KVM: s390: Use guest address to mark guest page dirty

Stop using the userspace address to mark the guest page dirty.
mark_page_dirty() expects a guest frame number, but was being passed a
host virtual frame number. When slot == NULL, mark_page_dirty_in_slot()
does nothing and does not complain.

This means that in some circumstances the dirtiness of the guest page
might have been lost.

Fix by adding two fields in struct kvm_s390_adapter_int to keep the
guest addressses, and use those for mark_page_dirty().

Fixes: f654706 ("KVM: s390/interrupt: do not pin adapter interrupt pages")
Reviewed-by: Steffen Eiden <seiden@linux.ibm.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Christoph Schlameuss <schlameuss@linux.ibm.com>
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>

Author: Claudio Imbrenda

arch/s390/kvm/interrupt.c

@@ -2768,13 +2768,13 @@ static int adapter_indicators_set(struct kvm *kvm,
 	bit = get_ind_bit(adapter_int->ind_addr,
 			  adapter_int->ind_offset, adapter->swap);
 	set_bit(bit, map);
-	mark_page_dirty(kvm, adapter_int->ind_addr >> PAGE_SHIFT);
+	mark_page_dirty(kvm, adapter_int->ind_gaddr >> PAGE_SHIFT);
 	set_page_dirty_lock(ind_page);
 	map = page_address(summary_page);
 	bit = get_ind_bit(adapter_int->summary_addr,
 			  adapter_int->summary_offset, adapter->swap);
 	summary_set = test_and_set_bit(bit, map);
-	mark_page_dirty(kvm, adapter_int->summary_addr >> PAGE_SHIFT);
+	mark_page_dirty(kvm, adapter_int->summary_gaddr >> PAGE_SHIFT);
 	set_page_dirty_lock(summary_page);
 	srcu_read_unlock(&kvm->srcu, idx);
 
@@ -2870,7 +2870,9 @@ int kvm_set_routing_entry(struct kvm *kvm,
 		if (kvm_is_error_hva(uaddr_s) || kvm_is_error_hva(uaddr_i))
 			return -EFAULT;
 		e->adapter.summary_addr = uaddr_s;
+		e->adapter.summary_gaddr = ue->u.adapter.summary_addr;
 		e->adapter.ind_addr = uaddr_i;
+		e->adapter.ind_gaddr = ue->u.adapter.ind_addr;
 		e->adapter.summary_offset = ue->u.adapter.summary_offset;
 		e->adapter.ind_offset = ue->u.adapter.ind_offset;
 		e->adapter.adapter_id = ue->u.adapter.adapter_id;

include/linux/kvm_host.h

@@ -645,7 +645,9 @@ static inline unsigned long *kvm_second_dirty_bitmap(struct kvm_memory_slot *mem
 
 struct kvm_s390_adapter_int {
 	u64 ind_addr;
+	u64 ind_gaddr;
 	u64 summary_addr;
+	u64 summary_gaddr;
 	u64 ind_offset;
 	u32 summary_offset;
 	u32 adapter_id;