Ubuntu 22.04.3 server still installs a 5.15 kernel, not 5.19

To access AMX hardware instructions on Intel Sapphire Rapids CPUs you need to be running Linux kernel 5.16 or later. To use many popular hardware drivers you have to run a 5.x series kernel, since many hardware vendors haven't yet built drivers for 6.x kernels. For this reason I'd like to install a 5.19 kernel and get 5.19 kernel updates as they are released.

A few weeks ago the Ubuntu kernel lifecycle page listed the 22.04.2 image as coming with a 5.19 kernel by default. Ubuntu kernel lifecycle page on 2023-08-10:

However, if you install 22.04.2-server you get a 5.15 kernel, not 5.19. If you install the HWE kernel package linux-generic-hwe-22.04 you get a 6.2 kernel, not 5.19.

support@ubuntu22042:~$ uname -a
Linux ubuntu22042 5.15.0-78-generic #85-Ubuntu SMP Fri Jul 7 15:25:09 UTC 2023 x86_64 x86_64 x86_64 GNU/Linux

Today the Ubuntu kernel lifecycle page lists 22.04.3 as coming with a 5.19 kernel by default, and the page removed the listing for 22.04.2 entirely. Ubuntu kernel lifecycle page on 2023-08-16:

However, if you install 22.04.3-server you get a 5.15 kernel, not 5.19:

support@ubuntu22043:~$ uname -a
Linux ubuntu22043 5.15.0-79-generic #86-Ubuntu SMP Mon Jul 10 16:07:21 UTC 2023 x86_64 x86_64 x86_64 GNU/Linux

If you install the HWE kernel package linux-generic-hwe-22.04 you get a 6.2 kernel.

There is a difference between 22.04.3-server and 22.04.3-desktop. If I install the 22.04.3-desktop ISO I get a 6.2 kernel with a default install:

support@ubuntu220403-desktop:~$ uname -a
Linux ubuntu220403-desktop 6.2.0-26-generic #26~22.04.1-Ubuntu SMP PREEMPT_DYNAMIC Thu Jul 13 16:27:29 UTC 2 x86_64 x86_64 x86_64 GNU/Linux

There are 5.19 kernel packages in the Ubuntu repo for 22.04. I can see them when I run apt-cache search 5.19 | grep generic. I can even install a specific 5.19 kernel by running:

sudo apt-get install --install-recommends linux-image-5.19.0-46-generic

However, that locks my kernel on 5.19.0-46, and even though 5.19.0-50 is available, apt-get upgrade won't update the kernel. I won't get patches automatically for 5.19.

What package do I need to install on 22.04.3-server to get a 5.19 kernel, as shown on the Ubuntu kernel lifecycle page, that will continue to get updates and patches for 5.19 as they are released?

The graphic has misled you.

Ubuntu Server 22.04 defaults to the GA (General Availability) kernel 5.15. HWE is optional. GA means that your system will remain on the kernel 5.15 path for the entire life of the release.

Ubuntu Desktop 22.04 defaults to the HWE (Hardware Enablement) kernel, which bumps every six months to match the six-month standard releases of Ubuntu. GA is optional:

  LTS      Standard   GA Kernel  HWE Kernel
 22.04                  5.15       5.15
 22.04.1                5.15       5.15
 22.04.2    22.10       5.15       5.19
 22.04.3    23.04       5.15       6.2
 22.04.4    23.10       5.15       TBD

Now let's look at your specific case:

There is no path to remain on an Ubuntu-provided 5.19 kernel. You can do so, of course, for as long as it's supported. You can keep using it after it's no longer supported...though obviously that means no support and no security patches and you're accepting risk.

• Oops, 23.10 support ended 20 July 2023, so that 5.19 kernel may soon be gone! Start testing your hardware with the 6.x kernel, and start filing bug reports!

The simple answer is that I am misunderstanding the intent of the Ubuntu Kernel Lifecycle page. Although it only lists LTS point releases, it lists the HWE kernel version that was available on the day that the LTS point release was published, which has nothing to do with what kernel you'll actually get if you install the specific LTS release that's listed.

If you install the desktop version of a release, you won't get a choice of kernel -- you'll automatically get the current HWE kernel, which has nothing to do with the kernel version listed on this page.

If you install the server version of a release you'll have the option of installing the GA kernel version (which is not listed on this page) or the current HWE kernel version, which has nothing to do with the kernel version listed on this page.

Since HWE follows a rolling update model, the kernel version listed on this page may no longer be available by the time you install a specific release. If you install 22.04.3-desktop today you won't get kernel 5.19, you'll get 6.2, even though 22.04.3 was only released 6 days ago.

In short, if you want to know what GA or HWE kernel you're going to get when you install a specific Ubuntu point release, don't bother checking the Ubuntu Kernel Lifecycle page, because it doesn't contain that information.