OvmfPkg/CcExitLib: Use the proper register when filtering MSRs

The MsrExit() routine uses an incorrect register to check for the CAA MSR.
Instead of checking RCX, the input register for RDMSR/WRMSR that holds the
MSR value, it is checking RAX, which results in failure to detect the CAA
MSR request. The check should only be checking the lower 32-bits of the
register (ECX), too.

Change the check in MsrExit() to check the MSR value contained in ECX.

Fixes: 47001ab98914 ("Ovmfpkg/CcExitLib: Provide SVSM discovery support")
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>

0 files changed, 0 insertions, 0 deletions