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

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: f65470661f36 ("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>