Revert "nSVM: Check for reserved encodings of TLB_CONTROL in nested VMCB"

[ Upstream commit a484755a ]

Revert KVM's made-up consistency check on SVM's TLB control.  The APM says
that unsupported encodings are reserved, but the APM doesn't state that
VMRUN checks for a supported encoding.  Unless something is called out
in "Canonicalization and Consistency Checks" or listed as MBZ (Must Be
Zero), AMD behavior is typically to let software shoot itself in the foot.

This reverts commit 174a921b.

Fixes: 174a921b ("nSVM: Check for reserved encodings of TLB_CONTROL in nested VMCB")
Reported-by: Stefan Sterz <s.sterz@proxmox.com>
Closes: https://lkml.kernel.org/r/b9915c9c-4cf6-051a-2d91-44cc6380f455%40proxmox.com


Cc: stable@vger.kernel.org
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Link: https://lore.kernel.org/r/20231018194104.1896415-2-seanjc@google.com


Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>