x86/shadow: don't pass wrong L4 MFN to guest_walk_tables()

x86/shadow: don't pass wrong L4 MFN to guest_walk_tables()

64-bit PV guest user mode runs on a different L4 table. Make sure
- the accessed bit gets set in the correct table (and in log-dirty
  mode the correct page gets marked dirty) during guest walks,
- the correct table gets audited by sh_audit_gw(),
- correct info gets logged by print_gw().

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: George Dunlap <george.dunlap@citrix.com>
master commit: db2af23d15077605f286d8ef86c8f5d9c1b8302a
master date: 2019-02-20 17:07:17 +0100