The struct used for GHCB-based page-state change requests uses a 40-bit
bit-field for the GFN, which is shifted by PAGE_SHIFT to generate a
64-bit address. However, anything beyond 40-bits simply gets shifted off
when doing this, which will cause issues when dealing with 1TB+
addresses. Fix this by casting the 40-bit GFN values to 64-bit ones
prior to shifting it by PAGE_SHIFT.
Fixes: ade62c18f4
("OvmfPkg/MemEncryptSevLib: add support to validate system RAM")
Signed-off-by: Michael Roth <michael.roth@amd.com>
Message-Id: <20231115175153.813213-1-michael.roth@amd.com>
Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>