firmware_uefi: Allow inspect or ohcldiag to reprocess UEFI logs with an increased log level by maheeraeron · Pull Request #2802 · microsoft/openvmm

maheeraeron · 2026-02-11T23:08:13Z

Enhances the inspect_mut on the UefiDevice such that you can now provide a log level to reprocess the UEFI diagnostics buffer with more verbosity. You can also choose to output this through tracing or stdout. The stdout option is used when issuing this same command through ohcldiag.

This works because the in-memory buffer for UEFI logs technically contains all logs up to the VERBOSE level.

By default we only project ERROR and WARN logs, but now we can get INFO and VERBOSE logs at runtime via inspect or ohcldiag

Copilot

Pull request overview

This PR enhances the UEFI diagnostics inspection capability by allowing dynamic log level overrides at runtime. The UEFI diagnostics buffer contains all logs up to the VERBOSE level, but by default only ERROR and WARN logs are projected. This change enables users to reprocess the buffer with increased verbosity (INFO or VERBOSE) via the inspect interface without requiring a restart.

Changes:

Added log_level_override: Option<LogLevel> parameter to diagnostics processing methods
Enhanced inspect_mut handler to accept "default", "info", or "full" values for runtime log level control
Updated all existing call sites to pass None, preserving default behavior

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

File	Description
`vm/devices/firmware/firmware_uefi/src/service/diagnostics/mod.rs`	Added `log_level_override` parameter to both `DiagnosticsServices::process_diagnostics` and `UefiDevice::process_diagnostics` methods with documentation updates
`vm/devices/firmware/firmware_uefi/src/lib.rs`	Enhanced inspect_mut handler to parse log level values ("default"/"info"/"full") and updated all call sites to pass `None` for the new parameter
`vm/devices/firmware/firmware_uefi/fuzz/fuzz_diagnostics.rs`	Updated fuzz test to pass `None` for the new log_level_override parameter

github-actions · 2026-02-12T00:10:55Z

At least one Petri test failed.

maheeraeron · 2026-02-13T19:25:21Z

openvmm/openvmm_entry/src/lib.rs

                    match value {
-                        Ok(node) => println!("{:#}", node),
+                        Ok(node) => match &node.kind {
+                            inspect::ValueKind::String(s) => println!("{s}"),


This was necessary because otherwise printing the return value of inspect didn't break up each log into their own line

vm/devices/firmware/firmware_uefi/src/lib.rs

maheeraeron · 2026-02-13T19:35:06Z

vm/devices/firmware/firmware_uefi/src/lib.rs

+                    |log| {
+                        let _ = writeln!(
+                            output,
+                            "[{}] [{}] (ticks: {}) {}",


so currently the output looks like:

PS C:\maa> .\ohcldiag-dev.exe UHVM1 inspect -u default vm/uefi/efi_diagnostics_dump "[ERROR] [PEI_CORE] (ticks: 7709416) InstallPermanentMemoryBuffer: - New Info=42FF000, Buffer Offset=50, Current Offset=1000, Size=4194224, Discarded=5464\n[ERROR] [PEI_CORE] (ticks: 7797332) SyncPcrAllocationsAndPcrMask!\n[ERROR] [PEI_CORE] (ticks: 8166883) PeiDelayedDispatchOnEndOfPei Count of dispatch cycles is 0\n[WARNING] [DXE] (ticks: 8290957) VmbusRootIsChannelAllowed: Channel not allowed during boot (525074DC-8985-46E2-8057-A307DC18A502).\n[WARNING] [DXE] (ticks: 8291028) VmbusRootIsChannelAllowed: Channel not allowed during boot (F8E65716-3CB3-4A06-9A60-1889C5CCCAB5).\n[WARNING] [DXE] (ticks: 8291088) VmbusRootIsChannelAllowed: Channel not allowed during boot (CFA8B69E-5B4A-4CC0-B98B-8BA1A1F3F95A).\n[WARNING] [DXE] (ticks: 8291400) VmbusRootIsChannelAllowed: Channel not allowed during boot (3375BAF4-9E15-4B30-B765-67ACB10D607B).\n[WARNING] [DXE] (ticks: 8291460) VmbusRootIsChannelAllowed: Channel not allowed during boot (57164F39-9115-4E78-AB55-382F3BD5422D).\n[WARNING] [DXE] (ticks: 8291519) VmbusRootIsChannelAllowed: Channel not allowed during boot (A9A0F4E7-5A45-4D96-B827-8A841E8C03E6).\n[WARNING] [DXE] (ticks: 8291578) VmbusRootIsChannelAllowed: Channel not allowed during boot (0E0B6031-5213-4934-818B-38D90CED39DB).\n[WARNING] [DXE] (ticks: 8291637) VmbusRootIsChannelAllowed: Channel not allowed during boot (9527E630-D0AE-497B-ADCE-E80AB0175CAF).\n[WARNING] [DXE] (ticks: 8291697) VmbusRootIsChannelAllowed: Channel not allowed during boot (35FA2E29-EA23-4236-96AE-3A6EBACBA440).\n[WARNING] [DXE] (ticks: 8291756) VmbusRootIsChannelAllowed: Channel not allowed during boot (276AACF4-AC15-426C-98DD-7521AD3F01FE).\n[WARNING] [DXE] (ticks: 8294702) FPDT: WARNING: SEC Performance Data Hob not found, ResetEnd will be set to 0!\n[ERROR] [DXE] (ticks: 8295776) OnVariablePolicyNotification: - Unable to locate variable policy protocol - Status=Not Found\n[ERROR] [DXE] (ticks: 9426410) OnVariablePolicyNotification: - Unable to locate variable policy protocol - Status=Not Found\n[WARNING] [DXE] (ticks: 10480382) AziHsm: Seal command size: 87 bytes, data size: 32 bytes\n[WARNING] [DXE] (ticks: 10480392) AziHsm: Parent handle: 0x80000000, command tag: 0x8002\n[ERROR] [DXE] (ticks: 11565269) Error: Image at 000F7BA9000 start failed: Unsupported\n[ERROR] [DXE] (ticks: 13690878) MnpStart: MnpStartSnp failed, Already started.\n[WARNING] [DXE] (ticks: 13816412) WARN [DE]: Failed to locate on-screen keyboard protocol (Not Found).\n[ERROR] [DXE] (ticks: 13828070) [Bds] Unable to boot!\n[WARNING] [DXE] (ticks: 13828347) Boot order is empty\n[ERROR] [DXE] (ticks: 13874746) Unable to locate any 964E5B22-6459-11D2-8E39-00A0C969723B handles - code=Not Found\n[WARNING] [DXE] (ticks: 13874760) Attempted to boot from HDD with FilterOnlyMedia, SelectAndBootDevice returned Not Found\n[ERROR] [DXE] (ticks: 13874809) AziHsm: Unable to Boot event triggered - clearing sensitive data\n[ERROR] [DXE] (ticks: 14112965) OnVariablePolicyNotification: - Unable to locate variable policy protocol - Status=Not Found\n[WARNING] [DXE] (ticks: 14207143) WARN [FP]: Failed to find the on-screen keyboard protocol (Not Found).\n[ERROR] [DXE] (ticks: 14223643) RenderTitlebar Parameter = B - LoadOption=0\n[WARNING] [DXE] (ticks: 14679545) MnpSyncSendPacket: No network cable detected.\n[WARNING] [DXE] (ticks: 21679726) MnpSyncSendPacket: No network cable detected.\n[WARNING] [DXE] (ticks: 113679353) MnpSyncSendPacket: No network cable detected.\n\n(0xb91 entries processed, 0x657d8 bytes read)" PS C:\maa> .\ohcldiag-dev.exe UHVM1 efi-diagnostics default [ERROR] [PEI_CORE] (ticks: 7709416) InstallPermanentMemoryBuffer: - New Info=42FF000, Buffer Offset=50, Current Offset=1000, Size=4194224, Discarded=5464 [ERROR] [PEI_CORE] (ticks: 7797332) SyncPcrAllocationsAndPcrMask! [ERROR] [PEI_CORE] (ticks: 8166883) PeiDelayedDispatchOnEndOfPei Count of dispatch cycles is 0 [WARNING] [DXE] (ticks: 8290957) VmbusRootIsChannelAllowed: Channel not allowed during boot (525074DC-8985-46E2-8057-A307DC18A502). [WARNING] [DXE] (ticks: 8291028) VmbusRootIsChannelAllowed: Channel not allowed during boot (F8E65716-3CB3-4A06-9A60-1889C5CCCAB5). [WARNING] [DXE] (ticks: 8291088) VmbusRootIsChannelAllowed: Channel not allowed during boot (CFA8B69E-5B4A-4CC0-B98B-8BA1A1F3F95A). [WARNING] [DXE] (ticks: 8291400) VmbusRootIsChannelAllowed: Channel not allowed during boot (3375BAF4-9E15-4B30-B765-67ACB10D607B). [WARNING] [DXE] (ticks: 8291460) VmbusRootIsChannelAllowed: Channel not allowed during boot (57164F39-9115-4E78-AB55-382F3BD5422D). [WARNING] [DXE] (ticks: 8291519) VmbusRootIsChannelAllowed: Channel not allowed during boot (A9A0F4E7-5A45-4D96-B827-8A841E8C03E6). [WARNING] [DXE] (ticks: 8291578) VmbusRootIsChannelAllowed: Channel not allowed during boot (0E0B6031-5213-4934-818B-38D90CED39DB). [WARNING] [DXE] (ticks: 8291637) VmbusRootIsChannelAllowed: Channel not allowed during boot (9527E630-D0AE-497B-ADCE-E80AB0175CAF). [WARNING] [DXE] (ticks: 8291697) VmbusRootIsChannelAllowed: Channel not allowed during boot (35FA2E29-EA23-4236-96AE-3A6EBACBA440). [WARNING] [DXE] (ticks: 8291756) VmbusRootIsChannelAllowed: Channel not allowed during boot (276AACF4-AC15-426C-98DD-7521AD3F01FE). [WARNING] [DXE] (ticks: 8294702) FPDT: WARNING: SEC Performance Data Hob not found, ResetEnd will be set to 0! [ERROR] [DXE] (ticks: 8295776) OnVariablePolicyNotification: - Unable to locate variable policy protocol - Status=Not Found [ERROR] [DXE] (ticks: 9426410) OnVariablePolicyNotification: - Unable to locate variable policy protocol - Status=Not Found [WARNING] [DXE] (ticks: 10480382) AziHsm: Seal command size: 87 bytes, data size: 32 bytes [WARNING] [DXE] (ticks: 10480392) AziHsm: Parent handle: 0x80000000, command tag: 0x8002 [ERROR] [DXE] (ticks: 11565269) Error: Image at 000F7BA9000 start failed: Unsupported [ERROR] [DXE] (ticks: 13690878) MnpStart: MnpStartSnp failed, Already started. [WARNING] [DXE] (ticks: 13816412) WARN [DE]: Failed to locate on-screen keyboard protocol (Not Found). [ERROR] [DXE] (ticks: 13828070) [Bds] Unable to boot! [WARNING] [DXE] (ticks: 13828347) Boot order is empty [ERROR] [DXE] (ticks: 13874746) Unable to locate any 964E5B22-6459-11D2-8E39-00A0C969723B handles - code=Not Found [WARNING] [DXE] (ticks: 13874760) Attempted to boot from HDD with FilterOnlyMedia, SelectAndBootDevice returned Not Found [ERROR] [DXE] (ticks: 13874809) AziHsm: Unable to Boot event triggered - clearing sensitive data [ERROR] [DXE] (ticks: 14112965) OnVariablePolicyNotification: - Unable to locate variable policy protocol - Status=Not Found [WARNING] [DXE] (ticks: 14207143) WARN [FP]: Failed to find the on-screen keyboard protocol (Not Found). [ERROR] [DXE] (ticks: 14223643) RenderTitlebar Parameter = B - LoadOption=0 [WARNING] [DXE] (ticks: 14679545) MnpSyncSendPacket: No network cable detected. [WARNING] [DXE] (ticks: 21679726) MnpSyncSendPacket: No network cable detected. [WARNING] [DXE] (ticks: 113679353) MnpSyncSendPacket: No network cable detected.

(and if you pass info or full, you get more logs)

Any preference on what the output format should look like?

Maybe we go:

[14679545 ticks] [WARNING] [DXE] MnpSyncSendPacket: No network cable detected.

instead?

maheeraeron · 2026-02-19T22:21:25Z

openhcl/ohcldiag-dev/src/main.rs

                let value = client.update(path, value).await?;
-                println!("{value}");
+                match value.kind {
+                    inspect::ValueKind::String(s) => println!("{s}"),


similarly, needed to do this so that output renders newlines correctly

Allow inspect to reprocess UEFI logs with increased log level

71ac2a8

Copilot AI review requested due to automatic review settings February 11, 2026 23:08

maheeraeron requested a review from a team as a code owner February 11, 2026 23:08

Copilot started reviewing on behalf of maheeraeron February 11, 2026 23:08 View session

Copilot AI reviewed Feb 11, 2026

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Add capability in ohcldiag

42fd1c4

maheeraeron commented Feb 13, 2026

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Set it to default by default

470921b

maheeraeron commented Feb 13, 2026

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vm/devices/firmware/firmware_uefi/src/lib.rs Outdated Show resolved Hide resolved

maheeraeron commented Feb 13, 2026

View reviewed changes

maheeraeron added 3 commits February 13, 2026 19:43

Fix newlines in inspect output

89ae120

Merge branch 'main' into user/maheeraeron/efidiagnostics-trace-loglevel

5e0f7c6

Fold two inspect nodes to one

f606a8c

maheeraeron commented Feb 19, 2026

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maheeraeron changed the title ~~firmware_uefi: Allow inspect to reprocess UEFI logs with an increased log level~~ firmware_uefi: Allow inspect or ohcldiag to reprocess UEFI logs with an increased log level Feb 19, 2026

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firmware_uefi: Allow inspect or ohcldiag to reprocess UEFI logs with an increased log level#2802

firmware_uefi: Allow inspect or ohcldiag to reprocess UEFI logs with an increased log level#2802
maheeraeron wants to merge 6 commits intomicrosoft:mainfrom
maheeraeron:user/maheeraeron/efidiagnostics-trace-loglevel

maheeraeron commented Feb 11, 2026 •

edited

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Pull request overview

Reviewed changes

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maheeraeron commented Feb 11, 2026 •

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