Add QEMU test for x86_64-unknown-uefi

[nicholasbishop]

The UEFI targets don't have std support yet, so the normal tests don't work. However, we can compile a simple no-std program and run it under QEMU to at least check that the target compiles, links, and runs.

Tested locally with: src/ci/docker/run.sh x86_64-uefi

[rust-highfive]

r? @jyn514

(rust-highfive has picked a reviewer for you, use r? to override)

[nicholasbishop]

I don't have any prior knowledge of the Rust CI, and I didn't see any existing CI jobs that looked like a good analog for what I was trying to do here. So, I'm not sure if this is the right way to go about it -- any feedback appreciated :)

CC @dvdhrm

[jyn514]

The tests themselves look vaguely right, although I think using QEMU is rather unusual.

What tier is UEFI? I was under the impression it's tier 3, which we don't test.

[nicholasbishop]

You are correct that UEFI is currently tier 3, however there is an open proposal to move to tier 2: rust-lang/compiler-team#555

[jyn514]

Ok. The way the tier system works is that tier 3 has support but no CI, tier 2 is built in CI but not tested, and only tier 1 is tested. So I can't accept this PR unless UEFI is tier 1 (which seems unlikely). Once your MCP is accepted, you can change it to build only and we can merge that.

[jyn514]

cc @joshtriplett to confirm I have the tier policy correct - only tier 1 has tests, right?

[dvdhrm]

(from https://doc.rust-lang.org/nightly/rustc/target-tier-policy.html)

Tier-2

• The target must build reliably in CI, for all components that Rust's CI considers mandatory.
• The approving teams may additionally require that a subset of tests pass in CI, such as enough to build a functional "hello world" program, ./x.py test --no-run, or equivalent "smoke tests". In particular, this requirement may apply if the target builds host tools, or if the tests in question provide substantial value via early detection of critical problems.

@jyn514, my interpretation is that basic target tests are allowed for Tier-2 targets, explicitly mentioning a hello-world program as suggested here. It is, however, unclear to me whether this requires approval by a team. The wording only defines the inverse, in that if it is asked for, it must be provided. Maybe Josh can shed some light on this.

[jyn514]

Ok, in that case I'll marked this as blocked on rust-lang/compiler-team#555.

[dvdhrm]

Thanks a lot for submitting this! Looks all good to me, a few minor questions inline.

[the8472]

The tests themselves look vaguely right, although I think using QEMU is rather unusual.

We already have some ARM tests running under emulation on x86 CI.

[the8472]

This might fit into the test-various job? That currently 37minutes so it's one of the shorter-running jobs.

[jyn514]

@nicholasbishop can you please make this change?

[nicholasbishop]

Done.

One thing to note is that the test-various Dockerfile is using Ubuntu 20.04, which provides a quite old QEMU (4.2.1). That version of QEMU likes to crash on exit with OMVF, we ran into that problem in the CI for uefi-rs in the past. I changed the test to not check the exit status of the VM, which I think is fine since we're checking the stdout for a specific string anyway.

[jyn514]

Hard coding the target and directory structure here makes me a little nervous ... I guess if it breaks it will break quickly in CI. It would still make me more comfortable to make this managed by bootstrap, but I won't block on that.

[jyn514]

r=me with #101703 (comment) done and the MCP accepted :)

[nicholasbishop]

@jyn514 the MCP has been accepted :)

[jyn514]

@bors r+ rollup=iffy

[bors]

📌 Commit 1e264ab has been approved by jyn514

It is now in the queue for this repository.

[nicholasbishop]

Is bors not working correctly here? https://bors.rust-lang.org/queue/rust doesn't show this PR as approved.

[jyn514]

ugh

@bors r- r+

[bors]

📌 Commit 1e264ab has been approved by jyn514

It is now in the queue for this repository.

[bors]

⌛ Testing commit 1e264ab with merge c2a5c3a...

[bors]

☀️ Test successful - checks-actions
Approved by: jyn514
Pushing c2a5c3a to master...

[rust-timer]

Finished benchmarking commit (c2a5c3a): comparison URL.

Overall result: ❌ regressions - no action needed

@rustbot label: -perf-regression

Instruction count

This is a highly reliable metric that was used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	0.3%	[0.3%, 0.3%]	1
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	0.3%	[0.3%, 0.3%]	1

Max RSS (memory usage)

Results

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	0.6%	[0.5%, 0.8%]	3
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-1.0%	[-1.0%, -1.0%]	1
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	0.2%	[-1.0%, 0.8%]	4

Cycles

Results

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	0.5%	[0.5%, 0.5%]	1
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-0.6%	[-0.6%, -0.6%]	2
Improvements ✅ (secondary)	-4.4%	[-4.4%, -4.4%]	1
All ❌✅ (primary)	-0.2%	[-0.6%, 0.5%]	3

[rust-timer]

Finished benchmarking commit (c2a5c3a): comparison URL.

Overall result: ❌ regressions - no action needed

@rustbot label: -perf-regression

Instruction count

This is a highly reliable metric that was used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	0.3%	[0.3%, 0.3%]	1
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	0.3%	[0.3%, 0.3%]	1

Max RSS (memory usage)

Results

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	0.6%	[0.5%, 0.8%]	3
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-1.0%	[-1.0%, -1.0%]	1
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	0.2%	[-1.0%, 0.8%]	4

Cycles

Results

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	0.5%	[0.5%, 0.5%]	1
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-0.6%	[-0.6%, -0.6%]	2
Improvements ✅ (secondary)	-4.4%	[-4.4%, -4.4%]	1
All ❌✅ (primary)	-0.2%	[-0.6%, 0.5%]	3