the cooling hardware. Add a new
"max-power" platform profile to properly reflect this operating mode.
Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org>
Acked-by: Rafael J. Wysocki (Intel) <rafael@kernel.org>
Signed-off-by: Derek J. Clark <derekjohn.clark@gmail.com>
Reviewed-by: Armin Wolf <W_Armin@gmx.de>
Reviewed-by: Mark Pearson <mpearson-lenovo@squebb.ca>
Link: https://patch.msgid.link/20251127151605.1018026-2-derekjohn.clark@gmail.com
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
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'nvidia/tegra', 'intel/vt-d', 'amd/amd-vi' and 'core' into next
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If the IOVA is limited to less than 48 the page table will be constructed
with a 3 level configuration which is unsupported by hardware.
Like the second stage the caller needs to pass in both the top_level an
the vasz to specify a table that has more levels than required to hold the
IOVA range.
Fixes: 6cbc09b7719e ("iommu/vt-d: Restore previous domain::aperture_end calculation")
Reported-by: Calvin Owens <calvin@wbinvd.org>
Closes: https://lore.kernel.org/r/8f257d2651eb8a4358fcbd47b0145002e5f1d638.1764237717.git.calvin@wbinvd.org
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Tested-by: Calvin Owens <calvin@wbinvd.org>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
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VT-d second stage HW specifies both the maximum IOVA and the supported
table walk starting points. Weirdly there is HW that only supports a 4
level walk but has a maximum IOVA that only needs 3.
The current code miscalculates this and creates a wrongly sized page table
which ultimately fails the compatibility check for number of levels.
This is fixed by allowing the page table to be created with both a vasz
and top_level input. The vasz will set the aperture for the domain while
the top_level will set the page table geometry.
Add top_level to vtdss and correct the logic in VT-d to generate the right
top_level and vasz from mgaw and sagaw.
Fixes: d373449d8e97 ("iommu/vt-d: Use the generic iommu page table")
Reported-by: Calvin Owens <calvin@wbinvd.org>
Closes: https://lore.kernel.org/r/8f257d2651eb8a4358fcbd47b0145002e5f1d638.1764237717.git.calvin@wbinvd.org
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Tested-by: Calvin Owens <calvin@wbinvd.org>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
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Convert all the legacy code directly accessing the pp fields in net_iov
to access them through @desc in net_iov.
Signed-off-by: Byungchul Park <byungchul@sk.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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The trace_marker_raw file in tracefs takes a buffer from user space that
contains an id as well as a raw data string which is usually a binary
structure. The structure used has the following:
struct raw_data_entry {
struct trace_entry ent;
unsigned int id;
char buf[];
};
Since the passed in "cnt" variable is both the size of buf as well as the
size of id, the code to allocate the location on the ring buffer had:
size = struct_size(entry, buf, cnt - sizeof(entry->id));
Which is quite ugly and hard to understand. Instead, add a helper macro
called struct_offset() which then changes the above to a simple and easy
to understand:
size = struct_offset(entry, id) + cnt;
This will likely come in handy for other use cases too.
Link: https://lore.kernel.org/all/CAHk-=whYZVoEdfO1PmtbirPdBMTV9Nxt9f09CK0k6S+HJD3Zmg@mail.gmail.com/
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Link: https://patch.msgid.link/20251126145249.05b1770a@gandalf.local.home
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Kees Cook <kees@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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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>
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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>
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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>
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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>
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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>
|
|
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>
|
|
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>
|
|
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>
|
|
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>
|
|
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>
|
|
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 error anymore.
Link: https://lkml.kernel.org/r/20251114190002.3311679-13-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>
Cc: Alexander Graf <graf@amazon.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Baoquan He <bhe@redhat.com>
Cc: Coiby Xu <coxu@redhat.com>
Cc: Dave Vasilevsky <dave@vasilevsky.ca>
Cc: Eric Biggers <ebiggers@google.com>
Cc: Kees Cook <kees@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Currently, clients of KHO must manually allocate memory (e.g., via
alloc_pages), calculate the page order, and explicitly call
kho_preserve_folio(). Similarly, cleanup requires separate calls to
unpreserve and free the memory.
Introduce a high-level API to streamline this common pattern:
- kho_alloc_preserve(size): Allocates physically contiguous, zeroed
memory and immediately marks it for preservation.
- kho_unpreserve_free(ptr): Unpreserves and frees the memory
in the current kernel.
- kho_restore_free(ptr): Restores the struct page state of
preserved memory in the new kernel and immediately frees it to the
page allocator.
[pasha.tatashin@soleen.com: build fixes]
Link: https://lkml.kernel.org/r/CA+CK2bBgXDhrHwTVgxrw7YTQ-0=LgW0t66CwPCgG=C85ftz4zw@mail.gmail.com
Link: https://lkml.kernel.org/r/20251114190002.3311679-4-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>
Cc: Alexander Graf <graf@amazon.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Baoquan He <bhe@redhat.com>
Cc: Coiby Xu <coxu@redhat.com>
Cc: Dave Vasilevsky <dave@vasilevsky.ca>
Cc: Eric Biggers <ebiggers@google.com>
Cc: Kees Cook <kees@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Allow users of KHO to cancel the previous preservation by adding the
necessary interfaces to unpreserve folio, pages, and vmallocs.
Link: https://lkml.kernel.org/r/20251101142325.1326536-4-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>
Cc: Alexander Graf <graf@amazon.com>
Cc: Changyuan Lyu <changyuanl@google.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Simon Horman <horms@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Zhu Yanjun <yanjun.zhu@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
The KHO framework uses a notifier chain as the mechanism for clients to
participate in the finalization process. While this works for a single,
central state machine, it is too restrictive for kernel-internal
components like pstore/reserve_mem or IMA. These components need a
simpler, direct way to register their state for preservation (e.g., during
their initcall) without being part of a complex, shutdown-time notifier
sequence. The notifier model forces all participants into a single
finalization flow and makes direct preservation from an arbitrary context
difficult. This patch refactors the client participation model by
removing the notifier chain and introducing a direct API for managing FDT
subtrees.
The core kho_finalize() and kho_abort() state machine remains, but clients
now register their data with KHO beforehand.
Link: https://lkml.kernel.org/r/20251101142325.1326536-3-pasha.tatashin@soleen.com
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Co-developed-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Alexander Graf <graf@amazo |
