[PATCH v10 07/19] KVM: s390: pv: module parameter to fence lazy destroy

From: Claudio Imbrenda
Date: Thu Apr 14 2022 - 04:04:31 EST


Add the module parameter "lazy_destroy", to allow the asynchronous destroy
mechanism to be switched off. This might be useful for debugging purposes.

The parameter is enabled by default.

Signed-off-by: Claudio Imbrenda <imbrenda@xxxxxxxxxxxxx>
Reviewed-by: Janosch Frank <frankja@xxxxxxxxxxxxx>
---
arch/s390/kvm/kvm-s390.c | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 156d1c25a3c1..c7a8829e852c 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -206,6 +206,11 @@ unsigned int diag9c_forwarding_hz;
module_param(diag9c_forwarding_hz, uint, 0644);
MODULE_PARM_DESC(diag9c_forwarding_hz, "Maximum diag9c forwarding per second, 0 to turn off");

+/* allow asynchronous deinit for protected guests */
+static int lazy_destroy = 1;
+module_param(lazy_destroy, int, 0444);
+MODULE_PARM_DESC(lazy_destroy, "Asynchronous destroy for protected guests");
+
/*
* For now we handle at most 16 double words as this is what the s390 base
* kernel handles and stores in the prefix page. If we ever need to go beyond
--
2.34.1