On Thu, Apr 01, 2021 at 10:25:43AM +0200, Vincent Bernat wrote:
> Type 41 defines the attributes of devices that are onboard. The
> original intent was to imply the BIOS had some level of control over
> the enablement of the associated devices.
>
> If network devices are present in this table, by default, udev will
> name the corresponding interfaces enoX, X being the instance number.
> Without such information, udev will fallback to using the PCI ID and
> this usually gives ens3 or ens4. This can be a bit annoying as the
> name of the network card may depend on the order of options and may
> change if a new PCI device is added earlier on the commande line.
> Being able to provide SMBIOS type 41 entry ensure the name of the
> interface won't change and helps the user guess the right name without
> booting a first time.
>
> This can be invoked with:
>
> $QEMU -netdev user,id=internet
> -device virtio-net-pci,mac=50:54:00:00:00:42,netdev=internet \
> -smbios type=41,designation='Onboard
> LAN',instance=1,kind=ethernet,pci=0000:00:09.0
>
> Which results in the guest seeing dmidecode data and the interface
> exposed as "eno1":
>
> $ dmidecode -t 41
> # dmidecode 3.3
> Getting SMBIOS data from sysfs.
> SMBIOS 2.8 present.Handle 0x2900, DMI type 41, 11 bytes
> Onboard Device
> Reference Designation: Onboard LAN
> Type: Ethernet
> Status: Enabled
> Type Instance: 1
> Bus Address: 0000:00:09.0
> $ udevadm info -p /sys/class/net/eno1 | grep ONBOARD
> E: ID_NET_NAME_ONBOARD=eno1
> E: ID_NET_LABEL_ONBOARD=Onboard LAN
>
> Signed-off-by: Vincent Bernat <vinc...@bernat.ch>
> ---
> hw/smbios/smbios.c | 119 +++++++++++++++++++++++++++++++++++
> include/hw/firmware/smbios.h | 11 ++++
> qemu-options.hx | 7 ++-
> 3 files changed, 136 insertions(+), 1 deletion(-)
>
> diff --git a/hw/smbios/smbios.c b/hw/smbios/smbios.c
> index f22c4f5b734e..46a08652dff4 100644
> --- a/hw/smbios/smbios.c
> +++ b/hw/smbios/smbios.c
> static void smbios_register_config(void)
> {
> qemu_add_opts(&qemu_smbios_opts);
> @@ -773,6 +826,26 @@ static void smbios_build_type_32_table(void)
> SMBIOS_BUILD_TABLE_POST;
> }
>
> +static void smbios_build_type_41_table(void)
> +{
> + unsigned instance = 0;
> + struct type41_instance *t41;
> +
> + QTAILQ_FOREACH(t41, &type41, next) {
> + SMBIOS_BUILD_TABLE_PRE(41, 0x2900 + instance, true);
> +
> + SMBIOS_TABLE_SET_STR(41, reference_designation_str,
> t41->designation);
> + t->device_type = t41->kind;
> + t->device_type_instance = t41->instance;
> + t->segment_group_number = cpu_to_le16(t41->pci.segment);
> + t->bus_number = t41->pci.bus;
> + t->device_number = t41->pci.device;
> +
> + SMBIOS_BUILD_TABLE_POST;
> + instance++;
> + }
> +}
> +
> static void smbios_build_type_127_table(void)
> {
> SMBIOS_BUILD_TABLE_PRE(127, 0x7F00, true); /* required */
> @@ -928,6 +1001,7 @@ void smbios_get_tables(MachineState *ms,
>
> smbios_build_type_32_table();
> smbios_build_type_38_table();
> + smbios_build_type_41_table();
> smbios_build_type_127_table();
>
> smbios_validate_table(ms);
> @@ -1224,6 +1298,51 @@ void smbios_entry_add(QemuOpts *opts, Error **errp)
> save_opt(&type17.part, opts, "part");
> type17.speed = qemu_opt_get_number(opts, "speed", 0);
> return;
> + case 41: {
> + struct type41_instance *t;
> + Error *local_err = NULL;
> + int pseg, pbus, pdevice, pfunction;
> +
> + if (!qemu_opts_validate(opts, qemu_smbios_type41_opts, errp)) {
> + return;
> + }
> + t = calloc(1, sizeof(struct type41_instance));
> + if (!t) {
> + error_setg(errp,
> + "Unable to allocate memory for a new type 41
> instance");
> + return;
> + }
QEMU uses GLib allocation functions throughout, which abort
on OOM. So replace this with g_new0.
Regards,
Daniel
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