KVM: s390: pv: avoid stalls for kvm_s390_pv_init_vm

[ Upstream commit 1e2aa46de526a5adafe580bca4c25856bb06f09e ]

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>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Message-Id: <20210920132502.36111-4-imbrenda@linux.ibm.com>
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/arch/s390/kvm/pv.c b/arch/s390/kvm/pv.c
index 0a85411..00d272d 100644 (file)
--- 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",