Re: [Qemu-devel] [PATCH 2/2] i386: Add a Virtual Machine Generation ID device.

[Gal Hammer <ghammer@redhat.com>]

Hi,

On 10/08/2014 20:22, Paolo Bonzini wrote:

> Il 10/08/2014 13:32, Gal Hammer ha scritto:
>> Based on Microsoft's sepecifications (paper can be dowloaded from
>> http://go.microsoft.com/fwlink/?LinkId=260709), add a device
>> description to the SSDT ACPI table.
>>
>> The GUID is set using a new "-vmgenid" command line parameter.
>>
>> Signed-off-by: Gal Hammer <ghammer@redhat.com>
>> ---
>>   hw/i386/acpi-build.c  | 23 +++++++++++++++++++++++
>>   hw/i386/ssdt-misc.dsl | 33 +++++++++++++++++++++++++++++++++
>>   qemu-options.hx       |  9 +++++++++
>>   vl.c                  | 11 +++++++++++
>>   4 files changed, 76 insertions(+)
>
> Please make this a new device (like pvpanic), instead of adding a new
> command-line option.

There is a problem with this request. I don't want to use ISA because it 
is obsolete, PCI is overkill for such a device and a SYSBUS (like HPET) 
device doesn't effect the command line options.

Did I miss something in SYSBUS and that's was the reason it didn't 
appear in the "-device ?" list?

>>
>> +    Scope(\_SB) {
>> +
>> +        Device(VMGI) {
>> +            Name(_HID, "QEMU0002")
>> +            Name(_CID, "VM_Gen_Counter")
>> +            Name(_DDN, "VM_Gen_Counter")
>> +
>> +            ACPI_EXTRACT_NAME_DWORD_CONST ssdt_acpi_vm_gid_addr
>> +            Name(VGIA, 0x12345678)
>> +
>> +            ACPI_EXTRACT_NAME_BUFFER16 ssdt_acpi_vm_gid
>> +            Name(VGID, Buffer(16) {
>> +                0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
>> +                0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 })
>> +
>> +            Method(_STA, 0, NotSerialized) {
>> +                Store(VGIA, Local0)
>> +                If (LEqual(Local0, Zero)) {
>> +                    Return (0x00)
>> +                } Else {
>> +                    Return (0x0F)
>> +                }
>> +            }
>> +
>> +            Method(ADDR, 0, Serialized) {
>> +                Store(Package(2) { }, Local0)
>> +                Store(VGIA, Index(Local0, 0))
>> +                Store(0x0000, Index(Local0, 1))
>> +                return (Local0)
>> +            }
>> +        }
>> +    }
>> +
>
> Please either put this in the DSDT, or omit the Device altogether if you
> put it in the SSDT and there is no VMGID device.

I'm not sure I understand this comment. I've put the new device in the 
SSDT table (like pvpanic) and add a _STA method which disable the device 
if no GUID's address is set (VGIA). The device doesn't show in the 
Device Manager if it was not added using the command line.

     Gal.

> Thanks,
>
> Paolo
>