Claude review: gpu: nova-core: gsp: support large RPCs via continuation record

[Claude Code Review Bot <claude-review@example.com>]

Patch Review

This is the core patch. Key design:

- `send_command` now wraps `send_single_command` via `SplitState::new(command)`.
- `SplitState::Single(command)` passes through to `send_single_command` directly — no extra allocation or copy for normal-sized commands.
- `SplitState::Split(command, continuations)` stages the variable payload into a `KVVec<u8>`, splits it at `MAX_FIRST_PAYLOAD`, and sends the remainder via `ContinuationRecord` commands.
- `ContinuationRecord` uses `type Command = ()` (zero-sized), so the entire queue element is payload.

**Observations:**

1. The `ContinuationRecords` struct has a `next()` method but doesn't implement the `Iterator` trait. The comment at line 1337 says `while let Some(continuation) = continuations.next()` with a note about turbofish being needed. Not implementing `Iterator` is likely intentional to avoid the trait's `Item` type requiring a lifetime, but a brief comment on why would help.

2. In `SplitState::new`:
```rust
let mut command_payload =
    KVVec::<u8>::from_elem(0u8, payload_len.min(Self::MAX_FIRST_PAYLOAD), GFP_KERNEL)?;
let mut continuation_payload =
    KVVec::<u8>::from_elem(0u8, payload_len - command_payload.len(), GFP_KERNEL)?;
```
This allocates `command_payload` of size `min(payload_len, MAX_FIRST_PAYLOAD)` and `continuation_payload` for the rest. The buffers are initialized to zero then overwritten by `init_variable_payload` — the double-write is acceptable as this is the oversized path.

3. `MsgFunction::ContinuationRecord` is added to the enum and `TryFrom`, maintaining alphabetical order established in patch 1. The binding `NV_VGPU_MSG_FUNCTION_CONTINUATION_RECORD` already exists in the tree (confirmed value 71).

4. The cover letter mentions "Continuation record for receive is not necessary to support at the moment" — this is documented inline as well, which is good.

No blocking issues. This looks correct.

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Generated by Claude Code Patch Reviewer