A microVM has no init unless something is it, and three of the jobs belong to
nothing else in the guest: reaping whatever the workload orphans, turning a
signal into an ordered shutdown, and being the guest end of the one channel
out.
None of it knows what it is running. The guest dials out on a fixed vsock port,
says its protocol version first, is handed one boot descriptor — a command
line, shares, output geometry, and what an exit means — and carries that out.
There is no code path that branches on which workload started, which is the
property the component exists to keep.
It reports and does not supervise. When the workload ends, the exit goes up the
channel and the session is over; `on_exit` says what the exit means, and
starting something again is a decision for the end that can see whether
restarting is repair or a loop. A signalled workload is reported as signalled
with no exit code, because reporting 0 for a killed process makes a kill look
like a clean run.
Two seams keep this testable without a VM, which is the reason for both of
them. Reaping runs against real forked children, with the subreaper bit making
a test process inherit orphans the way PID 1 does. The channel is generic over
the byte stream, so the exchange is driven over an in-memory pipe — the
transport contributes nothing to the protocol beyond ordering and framing.
The lifecycle types live in nesprotocol behind a feature, off by default: both
ends of the channel read one definition and cannot drift from it silently,
while the media components keep building without serde.
Mounting shares is not implemented in this build. The descriptor's mounts are
refused rather than ignored — a workload started without the shares it was
promised fails later, somewhere else, for a reason nobody can see from here.
The first executable form of our host requirements. Until now a machine
was qualified by a human reading a table of hard requirements — and a
requirement that nothing can check is one that is silently optional.
It also replaces a form. Everything we wanted from a prospective host is
measurable, and most of it **cannot be answered honestly by a human
anyway**: almost nobody knows their real upstream, and essentially
nobody has ever seen their own bufferbloat figure. What's left for the
questions is only what a machine cannot know — intent, and what someone
already pays.
## What it does
```
nesdoctor
```
- **Checks every hard requirement**: `/dev/kvm`, an AMD or Intel GPU
with a DRM render node, `VK_KHR_video_encode_queue` plus a codec,
`virglrenderer`, the two stores, the `io` cgroup controller,
`virtiofsd`. Pass / fail / **unknown**, and unknown is never collapsed
into fail — a machine we could not ask is not a machine that failed, and
losing a capable host to a missing `lspci` is the failure mode that
matters.
- **Measures upstream and, the point of the whole thing, added latency
under load.** Grade bands come from the frame budget rather than
convention: the network allowance is ~40 ms because render, encode,
decode, display and jitter buffer have already spent ~58 ms.
- **Reads Steam, only with an explicit yes**, for library size and shape
plus an hour-of-day histogram of launches — one sample per title, which
is a real distribution obtained without asking anybody anything.
- **Asks at most five questions**, branched on what was found, all
skippable.
## No server
Nothing is uploaded and no telemetry endpoint exists. The network test
talks to Cloudflare's public speed-test sink and to `1.1.1.1`, neither
of which is ours. The output is a line on the terminal that the person
may choose to paste.
The shareable line carries **no hostname, IP, username, game title or
path** — a size band rather than a size, hours rather than dates. The
long version, which does include titles and paths, stays in a local JSON
file the person is told the path of.
That is a property of the design and not a promise about our intentions:
there is nothing to switch on later.
```
nesdoctor 0.1.0 | linux/x86_64 | gpu=AMD Barcelo | cpu=12t ram=13G |
kvm=y venc=y zfs=n boxfs=n io=y | up=28Mbps rtt=179ms bloat=+19ms grade=B |
disk=91G | edge=KE/JNB | steam=1 titles/<100G | plays=20-03h n=74 |
role=- share=- pays=- | HOST-READY-LOCAL
```
## Five bugs found by running it, every one of which would have produced
wrong data
- **`vulkaninfo --summary` lists ZERO `VK_KHR_video` entries** where
full `vulkaninfo` lists five on the same machine. Preferring the summary
reported "not advertised" on a card that advertises it — a false
negative on the check most likely to disqualify a host.
- **btrfs subvolumes counted as separate disks**: `/`, `/home` and
`/srv` each reporting 91 GiB of one 91 GiB device. Now deduped by
backing device, which the two-stores check needs anyway since it wants
*separate devices*.
- **Proton and the Steam Linux Runtimes are installed like games and are
not games.** Five of eight entries on the test machine, so the title
count was 5× too high and the library-shape question was corrupted.
- **`--quiet` printed the whole questionnaire** before its summary line,
breaking the one thing `--quiet` promises. Prompts are now skipped when
output is quiet or stdin is not a terminal — and a pipe is explicitly
*not* treated as consent to read a Steam library, unlike `--yes`.
- Boot history was reporting `13.2 h/day` off **two days** of history.
Under a three-day span it now reports the span and no rate.
## One finding, now encoded as a verdict
The development connection measures **179 ms idle RTT, served from
Johannesburg**. That machine passes every other check and cannot host
for a European player, because it is distance and no upgrade shortens
it.
`HOST-READY-LOCAL` exists for exactly that case, and the wording is
deliberate:
> Every requirement passes and your uplink queues cleanly. But the idle
round trip to the nearest major network is already most of the latency
budget, and that is distance rather than a fault: no upgrade shortens
it. So this machine is a good host for people on your side of the world
and cannot be one for anybody else. **If you are somewhere without a
cloud gaming edge, that is not a consolation prize — it is the only way
anyone there gets a playable stream.**
## CI
- **`ci.yml` gains a `nesdoctor` job** — fmt, `clippy -D warnings`,
test, one real run. Scoped to this member deliberately: the rest of the
Rust half has never been under CI, so `--workspace` would turn every PR
red for unrelated reasons. Widen it one member at a time.
- **`release-nesdoctor.yml`** builds four targets on tag `nesdoctor-v*`
— x86_64 linux-musl, x86_64 windows-msvc, aarch64 and x86_64 macOS —
with `SHA256SUMS`. musl rather than glibc so one Linux binary runs on
every distro.
The step that justifies the workflow **runs the binary it just built,
network included**. `ring` under rustls resolves root certificates
through the host trust store, so a static musl build can compile cleanly
and then fail TLS on the machine it ships to — breaking the network
test, silently, and only for other people. The step fails the build if
the summary line comes back `net=unmeasured`.
## Dependencies
Four: `anyhow`, `clap`, `serde`, `ureq`. The VDF parser, every platform
probe and the text wrapping are in-tree. A binary handed to strangers
has a dependency tree that is part of its interface, so anything that
could be done with `std` is.
4 MB release binary.
## What it deliberately does not claim
- **A pass is not a promise.** Every check is a *necessary* condition,
and nothing here runs under load — a machine that passes can still fail
on block I/O.
- **The encode extension being advertised is not proof the path works.**
We have had a correct extension list over a broken path before, so that
row says so.
- **Whether `libvirglrenderer` carries the native-context patches cannot
be determined from outside**, so that row reports presence only and
stays `unknown` rather than `pass`.
<!-- greptile_comment -->
<h3>Greptile Summary</h3>
The PR adds the nesdoctor host-readiness executable, local Steam
analysis, network measurement, installers, CI validation, and
multi-platform release packaging. Two attempted correctness fixes remain
incomplete:
- physical disk deduplication does not resolve common device-mapper
source names before comparing backing devices
- unknown historical Steam appids can still be counted as game launches
without passing runtime filtering
<h3>Confidence Score: 3/5</h3>
The PR is not yet safe to merge because shared LVM-backed stores can be
reported as physically independent and unknown Steam tools can still be
reported as game launches.
The new disk resolver fails open for common device-mapper names,
preserving a false host-readiness verdict, while Steam history still
counts absent appids without determining whether they are games or
runtime tools.
**Files Needing Attention:** apps/nesdoctor/src/sys.rs,
apps/nesdoctor/src/hostreq.rs, apps/nesdoctor/src/steam.rs
<h3>Important Files Changed</h3>
| Filename | Overview |
|----------|----------|
| apps/nesdoctor/src/sys.rs | Adds system and disk discovery, but
unresolved device-mapper names undermine physical-backing comparisons. |
| apps/nesdoctor/src/hostreq.rs | Implements host requirement verdicts
and uses physical-device sets that can falsely classify shared LVM
backing as independent. |
| apps/nesdoctor/src/steam.rs | Adds manifest and launch-history
analysis, but unknown appids bypass runtime classification and
contaminate launch metrics. |
| apps/nesdoctor/src/net.rs | Adds bounded upload-based upstream and
bufferbloat measurement; the previously reported unbounded request path
is addressed. |
| .github/workflows/release-nesdoctor.yml | Builds, smoke-tests,
packages, checksums, and publishes the four release targets. |
| .github/workflows/ci.yml | Adds focused formatting, linting, testing,
and offline execution checks for nesdoctor. |
<h3>Flowchart</h3>
```mermaid
%%{init: {'theme': 'neutral'}}%%
flowchart LR
Run[nesdoctor] --> Host[Host requirement probes]
Run --> Net[Upload and latency measurement]
Run --> Consent{Steam consent}
Consent -->|yes| Steam[Installed manifests and LastPlayed records]
Host --> Physical[Resolve filesystem sources to physical devices]
Physical --> Verdict[Host readiness verdict]
Net --> Report[Detailed JSON and shareable summary]
Steam --> Report
Verdict --> Report
```
<details><summary>Prompt To Fix All With AI</summary>
`````markdown
### Issue 1
apps/nesdoctor/src/sys.rs:369-374
**Mapper devices remain unresolved**
When root and box-store filesystems are separate LVM or dm-crypt mappings on the same physical disk, `df` supplies `/dev/mapper/...` names that do not exist under `/sys/class/block`. This branch returns those unrelated logical names unchanged, so the overlap check passes stores that still share one physical I/O queue.
### Issue 2
apps/nesdoctor/src/steam.rs:247-250
**Unknown appids bypass runtime filtering**
If `localconfig.vdf` retains `LastPlayed` data for an uninstalled Proton build, Steam runtime, or other non-game tool, its appid is absent from the installed-manifest map and this branch treats it as an uninstalled game. The tool activity then changes the launch histogram, peak window, and shareable `n` value.
---
For each issue above, determine whether it is valid and should be fixed. If so, fix it directly.
`````
</details>
<sub>Reviews (5): Last reviewed commit: ["fix(nesdoctor): three valid P1
findings
..."](7afc8929a6)
| [Re-trigger
Greptile](https://app.greptile.com/api/retrigger?id=59231233)</sub>
> Greptile also left **2 inline comments** on this PR.
<!-- /greptile_comment -->
`apps/nescapture/Cargo.toml` carried `[profile.release]` with `opt-level = 3`
and `lto = "thin"`. Cargo only reads `[profile.*]` from the workspace root and
warns about a member that writes one, so `cargo build --release --workspace`
— which is what build/Dockerfile runs — ignored it. The Vulkan capture layer
that ends up in the guest image was built at the default release profile, and
the warning saying so scrolled past on every build.
`opt-level = 3` is already the release default, so `lto = "thin"` is the only
part that was actually lost. It moves to the workspace root, where Cargo
reads it, and now applies to all five members — the same rule as
`[workspace.dependencies]` right above it: what must not differ between
members is stated once.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
The component nescapture, neswire and nescope all talk to, and the only
thing in the guest that speaks to the client. It muxes their frames into
one iroh QUIC endpoint and fans input back.
Renamed from nestri-guest-hub, which named a location rather than a job.
Four files came across unchanged -- session.rs, ipc_listener.rs,
ticket.rs, screenshot.rs. Between them they mention Steam zero times, and
they import only nesprotocol's open modules; the control feature carrying
LaunchIntent and SteamIdentity is used exclusively by the three files that
are staying closed. The two clusters shared a main.rs and nothing else, so
there was no untangling to do -- only a cut.
main.rs loses --proton, --steamclient-so, --root and the game uid/gid,
and no longer ends by handing the process to a controller. It runs until
it is stopped. Deciding when the box is finished belongs to nesinit.
The ticket used to leave via that controller, so it needed a new way out:
neshub now serves it on a socket and nesinit dials for it. Listening
rather than dialling matches every other socket here and means no startup
ordering to get wrong.
Three tests, where there were none -- the ticket crosses a process
boundary as text now, so a round trip that drops a field would otherwise
be found by whoever cannot connect.
A Vulkan implicit layer that captures frames from inside the workload's own
process and encodes them on the GPU they were drawn on. Fourth and last of this
batch, imported as a tree from `nestrilabs/nescapture` on the same terms.
Filed under `apps/` rather than `crates/` despite building a cdylib. The rule
here is what a thing *is*, not what it compiles to: this is a finished artefact
that gets installed into an image beside its layer manifest, not a library
another crate in this tree depends on. `crates/` is for the latter, and putting
this there would make the distinction useless the first time someone looked.
Wired to the workspace, `nesprotocol` by path. Its description named the
transport component; that reads better as what it actually is — where the frames
go — so it says that instead.
Whole workspace builds and tests: 21 across four members.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Captures a session's audio and hands it to the transport over a local socket.
Third component in, imported as a tree from `nestrilabs/neswire` on the same
terms as the previous two.
Wired to the workspace, `nesprotocol` by path. 4 tests pass.
`bin/hub-stub.rs` is a stand-in for the transport's listener, which is what lets
this be developed and tested without the rest of a box existing. It names the
transport by its old name, and is left for the rename commit along with the two
in the compositor.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
A headless Wayland compositor for a single fullscreen client, and the second
component into this repo. Imported as a tree from `nestrilabs/nescope` for the
same reason as the last one: the upstream repo is private, its history has never
been reviewed for publication, and a squash is what keeps that history from
becoming permanent here.
Wired to the workspace — versions from the root, `nesprotocol` by path instead
of a sibling directory. 8 tests pass.
It knows a lot about Steam, and all of it stays. `steam_app_*` window classes,
a launcher that exits before the game it started, a client that shows a login
screen with no Vulkan frames in it: that is third-party behaviour a compositor
for games has to handle, and describing it reveals nothing about how we are put
together. The rule is about topology, not vocabulary.
Two comments still name the transport by its old name and are left for the
commit that renames it, so that rename reads as one change rather than as
noise spread across four imports.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
First component into this repo. Renamed from `nestri-protocol` — everything
else in the family carries the `nes` prefix and this was the odd one out.
**Imported as a tree, not as history.** The upstream repo is private, so its
commits and commit messages have never been reviewed for what may be published,
and squashing avoids the failure this project has already documented once: a
repo published wholesale carries private history with it, permanently. Origin is
`nestrilabs/nestri-protocol`, and this is its state today rather than its past.
The `control` module is deliberately left behind. It carries the host↔guest
control channel, and its types are shaped by a payload that has no business
being described in a public repo — a box is supposed to be able to run anything.
It was already an optional feature that nothing here enables, so leaving it out
costs nothing today and stops a boundary from being crossed by accident.
What lands is the media protocol: frames, audio, cursor, input and stats. One
definition shared by both ends, so no two can drift silently. 9 tests pass.
One pre-existing clippy warning (`input.rs`, too many arguments) is left alone
on purpose — an import commit should be a faithful copy, and mixing a cleanup
into one makes both harder to read.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
This repo holds both languages, so it needs both workspaces. Layout is the same
rule on each side — apps/ for what runs, crates/ and packages/ for what is
shared, split by what a thing is rather than what it is written in.
Members are empty because nothing has moved in yet. Versions are pinned once at
the root so two crates cannot disagree about a dependency.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
This adds:
- [x] Keyboard and mouse handling on the frontend
- [x] Video and audio streaming from the backend to the frontend
- [x] Input server that works with Websockets
Update - 17/11
- [ ] Master docker container to run this
- [ ] Steam runtime
- [ ] Entrypoint.sh
---------
Co-authored-by: Kristian Ollikainen <14197772+DatCaptainHorse@users.noreply.github.com>
Co-authored-by: Kristian Ollikainen <DatCaptainHorse@users.noreply.github.com>
