On 8/28/25 17:29, Nuno Das Neves wrote:
> On 8/27/2025 5:59 PM, Mukesh Rathor wrote:
>> Somehow vmbus driver is hinged on CONFIG_HYPERV. It appears this is initial
>> code that did not get addressed when the scope of CONFIG_HYPERV went beyond
>> vmbus. This commit creates a fine grained HYPERV_VMBUS option and updates
>> drivers that depend on VMBUS.
>>
>
> The commit message can be improved. The docs are helpful here:
> https://docs.kernel.org/process/submitting-patches.html#describe-your-changes
>
> In particular, some clearer reasons for the change.
> e.g.
> - CONFIG_HYPERV encompasses too much right now. It's not always clear what
> depends on builtin hyperv code and what depends on vmbus.
>
> - Since there is so much builtin hyperv code, building CONFIG_HYPERV as a
> module doesn't make intuitive sense. Building vmbus support as a module
> does.
>
> - There are actually some real scenarios someone may want to compile with
> CONFIG_HYPERV but without vmbus, like baremetal root partition.
>
> FWIW I think it's a good idea, interested to hear what others think.
Sorry, you had mentioned it and I expanded the cover letter and forgot the
commit message here. You said it better than I could above, so I can just use
that in V1 next week if no other comments.
Thanks,
-Mukesh
> Nuno
>
>> Signed-off-by: Mukesh Rathor <mrat...@linux.microsoft.com>
>> ---
>> drivers/gpu/drm/Kconfig | 2 +-
>> drivers/hid/Kconfig | 2 +-
>> drivers/hv/Kconfig | 12 +++++++++---
>> drivers/hv/Makefile | 2 +-
>> drivers/input/serio/Kconfig | 4 ++--
>> drivers/net/hyperv/Kconfig | 2 +-
>> drivers/pci/Kconfig | 2 +-
>> drivers/scsi/Kconfig | 2 +-
>> drivers/uio/Kconfig | 2 +-
>> drivers/video/fbdev/Kconfig | 2 +-
>> include/asm-generic/mshyperv.h | 8 +++++---
>> net/vmw_vsock/Kconfig | 2 +-
>> 12 files changed, 25 insertions(+), 17 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
>> index f7ea8e895c0c..58f34da061c6 100644
>> --- a/drivers/gpu/drm/Kconfig
>> +++ b/drivers/gpu/drm/Kconfig
>> @@ -398,7 +398,7 @@ source "drivers/gpu/drm/imagination/Kconfig"
>>
>> config DRM_HYPERV
>> tristate "DRM Support for Hyper-V synthetic video device"
>> - depends on DRM && PCI && HYPERV
>> + depends on DRM && PCI && HYPERV_VMBUS
>> select DRM_CLIENT_SELECTION
>> select DRM_KMS_HELPER
>> select DRM_GEM_SHMEM_HELPER
>> diff --git a/drivers/hid/Kconfig b/drivers/hid/Kconfig
>> index a57901203aeb..fe3dc8c0db99 100644
>> --- a/drivers/hid/Kconfig
>> +++ b/drivers/hid/Kconfig
>> @@ -1162,7 +1162,7 @@ config GREENASIA_FF
>>
>> config HID_HYPERV_MOUSE
>> tristate "Microsoft Hyper-V mouse driver"
>> - depends on HYPERV
>> + depends on HYPERV_VMBUS
>> help
>> Select this option to enable the Hyper-V mouse driver.
>>
>> diff --git a/drivers/hv/Kconfig b/drivers/hv/Kconfig
>> index 2e8df09db599..08c4ed005137 100644
>> --- a/drivers/hv/Kconfig
>> +++ b/drivers/hv/Kconfig
>> @@ -44,18 +44,24 @@ config HYPERV_TIMER
>>
>> config HYPERV_UTILS
>> tristate "Microsoft Hyper-V Utilities driver"
>> - depends on HYPERV && CONNECTOR && NLS
>> + depends on HYPERV_VMBUS && CONNECTOR && NLS
>> depends on PTP_1588_CLOCK_OPTIONAL
>> help
>> Select this option to enable the Hyper-V Utilities.
>>
>> config HYPERV_BALLOON
>> tristate "Microsoft Hyper-V Balloon driver"
>> - depends on HYPERV
>> + depends on HYPERV_VMBUS
>> select PAGE_REPORTING
>> help
>> Select this option to enable Hyper-V Balloon driver.
>>
>> +config HYPERV_VMBUS
>> + tristate "Microsoft Hyper-V Vmbus driver"
>> + depends on HYPERV
>> + help
>> + Select this option to enable Hyper-V Vmbus driver.
>> +
>> config MSHV_ROOT
>> tristate "Microsoft Hyper-V root partition support"
>> depends on HYPERV && (X86_64 || ARM64)
>> @@ -75,7 +81,7 @@ config MSHV_ROOT
>>
>> config MSHV_VTL
>> tristate "Microsoft Hyper-V VTL driver"
>> - depends on X86_64 && HYPERV_VTL_MODE
>> + depends on X86_64 && HYPERV_VTL_MODE && HYPERV_VMBUS
>> # Mapping VTL0 memory to a userspace process in VTL2 is supported in
>> OpenHCL.
>> # VTL2 for OpenHCL makes use of Huge Pages to improve performance on
>> VMs,
>> # specially with large memory requirements.
>> diff --git a/drivers/hv/Makefile b/drivers/hv/Makefile
>> index c53a0df746b7..050517756a82 100644
>> --- a/drivers/hv/Makefile
>> +++ b/drivers/hv/Makefile
>> @@ -1,5 +1,5 @@
>> # SPDX-License-Identifier: GPL-2.0
>> -obj-$(CONFIG_HYPERV) += hv_vmbus.o
>> +obj-$(CONFIG_HYPERV_VMBUS) += hv_vmbus.o
>> obj-$(CONFIG_HYPERV_UTILS) += hv_utils.o
>> obj-$(CONFIG_HYPERV_BALLOON) += hv_balloon.o
>> obj-$(CONFIG_MSHV_ROOT) += mshv_root.o
>> diff --git a/drivers/input/serio/Kconfig b/drivers/input/serio/Kconfig
>> index 17edc1597446..c7ef347a4dff 100644
>> --- a/drivers/input/serio/Kconfig
>> +++ b/drivers/input/serio/Kconfig
>> @@ -276,8 +276,8 @@ config SERIO_OLPC_APSP
>>
>> config HYPERV_KEYBOARD
>> tristate "Microsoft Synthetic Keyboard driver"
>> - depends on HYPERV
>> - default HYPERV
>> + depends on HYPERV_VMBUS
>> + default HYPERV_VMBUS
>> help
>> Select this option to enable the Hyper-V Keyboard driver.
>>
>> diff --git a/drivers/net/hyperv/Kconfig b/drivers/net/hyperv/Kconfig
>> index c8cbd85adcf9..982964c1a9fb 100644
>> --- a/drivers/net/hyperv/Kconfig
>> +++ b/drivers/net/hyperv/Kconfig
>> @@ -1,7 +1,7 @@
>> # SPDX-License-Identifier: GPL-2.0-only
>> config HYPERV_NET
>> tristate "Microsoft Hyper-V virtual network driver"
>> - depends on HYPERV
>> + depends on HYPERV_VMBUS
>> select UCS2_STRING
>> select NLS
>> help
>> diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig
>> index 9a249c65aedc..7065a8e5f9b1 100644
>> --- a/drivers/pci/Kconfig
>> +++ b/drivers/pci/Kconfig
>> @@ -221,7 +221,7 @@ config PCI_LABEL
>>
>> config PCI_HYPERV
>> tristate "Hyper-V PCI Frontend"
>> - depends on ((X86 && X86_64) || ARM64) && HYPERV && PCI_MSI && SYSFS
>> + depends on ((X86 && X86_64) || ARM64) && HYPERV_VMBUS && PCI_MSI &&
>> SYSFS
>> select PCI_HYPERV_INTERFACE
>> select IRQ_MSI_LIB
>> help
>> diff --git a/drivers/scsi/Kconfig b/drivers/scsi/Kconfig
>> index 5522310bab8d..19d0884479a2 100644
>> --- a/drivers/scsi/Kconfig
>> +++ b/drivers/scsi/Kconfig
>> @@ -589,7 +589,7 @@ config XEN_SCSI_FRONTEND
>>
>> config HYPERV_STORAGE
>> tristate "Microsoft Hyper-V virtual storage driver"
>> - depends on SCSI && HYPERV
>> + depends on SCSI && HYPERV_VMBUS
>> depends on m || SCSI_FC_ATTRS != m
>> default HYPERV
>> help
>> diff --git a/drivers/uio/Kconfig b/drivers/uio/Kconfig
>> index b060dcd7c635..6f86a61231e6 100644
>> --- a/drivers/uio/Kconfig
>> +++ b/drivers/uio/Kconfig
>> @@ -140,7 +140,7 @@ config UIO_MF624
>>
>> config UIO_HV_GENERIC
>> tristate "Generic driver for Hyper-V VMBus"
>> - depends on HYPERV
>> + depends on HYPERV_VMBUS
>> help
>> Generic driver that you can bind, dynamically, to any
>> Hyper-V VMBus device. It is useful to provide direct access
>> diff --git a/drivers/video/fbdev/Kconfig b/drivers/video/fbdev/Kconfig
>> index c21484d15f0c..72c63eaeb983 100644
>> --- a/drivers/video/fbdev/Kconfig
>> +++ b/drivers/video/fbdev/Kconfig
>> @@ -1774,7 +1774,7 @@ config FB_BROADSHEET
>>
>> config FB_HYPERV
>> tristate "Microsoft Hyper-V Synthetic Video support"
>> - depends on FB && HYPERV
>> + depends on FB && HYPERV_VMBUS
>> select DMA_CMA if HAVE_DMA_CONTIGUOUS && CMA
>> select FB_IOMEM_HELPERS_DEFERRED
>> help
>> diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
>> index 1d2ad1304ad4..66c58c91b530 100644
>> --- a/include/asm-generic/mshyperv.h
>> +++ b/include/asm-generic/mshyperv.h
>> @@ -165,6 +165,7 @@ static inline u64 hv_generate_guest_id(u64
>> kernel_version)
>>
>> void __init hv_mark_resources(void);
>>
>> +#if IS_ENABLED(CONFIG_HYPERV_VMBUS)
>> /* Free the message slot and signal end-of-message if required */
>> static inline void vmbus_signal_eom(struct hv_message *msg, u32
>> old_msg_type)
>> {
>> @@ -200,6 +201,10 @@ static inline void vmbus_signal_eom(struct hv_message
>> *msg, u32 old_msg_type)
>> }
>> }
>>
>> +extern int vmbus_interrupt;
>> +extern int vmbus_irq;
>> +#endif /* CONFIG_HYPERV_VMBUS */
>> +
>> int hv_get_hypervisor_version(union hv_hypervisor_version_info *info);
>>
>> void hv_setup_vmbus_handler(void (*handler)(void));
>> @@ -213,9 +218,6 @@ void hv_setup_crash_handler(void (*handler)(struct
>> pt_regs *regs));
>> void hv_remove_crash_handler(void);
>> void hv_setup_mshv_handler(void (*handler)(void));
>>
>> -extern int vmbus_interrupt;
>> -extern int vmbus_irq;
>> -
>> #if IS_ENABLED(CONFIG_HYPERV)
>> /*
>> * Hypervisor's notion of virtual processor ID is different from
>> diff --git a/net/vmw_vsock/Kconfig b/net/vmw_vsock/Kconfig
>> index 56356d2980c8..8e803c4828c4 100644
>> --- a/net/vmw_vsock/Kconfig
>> +++ b/net/vmw_vsock/Kconfig
>> @@ -72,7 +72,7 @@ config VIRTIO_VSOCKETS_COMMON
>>
>> config HYPERV_VSOCKETS
>> tristate "Hyper-V transport for Virtual Sockets"
>> - depends on VSOCKETS && HYPERV
>> + depends on VSOCKETS && HYPERV_VMBUS
>> help
>> This module implements a Hyper-V transport for Virtual Sockets.
>>
