refactor vmcall-raw send/receive, reject invalid VMM responses#867
Open
haitaohuang wants to merge 3 commits into
Open
refactor vmcall-raw send/receive, reject invalid VMM responses#867haitaohuang wants to merge 3 commits into
haitaohuang wants to merge 3 commits into
Conversation
Extract the duplicated poll logic from vmcall_service_migtd_send and vmcall_service_migtd_receive into poll_vmcall_completion(). The shared function handles: interrupt flag check, data_status parsing, flag consumption after final status, and success/error determination. Each caller only adds its operation-specific logic (send returns data_length, receive copies payload to private Vec). Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Signed-off-by: Haitao Huang <haitaohuang@microsoft.com>
A hostile VMM can complete a tdvmcall_migtd_receive with status=VMM_SUCCESS but data_length=0. The previous implementation let this propagate as Ok(0) through VmcallRaw::recv, which would stall the caller's read loop indefinitely (no forward progress, no error). Reject zero-length success inside the receive poll_fn closure with VmcallRawError::Malformed, which surfaces to upstream callers as a network error instead of an infinite spin. Also stop relying on the post-completion data_length on the send path (per spec, data_length is owned by MigTD when status=0 and is not a meaningful VMM-reported value after completion). The previously returned value was already discarded by VmcallRaw::send, so this is a no-op in behavior but makes the spec contract explicit. Document this in the poll_vmcall_completion doc comment. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Signed-off-by: Haitao Huang <haitaohuang@microsoft.com>
When the migration context has been destroyed (no entry in VMCALL_MIG_CONTEXT_FLAGS for the request id), any interrupt injection from the VMM should be rejected. Previously the else branch discarded the error with `let _ = ...`, allowing execution to fall through and treat DMA buffer contents as a valid VMM response. Return an error immediately so the caller rejects the stale injection. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Signed-off-by: Haitao Huang <haitaohuang@microsoft.com>
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
No description provided.