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
c97294ec1b9e36887e119589d456557d72ab37b5.
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>
static int legacy_acpi_table_size;
static bool smbios_defaults = true;
static bool smbios_legacy_mode;
+static bool smbios_uuid_encoded = true;
/* Make sure that guest addresses aligned at 1Gbyte boundaries get mapped to
* host addresses aligned at 1Gbyte boundaries. This way we can use 1GByte
* pages in the host.
MachineClass *mc = MACHINE_GET_CLASS(machine);
/* These values are guest ABI, do not change */
smbios_set_defaults("QEMU", "Standard PC (i440FX + PIIX, 1996)",
- mc->name, smbios_legacy_mode);
+ mc->name, smbios_legacy_mode, smbios_uuid_encoded);
}
/* allocate ram and load rom/bios */
static void pc_compat_2_1(MachineState *machine)
{
+ smbios_uuid_encoded = false;
}
static void pc_compat_2_0(MachineState *machine)
static bool has_acpi_build = true;
static bool smbios_defaults = true;
static bool smbios_legacy_mode;
+static bool smbios_uuid_encoded = true;
/* Make sure that guest addresses aligned at 1Gbyte boundaries get mapped to
* host addresses aligned at 1Gbyte boundaries. This way we can use 1GByte
* pages in the host.
MachineClass *mc = MACHINE_GET_CLASS(machine);
/* These values are guest ABI, do not change */
smbios_set_defaults("QEMU", "Standard PC (Q35 + ICH9, 2009)",
- mc->name, smbios_legacy_mode);
+ mc->name, smbios_legacy_mode, smbios_uuid_encoded);
}
/* allocate ram and load rom/bios */
static void pc_compat_2_1(MachineState *machine)
{
+ smbios_uuid_encoded = false;
}
static void pc_compat_2_0(MachineState *machine)
static uint8_t *smbios_entries;
static size_t smbios_entries_len;
static bool smbios_legacy = true;
+static bool smbios_uuid_encoded = true;
/* end: legacy structures & constants for <= 2.0 machines */
smbios_maybe_add_str(1, offsetof(struct smbios_type_1, family_str),
type1.family);
if (qemu_uuid_set) {
+ /* We don't encode the UUID in the "wire format" here because this
+ * function is for legacy mode and needs to keep the guest ABI, and
+ * because we don't know what's the SMBIOS version advertised by the
+ * BIOS.
+ */
smbios_add_field(1, offsetof(struct smbios_type_1, uuid),
qemu_uuid, 16);
}
SMBIOS_BUILD_TABLE_POST;
}
+/* Encode UUID from the big endian encoding described on RFC4122 to the wire
+ * format specified by SMBIOS version 2.6.
+ */
+static void smbios_encode_uuid(struct smbios_uuid *uuid, const uint8_t *buf)
+{
+ memcpy(uuid, buf, 16);
+ if (smbios_uuid_encoded) {
+ uuid->time_low = bswap32(uuid->time_low);
+ uuid->time_mid = bswap16(uuid->time_mid);
+ uuid->time_hi_and_version = bswap16(uuid->time_hi_and_version);
+ }
+}
+
static void smbios_build_type_1_table(void)
{
SMBIOS_BUILD_TABLE_PRE(1, 0x100, true); /* required */
SMBIOS_TABLE_SET_STR(1, version_str, type1.version);
SMBIOS_TABLE_SET_STR(1, serial_number_str, type1.serial);
if (qemu_uuid_set) {
- memcpy(t->uuid, qemu_uuid, 16);
+ smbios_encode_uuid(&t->uuid, qemu_uuid);
} else {
- memset(t->uuid, 0, 16);
+ memset(&t->uuid, 0, 16);
}
t->wake_up_type = 0x06; /* power switch */
SMBIOS_TABLE_SET_STR(1, sku_number_str, type1.sku);
}
void smbios_set_defaults(const char *manufacturer, const char *product,
- const char *version, bool legacy_mode)
+ const char *version, bool legacy_mode,
+ bool uuid_encoded)
{
smbios_have_defaults = true;
smbios_legacy = legacy_mode;
+ smbios_uuid_encoded = uuid_encoded;
/* drop unwanted version of command-line file blob(s) */
if (smbios_legacy) {
void smbios_entry_add(QemuOpts *opts);
void smbios_set_cpuid(uint32_t version, uint32_t features);
void smbios_set_defaults(const char *manufacturer, const char *product,
- const char *version, bool legacy_mode);
+ const char *version, bool legacy_mode,
+ bool uuid_encoded);
uint8_t *smbios_get_table_legacy(size_t *length);
void smbios_get_tables(uint8_t **tables, size_t *tables_len,
uint8_t **anchor, size_t *anchor_len);
uint8_t embedded_controller_minor_release;
} QEMU_PACKED;
+/* UUID encoding. The time_* fields are little-endian, as specified by SMBIOS
+ * version 2.6.
+ */
+struct smbios_uuid {
+ uint32_t time_low;
+ uint16_t time_mid;
+ uint16_t time_hi_and_version;
+ uint8_t clock_seq_hi_and_reserved;
+ uint8_t clock_seq_low;
+ uint8_t node[6];
+} QEMU_PACKED;
+
/* SMBIOS type 1 - System Information */
struct smbios_type_1 {
struct smbios_structure_header header;
uint8_t product_name_str;
uint8_t version_str;
uint8_t serial_number_str;
- uint8_t uuid[16];
+ struct smbios_uuid uuid;
uint8_t wake_up_type;
uint8_t sku_number_str;
uint8_t family_str;
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;