KVM: s390: vsie: correctly set and handle guest TOD
Guest 2 sets up the epoch of guest 3 from his point of view. Therefore,
we have to add the guest 2 epoch to the guest 3 epoch. We also have to take
care of guest 2 epoch changes on STP syncs. This will work just fine by
also updating the guest 3 epoch when a vsie_block has been set for a VCPU.
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
diff --git a/arch/s390/kvm/vsie.c b/arch/s390/kvm/vsie.c
index 90781ba..6895e7b 100644
--- a/arch/s390/kvm/vsie.c
+++ b/arch/s390/kvm/vsie.c
@@ -843,12 +843,21 @@
static void register_shadow_scb(struct kvm_vcpu *vcpu,
struct vsie_page *vsie_page)
{
+ struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
+
WRITE_ONCE(vcpu->arch.vsie_block, &vsie_page->scb_s);
/*
* External calls have to lead to a kick of the vcpu and
* therefore the vsie -> Simulate Wait state.
*/
atomic_or(CPUSTAT_WAIT, &vcpu->arch.sie_block->cpuflags);
+ /*
+ * We have to adjust the g3 epoch by the g2 epoch. The epoch will
+ * automatically be adjusted on tod clock changes via kvm_sync_clock.
+ */
+ preempt_disable();
+ scb_s->epoch += vcpu->kvm->arch.epoch;
+ preempt_enable();
}
/*