mainline inclusion
from mainline-5.15
commit cb0f722a
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5NGRU
CVE: NA

-------------------------------------------------

When the 5-level page table CPU flag is set in the host, but the guest
has CR4.LA57=0 (including the case of a 32-bit guest), the top level of
the shadow NPT page tables will be fixed, consisting of one pointer to
a lower-level table and 511 non-present entries.  Extend the existing
code that creates the fixed PML4 or PDP table, to provide a fixed PML5
table if needed.

This is not needed on EPT because the number of layers in the tables
is specified in the EPTP instead of depending on the host CR4.
Suggested-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NWei Huang <wei.huang2@amd.com>
Message-Id: <20210818165549.3771014-3-wei.huang2@amd.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NXie Haocheng <haocheng.xie@amd.com>