Interface proposal for the split TD partitioning VMM #355
Conversation
This file contains 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
|
The markdown doc is converted to a pdf file, which is now uploaded to this PR. |
|
Hi @joergroedel, this document is updated with describing a basic vcpu run loop implementation in the user mode VMM to enter guest and handle simple vmexit event, with utilizing the syscalls outlined in the X86-64 Syscall API/ABI Document. And here is the pdf version. Would you please let us know if this is on the right direction or not? Thanks! |
Add design doc USER-MODE-VMM.md and related picture resources. This doc majorly takes about the interfaces between the user mode VMM and the COCONUT-SVSM kernel, and how the user mode VMM is implemented via the syscalls. Signed-off-by: Chuanxiao Dong <[email protected]>
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
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Outdated suggestions cannot be applied.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.
This draft PR is opened to collect review comments and discussions, but not to merge.
The TD partitioning VMM was implemented fully in the coconut-svsm kernel mode, which runs the coconut-svsm as a L1 VMM in TD and a Linux OS as a L2 guest. The code is published here.
Following the development plan, most parts of this TD partitioning VMM should be moved to the user mode for security reasons, while keeping the necessary parts (e.g., executing TDCALL instruction) left in the svsm kernel. We made a document, available for preview here, which discusses the high-level architecture of the split TD partitioning VMM and outlines the key VMM interfaces between user mode and kernel mode. In short, the proposal is to use the common file based syscalls ABI, e.g., open, ioctl, mmap as the VMM interfaces, and clone syscall to create multiple vCPU threads which shares the same user mode address space.
Before moving forward, we would like to use this PR to collect the review comments from the community about this proposal and possibility of extending it for SEV user mode VMM, as well as any alternative proposals that the community prefers. We would greatly appreciate it if you could take some time to review and share your thoughts.