Great job, looking forward to getting this merged! 🎉

Reviewed 21 of 21 files at r1, all commit messages.
Reviewable status: all files reviewed, 3 unresolved discussions (waiting on @dlon)

test/test-manager/src/tests/helpers.rs line 99 at r1 (raw file):

pub async fn send_guest_probes(
    rpc: ServiceClient,
    interface: Option<String>,

This argument does not have to be an Option<String>, it could safely be just a String.
I did not find any instance where None was passed as the interface argument.

Code quote:

interface: Option<String>

test/test-runner/src/net.rs line 56 at r1 (raw file):

    log::debug!("Connecting from {bind_addr} to {destination}/TCP");

    tokio::task::spawn_blocking(move || {

What is the motivation for this change?
I suggest reverting this change and use the tokio::net::TcpStream, instead of manually putting synchronous I/O on a blocking-friendly thread.

Code quote:

tokio::task::spawn_blocking(move || {

test/test-runner/src/net.rs line 121 at r1 (raw file):

    }

    let _ = tokio::task::spawn_blocking(move || {

dito

Code quote:

 let _ = tokio::task::spawn_blocking(move || {

Reviewable status: all files reviewed, 3 unresolved discussions (waiting on @MarkusPettersson98)

test/test-runner/src/net.rs line 56 at r1 (raw file):

connect() sometimes fails due to EINPROGRESS. I'm not sure whether it's fine to convert the socket to a tokio::net::TcpStream in this state. I suppose we could use blocking I/O only for connect().

Reviewable status: all files reviewed, 3 unresolved discussions (waiting on @MarkusPettersson98)

test/test-manager/src/tests/helpers.rs line 99 at r1 (raw file):

We're calling send_guest_probes_without_monitor in install.rs. Should this function not have the same interface as that one?

Reviewable status: all files reviewed, 3 unresolved discussions (waiting on @dlon)

test/test-manager/src/tests/helpers.rs line 99 at r1 (raw file):

I think a function's interface should reflect what it actually needs - in this case I find it a bit leaky to have send_guest_probes also take interface as an Optional<String> just because it calls send_guest_probes_without_monitor 😊

test/test-runner/src/net.rs line 56 at r1 (raw file):

Alright, nevermind then!

Reviewable status: 18 of 21 files reviewed, 3 unresolved discussions (waiting on @MarkusPettersson98)

test/test-manager/src/tests/helpers.rs line 99 at r1 (raw file):

Done.

Reviewed 2 of 3 files at r2, 1 of 1 files at r3, all commit messages.
Reviewable status: complete! all files reviewed, all discussions resolved