linux.git/include/linux/hyperv.h, branch v7.2-rc1 Linux kernel source tree 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 Linus Torvalds torvalds@linux-foundation.org 2026-06-15T07:11:17+00:00 36808d5e983985bbda87e01059cccc071fe3ec8d 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<T> 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 ... 
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<T>
  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 Danilo Krummrich dakr@kernel.org 2026-05-05T13:37:23+00:00 331d8900121a1d74ecd45cd2db742ddcb5a0a565 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 <mhklinux@outlook.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Link: https://lore.kernel.org/driver-core/DGRGTIRHA62X.3RY09D9SOK77P@kernel.org/ [1] Reported-by: Gui-Dong Han <hanguidong02@gmail.com> Closes: https://bugzilla.kernel.org/show_bug.cgi?id=220789 Fixes: d765edbb301c ("vmbus: add driver_override support") Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://patch.msgid.link/20260505133935.3772495-4-dakr@kernel.org Signed-off-by: Danilo Krummrich <dakr@kernel.org> 
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 <mhklinux@outlook.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Link: https://lore.kernel.org/driver-core/DGRGTIRHA62X.3RY09D9SOK77P@kernel.org/ [1]
Reported-by: Gui-Dong Han <hanguidong02@gmail.com>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=220789
Fixes: d765edbb301c ("vmbus: add driver_override support")
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://patch.msgid.link/20260505133935.3772495-4-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
mshv: Add conditional VMBus dependency 2026-05-27T22:11:05+00:00 Michael Kelley mhklinux@outlook.com 2026-05-26T14:13:04+00:00 840b740a35bf969734e0f2e44c21289fdd03079e 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 <arnd@arndb.de> Closes: https://lore.kernel.org/all/20260520074044.923728-1-arnd@kernel.org/ Signed-off-by: Michael Kelley <mhklinux@outlook.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Jork Loeser <jloeser@linux.microsoft.com> Reviewed-by: Hardik Garg <hargar@linux.microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org> 
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 <arnd@arndb.de>
Closes: https://lore.kernel.org/all/20260520074044.923728-1-arnd@kernel.org/
Signed-off-by: Michael Kelley <mhklinux@outlook.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Jork Loeser <jloeser@linux.microsoft.com>
Reviewed-by: Hardik Garg <hargar@linux.microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Drivers: hv: vmbus: Provide option to skip VMBus unload on panic 2026-05-13T22:29:32+00:00 Michael Kelley mhklinux@outlook.com 2026-02-17T18:23:34+00:00 c5c3ef8d49e15d2fc1cec4ad7c91d81b99977440 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 <mhklinux@outlook.com> Reviewed-by: Long Li <longli@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org> 
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 <mhklinux@outlook.com>
Reviewed-by: Long Li <longli@microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
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 Linus Torvalds torvalds@linux-foundation.org 2026-04-22T16:50:46+00:00 8fd12b03c7c888303c3c45559d8c3e270a916f9f 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 
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 Dexuan Cui decui@microsoft.com 2026-04-09T21:52:32+00:00 0d5acba6331c326f394a677daf49a67f44a0416a 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 <mrathor@linux.microsoft.com> Signed-off-by: Dexuan Cui <decui@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org> 
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 <mrathor@linux.microsoft.com>
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
drivers: hv: vmbus: replace deprecated mmap hook with mmap_prepare 2026-04-05T20:53:44+00:00 Lorenzo Stoakes (Oracle) ljs@kernel.org 2026-03-20T22:39:44+00:00 f98cb7ca4aa44645347771c2c2a9724bc210c49e The f_op->mmap interface is deprecated, so update the vmbus driver to use its successor, mmap_prepare. This updates all callbacks which referenced the function pointer hv_mmap_ring_buffer to instead reference hv_mmap_prepare_ring_buffer, utilising the newly introduced compat_set_desc_from_vma() and __compat_vma_mmap() to be able to implement this change. The UIO HV generic driver is the only user of hv_create_ring_sysfs(), which is the only function which references vmbus_channel->mmap_prepare_ring_buffer which, in turn, is the only external interface to hv_mmap_prepare_ring_buffer. This patch therefore updates this caller to use mmap_prepare instead, which also previously used vm_iomap_memory(), so this change replaces it with its mmap_prepare equivalent, mmap_action_simple_ioremap(). [akpm@linux-foundation.org: restore struct vmbus_channel comment, per Michael Kelley] Link: https://lkml.kernel.org/r/05467cb62267d750e5c770147517d4df0246cda6.1774045440.git.ljs@kernel.org Signed-off-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Tested-by: Michael Kelley <mhklinux@outlook.com> Acked-by: Vlastimil Babka (SUSE) <vbabka@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alexandre Torgue <alexandre.torgue@foss.st.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Bodo Stroesser <bostroesser@gmail.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Clemens Ladisch <clemens@ladisch.de> Cc: David Hildenbrand <david@kernel.org> Cc: David Howells <dhowells@redhat.com> Cc: Dexuan Cui <decui@microsoft.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: K. Y. Srinivasan <kys@microsoft.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Long Li <longli@microsoft.com> Cc: Marc Dionne <marc.dionne@auristor.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Miquel Raynal <miquel.raynal@bootlin.com> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Richard Weinberger <richard@nod.at> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vignesh Raghavendra <vigneshr@ti.com> Cc: Wei Liu <wei.liu@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> 
The f_op->mmap interface is deprecated, so update the vmbus driver to use
its successor, mmap_prepare.

This updates all callbacks which referenced the function pointer
hv_mmap_ring_buffer to instead reference hv_mmap_prepare_ring_buffer,
utilising the newly introduced compat_set_desc_from_vma() and
__compat_vma_mmap() to be able to implement this change.

The UIO HV generic driver is the only user of hv_create_ring_sysfs(),
which is the only function which references
vmbus_channel->mmap_prepare_ring_buffer which, in turn, is the only
external interface to hv_mmap_prepare_ring_buffer.

This patch therefore updates this caller to use mmap_prepare instead,
which also previously used vm_iomap_memory(), so this change replaces it
with its mmap_prepare equivalent, mmap_action_simple_ioremap().

[akpm@linux-foundation.org: restore struct vmbus_channel comment, per Michael Kelley]
Link: https://lkml.kernel.org/r/05467cb62267d750e5c770147517d4df0246cda6.1774045440.git.ljs@kernel.org
Signed-off-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Acked-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexandre Torgue <alexandre.torgue@foss.st.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Bodo Stroesser <bostroesser@gmail.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Clemens Ladisch <clemens@ladisch.de>
Cc: David Hildenbrand <david@kernel.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Dexuan Cui <decui@microsoft.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Long Li <longli@microsoft.com>
Cc: Marc Dionne <marc.dionne@auristor.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Miquel Raynal <miquel.raynal@bootlin.com>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Richard Weinberger <richard@nod.at>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vignesh Raghavendra <vigneshr@ti.com>
Cc: Wei Liu <wei.liu@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Drivers: hv: VMBus protocol version 6.0 2025-11-15T06:18:14+00:00 Roman Kisel romank@linux.microsoft.com 2025-10-08T23:34:04+00:00 6802d8af47d1dccd9a74a1f708fb9129244ef843 The confidential VMBus is supported starting from the protocol version 6.0 onwards. Provide the required definitions. No functional changes. Signed-off-by: Roman Kisel <romank@linux.microsoft.com> Reviewed-by: Alok Tiwari <alok.a.tiwari@oracle.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Wei Liu <wei.liu@kernel.org> 
The confidential VMBus is supported starting from the protocol
version 6.0 onwards.

Provide the required definitions. No functional changes.

Signed-off-by: Roman Kisel <romank@linux.microsoft.com>
Reviewed-by: Alok Tiwari <alok.a.tiwari@oracle.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Drivers: hv: Simplify data structures for VMBus channel close message 2025-09-08T22:11:03+00:00 Michael Kelley mhklinux@outlook.com 2025-08-31T16:04:06+00:00 2d0ddbb65cef99aab241378b0f4ff2d6ea8c3a5a struct vmbus_close_msg is used for sending the VMBus channel close message. It contains a struct vmbus_channel_msginfo, which has a flex array member at the end. The latter's presence in the middle of struct vmbus_close_msg causes warnings when built with -Wflex-array-member-not-at-end. But the struct vmbus_channel_msginfo is unused because the Hyper-V host does not send a response to the channel close message. So remove the struct vmbus_channel_msginfo. Then, since the only remaining field is struct vmbus_channel_close_channel, also remove the containing struct vmbus_close_msg and directly use struct vmbus_channel_close_channel. Besides eliminating unnecessary complexity, these changes resolve the -Wflex-array-member-not-at-end warnings. Signed-off-by: Michael Kelley <mhklinux@outlook.com> Reviewed-by: Tianyu Lan <tiala@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org> 
struct vmbus_close_msg is used for sending the VMBus channel close
message. It contains a struct vmbus_channel_msginfo, which has a
flex array member at the end. The latter's presence in the middle
of struct vmbus_close_msg causes warnings when built with
-Wflex-array-member-not-at-end.

But the struct vmbus_channel_msginfo is unused because the Hyper-V host
does not send a response to the channel close message. So remove the
struct vmbus_channel_msginfo. Then, since the only remaining field is
struct vmbus_channel_close_channel, also remove the containing struct
vmbus_close_msg and directly use struct vmbus_channel_close_channel.
Besides eliminating unnecessary complexity, these changes resolve the
-Wflex-array-member-not-at-end warnings.

Signed-off-by: Michael Kelley <mhklinux@outlook.com>
Reviewed-by: Tianyu Lan <tiala@microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Merge tag 'hyperv-next-signed-20250602' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux 2025-06-03T15:39:20+00:00 Linus Torvalds torvalds@linux-foundation.org 2025-06-03T15:39:20+00:00 c00b28502470b7677c2f4ee2e9c899205fa78e27 Pull hyperv updates from Wei Liu: - Support for Virtual Trust Level (VTL) on arm64 (Roman Kisel) - Fixes for Hyper-V UIO driver (Long Li) - Fixes for Hyper-V PCI driver (Michael Kelley) - Select CONFIG_SYSFB for Hyper-V guests (Michael Kelley) - Documentation updates for Hyper-V VMBus (Michael Kelley) - Enhance logging for hv_kvp_daemon (Shradha Gupta) * tag 'hyperv-next-signed-20250602' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: (23 commits) Drivers: hv: Always select CONFIG_SYSFB for Hyper-V guests Drivers: hv: vmbus: Add comments about races with "channels" sysfs dir Documentation: hyperv: Update VMBus doc with new features and info PCI: hv: Remove unnecessary flex array in struct pci_packet Drivers: hv: Remove hv_alloc/free_* helpers Drivers: hv: Use kzalloc for panic page allocation uio_hv_generic: Align ring size to system page uio_hv_generic: Use correct size for interrupt and monitor pages Drivers: hv: Allocate interrupt and monitor pages aligned to system page boundary arch/x86: Provide the CPU number in the wakeup AP callback x86/hyperv: Fix APIC ID and VP index confusion in hv_snp_boot_ap() PCI: hv: Get vPCI MSI IRQ domain from DeviceTree ACPI: irq: Introduce acpi_get_gsi_dispatcher() Drivers: hv: vmbus: Introduce hv_get_vmbus_root_device() Drivers: hv: vmbus: Get the IRQ number from DeviceTree dt-bindings: microsoft,vmbus: Add interrupt and DMA coherence properties arm64, x86: hyperv: Report the VTL the system boots in arm64: hyperv: Initialize the Virtual Trust Level field Drivers: hv: Provide arch-neutral implementation of get_vtl() Drivers: hv: Enable VTL mode for arm64 ... 
Pull hyperv updates from Wei Liu:

 - Support for Virtual Trust Level (VTL) on arm64 (Roman Kisel)

 - Fixes for Hyper-V UIO driver (Long Li)

 - Fixes for Hyper-V PCI driver (Michael Kelley)

 - Select CONFIG_SYSFB for Hyper-V guests (Michael Kelley)

 - Documentation updates for Hyper-V VMBus (Michael Kelley)

 - Enhance logging for hv_kvp_daemon (Shradha Gupta)

* tag 'hyperv-next-signed-20250602' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: (23 commits)
  Drivers: hv: Always select CONFIG_SYSFB for Hyper-V guests
  Drivers: hv: vmbus: Add comments about races with "channels" sysfs dir
  Documentation: hyperv: Update VMBus doc with new features and info
  PCI: hv: Remove unnecessary flex array in struct pci_packet
  Drivers: hv: Remove hv_alloc/free_* helpers
  Drivers: hv: Use kzalloc for panic page allocation
  uio_hv_generic: Align ring size to system page
  uio_hv_generic: Use correct size for interrupt and monitor pages
  Drivers: hv: Allocate interrupt and monitor pages aligned to system page boundary
  arch/x86: Provide the CPU number in the wakeup AP callback
  x86/hyperv: Fix APIC ID and VP index confusion in hv_snp_boot_ap()
  PCI: hv: Get vPCI MSI IRQ domain from DeviceTree
  ACPI: irq: Introduce acpi_get_gsi_dispatcher()
  Drivers: hv: vmbus: Introduce hv_get_vmbus_root_device()
  Drivers: hv: vmbus: Get the IRQ number from DeviceTree
  dt-bindings: microsoft,vmbus: Add interrupt and DMA coherence properties
  arm64, x86: hyperv: Report the VTL the system boots in
  arm64: hyperv: Initialize the Virtual Trust Level field
  Drivers: hv: Provide arch-neutral implementation of get_vtl()
  Drivers: hv: Enable VTL mode for arm64
  ...