SB.PCI0.SMB0 device drivers unavailable

[Rafal Kupiec]

QEMU 4.2 introduces new device with this code:

static void build_smb0(Aml *table, I2CBus *smbus, int devnr, int func)
{
    Aml *scope = aml_scope("_SB.PCI0");
    Aml *dev = aml_device("SMB0");

    aml_append(dev, aml_name_decl("_HID", aml_eisaid("APP0005")));
    aml_append(dev, aml_name_decl("_ADR", aml_int(devnr << 16 | func)));
    build_acpi_ipmi_devices(dev, BUS(smbus), "\\_SB.PCI0.SMB0");
    aml_append(scope, dev);
    aml_append(table, scope);
}

It is detected by Windows 10 as 'Unknown Device' and there is no driver available.
Please provide a working Windows driver or give ability to disable this device.

[Deorder (deorder)]

I noticed this as well. Apparently it was introduced in the following commit:

https://github.com/qemu/qemu/commit/ebe15582cafeb944a1c6e99aa526e81a1551c567

Saying:

---
pc: Add an SMB0 ACPI device to q35

This is so I2C devices can be found in the ACPI namespace. Currently
that's only IPMI, but devices can be easily added now.

Adding the devices required some PCI information, and the bus itself
to be added to the PCMachineState structure.

Note that this only works on Q35, the ACPI for PIIX4 is not capable
of handling an SMBus device.

Cc: Michael S. Tsirkin <email address hidden>
Cc: Igor Mammedov <email address hidden>
Signed-off-by: Corey Minyard <email address hidden>
Reviewed-by: Paolo Bonzini <email address hidden>
---

[Rafal Kupiec (belliash)]

Any progress? When will you provide a Windows driver for this and/or ability to disable this device in Qemu?

[Eric Corriveau (ec911)]

I'm also having this issue on a Win 10 VM running on a unRaid server.

[John Snow (jnsnow)]

Hi, although this isn't my area of expertise, the bug caught my eye. Peter Maydell points out that there is a commit that addresses this issue: https://github.com/qemu/qemu/commit/aefcaf9d1b3ebb30981627bd08f595211a648a62

It just never made its way back here to launchpad.