[ Upstream commit bf03d4f9 ]

Checking for 32-bit PAE is quite common around code that fiddles with
the PDPTRs.  Add a function to compress all checks into a single
invocation.

Moving to the common helper also fixes a subtle bug in kvm_set_cr3()
where it fails to check is_long_mode() and results in KVM incorrectly
attempting to load PDPTRs for a 64-bit guest.
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[sean: backport to 4.x; handle vmx.c split in 5.x, call out the bugfix]
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Tested-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>