chore(docs/linux-4.14): update documentation

We are dropping support for Linux 4.14 so reflect it in the docs.

Signed-off-by: Pablo Barbáchano <[email protected]>

Author: pb8o

CHANGELOG.md

@@ -14,6 +14,14 @@ and this project adheres to
 
 ### Deprecated
 
+### Removed
+
+- [#4689](https://github.com/firecracker-microvm/firecracker/pull/4689): Drop
+  support for host kernel 4.14. Linux 4.14 reached end-of-life in
+  [January 2024](https://lore.kernel.org/lkml/2024011046-ecology-tiptoeing-ce50@gregkh/).
+  The minimum supported kernel now is 5.10. Guest kernel 4.14 is still
+  supported.
+
 ### Fixed
 
 ## \[1.8.0\]
@@ -140,10 +148,12 @@ and this project adheres to
   supported snapshot version format. This change renders all previous
   Firecracker snapshots (up to Firecracker version v1.6.0) incompatible with the
   current Firecracker version.
+
 - [#4449](https://github.com/firecracker-microvm/firecracker/pull/4449): Added
   information about page size to the payload Firecracker sends to the UFFD
   handler. Each memory region object now contains a `page_size_kib` field. See
   also the [hugepages documentation](docs/hugepages.md).
+
 - [#4498](https://github.com/firecracker-microvm/firecracker/pull/4498): Only
   use memfd to back guest memory if a vhost-user-blk device is configured,
   otherwise use anonymous private memory. This is because serving page faults of

README.md

@@ -132,9 +132,9 @@ We test all combinations of:
 
 | Instance  | Host OS & Kernel  | Guest Rootfs | Guest Kernel |
 | :-------- | :---------------- | :----------- | :----------- |
-| c5n.metal | al2    linux_4.14 | ubuntu 22.04 | linux_4.14   |
-| m5n.metal | al2    linux_5.10 |              | linux_5.10   |
-| m6i.metal | al2023 linux_6.1  |              |              |
+| c5n.metal | al2    linux_5.10 | ubuntu 22.04 | linux_4.14   |
+| m5n.metal | al2023 linux_6.1  |              | linux_5.10   |
+| m6i.metal |                   |              |              |
 | m6a.metal |                   |              |              |
 | m6g.metal |                   |              |              |
 | m7g.metal |                   |              |              |

docs/kernel-policy.md

@@ -9,7 +9,7 @@ We are continuously validating the currently supported Firecracker releases (as
 per [Firecracker’s release policy](../docs/RELEASE_POLICY.md)) using a
 combination of:
 
-- host linux kernel versions 4.14, 5.10, and 6.1;
+- host linux kernel versions 5.10, and 6.1;
 - guest linux kernel versions 4.14, and 5.10.
 
 While other versions and other kernel configs might work, they are not
@@ -23,7 +23,6 @@ release only if compatibility changes are required.
 
 | Host kernel | Guest kernel v4.14 | Guest kernel v5.10 | Min. end of support |
 | ----------: | :----------------: | :----------------: | ------------------: |
-|       v4.14 |         Y          |         Y          |          2021-01-22 |
 |       v5.10 |         Y          |         Y          |          2024-01-31 |
 |        v6.1 |         Y          |         Y          |          2025-10-12 |
 
@@ -121,10 +120,6 @@ following configurations:
 
 ## Caveats
 
-- When using a 4.14 host and a 5.10 guest, we disable the SVE extension in the
-  guest. This is due to the introduction of the SVE extension in Graviton3,
-  which causes the default 5.10 guest (with SVE support enabled), to crash if
-  run with a 4.14 host which does not support SVE.
 - [Snapshot compatibility across kernel versions](snapshotting/snapshot-support.md#snapshot-compatibility-across-kernel-versions)
 - When booting with kernels that support both ACPI and legacy boot mechanisms
   Firecracker passes VirtIO devices to the guest twice, once through ACPI and a

docs/snapshotting/handling-page-faults-on-snapshot-resume.md

@@ -24,9 +24,9 @@ descriptor object (UFFD).
 
 ### Creating a UFFD object
 
-#### Kernels 4.14 and 5.10
+#### Kernel 5.10
 
-For (host) kernels 4.14 and 5.10 UFFD objects are created by calling into
+For host kernel 5.10 UFFD objects are created by calling into
 [`userfaultfd` syscall](https://man7.org/linux/man-pages/man2/userfaultfd.2.html).
 
 #### Kernel 6.1

docs/snapshotting/snapshot-support.md

@@ -664,8 +664,6 @@ m6i won't work on an m6g instance.
 
 | *CPU family* | *taken on host kernel* | *restored on host kernel* | *working?* |
 | ------------ | ---------------------- | ------------------------- | ---------- |
-| **x86_64**   | 4.14                   | 5.10                      | Y          |
-| **all**      | 5.10                   | 4.14                      | N          |
 | **all**      | 5.10                   | 6.1                       | Y          |
 | **all**      | 6.1                    | 5.10                      | Y          |
 

docs/snapshotting/versioning.md

@@ -85,10 +85,9 @@ The current implementation relies on the
 
 ### Host kernel
 
-The minimum kernel version required by Firecracker snapshots is 4.14. Snapshots
-can be saved and restored on the same kernel version without any issues. There
-might be issues when restoring snapshots created on different host kernel
-version even when using the same Firecracker version.
+Snapshots can be saved and restored on the same kernel version without any
+issues. There might be issues when restoring snapshots created on different host
+kernel version even when using the same Firecracker version.
 
 SnapshotCreate and SnapshotLoad operations across different host kernels is
 considered unstable in Firecracker as the saved KVM state might have different

tests/README.md

@@ -67,7 +67,7 @@ regardless of success or failure, pass the `-s` flag, e.g.
 
 ### Dependencies
 
-- A bare-metal `Linux` host with `uname -r` >= 4.14 and KVM enabled (`/dev/kvm`
+- A bare-metal `Linux` host with `uname -r` >= 5.10 and KVM enabled (`/dev/kvm`
   device node exists)
 - Docker
 - `awscli` version 2