The A20 mask is only applied to the final memory access. Nested
page tables are always walked with the raw guest-physical address.
Unlike the previous patch, in this one the masking must be kept, but
it was done too early.
Cc: qemu-stable@nongnu.org
Fixes: 4a1e9d4d11c ("target/i386: Use atomic operations for pte updates", 2022-10-18)
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
b5a9de3259