linux-drivers/
drivers/hv

Microsoft Hyper-V guest integration (VMBus and friends)

The guest-side plumbing that lets Linux run efficiently as a virtual machine on Microsoft's Hyper-V hypervisor, which powers Windows Server, Windows 11 VMs, and Azure. It includes VMBus, the channel carrying paravirtualized network, storage, and input traffic between the Linux guest and Windows host, plus memory ballooning and the newer MSHV/VTL interfaces.

keep conf=0.95 deploy=high replacement=none subsystem=hv category=virtualization
95%

recommendation

It should stay because Hyper-V is a current, heavily deployed Microsoft product and Linux guests on Windows Server 2025, Windows 11, and Azure rely on this code for usable network and storage performance. Upstream activity is healthy, with Microsoft engineers still landing new feature work in 2026, including additions for the MSHV/VTL stack. There is no in-kernel replacement and no sign of any retirement effort.

repository signals

36 files
24,013 source lines
303 commits, 5y
+14,706 / −3,586 lines added / removed, 5y
100 authors, 5y
monthly commits · 2021-04-21 → 2026-04-21 · 303 total · active in 56/61 months
2021 2022 2023 2024 2025 2026 2021-04: 2 commits · +80 −16 2021-05: 3 commits · +19 −16 2021-06: 1 commit · +69 −0 2021-07: 7 commits · +285 −41 2021-08: 3 commits · +6 −3 2021-09: 0 commits · +0 −0 2021-10: 8 commits · +267 −95 2021-11: 2 commits · +2 −1 2021-12: 4 commits · +18 −3 2022-01: 5 commits · +27 −21 2022-02: 6 commits · +16 −8 2022-03: 8 commits · +122 −20 2022-04: 8 commits · +120 −85 2022-05: 4 commits · +59 −80 2022-06: 2 commits · +2 −1 2022-07: 3 commits · +180 −33 2022-08: 5 commits · +120 −57 2022-09: 6 commits · +82 −34 2022-10: 2 commits · +3 −3 2022-11: 4 commits · +8 −4 2022-12: 0 commits · +0 −0 2023-01: 5 commits · +22 −19 2023-02: 2 commits · +5 −1 2023-03: 11 commits · +165 −194 2023-04: 3 commits · +260 −254 2023-05: 3 commits · +42 −29 2023-06: 2 commits · +12 −13 2023-07: 0 commits · +0 −0 2023-08: 12 commits · +243 −84 2023-09: 0 commits · +0 −0 2023-10: 2 commits · +4 −3 2023-11: 1 commit · +30 −1 2023-12: 1 commit · +1 −1 2024-01: 2 commits · +80 −116 2024-02: 2 commits · +28 −32 2024-03: 10 commits · +186 −510 2024-04: 1 commit · +1 −5 2024-05: 3 commits · +104 −135 2024-06: 2 commits · +2 −9 2024-07: 2 commits · +6 −6 2024-08: 3 commits · +35 −6 2024-09: 1 commit · +2 −2 2024-10: 2 commits · +12 −10 2024-11: 3 commits · +30 −9 2024-12: 1 commit · +1 −1 2025-01: 7 commits · +169 −98 2025-02: 5 commits · +310 −20 2025-03: 8 commits · +5,599 −56 2025-04: 6 commits · +85 −15 2025-05: 11 commits · +188 −115 2025-06: 2 commits · +7 −1 2025-07: 4 commits · +17 −18 2025-08: 3 commits · +11 −53 2025-09: 8 commits · +55 −37 2025-10: 26 commits · +884 −371 2025-11: 12 commits · +1,632 −89 2025-12: 15 commits · +972 −336 2026-01: 15 commits · +1,497 −126 2026-02: 19 commits · +494 −270 2026-03: 5 commits · +30 −20 2026-04: 0 commits · +0 −0

sources

  1. lore.kernel.org

    Upstream Linux Hyper-V/VMBus code is still receiving active feature work in 2026; this patch exports `vmbus_interrupt` for the `mshv_vtl` module and touches `drivers/hv/vmbus_drv.c`.

  2. lore.kernel.org

    A 2026 v2 patch series is still restructuring shared Hyper-V/VMBus code, indicating active maintenance rather than retirement.

  3. learn.microsoft.com

    Microsoft documents Hyper-V as a current virtualization platform for Windows Server 2025, Windows 11, and Azure Local, showing it remains a current product in new deployments.

  4. learn.microsoft.com

    Microsoft's current guest-support documentation says Hyper-V supports Linux and FreeBSD VMs on Windows Server 2025/2022/2019/2016, Windows 11/10, and Azure Local, and recommends Hyper-V-specific devices for Linux guests.

codex reasoning notes (technical)

`drivers/hv` is the Microsoft Hyper-V guest driver stack (Kconfig says 'Microsoft Hyper-V guest support', including VMBus, utils, balloon, and newer MSHV/VTL pieces). I identified the family by local shell inspection of `drivers/hv/Kconfig` and module descriptions. Lore grounding: `lore_file_timeline` on `drivers/hv/vmbus_drv.c` showed heavy activity from 2021-2026 with newest touches on 2026-04-23; the cited lore URLs came directly from that MCP result. I attempted targeted removal/deprecation searches in lore (`lore_regex`, `lore_substr_subject`) plus `lei`, but regex/substring queries timed out and `lei` could not start in this sandbox, so I found no positive evidence of an upstream removal effort. Deployment evidence came from web search on Microsoft Learn pages showing Hyper-V is current in Windows Server 2025/Azure Local and that Linux guests are expected to use Hyper-V-specific devices. Because this is an actively maintained, currently deployed VM-guest interface with no natural in-kernel replacement, the correct hint is `keep`.