linux-kernel - [PATCH] mshv: Make MSHV mutually exclusive with KEXEC

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Message-ID: 
 <176920684805.250171.6817228088359793537.stgit@skinsburskii-cloud-desktop.internal.cloudapp.net>
Date: Fri, 23 Jan 2026 22:20:53 +0000
From: Stanislav Kinsburskii <skinsburskii@...ux.microsoft.com>
To: kys@...rosoft.com, haiyangz@...rosoft.com, wei.liu@...nel.org,
 decui@...rosoft.com, longli@...rosoft.com
Cc: linux-hyperv@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH] mshv: Make MSHV mutually exclusive with KEXEC

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.

Signed-off-by: Stanislav Kinsburskii <skinsburskii@...ux.microsoft.com>
---
 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