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",
