On Wed, 20 May 2026, Arnd Bergmann wrote:
From: Arnd Bergmann <[email protected]>When the vmbus driver is not part of the kernel, the mvhv_root driver now fails to link: ERROR: modpost: "hv_vmbus_exists" [drivers/hv/mshv_root.ko] undefined! Avoid this by adding an explicit Kconfig dependency. Note that stubbing out the hv_vmbus_exists() based on configuration would also work for some cases, but not with MSHV_ROOT=y and HYPERV_VMBUS=m. Fixes: f1a9e67c1138 ("mshv: limit SynIC management to MSHV-owned resources") Signed-off-by: Arnd Bergmann <[email protected]> --- drivers/hv/Kconfig | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/hv/Kconfig b/drivers/hv/Kconfig index 52af086fdeb2..21193b571a80 100644 --- a/drivers/hv/Kconfig +++ b/drivers/hv/Kconfig @@ -75,6 +75,7 @@ config MSHV_ROOT # e.g. When withdrawing memory, the hypervisor gives back 4k pages in # no particular order, making it impossible to reassemble larger pages depends on PAGE_SIZE_4KB + depends on HYPERV_VMBUS select EVENTFD select VIRT_XFER_TO_GUEST_WORK select HMM_MIRROR -- 2.39.5
Yes, this is the right short-term fix. We will need to solve the root case (no VMBUS required) with a separate SYNIC driver abstraction.
Reviewed-by: Jork Loeser <[email protected]> Thank you! Jork
