Re: [PATCH] mshv: Make MSHV mutually exclusive with KEXEC

[Anirudh Rayabharam]

On Fri, Jan 23, 2026 at 10:20:53PM +0000, Stanislav Kinsburskii wrote:
> The MSHV driver deposits kernel-allocated pages to the hypervisor during
> runtime and never withdraws them. This creates a fundamental incompatibility
> with KEXEC, as these deposited pages remain unavailable to the new kernel
> loaded via KEXEC, leading to potential system crashes upon kernel accessing
> hypervisor deposited pages.
> 
> Make MSHV mutually exclusive with KEXEC until proper page lifecycle
> management is implemented.

Someone might want to stop all guest VMs and do a kexec. Which is valid
and would work without any issue for L1VH.

Also, I don't think it is reasonable at all that someone needs to
disable basic kernel functionality such as kexec in order to use our
driver.

Thanks,
Anirudh.

> 
> Signed-off-by: Stanislav Kinsburskii <skinsburskii@xxxxxxxxxxxxxxxxxxx>
> ---
>  drivers/hv/Kconfig |    1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/hv/Kconfig b/drivers/hv/Kconfig
> index 7937ac0cbd0f..cfd4501db0fa 100644
> --- a/drivers/hv/Kconfig
> +++ b/drivers/hv/Kconfig
> @@ -74,6 +74,7 @@ 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 !KEXEC
>  	select EVENTFD
>  	select VIRT_XFER_TO_GUEST_WORK
>  	select HMM_MIRROR
> 
>