kernel/linux.git/include/linux/hyperv.h, branch v7.3-rc1

Drivers: hv: Remove support for WS2012/2012R2 & Win8/8.1 version of Hyper-V

2026-08-24T00:35:41+00:00

Linux code for running as a Hyper-V guest includes special cases for running on Hyper-V in WS2012/2012R2 and Windows 8/8.1. These versions were initially released 14 years ago, and official support ended in 2023 (unless a customer has contracted for extended security updates). Given the release of subsequent versions with improved functionality, there's no need to continue to support the latest Linux kernels on these versions of Hyper-V. If someone is running Linux on one of these older Hyper-V versions and doesn't want to upgrade, they can continue to do so as presumably they don't want upgrade the Linux version either. Simplify Linux code by removing special cases for running on these old versions of Hyper-V. Remove the negotiation of the VMBus protocol versions for WS2012/Win8, and remove special case code based on those VMBus protocol versions. Also update the balloon and snapshot drivers to no longer negotiate driver-specific protocol versions for these older Hyper-V versions, and remove any related special cases. Signed-off-by: Michael Kelley Signed-off-by: Wei Liu

Drivers: hv: vmbus: Add vmbus_alloc_buffer()/vmbus_free_buffer() for CoCo VMs

2026-08-24T00:33:24+00:00

On CoCo VMs without confidential VMBus, the netvsc send and receive buffers must be made host-visible by decrypting them. These buffers are vmalloc'ed, but set_memory_decrypted()/encrypted() do not work on vmalloc'ed memory. This use case is (so far) unique to netvsc, so solve it locally rather than changing the set_memory() or allocation APIs. Add vmbus_alloc_buffer()/vmbus_free_buffer() to the VMBus core. When the guest's isolation model requires it, allocate the buffer as a list of physically-contiguous chunks via alloc_pages_node(), starting at MAX_PAGE_ORDER and falling back to smaller orders so the allocation still succeeds under memory fragmentation. Each chunk is decrypted in place via set_memory_decrypted() on its direct-map address, and the chunks are then stitched into a single virtually-contiguous range with vmap(). Buffers that do not need decryption keep using vzalloc(). To free the buffer, vmbus_free_buffer() calls vunmap() on the range then re-encrypts and frees each chunk individually; any chunk that fails re-encryption is leaked to prevent accidentally freeing decrypted memory. This approach minimizes scattering of decrypted 4 KiB pages through the kernel direct map and the resulting shattering of large page mappings. Signed-off-by: Kameron Carr Reviewed-by: Michael Kelley Signed-off-by: Wei Liu

Drivers: hv: vmbus: add vmbus_establish_gpadl_caller_decrypted()

2026-08-24T00:33:24+00:00

Add a new vmbus_establish_gpadl_caller_decrypted() for callers that want to decrypt their own buffers. Add a new hv_gpadl_type, HV_GPADL_BUFFER_DECRYPTED, to communicate the decryption status of the buffer. No functional change for existing callers. Signed-off-by: Kameron Carr Reviewed-by: Michael Kelley Signed-off-by: Wei Liu

Replace by more specific (headers)

2026-07-03T05:38:16+00:00

is included in a many files: $ git grep '' ef0c9f75a195 | wc -l 1598 ; some of them are widely used headers. To stop mixing up different and unrelated driver( type)s let the subsystem headers only use the subset of the recently split that are relevant for them. The fallout (I hope) is addressed in the previous commits that handle sources relying on e.g. pulling in the full legacy header and thus providing pci_device_id. Acked-by: Danilo Krummrich Acked-by: Takashi Sakamoto Link: https://patch.msgid.link/199fe46b624ba07fb9bd3e0cd6ff13757932cb5f.1782808461.git.u.kleine-koenig@baylibre.com Signed-off-by: Uwe Kleine-König (The Capable Hub)

Merge tag 'driver-core-7.2-rc1' of gitolite.kernel.org:pub/scm/linux/kernel/git/driver-core/driver-core

2026-06-15T07:11:17+00:00

Pull driver core updates from Danilo Krummrich: "Deferred probe: - Fix race where deferred probe timeout work could be permanently canceled by using mod_delayed_work() - Fix missing jiffies conversion in deferred_probe_extend_timeout() - Guard timeout extension with delayed_work_pending() to prevent premature firing - Use system_percpu_wq instead of the deprecated system_wq - Update deferred_probe_timeout documentation device: - Replace direct struct device bitfield access (can_match, dma_iommu, dma_skip_sync, dma_ops_bypass, state_synced, dma_coherent, of_node_reused, offline, offline_disabled) with flag-based accessors using bit operations - Reject devices with unregistered buses - Delete unused DEVICE_ATTR_PREALLOC() - Add low-level device attribute macros with const show/store callbacks, allowing device attributes to reside in read-only memory - Move core device attributes to read-only memory - Constify group array pointers in driver_add_groups() / driver_remove_groups(), struct bus_type, and struct device_driver device property: - Fix fwnode reference leak in fwnode_graph_get_endpoint_by_id() - Initialize all fields of fwnode_handle in fwnode_init() - Provide swnode_get()/swnode_put() wrappers around kobject_get/put() - Allow passing struct software_node_ref_args pointers directly to PROPERTY_ENTRY_REF() driver_override: - Migrate amba, cdx, vmbus, and rpmsg to the generic driver_override infrastructure, fixing a UAF from unsynchronized access to driver_override in bus match() callbacks - Remove the now-unused driver_set_override() firmware loader: - Fix recursive lock deadlock in device_cache_fw_images() when async work falls back to synchronous execution - Fix device reference leak in firmware_upload_register() platform: - Pass KBUILD_MODNAME through the platform driver registration macro to create module symlinks in sysfs for built-in drivers; move module_kset initialization to a pure_initcall and tegra cbb registration to core_initcall to ensure correct ordering - Pass THIS_MODULE implicitly through a coresight_init_driver() macro sysfs: - Upgrade OOB write detection in sysfs_kf_seq_show() from printk to WARN - Add return value clamping to sysfs_kf_read() Rust: - ACPI: Fix missing match data for PRP0001 by exporting acpi_of_match_device() - Auxiliary: Replace drvdata() with dedicated registration data on auxiliary_device. drvdata() exposed the driver's bus device private data beyond the driver's own scope, creating ordering constraints and forcing the data to outlive all registrations that access it. Registration data is instead scoped structurally to the Registration object, making lifecycle ordering enforced by construction rather than convention. - Rust-native device driver lifetimes (HRT): Allow Rust device drivers to carry a lifetime parameter on their bus device private data, tied to the device binding scope -- the interval during which a bus device is bound to a driver. Device resources like pci::Bar<'a> and IoMem<'a> can be stored directly in the driver's bus device private data with a lifetime bounded by the binding scope, so the compiler enforces at build time that they do not outlive the binding. This removes Devres indirection from every access site and eliminates try_access() failure paths in destructors. Bus driver traits use a Generic Associated Type (GAT) Data<'bound> to introduce the lifetime on the private data, rather than parameterizing the Driver trait itself. Auxiliary registration data, where the lifetime is not introduced by a trait callback but must be threaded through Registration, uses the ForLt trait (a type-level abstraction for types generic over a lifetime). Misc: - Fix DT overlayed devices not probing by reverting the broken treewide overlay fix and re-running fw_devlink consumer pickup when an overlay is applied to a bound device - Use root_device_register() for faux bus root device; add sanity check for failed bus init - Fix dev_has_sync_state() data race with READ_ONCE() and move it to base.h - Avoid spurious device_links warning when removing a device while its supplier is unbinding - Switch ISA bus to dynamic root device - Fix suspicious RCU usage in kernfs_put() - Remove devcoredump exit callback - Constify devfreq_event_class" * tag 'driver-core-7.2-rc1' of gitolite.kernel.org:pub/scm/linux/kernel/git/driver-core/driver-core: (81 commits) software node: allow passing reference args to PROPERTY_ENTRY_REF() driver core: platform: set mod_name in driver registration coresight: pass THIS_MODULE implicitly through a macro kernel: param: initialize module_kset in a pure_initcall soc/tegra: cbb: Move driver registration from pure_initcall to core_initcall firmware_loader: Fix recursive lock in device_cache_fw_images() driver core: Use system_percpu_wq instead of system_wq driver core: remove driver_set_override() rpmsg: use generic driver_override infrastructure Drivers: hv: vmbus: use generic driver_override infrastructure cdx: use generic driver_override infrastructure amba: use generic driver_override infrastructure rust: devres: add 'static bound to Devres samples: rust: rust_driver_auxiliary: showcase lifetime-bound registration data rust: auxiliary: generalize Registration over ForLt rust: types: add `ForLt` trait for higher-ranked lifetime support gpu: nova-core: separate driver type from driver data samples: rust: rust_driver_pci: use HRT lifetime for Bar rust: io: make IoMem and ExclusiveIoMem lifetime-parameterized rust: pci: make Bar lifetime-parameterized ...

Drivers: hv: vmbus: use generic driver_override infrastructure

2026-05-30T20:25:36+00:00

When a driver is probed through __driver_attach(), the bus' match() callback is called without the device lock held, thus accessing the driver_override field without a lock, which can cause a UAF. Fix this by using the driver-core driver_override infrastructure taking care of proper locking internally. Note that calling match() from __driver_attach() without the device lock held is intentional. [1] Tested-by: Michael Kelley Reviewed-by: Michael Kelley Link: https://lore.kernel.org/driver-core/DGRGTIRHA62X.3RY09D9SOK77P@kernel.org/ [1] Reported-by: Gui-Dong Han Closes: https://bugzilla.kernel.org/show_bug.cgi?id=220789 Fixes: d765edbb301c ("vmbus: add driver_override support") Reviewed-by: Greg Kroah-Hartman Link: https://patch.msgid.link/20260505133935.3772495-4-dakr@kernel.org Signed-off-by: Danilo Krummrich

mshv: Add conditional VMBus dependency

2026-05-27T22:11:05+00:00

When the VMBus driver is not part of the kernel (CONFIG_HYPERV_VMBUS=n), the MSHV root driver fails to link: ERROR: modpost: "hv_vmbus_exists" [drivers/hv/mshv_root.ko] undefined! Fix this while meeting these requirements: * It must be possible to include the MSHV root driver without the VMBus driver. In such case, the MSHV root driver can be built-in to the kernel image, or it can be built as a separate module. * If both the MSHV root driver and the VMBus driver are present, the MSHV root driver and VMBus driver can both be built-in, or they can both be separate modules. Or the MSHV root driver can be a module while the VMBus driver can be built-in, but the reverse is disallowed. Regardless of the build choices, the VMBus driver must be loaded before the MSHV driver in order for the SynIC to be managed properly (see comments in the MSHV SynIC code). The fix has two parts: * Add a Kconfig entry for MSHV_ROOT to depend on HYPERV_VMBUS if HYPERV_VMBUS is present. The entry disallows MSHV_ROOT being built-in when HYPERV_VMBUS is a module, but without requiring that HYPERV_VMBUS be built. * Add a stub implementation of hv_vmbus_exists() for when the VMBus driver is not present so that the MSHV root driver has no module dependency on VMBus. When the VMBus driver *is* present, the module dependency ensures that the VMBus driver loads first when both are built as modules. Existing code ensures that the VMBus driver loads first if it is built-in. The VMBus driver uses subsys_initcall(), which is initcall level 4. The MSHV root driver uses module_init(), which becomes device_init() when built-in, and device_init() is initcall level 6. Reported-by: Arnd Bergmann Closes: https://lore.kernel.org/all/20260520074044.923728-1-arnd@kernel.org/ Signed-off-by: Michael Kelley Acked-by: Arnd Bergmann Reviewed-by: Jork Loeser Reviewed-by: Hardik Garg Signed-off-by: Wei Liu

Drivers: hv: vmbus: Provide option to skip VMBus unload on panic

2026-05-13T22:29:32+00:00

Currently, VMBus code initiates a VMBus unload in the panic path so that if a kdump kernel is loaded, it can start fresh in setting up its own VMBus connection. However, a driver for the VMBus virtual frame buffer may need to flush dirty portions of the frame buffer back to the Hyper-V host so that panic information is visible in the graphics console. To support such flushing, provide exported functions for the frame buffer driver to specify that the VMBus unload should not be done by the VMBus driver, and to initiate the VMBus unload itself. Together these allow a frame buffer driver to delay the VMBus unload until after it has completed the flush. Ideally, the VMBus driver could use its own panic-path callback to do the unload after all frame buffer drivers have finished. But DRM frame buffer drivers use the kmsg dump callback, and there are no callbacks after that in the panic path. Hence this somewhat messy approach to properly sequencing the frame buffer flush and the VMBus unload. Fixes: 3671f3777758 ("drm/hyperv: Add support for drm_panic") Signed-off-by: Michael Kelley Reviewed-by: Long Li Signed-off-by: Wei Liu

Merge tag 'hyperv-next-signed-20260421' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux

2026-04-22T16:50:46+00:00

Pull Hyper-V updates from Wei Liu: - Fix cross-compilation for hv tools (Aditya Garg) - Fix vmemmap_shift exceeding MAX_FOLIO_ORDER in mshv_vtl (Naman Jain) - Limit channel interrupt scan to relid high water mark (Michael Kelley) - Export hv_vmbus_exists() and use it in pci-hyperv (Dexuan Cui) - Fix cleanup and shutdown issues for MSHV (Jork Loeser) - Introduce more tracing support for MSHV (Stanislav Kinsburskii) * tag 'hyperv-next-signed-20260421' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: x86/hyperv: Skip LP/VP creation on kexec x86/hyperv: move stimer cleanup to hv_machine_shutdown() Drivers: hv: vmbus: fix hyperv_cpuhp_online variable shadowing mshv: Add tracepoint for GPA intercept handling mshv_vtl: Fix vmemmap_shift exceeding MAX_FOLIO_ORDER tools: hv: Fix cross-compilation Drivers: hv: vmbus: Export hv_vmbus_exists() and use it in pci-hyperv mshv: Introduce tracing support Drivers: hv: vmbus: Limit channel interrupt scan to relid high water mark

Drivers: hv: vmbus: Export hv_vmbus_exists() and use it in pci-hyperv

2026-04-14T04:42:44+00:00

With commit f84b21da3624 ("PCI: hv: Don't load the driver for baremetal root partition"), the bare metal Linux root partition won't use the pci-hyperv driver, but when a Linux VM runs on the Linux root partition, pci-hyperv's module_init function init_hv_pci_drv() can still run, e.g. in the case of CONFIG_PCI_HYPERV=y, even if the VMBus driver is not used in such a VM (i.e. the hv_vmbus driver's init function returns -ENODEV due to vmbus_root_device being NULL). In such a Linux VM, init_hv_pci_drv() runs with a side effect: the 3 hvpci_block_ops callbacks are set to functions that depend on hv_vmbus. Later, when the MLX driver in such a VM invokes the callbacks, e.g. in drivers/net/ethernet/mellanox/mlx5/core/lib/hv.c: mlx5_hv_register_invalidate(), hvpci_block_ops.reg_blk_invalidate() is hv_register_block_invalidate() rather than a NULL function pointer, and hv_register_block_invalidate() assumes that it can find a struct hv_pcibus_device from pdev->bus->sysdata, which is false in such a VM. Consequently, hv_register_block_invalidate() -> get_pcichild_wslot() -> spin_lock_irqsave() may hang since it can be accessing an invalid spinlock pointer. Fix the issue by exporting hv_vmbus_exists() and using it in pci-hyperv: hv_root_partition() is true and hv_nested is false ==> hv_vmbus_exists() is false. hv_root_partition() is true and hv_nested is true ==> hv_vmbus_exists() is true. hv_root_partition() is false ==> hv_vmbus_exists() is true. While at it, rename vmbus_exists() to hv_vmbus_exists() to follow the convention that all public functions have the hv_ prefix; also change the return value's type from int to bool to make the code more readable; also move the two pr_info() calls. Reported-by: Mukesh Rathor Signed-off-by: Dexuan Cui Signed-off-by: Wei Liu