Re: [PATCH v3 9/9] gpu: nova-core: gsp: add tests for SplitState

[Alexandre Courbot]

On Thu Feb 26, 2026 at 8:45 PM JST, Eliot Courtney wrote:
> Add tests for SplitState. They cover boundary conditions at the split
> points to make sure the right number of continuation records are made.
> They also check that the data concatenated is correct.
>
> Tested-by: Zhi Wang <zhiw@xxxxxxxxxx>
> Signed-off-by: Eliot Courtney <ecourtney@xxxxxxxxxx>
> ---
>  drivers/gpu/nova-core/gsp/commands.rs | 114 ++++++++++++++++++++++++++++++++++
>  1 file changed, 114 insertions(+)
>
> diff --git a/drivers/gpu/nova-core/gsp/commands.rs b/drivers/gpu/nova-core/gsp/commands.rs
> index 6ffd0b9cbf05..74f875755e53 100644
> --- a/drivers/gpu/nova-core/gsp/commands.rs
> +++ b/drivers/gpu/nova-core/gsp/commands.rs
> @@ -384,3 +384,117 @@ fn init_variable_payload(
>          }
>      }
>  }
> +
> +#[kunit_tests(nova_core_gsp_commands)]
> +mod tests {
> +    use super::*;
> +
> +    struct TestPayload {
> +        data: KVVec<u8>,
> +    }
> +
> +    impl TestPayload {
> +        fn generate_pattern(len: usize) -> Result<KVVec<u8>> {
> +            let mut data = KVVec::with_capacity(len, GFP_KERNEL)?;
> +            for i in 0..len {
> +                data.push(i as u8, GFP_KERNEL)?;
> +            }
> +            Ok(data)
> +        }
> +
> +        fn new(len: usize) -> Result<Self> {
> +            Ok(Self {
> +                data: Self::generate_pattern(len)?,
> +            })
> +        }
> +    }
> +
> +    impl CommandToGsp for TestPayload {
> +        const FUNCTION: MsgFunction = MsgFunction::Nop;
> +        type Command = ();

Since we are testing the size of the data written on the command queue,
can you make the command itself larger than 0 bytes? Otherwise there is
a potential for missing errors.

I'm saying that because it actually happened to me, I used
`MAX_CMD_SIZE` instead of `MAX_CMD_SIZE - size_of::<C::Command>()`
somewhere, and despite it being broken the tests were passing.