Commit 63c50d3ff2 changed the check that is
used to determine if SEV-ES is active. Originally, a CMP instruction with
a supporting JZ instruction was used for the check. It was changed to use
the BT instruction but not JZ instruction. The result of a BT instruction
changes the the carry flag (CF) and not the zero flag (ZF). As a result,
the wrong condition is being checked. Update the JZ to a JNC to properly
detect if SEV-ES is active.
Fixes: 63c50d3ff2 ("OvmfPkg/ResetVector: cache the SEV status MSR...")
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
e674096acc