Drivers: hv: Add CONFIG_HYPERV_VMBUS option

mrathor99 · liuw · commit 94b04355e639 · 2025-10-01T00:00:42.000Z
At present VMBus driver is hinged off of CONFIG_HYPERV which entails
lot of builtin code and encompasses too much. It's not always clear
what depends on builtin hv code and what depends on VMBus. Setting
CONFIG_HYPERV as a module and fudging the Makefile to switch to builtin
adds even more confusion. VMBus is an independent module and should have
its own config option. Also, there are scenarios like baremetal dom0/root
where support is built in with CONFIG_HYPERV but without VMBus. Lastly,
there are more features coming down that use CONFIG_HYPERV and add more
dependencies on it.

So, create a fine grained HYPERV_VMBUS option and update Kconfigs for
dependency on VMBus.

Signed-off-by: Mukesh Rathor &lt;mrathor@linux.microsoft.com&gt;
Acked-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;	# drivers/pci
Signed-off-by: Wei Liu &lt;wei.liu@kernel.org&gt;
diff --git 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
@@ -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
@@ -45,18 +45,25 @@ 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
+	default 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)
diff --git 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
@@ -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
@@ -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
@@ -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
@@ -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
@@ -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
@@ -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
@@ -163,6 +163,7 @@ static inline u64 hv_generate_guest_id(u64 kernel_version)
 	return guest_id;
 }
 
+#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)
 {
@@ -198,6 +199,10 @@ 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));
@@ -211,9 +216,6 @@ 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
@@ -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.
 
