[PATCH v5 03/14] KVM: s390: pv: avoid stalls for kvm_s390_pv_init_vm

Claudio Imbrenda
2021-09-20T13:25:25Z

When the system is heavily overcommitted, kvm_s390_pv_init_vm might
generate stall notifications.

Fix this by using uv_call_sched instead of just uv_call. This is ok because
we are not holding spinlocks.

Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Fixes: 214d9bbcd3a672 ("s390/mm: provide memory management functions for protected KVM guests")
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
---
arch/s390/kvm/pv.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/s390/kvm/pv.c b/arch/s390/kvm/pv.c
index 0a854115100b..00d272d134c2 100644
--- a/arch/s390/kvm/pv.c
+++ b/arch/s390/kvm/pv.c
@@ -195,7 +195,7 @@ int kvm_s390_pv_init_vm(struct kvm *kvm, u16 *rc, u16 *rrc)
uvcb.conf_base_stor_origin = (u64)kvm->arch.pv.stor_base;
uvcb.conf_virt_stor_origin = (u64)kvm->arch.pv.stor_var;

- cc = uv_call(0, (u64)&uvcb);
+ cc = uv_call_sched(0, (u64)&uvcb);
*rc = uvcb.header.rc;
*rrc = uvcb.header.rrc;
KVM_UV_EVENT(kvm, 3, "PROTVIRT CREATE VM: handle %llx len %llx rc %x rrc %x",
--
2.31.1