[SRU][canonical-kernel-snap/main][kernel-snaps-uc24.04/pc][PATCH v5 0/1] add nvidia-550 driver components

Wed Feb 12 14:28:37 UTC 2025

While this is quite complex it does fit with my expectations as far as
initial components support is concerned.

I note that it does burn in a bunch of versions.  In the short term these
will have to be managed manually.  It is intended that in the medium term
we will provide a simpler install target to reduce the extent of those.  It
is also intended that these will be supplied by swm when templating the
snapcraft.yaml.

Acked-by: Andy Whitcroft <apw at canonical.com>

-apw

On Thu, Jan 30, 2025 at 1:07 AM Aaron Jauregui <aaron.jauregui at canonical.com>
wrote:

> BugLink: https://bugs.launchpad.net/bugs/2088970
>
> [Changes between v4 and v5]
> - No longer using a workaround script to match ko and userspace
>   versions, instead settling on hardcoding in versions after a discussion
>   with apw. This is a temporary solution, as snapcraft is working on a way
>   to be able to specify deb versions from within an override block.
>
> - Fixed links to canonical-kernel-snaps repo
> - renamed nouveau component to nouveau-ko
> - Expanded comments regarding lib cleanup and pruning libc from
>   nvidia-user component.
>
> [Changes between v3 and v4]
> - Patchset no longer RFC, as snapd component support should be landing
>   in latest/stable.
>
> - Fixed a bug in the build process that could result in version
>   mismatches of nvidia libraries between the ko and user components
>   depending on the status of the deb archives for each. This required an
>   overhaul of the build scripts. This is intended as a temporary solution,
>   and I intend to replace it with an swm template-based approach soon.
>
> - Added a cleanup stanza for the nvidia-550-user component. Testing
>   discovered issues with conflicts created by mesa libraries that
>   should not be present in the component, so these are pruned.
>
> [Changes between v2 and v3]
>   - cleaned up scripts and comments
>   - added better summaries/descriptions for components
>   - restructured hooks directory into per-component subdirectories
>   - shifted organize blocks to respective components
>   - replaced post-refresh hook copying with corresponding files in the
>     hooks directory (note: snapcraft did not support using symlinks for
>     this)
>   - updated [Impact] section with more detailed information
>
> [Changes between v1 and v2]
>
> kernel-snaps-u24.04:
>   - replaced TODO HACK FOR HOOKS
>   - updated nvidia userspace component type to standard
>
> hooks:
>   - included install hook for the pc-kernel to install nouveau
>     component by default
>
> [Impact]
> Snap components are a way to have optional content for snaps available
> for install without resorting to building a completely new snap. It's
> useful to think of them as lazy loading for snaps. Concretely, components
> are themselves snaps with locked-down functionality that are mounted
> within their parent snap's filesystem. Component revisions are tied 1 to
> 1 with their parent snap revision at upload time, meaning that any refresh
> also refreshes the components tied to the snap. This also means that
> components MUST be uploaded alongside the parent snap, or the store will
> reject the upload.
>
> We use components here with the aim of providing a way for nvidia
> drivers to be selected for the pc-kernel without having to rebuild,
> targetting the nvidia-550 driver as a starting point with the aim of
> supporting more driver versions in the future. Since nouveau, currently
> included in the pc-kernel, conflicts with nvidia, we replace the nouveau
> .ko with a component compatible with the nvidia component scheme.
>
> Images are intended to be built either with a nvidia graphics component
> either preloaded by being declared in the model, or at first boot, where
> the
> pc-kernel's install hook will detect that no nvidia graphics component
> exists
> and download nouveau. This should cover the uppgrade case for users of the
> existing pc-kernel that rely on nouveau. I am working on further
> functionality
> allowing for snap set to configure the desired graphics version and either
> configure it (if the component exists on disk) or to fetch it from the
> store.
>
> The implemented components rely on install, refresh, and remove hooks
> for the respective functionality. These are intended to be placed in
> canonical-kernel-snaps. All 3 implemented components have a post-refresh
> hook
> that is identical to their install hook.
>
>   - For the nvidia-ko and nouveau hooks, these hooks copy the corresponding
>     kernel modules to $SNAP_DATA/$(uname -r)/graphics, with the nvidia-ko
> hook
>     linking the modules and attaching their module signatures before moving
>     them. Both components' remove hooks delete the graphics directory. The
>     nouveau hooks are intended to be generic kernel module component hooks
>     with a special case for nouveau.
>
>   - For the nvidia-user hooks, a directory corresponding to the
> kernel-gpu-2404
>     interface is created. A sentinel file is placed in the directory to be
> able
>     to notify the consumer of the kernel-gpu-2404 interface of file changes
>     (e.g. a refresh). All the libraries in the component are copied into
> this
>     directory. A mangler script is added for the consuming snap to have the
>     correct environment variables present when using the provided
> libraries.
>
> Nvidia components are mostly self-contained, but a few changes to the
> pc-kernel
> snap were required. files/meta/kernel.yaml is required to enable kernel
> module support in snapd. The kernel-gpu-2404 content interface is
> declared for exposing nvidia userspace libraries, and is not intended to
> be accessed directly by users.
>
> The current test plan on our end to my understanding includes smoke
> testing for
> both the ubuntu core use case and the hybrid case with tpm-backed fde
> (emulated
> through kvm, as hardware testing is currently not functional for tpm-backed
> fde).  Cert should be in charge of testing beyond this, but I don't have
> much
> information about this yet. I should be able to confirm this and explain
> the
> test plan in better detail early next week.
>
> [Test case]
> Nvidia components can be installed as follows:
>
>  $ snap install pc-kernel+nvidia-550-ko pc-kernel+nvidia-550-user
>
> The components install their files in $SNAP_DATA/modules/$(uname
> -r)/graphics
>
> [Regression potential]
> There is potential for regressions to be introduced by the pc-kernel
> install
> hook, as it is executed on every install and and refresh event. If this
> script fails, the installation or update of the snap will abort.
>
> Aaron Jauregui (1):
>   snapcraft.yaml: Add nvidia-550 and nouveau component support
>
>  files/meta/kernel.yaml |   1 +
>  snapcraft.yaml         | 131 ++++++++++++++++++++++++++++++++++++++++-
>  2 files changed, 130 insertions(+), 2 deletions(-)
>  create mode 100644 files/meta/kernel.yaml
>
> Aaron Jauregui (1):
>   nvidia-hooks: add hooks for nvidia kernel components
>
>  hooks/module/install.module                   | 21 ++++++++++++++++
>  hooks/module/post-refresh.module              | 21 ++++++++++++++++
>  hooks/module/remove.module                    | 13 ++++++++++
>  hooks/nvidia-ko/install.nvidia-ko             | 25 +++++++++++++++++++
>  hooks/nvidia-ko/post-refresh.nvidia-ko        | 25 +++++++++++++++++++
>  hooks/nvidia-ko/remove.nvidia-ko              |  6 +++++
>  hooks/nvidia-user/install.nvidia-user         | 18 +++++++++++++
>  .../kernel-gpu-2404-provider-mangler          | 12 +++++++++
>  hooks/nvidia-user/remove.nvidia-user          | 10 ++++++++
>  hooks/pc-kernel/install.pc-kernel             |  6 +++++
>  hooks/pc-kernel/post-refresh.pc-kernel        |  6 +++++
>  11 files changed, 163 insertions(+)
>  create mode 100644 hooks/module/install.module
>  create mode 100644 hooks/module/post-refresh.module
>  create mode 100644 hooks/module/remove.module
>  create mode 100644 hooks/nvidia-ko/install.nvidia-ko
>  create mode 100644 hooks/nvidia-ko/post-refresh.nvidia-ko
>  create mode 100644 hooks/nvidia-ko/remove.nvidia-ko
>  create mode 100644 hooks/nvidia-user/install.nvidia-user
>  create mode 100644 hooks/nvidia-user/kernel-gpu-2404-provider-mangler
>  create mode 100644 hooks/nvidia-user/remove.nvidia-user
>  create mode 100644 hooks/pc-kernel/install.pc-kernel
>  create mode 100644 hooks/pc-kernel/post-refresh.pc-kernel
>
> --
> 2.43.0
>
>
> --
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>
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