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fix(minvmd): bump libkrun to v1.19.6 and refuse a vsock stream whose host socket fails - #2105
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…host socket fails The macOS libkrun VMM aborted (SIGABRT) when a guest opened a vsock stream to a host-mapped unix-socket port and socket(AF_UNIX) failed on the host: the muxer unwrapped UnixProxy::new(), so one failed host socket took the whole VM down. Carry vendor/libkrun/patches/0002, which answers the guest with OP_RST and logs the errno instead, the same refusal the muxer already sends for a connect to a listening-mapped port. The patch is in git format-patch form so it can go upstream unchanged; drop it when a pin includes the fix. Bump the macOS pin from v1.19.4 to v1.19.6 (227b2de6) for the upstream vsock fixes: release proxies after clean shutdown (a host fd leaked per cleanly closed stream), remove refused connections without waiting for the reaper, and drop the proxy_map guard before removing a proxy. The carried 0001 patch still applies on v1.19.6. Closes #2103 Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01NSAwDroXL6KqsSxUzdbZGw
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Included review availability: This review used your included allowance. 3 included reviews remain after this review. Your included PR review attempts over the past 7 days set your current allowance at 5 reviews per hour. 📝 WalkthroughWalkthroughThe changes configure libkrun logging, update carried vsock proxy handling, and revise licensing attributions for release artifacts. The vsock patches reset guest connections when proxy setup fails and disarm proxy polling after full shutdown. Changeslibkrun logging configuration
vsock proxy handling
Release-artifact attributions
Priority: ➖ Normal Estimated code review effort: 3 (Moderate) | ~20 minutes Change: Bug fix · Severity of issue fixed: Medium Suggested reviewers: Merge Risk: 🔵 Low · up to A guest connection may time out rather than receive an immediate refusal when its receive queue is saturated. This is a bounded follow-up risk, not a demonstrated reason to block the release. 🚥 Pre-merge checks | ✅ 5✅ Passed checks (5 passed)
✨ Finishing Touches🧪 Generate unit tests (beta)
A rabbit checks the logs at night, Comment |
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Repro on a macOS host (48 GB, 18 cores) with this branch's dylib (v1.19.6 plus 0001 and 0002, built by
What this shows and doesn't: the v1.19.6 bump plus both patches are stable under the exact workload that aborted 1.19.0, and the vsock changes don't regress the session plane. It does not show 0002's refusal path firing. The host was never under fd or memory pressure, so |
1.19.6 still unwraps UnixProxy::new() for a guest-to-host stream, so a transient EMFILE/ENFILE/ENOBUFS on the host aborts the whole VMM. Carry 0002 from gominimal/minimal#2105 (identical file): log and answer that stream with OP_RST instead. Applies cleanly on v1.19.6 after 0001. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
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@bryan-minimal I am pretty sure that we don't use the pkgs variant anymore. We always build krun ourselves now. We statically link it for linux in order to get a muslc build. IIRC |
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Second cold run, same result: a fully cold |
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Correction to this PR's description, per @norrietaylor's note: the Linux minvmd doesn't use the gominimal/pkgs libkrun. |
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Max-effort review at f76353c: 10 finder angles, one verifier per candidate, then a sweep. 15 findings kept; 2 refuted candidates dropped.
Blocking
- The v1.19.6 bump (upstream b13ddc5) makes the macOS
__krun-vmmvsock thread busy-spin at 100% of a core after every guest-first stream close (READY marker, gvproxy control, report door). Linux is unaffected, which is why the Linux-only checks missed it. - Patch 0002 refuses only a
socket()failure; a failed hostconnect()still gets OP_RESPONSE and an unpolled proxy, so guest egress comes up silently dead.
Details are inline.
Findings on lines outside the diff
justfile:99(outside the diff) — MEDIUM — The localjustVM recipes exercise neither this bump nor the patch, on either host. On Linux,libkrun-staticskips whenever{{krun-static}}/libkrun.aexists, and that path is not keyed by the pin (justfile:17, 98-99), so existing checkouts keep linking v1.19.4. On macOS,minvmd-buildandtest-vm(justfile:132-135, 640-655) build without LIBKRUN_PREFIX, so crates/minvmd/build.rs:88 silently falls back to Homebrew's libkrun (1.19.0 on this host). No macOS recipe ever builds the vendored pin.
After merge, a developer runs just minvmd-build, just test-vm or just e2e, as AGENTS.md asks for VM-path changes, and gets a green run that never loaded v1.19.6 or 0002. On Linux even just clean is not enough to relink minvmd, because cargo does not track the native lib, so cargo clean -p minvmd is also needed. The PR body's proposed Mac repro (low RLIMIT_NOFILE, then dial the shuttle port) would still SIGABRT against the Homebrew dylib and read as 'the patch does not work', and the macOS spin above cannot be reproduced locally either. Only CI and the release load the pin; just ci is unaffected. Fix: key krun-static on the lock commit and the patches' hash, as the CI cache does, and add a [macos] recipe that runs scripts/build-libkrun-macos.sh into a pin-keyed prefix and exports LIBKRUN_PREFIX to minvmd-build and test-vm.
| version=v1.19.4 | ||
| commit=728df8125077d0db44265f6e997c72b81b65c015 | ||
| version=v1.19.6 | ||
| commit=227b2de6ed323fe180e02f871c5f325a90c13cc2 |
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HIGH — The bump pulls in upstream b13ddc5. On a full guest shutdown its UnixProxy::shutdown() runs do_shutdown, push_reset, release() and sets status = Closed, but it returns polling = None (libkrun unix.rs:608-616). On macOS the dead fd's level-triggered EVFILT_READ stays armed, so the __krun-vmm vsock muxer thread busy-spins at 100% of a core after every guest-first close of a unix-mapped stream, until the reaper drops the proxy.
macOS host. The guest closes first by design for the READY marker (crates/minimald/src/guest.rs:292-293: write_all, shutdown, drop), every gvproxy control request (crates/minimald/src/net/policy.rs:1022, 'closing from the guest side') and every report-door round (crates/minvmd/src/control.rs:535). A Linux guest close sends OP_SHUTDOWN with RCV|SEND, and b13ddc5 marks the proxy Closed without disarming it. libkrun's kqueue emulation (utils/src/macos/epoll.rs:175-179, 300-308) reports IN|READ_HANG_UP and never HANG_UP. UnixProxy::process_event ignores IN unless the proxy is Connected (unix.rs:664, 703), so muxer_thread.rs:180-196 keeps re-waiting on an always-ready knote. A probe on the patched krun-utils measured about 3.9M wakeups/s and 1 CPU-second per second. v1.19.4 woke once and disarmed (recv()==0 -> Close -> polling = EventSet::empty()). Each close burns a core for the reaper's 5 s TIMEOUT. When the reaper's elapsed==0 case leaves its timeout at Duration::MAX (reaper.rs:36-55; about a fifth of isolated releases in a simulation), the spin lasts until some later release. Linux hosts take the EPOLLHUP -> HANG_UP arm and do not spin, which is why the Linux-only verification missed it; upstream main has the same code. Fix: carry a patch that returns polling = Some((self.id, self.fd.as_raw_fd(), EventSet::empty())) from that branch.
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Confirmed at 227b2de6: the full-shutdown branch of UnixProxy::shutdown() returns release() with polling: None (unix.rs:608-617), the macOS epoll emulation reports an EOF on EVFILT_READ as IN | READ_HANG_UP and never HANG_UP (utils/src/macos/epoll.rs:300-304), and process_event() ignores IN unless the proxy is Connected. Upstream main has the same code in unix_proxy/mod.rs. I didn't re-measure the wakeup rate or check the reaper Duration::MAX case.
Fixed in b15650a: new patch 0003 sets update.polling = Some((self.id, self.fd.as_raw_fd(), EventSet::empty())) in that branch. It's carried defensively, since dev-host measured no spin for one trigger shape, and the macOS dylib needs rebuilding on dev-host to exercise it. Sent upstream separately as libkrun/libkrun#916. 55c9fea records that in the patch header.
| + return; | ||
| + } | ||
| + }; | ||
| let tsi = TsiConnectReq { |
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HIGH — The patch refuses the stream only when socket() fails. When the host connect() fails, process_op_request still sends OP_RESPONSE and inserts an Idle proxy that is never polled (muxer.rs:594-597). The guest's connect() therefore succeeds into a black hole instead of failing with the ECONNRESET the PR promises.
Two triggers: gvproxy is missing or failed to spawn (crates/minvmd/src/cmd/run.rs:803-830 boots 'without guest egress'), or the gate or report-door socket stops listening mid-run. In both cases the vsock port stays registered (crates/minvmd/src/vm.rs:389-395, whose comment assumes 'the guest's connect simply fails'). UnixProxy::connect's Err arm (unix.rs:420-436; ENOENT/ECONNREFUSED/EAGAIN) leaves status Idle with no polling and only pushes a DGRAM ConnResponse, which the stream guest drops. confirm_connect (unix.rs:459-463) then sends OP_RESPONSE regardless. So minimald's connect_switch_vsock (crates/minimald/src/net/switch.rs:477-485) succeeds, root egress logs 'up' with eth0 and a default route, and every packet is silently swallowed. That is the dead-egress EHOSTUNREACH symptom from #760. A report ask to a dead door blocks without bound. The fd lives until the guest closes. Fix in the same function: after connect(), if the proxy is neither Connected nor Connecting, push MuxerRx::Reset and skip confirm_connect and the insert. Do not use ProxyRemoval::Immediate here, because the proxy_map write lock is held.
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Confirmed: UnixProxy::connect()'s Err arm leaves the proxy Idle with no polling and pushes only the DGRAM ConnResponse, and confirm_connect() then sends OP_RESPONSE regardless (unix.rs:343-402).
Fixed in b15650a. After unix.connect(), if the proxy is neither Connected nor Connecting, 0002 logs the port and path with error!, pushes MuxerRx::Reset via self.push_packet, and returns before confirm_connect and the proxy_map insert. It doesn't use ProxyRemoval::Immediate, so there's no re-entry on the held write lock. 0002 now covers "the host leg can't be established" (socket or connect). The same change is on libkrun/libkrun#915 as ba1bd27.
| + // Creating the host socket can fail transiently (e.g. | ||
| + // EMFILE, ENFILE, ENOBUFS). Refuse this connection | ||
| + // instead of taking the whole VM down. | ||
| + error!( |
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MEDIUM — The new error!() is a no-op in production. minvmd installs libkrun's logger only when MINVMD_KRUN_LOG is set (crates/minvmd/src/krun/ctx.rs:371-373), and libkrun's own log statics never reach minvmd's tracing. A refusal therefore leaves no host-side trace, and the commit message's 'Log the error, which carries the errno' is false as shipped.
Take the #2103 build-load case, where socket(AF_UNIX) fails with EMFILE. Before this patch the panic message, errno included, went to the VMM's stderr and on to run.log (crates/minvmd/src/cmd/run.rs:266-271, 878-912), which min bug collects (crates/minimal/src/diag/collect.rs:389-401); macOS also wrote an .ips crash report. After the patch the guest sees an unexplained ECONNRESET, possibly followed by a permanently degraded network, and nothing on the host records why. A loud, diagnosable failure becomes a silent one. Fix: have minvmd call krun_init_log at error level (KRUN_LOG_OPTION_NO_ENV) by default, so libkrun's error!() lines land in run.log.
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Confirmed: krun_create_ctx installs no logger. Only krun_init_log / krun_set_log_level do, and minvmd called krun_init_log only when MINVMD_KRUN_LOG was set.
Fixed in 69c6e44. Context::create() now always calls krun_init_log: at error level with KRUN_LOG_OPTION_NO_ENV by default, so minvmd's own RUST_LOG can't change it, or at the MINVMD_KRUN_LOG level when set (off silences it). libkrun's error!() lines, including 0002's refusals, now reach the VMM stderr and so run.log. The level choice is a pure log_settings() with two new unit tests.
| + local_port: pkt.dst_port(), | ||
| + peer_port: pkt.src_port(), | ||
| + }; | ||
| + push_packet(self.cid, rx, &self.rxq, queue, mem); |
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LOW — The RST turns a transient host failure into a permanent guest degradation for one-shot consumers. minimald brings root egress up exactly once (crates/minimald/src/main.rs:1191-1196), and the gvproxy range probe maps any non-TimedOut error to Absent (crates/minimald/src/net/policy.rs:830-840, crates/minimald/src/sessions.rs:487-516). One refused stream at the wrong moment leaves the VM up without egress for its whole life.
The VMM briefly hits EMFILE/ENFILE while minimald dials the switch or runs the range probe. The guest gets ECONNRESET, bring_up_root_egress fails once and never retries, and sessions fall back to the gvproxy-Absent networking. The VM looks healthy, the host logs nothing (see the error!() finding), and minvmd does not restart it. Before the patch the same moment aborted the VM, which was at least visible. The trigger is unlikely at boot (fresh VMM, RLIMIT_NOFILE 65536). Fix: retry those callers with bounded backoff on ECONNRESET.
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Not changed in this PR. Bounded retry in the one-shot callers (root egress bring-up, the gvproxy range probe) is minimald work, and it's going into a separate follow-up issue. Since 69c6e44, a refusal at least leaves an error! line in run.log rather than nothing.
| + return; | ||
| + } | ||
| + }; | ||
| let tsi = TsiConnectReq { |
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LOW — The same guest-triggered path still aborts the VMM on a host-resource failure on macOS. After a successful connect, process_proxy_update calls update_polling, whose Epoll::ctl(Add) runs assert_eq!(ret, 0) on kevent(EV_ADD) (libkrun src/utils/src/macos/epoll.rs:208). A kevent failure under resource pressure therefore still takes __krun-vmm and the whole VM down.
On a macOS host under #2103-style pressure, socket() and connect() succeed but registering the new fd with kqueue fails, for example ENOMEM allocating the knote. The assert panics on the event-manager thread and the VMM aborts, which is the outcome the patch exists to remove ('instead of taking the whole VM down'). This is low probability, since XNU rarely fails EV_ADD. The patch's goal is still only partly met on this path. Fix: propagate the kevent error and refuse the stream with a Reset instead of asserting.
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Confirmed: assert_eq!(ret, 0) after kevent(EV_ADD) in utils/src/macos/epoll.rs:208. Not changed here. Propagating the kevent error is a separate upstream change in krun-utils, and it's going into a follow-up issue.
| @@ -9,7 +9,7 @@ Third-party attributions | |||
| The macOS (darwin/arm64) release artifacts redistribute the following | |||
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MEDIUM — The libkrun attribution is still scoped to 'The macOS (darwin/arm64) release artifacts' (NOTICE:9-12; docs/internal/licensing.md:64-70), yet the Linux amd64/arm64 release minvmd statically links the same pin plus both carried patches. The PR body repeats the error: it says it 'covers only the macOS dylib' and points Linux at gominimal/pkgs#835.
scripts/build-libkrun-linux.sh:93-95 applies every vendor/libkrun/patches/.patch, and release.yml (229-240) and ci-linux-kvm.yml (184) build through it. The shipped minvmd-linux- binaries therefore contain a modified libkrun v1.19.6 that NOTICE does not attribute for those artifacts. That attribution gap dates from #1070 and is re-touched here without being fixed. Reviewers and release owners who trust the PR body will believe Linux users stay unfixed and wait on the wrong package (pkgs' libkrun only feeds nightly-tests and just libkrun). The vendor/libkrun/libkrun.lock:1-3 header ('pinned source build for macOS') is stale for the same reason. Fix: widen the NOTICE and licensing.md scope to the Linux release, and correct the PR body and the lock header.
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Confirmed: scripts/build-libkrun-linux.sh applies every vendor/libkrun/patches/*.patch, and the release's minvmd-linux-* jobs build through it. Fixed in 2e19180. NOTICE and docs/internal/licensing.md now attribute libkrun v1.19.6, modified by the carried patches, for both the macOS dylib and the statically linked Linux minvmd. The libkrun.lock header now describes both builds. The PR body now says it covers Linux and macOS and that gominimal/pkgs#835 doesn't apply.
| The TSI stream and dgram proxy creation paths already handle this error; | ||
| this was the only guest-triggered proxy construction that unwrapped it. | ||
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| Assisted-by: Claude Code: opus-5.5 |
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LOW — Updated: the upstream submission exists. containers/libkrun#915 (opened 19:53Z by the same author) is this change rebased onto upstream main, with Signed-off-by:. The DCO and does-not-apply points no longer stand for the upstream copy.
What remains is on this file: the carried patch still has no Signed-off-by:, and neither the patch header, libkrun.lock nor the PR body names containers/libkrun#915 as the change that retires it. Record it (for example Upstream: https://github.com/containers/libkrun/pull/915 in the patch header) so the next bump knows to drop 0002 once that merges, rather than conflicting with it.
Note that #915 carries the same scope as 0002, so the connect()-failure and silent-error! findings apply to the upstream PR too.
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Fixed in b15650a. 0002's header now carries Upstream: https://github.com/libkrun/libkrun/pull/915 and Signed-off-by: Karl Godard <karl@minimal.dev>, and the new 0003 carries Signed-off-by plus Upstream: https://github.com/libkrun/libkrun/pull/916 (55c9fea). #915 now has the connect-failure (ba1bd27) and unmapped-port (a425e6d) commits and an updated description. The logging finding was minvmd-side, so it has no upstream counterpart.
| - .unwrap(); | ||
| + ) { | ||
| + Ok(unix) => unix, | ||
| + Err(e) => { |
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LOW — The bug fix ships without a regression test, contrary to CONTRIBUTING.md:116 ('Bug fixes should include a regression test'). Nothing exercises the new Err arm, and the PR body says the abort was never reproduced.
A later libkrun bump that reworks process_op_request (upstream main already differs from this patch's context) can silently drop or break the refusal, and CI stays green because no test makes UnixProxy::new fail. The next EMFILE then aborts the VM again. Upstream's tests/test_cases/src/test_vsock_host_connect_refused.rs, added by 8cdf330 in this same bump, is a ready harness shape: lower RLIMIT_NOFILE in the VMM, dial a listen=false port, and assert ECONNRESET with the VM still up.
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Not in this PR. A VM-level regression test (low RLIMIT_NOFILE in the VMM, dial a listen=false port, expect ECONNRESET with the VM up) is going into a follow-up issue. This round checked the patches with git apply --check plus cargo check/clippy -D warnings on krun-devices --features blk,net at 227b2de6.
| Apache-2.0 components, pinned in `vendor/`: | ||
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| - libkrun v1.19.4 (`vendor/libkrun/libkrun.lock`), shipped as | ||
| - libkrun v1.19.6 (`vendor/libkrun/libkrun.lock`), distributed as |
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LOW — The PR edits docs/internal/licensing.md, but just lint-prose docs/internal/licensing.md still reports 29 Vale alerts (16 errors, e.g. ShipOveruse at line 58 and ste.Semicolon at line 75), and AGENTS.md requires 'Drive files you edit to zero'.
just lint-prose, which lints the markdown a branch touches, exits 1 on this branch. AGENTS.md (Conventions: 'Prose: ... Drive files you edit to zero') is broken for an edited file. It is not a CI gate, so it lands unless a reviewer runs it.
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Fixed in 2e19180: just lint-prose docs/internal/licensing.md now reports 0 errors, 0 warnings, 0 suggestions.
| + local_port: pkt.dst_port(), | ||
| + peer_port: pkt.src_port(), | ||
| + }; | ||
| + push_packet(self.cid, rx, &self.rxq, queue, mem); |
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NIT — The Err arm wires push_packet(self.cid, rx, &self.rxq, queue, mem) by hand, while VsockMuxer already has fn push_packet(&self, rx: MuxerRx) (muxer.rs:189) that does exactly this with the muxer's own cid, queue and mem. self.push_packet(MuxerRx::Reset { .. }) compiles at that point.
Cleanup only. The hand-wired call adds a third copy of the cid/rxq/queue/mem plumbing the method exists to hide, and grows a carried patch that must be rebased at every bump. Change only the new Err arm and leave the pre-existing listen arm alone.
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Fixed in b15650a. The new arms (socket failure, connect failure, unmapped port) all use self.push_packet(MuxerRx::Reset { .. }), which compiles with the proxy_map write guard held. The pre-existing listen arm is unchanged.
… polling closed unix proxies Widen the carried libkrun patch 0002 from "socket() failed" to "the host leg could not be established". When the host connect() fails (gvproxy not running, a gate or report-door socket that stopped listening), libkrun used to send OP_RESPONSE anyway and keep an unpolled proxy, so the guest's connect() succeeded into a connection that never carried data. It now answers OP_RST, as it does for a socket() failure. The patch also answers OP_RST when the guest dials a vsock port with no mapping, which libkrun used to drop, leaving the guest to wait out its connect timeout. The new arms use VsockMuxer::push_packet. The patch header now carries Signed-off-by and the upstream PR it tracks (libkrun/libkrun#915). Add patch 0003. Since v1.19.5 (upstream b13ddc5) a guest's full shutdown of a unix-mapped stream marks the proxy Closed but leaves its fd armed for reading. On macOS the shut-down fd reports IN plus READ_HANG_UP, never HANG_UP, and process_event ignores IN on a proxy that is not Connected, so the vsock muxer thread can spin until the reaper drops the proxy. 0003 disarms the fd in that branch. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01NSAwDroXL6KqsSxUzdbZGw
minvmd installed libkrun's logger only when MINVMD_KRUN_LOG was set, so in production every libkrun error!() went nowhere, including the refusal that the carried vsock patch logs in place of the old abort. Initialise libkrun's logger at error level by default, with KRUN_LOG_OPTION_NO_ENV so minvmd's own RUST_LOG does not change libkrun's level. The VMM's stderr is captured in run.log, which `min bug` collects. MINVMD_KRUN_LOG still overrides the level, and `off` silences libkrun. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01NSAwDroXL6KqsSxUzdbZGw
The Linux (amd64, arm64) release minvmd statically links the same pinned libkrun, with the carried patches, through scripts/build-libkrun-linux.sh. NOTICE and docs/internal/licensing.md scoped the libkrun attribution to the macOS artifacts only, and the libkrun.lock header still described a macOS-only pin. Widen both, note that the patches modify libkrun, and bring licensing.md to zero Vale alerts. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01NSAwDroXL6KqsSxUzdbZGw
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01NSAwDroXL6KqsSxUzdbZGw
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Actionable comments posted: 1
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Review comments at @crates/minvmd/src/krun/ctx.rs:
- Line 405: Update the explicit-level return in the log-level selection logic to
use `raw::LOG_OPTION_NO_ENV` instead of `raw::LOG_OPTIONS_DEFAULT`, preventing
`RUST_LOG` from overriding `MINVMD_KRUN_LOG`; preserve the selected level.
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Included review availability: This review used your included allowance. 4 included reviews remain after this review. Your included PR review attempts over the past 7 days set your current allowance at 5 reviews per hour.
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minimal-review — approval withheld
Verdict COMMENT — APPROVE withheld: 15 unresolved threads — norrietaylor vendor/libkrun/libkrun.lock:11, norrietaylor vendor/libkrun/patches/0002-vsock-refuse-stream-when-unix-proxy-creation-fails.patch:81, norrietaylor vendor/libkrun/patches/0002-vsock-refuse-stream-when-unix-proxy-creation-fails.patch:70, norrietaylor vendor/libkrun/patches/0002-vsock-refuse-stream-when-unix-proxy-creation-fails.patch, norrietaylor vendor/libkrun/patches/0002-vsock-refuse-stream-when-unix-proxy-creation-fails.patch:81, …. No findings.
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The refusal path is now proven directly. The regression tests on libkrun/libkrun#915 (b4a5b58) ran on a macOS host: 2/2 pass with the fix, and 0/2 on upstream main before it. Before the fix, the EMFILE test kills the VMM on the exact production unwrap, |
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@norrietaylor follow-up on your review, covering the gaps the inline replies left: The Where the deferred items went:
Regression test: it exists now, upstream on libkrun/libkrun#915 (b4a5b58), and it ran on a macOS host:
#2112 stays open for a test in this repo's VM lane. Also since your review:
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…G level An explicit MINVMD_KRUN_LOG level now also initialises libkrun's logger with KRUN_LOG_OPTION_NO_ENV, so RUST_LOG cannot override it (for example MINVMD_KRUN_LOG=off with RUST_LOG=trace). The now-unused LOG_OPTIONS_DEFAULT constant goes. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01F8sLgtJAzSVuYQZtd2q81n
The Linux release fetches and ships gvproxy-linux-amd64 and gvproxy-linux-arm64 from the same v0.8.9 pin, so NOTICE and the licensing note now name both platforms, matching the libkrun entry. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01F8sLgtJAzSVuYQZtd2q81n
* Update libkrun to 1.19.6 * libkrun: carry the vsock unix-proxy refusal patch (minimal#2103) 1.19.6 still unwraps UnixProxy::new() for a guest-to-host stream, so a transient EMFILE/ENFILE/ENOBUFS on the host aborts the whole VMM. Carry 0002 from gominimal/minimal#2105 (identical file): log and answer that stream with OP_RST instead. Applies cleanly on v1.19.6 after 0001. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> --------- Co-authored-by: gominimal-pkgmgr-mgr[bot] <285843623+gominimal-pkgmgr-mgr[bot]@users.noreply.github.com> Co-authored-by: bryan <bryan@minimal.dev> Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
Closes #2103.
This PR covers both hosts.
vendor/libkrunpins the libkrun that the macOS release ships aslibkrun.1.dylib(scripts/build-libkrun-macos.sh) and the staticlibkrun.athat the Linux amd64/arm64 releaseminvmdlinks (scripts/build-libkrun-linux.sh). Both builds apply every patch invendor/libkrun/patches/. gominimal/pkgs#835 does not apply here: the pkgslibkrunpackage only feedsnightly-testsandjust libkrun, not a release.What changes
Pin bump:
vendor/libkrun/libkrun.lockfrom v1.19.4 to v1.19.6 (227b2de6). This brings the upstream vsock fixes that #2103 calls out:0001-vsock-bound-outstanding-packets.patchstays. It still applies cleanly on v1.19.6.Patch 0002: refuse a vsock stream whose host leg can't be established. When a guest opens a stream to a host-mapped unix-socket port (
krun_add_vsock_port2(.., listen = false): the gvproxy shuttle, the gate, the report door),process_op_request()creates and connects the host leg. 0002 answersOP_RST(the guest'sconnect()fails with ECONNRESET) and keeps the VM running when:UnixProxy::new()fails, meaningsocket(AF_UNIX)failed (EMFILE, ENFILE, ENOBUFS, ENOMEM). The oldunwrap()aborted the whole__krun-vmm: the SIGABRT inprocess_stream_txfrom the issue's crash reports.connect()fails (gvproxy not running, a gate or report-door socket that stopped listening). libkrun used to sendOP_RESPONSEanyway and keep an unpolled proxy, so the guest's connect succeeded into a dead stream.Nothing is inserted into
proxy_mapon any of these paths. Upstream: libkrun/libkrun#915.Patch 0003: stop polling a unix proxy closed by a full shutdown. Since b13ddc5, a guest's full shutdown marks the proxy
Closedbut leaves its fd armed for reading. On macOS the shut-down fd reportsIN | READ_HANG_UP, neverHANG_UP, andprocess_event()ignoresINon a proxy that isn'tConnected, so the vsock muxer thread can spin until the reaper drops the proxy. Linux takes theHANG_UParm and is unaffected. 0003 disarms the fd in that branch. It's defensive: dev-host measured no spin on a macOS host for one trigger shape. Upstream: libkrun/libkrun#916.minvmd logs libkrun errors by default.
Context::create()now callskrun_init_logat error level withKRUN_LOG_OPTION_NO_ENVwhenMINVMD_KRUN_LOGis unset, so libkrun'serror!()lines reach the VMM's stderr, including 0002's refusals for host-side failures (socket()orconnect()failing), and sorun.log, whichmin bugcollects.MINVMD_KRUN_LOGstill overrides the level (andRUST_LOGcan't), andoffsilences libkrun. The unmapped-port refusal logs atdebug!on purpose: a guest dialing a port nothing is mapped to is a guest-side mistake with no host remedy, and aterror!an untrusted guest could flood the host'srun.log.Attribution.
NOTICEanddocs/internal/licensing.mdnow attribute the patched libkrun v1.19.6 in the Linux release too, and thelibkrun.lockheader no longer calls the pin macOS-only.Verification
227b2de6: 0001, 0002 and 0003 each passgit apply --check, thengit apply, in sorted order, the way both build scripts apply them.cargo checkandcargo clippy --locked -- -D warningsonkrun-devices --features blk,net(the release feature set) pass, andcargo fmt -- --checkis clean. This compiles the shared muxer code on Linux. It does not compile the#[cfg(target_os = "macos")]paths, but the patches add none.cargo check,cargo clippy --all-targets -D warnings, andjust test-one krun::ctx -p minvmd --lib(9 passed, including the two newlog_settings_*tests). Thekrunmodule only compiles when libkrun is found, so those ran against a stublibkrun.so.just lint-prose docs/internal/licensing.md: zero alerts.Repro evidence, and what it doesn't show
On a macOS host (48 GB, 18 cores) with this branch's dylib at f76353c (v1.19.6 plus 0001 and the socket-only 0002), the guest build that aborted the libkrun 1.19.0 VMM twice in one day ran to completion: a fully cold
CARGO_BUILD_JOBS=4 just test, 632 crates, then nextest. No crash, the same VMM process before and after, no newminvmd-*.ips, and the VMM's fd count flat at 117.That shows v1.19.6 plus the patches is stable under the workload that aborted 1.19.0. The refusal paths themselves are now proven directly by regression tests on libkrun/libkrun#915 (b4a5b58), run on a macOS host: 2/2 pass with the fix, 0/2 on upstream main before it. The EMFILE test aborts the old VMM on the production unwrap (
CreatingSocket(Os { code: 24, … "Too many open files" })), and the connect-failure test shows the old code giving the guest a "connected" dead stream. Two furtherjust testpasses on a dylib with 0001–0003 kept the VMM up, with no busy-spin after guest-first closes.🤖 Generated with Claude Code
https://claude.ai/code/session_01NSAwDroXL6KqsSxUzdbZGw
Summary by CodeRabbit
Bug Fixes
Improvements
Documentation