KVM: grow_halt_poll_ns() should never shrink vCPU halt_poll_ns
grow_halt_poll_ns() have a strange behavior in case
(halt_poll_ns_grow == 0) && (vcpu->halt_poll_ns != 0).
In this case, vcpu->halt_pol_ns will be set to zero.
That results in shrinking instead of growing.
Fix issue by changing grow_halt_poll_ns() to not modify
vcpu->halt_poll_ns in case halt_poll_ns_grow is zero
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Nir Weiner <nir.weiner@oracle.com>
Suggested-by: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 5a066fc..e316a2d 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3631,8 +3631,11 @@ static void kvmppc_wait_for_exec(struct kvmppc_vcore *vc,
static void grow_halt_poll_ns(struct kvmppc_vcore *vc)
{
+ if (!halt_poll_ns_grow)
+ return;
+
/* 10us base */
- if (vc->halt_poll_ns == 0 && halt_poll_ns_grow)
+ if (vc->halt_poll_ns == 0)
vc->halt_poll_ns = 10000;
else
vc->halt_poll_ns *= halt_poll_ns_grow;