[PATCH v13 6/6] KVM: s390: pv: module parameter to fence asynchronous destroy

From: Claudio Imbrenda
Date: Wed Aug 10 2022 - 08:57:06 EST


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

The parameter is enabled by default since the feature is opt-in anyway.

Signed-off-by: Claudio Imbrenda <imbrenda@xxxxxxxxxxxxx>
Reviewed-by: Janosch Frank <frankja@xxxxxxxxxxxxx>
---
arch/s390/kvm/kvm-s390.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 4a20a6be6601..8c7af96c4546 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -209,7 +209,13 @@ 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");

-static int async_destroy;
+/*
+ * allow asynchronous deinit for protected guests; enable by default since
+ * the feature is opt-in anyway
+ */
+static int async_destroy = 1;
+module_param(async_destroy, int, 0444);
+MODULE_PARM_DESC(async_destroy, "Asynchronous destroy for protected guests");

/*
* For now we handle at most 16 double words as this is what the s390 base
--
2.37.1