This is a note to let you know that I've just added the patch titled KVM: s390: pv: avoid stalls for kvm_s390_pv_init_vm to the 5.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: kvm-s390-pv-avoid-stalls-for-kvm_s390_pv_init_vm.patch and it can be found in the queue-5.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit d041c1d9a1ec85af034272002d2f49a1248e3d5d Author: Claudio Imbrenda <imbrenda@xxxxxxxxxxxxx> Date: Mon Sep 20 15:24:51 2021 +0200 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@xxxxxxxxxxxxx> Fixes: 214d9bbcd3a672 ("s390/mm: provide memory management functions for protected KVM guests") Reviewed-by: Christian Borntraeger <borntraeger@xxxxxxxxxx> Reviewed-by: Janosch Frank <frankja@xxxxxxxxxxxxx> Message-Id: <20210920132502.36111-4-imbrenda@xxxxxxxxxxxxx> Signed-off-by: Janosch Frank <frankja@xxxxxxxxxxxxx> Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/arch/s390/kvm/pv.c b/arch/s390/kvm/pv.c index 0a854115100b4..00d272d134c24 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",