From bbac5374b537ad81ce70d8434e1364b549e3d4a1 Mon Sep 17 00:00:00 2001 From: Nadav Amit Date: Tue, 19 Jun 2018 16:00:27 -0700 Subject: [PATCH] vmw_balloon: fix VMCI use when balloon built into kernel commit c3cc1b0fc27508da53fe955a3b23d03964410682 upstream. Currently, when all modules, including VMCI and VMware balloon are built into the kernel, the initialization of the balloon happens before the VMCI is probed. As a result, the balloon fails to initialize the VMCI doorbell, which it uses to get asynchronous requests for balloon size changes. The problem can be seen in the logs, in the form of the following message: "vmw_balloon: failed to initialize vmci doorbell" The driver would work correctly but slightly less efficiently, probing for requests periodically. This patch changes the balloon to be initialized using late_initcall() instead of module_init() to address this issue. It does not address a situation in which VMCI is built as a module and the balloon is built into the kernel. Fixes: 48e3d668b790 ("VMware balloon: Enable notification via VMCI") Cc: stable@vger.kernel.org Reviewed-by: Xavier Deguillard Signed-off-by: Nadav Amit Signed-off-by: Greg Kroah-Hartman --- drivers/misc/vmw_balloon.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/misc/vmw_balloon.c b/drivers/misc/vmw_balloon.c index fe56e72f9463..5f8b583c6e41 100644 --- a/drivers/misc/vmw_balloon.c +++ b/drivers/misc/vmw_balloon.c @@ -1297,7 +1297,14 @@ static int __init vmballoon_init(void) return 0; } -module_init(vmballoon_init); + +/* + * Using late_initcall() instead of module_init() allows the balloon to use the + * VMCI doorbell even when the balloon is built into the kernel. Otherwise the + * VMCI is probed only after the balloon is initialized. If the balloon is used + * as a module, late_initcall() is equivalent to module_init(). + */ +late_initcall(vmballoon_init); static void __exit vmballoon_exit(void) { -- 2.20.1