OvmfPkg/AcpiPlatformDxe: Measure ACPI table from QEMU in TDVF
https://bugzilla.tianocore.org/show_bug.cgi?id=4245
QEMU provides the following three files for guest to install the ACPI
tables:
- etc/acpi/rsdp
- etc/acpi/tables
- etc/table-loader
"etc/acpi/rsdp" and "etc/acpi/tables" are similar, they are only kept
separate because they have different allocation requirements in SeaBIOS.
Both of these fw_cfg files contain preformatted ACPI payload.
"etc/acpi/rsdp" contains only the RSDP table, while "etc/acpi/tables"
contains all other tables, concatenated. To be noted, the tables in these
two files have been filled in by qemu, but two kinds of fields are
incomplete: pointers to other tables and checksums (which depend on the
pointers).
"/etc/table-loader" is a linker/loader which provides the commands to
"patch" the tables in "etc/acpi/tables" and then install them. "Patch"
means to fill the pointers and compute the checksum.
From the security perspective these 3 files are the raw data downloaded
from qemu. They should be measured and extended before they're consumed.
Cc: Erdem Aktas <erdemaktas@google.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Michael Roth <michael.roth@amd.com>
Signed-off-by: Min Xu <min.m.xu@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>