Re: [PATCH v3 0/6] gpu: nova-core: run unload sequence upon unbinding

[John Hubbard <jhubbard@nvidia.com>]

On 4/22/26 6:40 AM, Alexandre Courbot wrote:
> Currently the GSP is left running and the WPR2 memory region untouched
> when the driver is unbound. This is obviously not ideal for at least two
> reasons:

Hi,

Is this ready to merge, or are you looking for more reviews?

thanks,
-- 
John Hubbard

> 
> - Probing requires setting up the WPR2 region, which cannot be done if
>   there is already one in place. Hence the current requirement to reset
>   the GPU (using e.g. `echo 1 >/sys/bus/pci/devices/.../reset`) before
>   the driver can be probed again after removal.
> - The running GSP may still attempt to access shared memory regions
>   which the kernel might recycle.
> 
> On top of that, there is a nasty bug in the Blackwell VBIOS that
> sometimes borks the GPU upon PCI reset, requiring a reboot. So relying
> on the PCI reset to unload/reload Nova is really not practical here.
> 
> This series does what is needed to leave the GPU in a clean state after
> unbind, for all currently supported GPUs. Blackwell support is trivial
> and will be added alongside the Blackwell series [1] if this can be
> merged first.
> 
> The first patch adds a `warn_on_err` utility macro to the kernel crate
> as it is useful to warn on failures in the driver unbind path, but I can
> remove it if it is not deemed useful.
> 
> This series applies cleanly on `master` as of today.
> 
> [1] https://lore.kernel.org/all/20260411024953.473149-1-jhubbard@nvidia.com/
> 
> Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
> ---
> Changes in v3:
> - Disambiguate doccomment for `warn_on_err`.
> - Test the correct bit instead of the whole register value to determine
>   that the GSP has stopped.
> - Use an enum instead of a boolean to encode the power level when
>   shutting down the GSP.
> - Add missing newline to `dev_err`.
> - Add missing doccomments for new types.
> - Use values from bindings instead of magic numbers.
> - Remove the redundant `get_gsp_info` function.
> - Better document Booter Unloader mailbox sentinel value, and check the
>   value of mbox0 upon return.
> - Link to v2: https://patch.msgid.link/20260421-nova-unload-v2-0-2fe54963af8b@nvidia.com
> 
> Changes in v2:
> - Rebase on top of `master` and remove unneeded/obsolete preparatory patches.
> - Tidy up the imports of commands from the `fw` module in the `gsp` module.
> - Link to v1: https://patch.msgid.link/20251216-nova-unload-v1-0-6a5d823be19d@nvidia.com
> 
> ---
> Alexandre Courbot (6):
>       rust: add warn_on_err macro
>       gpu: nova-core: use warn_on_err macro
>       gpu: nova-core: remove unneeded get_gsp_info proxy function
>       gpu: nova-core: do not import firmware commands into GSP command module
>       gpu: nova-core: send UNLOADING_GUEST_DRIVER GSP command upon unloading
>       gpu: nova-core: run Booter Unloader and FWSEC-SB upon unbinding
> 
>  drivers/gpu/nova-core/firmware/booter.rs          |   1 -
>  drivers/gpu/nova-core/firmware/fwsec.rs           |   1 -
>  drivers/gpu/nova-core/gpu.rs                      |  21 +++--
>  drivers/gpu/nova-core/gsp/boot.rs                 | 100 +++++++++++++++++++++-
>  drivers/gpu/nova-core/gsp/commands.rs             |  69 +++++++++++----
>  drivers/gpu/nova-core/gsp/fw.rs                   |   4 +
>  drivers/gpu/nova-core/gsp/fw/commands.rs          |  44 ++++++++++
>  drivers/gpu/nova-core/gsp/fw/r570_144/bindings.rs |  11 +++
>  drivers/gpu/nova-core/regs.rs                     |   5 ++
>  rust/kernel/bug.rs                                |  10 +++
>  10 files changed, 241 insertions(+), 25 deletions(-)
> ---
> base-commit: b4e07588e743c989499ca24d49e752c074924a9a
> change-id: 20251216-nova-unload-4029b3b76950
> 
> Best regards,
> --  
> Alexandre Courbot <acourbot@nvidia.com>
>