[0/3] x86: M2P maintenance adjustments (step 1)

Message

Jan Beulich Aug. 6, 2020, 9:22 a.m. UTC

As pointed out by Andrew, maintaining the compat M2P when !PV32
(or when "pv=no-32" was given) is a pointless waste of memory. Do
away with this, with a possible plan to subsequently use the
compat instance instead of the native one in shim mode with a
32-bit guest (requiring more intrusive rework, in particular to
delay setting up the M2P until the bitness of the client domain
is known).

1: slightly re-arrange 32-bit handling in dom0_construct_pv()
2: don't maintain compat M2P when !PV32
3: don't override INVALID_M2P_ENTRY with SHARED_M2P_ENTRY

Jan