Re: [Qemu-devel] Windows does not support DataTableRegion at all [was: docs: describe QEMU's VMGenID design]

[Laszlo Ersek <lersek@redhat.com>]

On 09/13/15 14:34, Michael S. Tsirkin wrote:
> On Sun, Sep 13, 2015 at 01:56:44PM +0200, Laszlo Ersek wrote:
>> As the subject suggests, I have terrible news.
>>
>> I'll preserve the full context here, so that it's easy to scroll back to
>> the ASL for reference.
>>
>> I'm also CC'ing edk2-devel, because a number of BIOS developers should
>> be congregating there.
> 
> Wow, bravo! It does look like we need to go back to
> the drawing board.

Thank you. :)

> The only crazy thing you didn't try is to use
> an XSDT instead of the DSDT.
> I find it unlikely that this will help ...
> 

Actually, I forgot to mention it, but I *did* try to use XSDT, sort of automatically. I had mentioned earlier that EFI_ACPI_TABLE_PROTOCOL automatically links stuff into both RSDT and XSDT, and I verified in this case that the UEFI ACPI Data Table *was* linked into the XSDT.

----*----

[root@ovmf-fedora acpi.6]# dmesg | grep UEFI
[    0.000000] ACPI: UEFI 0x000000003E8F1000 00003E (v01 BOCHS  QEMUPARM 00000001 BXPC 00000001)

----*----

[root@ovmf-fedora acpi.6]# cat xsdt.dsl 
/*
 * Intel ACPI Component Architecture
 * AML/ASL+ Disassembler version 20150515-64
 * Copyright (c) 2000 - 2015 Intel Corporation
 * 
 * Disassembly of xsdt.dat, Sun Sep 13 14:54:17 2015
 *
 * ACPI Data Table [XSDT]
 *
 * Format: [HexOffset DecimalOffset ByteLength]  FieldName : FieldValue
 */

[000h 0000   4]                    Signature : "XSDT"    [Extended System Description Table]
[004h 0004   4]                 Table Length : 0000004C
[008h 0008   1]                     Revision : 01
[009h 0009   1]                     Checksum : 90
[00Ah 0010   6]                       Oem ID : "BOCHS "
[010h 0016   8]                 Oem Table ID : "BXPCFACP"
[018h 0024   4]                 Oem Revision : 00000001
[01Ch 0028   4]              Asl Compiler ID : "    "
[020h 0032   4]        Asl Compiler Revision : 01000013

[024h 0036   8]       ACPI Table Address   0 : 000000003FEF5000
[02Ch 0044   8]       ACPI Table Address   1 : 000000003FEF4000
[034h 0052   8]       ACPI Table Address   2 : 000000003FEF3000
[03Ch 0060   8]       ACPI Table Address   3 : 000000003FEF2000
[044h 0068   8]       ACPI Table Address   4 : 000000003E8F1000

Raw Table Data: Length 76 (0x4C)

  0000: 58 53 44 54 4C 00 00 00 01 90 42 4F 43 48 53 20  // XSDTL.....BOCHS 
  0010: 42 58 50 43 46 41 43 50 01 00 00 00 20 20 20 20  // BXPCFACP....    
  0020: 13 00 00 01 00 50 EF 3F 00 00 00 00 00 40 EF 3F  // .....P.?.....@.?
  0030: 00 00 00 00 00 30 EF 3F 00 00 00 00 00 20 EF 3F  // .....0.?..... .?
  0040: 00 00 00 00 00 10 8F 3E 00 00 00 00              // .......>....

----*----

See "ACPI Table Address 4", 3E8F1000.

Thanks!
Laszlo