KVM: x86: Allow CPU to force vendor-specific TDP level

mainline inclusion
from mainline-v5.15
commit 746700d2
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I6B4YT


CVE: NA

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

AMD future CPUs will require a 5-level NPT if host CR4.LA57 is set.
To prevent kvm_mmu_get_tdp_level() from incorrectly changing NPT level
on behalf of CPUs, add a new parameter in kvm_configure_mmu() to force
a fixed TDP level.

Signed-off-by: Wei Huang <wei.huang2@amd.com>
Message-Id: <20210818165549.3771014-2-wei.huang2@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Xie Haocheng <haocheng.xie@amd.com>