smbios: Encode UUID according to SMBIOS specification

Differently from older versions, SMBIOS version 2.6 is explicit about
the encoding of UUID fields:

> Although RFC 4122 recommends network byte order for all fields, the PC
> industry (including the ACPI, UEFI, and Microsoft specifications) has
> consistently used little-endian byte encoding for the first three fields:
> time_low, time_mid, time_hi_and_version. The same encoding, also known as
> wire format, should also be used for the SMBIOS representation of the UUID.
>
> The UUID {00112233-4455-6677-8899-AABBCCDDEEFF} would thus be represented
> as 33 22 11 00 55 44 77 66 88 99 AA BB CC DD EE FF.

The dmidecode tool implements this and decodes the above "wire format"
when SMBIOS version >= 2.6. We moved from SMBIOS version 2.4 to 2.8 when
we started building the SMBIOS entry point inside QEMU, on commit
c97294ec1b.

Change smbios_build_type_1_table() to encode the UUID as specified.

To make sure we won't change the guest-visible UUID when upgrading to a
newer QEMU version, keep the old behavior on pc-*-2.1 and older.

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Eduardo Habkost 2014-10-29 11:26:08 -02:00 committed by Michael S. Tsirkin
parent 2cad57c717
commit caad057bb6
5 changed files with 48 additions and 7 deletions

3
vl.c
View file

@ -190,6 +190,9 @@ int nb_numa_nodes;
int max_numa_nodeid;
NodeInfo numa_info[MAX_NODES];
/* The bytes in qemu_uuid[] are in the order specified by RFC4122, _not_ in the
* little-endian "wire format" described in the SMBIOS 2.6 specification.
*/
uint8_t qemu_uuid[16];
bool qemu_uuid_set;