Re: [PATCH v2 6/9] hw/i386: declare ACPI mother board resource for MMCONFIG region

[Igor Mammedov <imammedo@redhat.com>]

On Mon,  8 Feb 2021 13:57:25 -0800
isaku.yamahata@gmail.com wrote:

> From: Isaku Yamahata <isaku.yamahata@intel.com>
> 
> Declare PNP0C01 device to reserve MMCONFIG region to conform to the
> spec better and play nice with guest BIOSes/OSes.
> 
> According to PCI Firmware Specification, MMCONFIG region must be
> reserved by declaring a motherboard resource.
could you point to concrete spec version/chapter where it stated.
(should be part of commit message)

> It's optional to reserve
> the region in memory map by Int 15 E820h or EFIGetMemoryMap.

> If guest BIOS doesn't reserve the region in memory map without the
> reservation by mother board resource, guest linux abandons to use
> MMCFG.
can parse this, can you rephrase and avoid double negation, please?

> TDVF [0] [1] doesn't reserve MMCONFIG the region in memory map.
> On the other hand OVMF reserves it in memory map without declaring a
> motherboard resource. With memory map reservation, linux guest uses
> MMCONFIG region. However it doesn't comply to PCI Firmware
> specification.
> 
> [0] TDX: Intel Trust Domain Extension
>     https://software.intel.com/content/www/us/en/develop/articles/intel-trust-domain-extensions.html
> [1] TDX Virtual Firmware
>     https://github.com/tianocore/edk2-staging/tree/TDVF
> 
> The change to DSDT is as follows.
> @@ -68,32 +68,90 @@
> 
>                      If ((CDW3 != Local0))
>                      {
>                          CDW1 |= 0x10
>                      }
> 
>                      CDW3 = Local0
>                  }
>                  Else
>                  {
>                      CDW1 |= 0x04
>                  }
> 
>                  Return (Arg3)
>              }
>          }
> +
> +        Device (DRAC)
> +        {
> +            Name (_HID, "PNP0C01" /* System Board */)  // _HID: Hardware ID
> +            OperationRegion (DRR0, PCI_Config, 0x60, 0x08)
> +            Field (DRR0, DWordAcc, NoLock, Preserve)
> +            {
> +                PEBL,   32,
> +                PEBH,   32
> +            }
> +
> +            Name (RBUF, ResourceTemplate ()
> +            {
> +                QWordMemory (ResourceProducer, PosDecode, MinFixed, MaxFixed, NonCacheable, ReadWrite,
> +                    0x0000000000000000, // Granularity
> +                    0x0000000000000000, // Range Minimum
> +                    0x0000000000000000, // Range Maximum
> +                    0x0000000000000000, // Translation Offset
> +                    0x0000000000000000, // Length
> +                    ,, _Y00, AddressRangeMemory, TypeStatic)
> +            })
> +            Method (_CRS, 0, Serialized)  // _CRS: Current Resource Settings
> +            {
> +                CreateDWordField (RBUF, \_SB.DRAC._Y00._MIN, MINL)  // _MIN: Minimum Base Address
> +                CreateDWordField (RBUF, 0x12, MINH)
> +                CreateDWordField (RBUF, \_SB.DRAC._Y00._MAX, MAXL)  // _MAX: Maximum Base Address
> +                CreateDWordField (RBUF, 0x1A, MAXH)
> +                CreateQWordField (RBUF, \_SB.DRAC._Y00._LEN, _LEN)  // _LEN: Length
> +                Local0 = PEBL /* \_SB_.DRAC.PEBL */
> +                Local1 = (Local0 & One)
> +                Local2 = (Local0 & 0x06)
> +                Local3 = (Local0 & 0xFFFFFFF8)
> +                Local4 = PEBH /* \_SB_.DRAC.PEBH */
> +                If ((Local1 == One))
> +                {
> +                    MINL = Local3
> +                    MINH = Local4
> +                    MAXL = Local3
> +                    MAXH = Local4
> +                    If ((Local2 == Zero))
> +                    {
> +                        _LEN = 0x10000000
> +                    }
> +
> +                    If ((Local2 == 0x02))
> +                    {
> +                        _LEN = 0x08000000
> +                    }
> +
> +                    If ((Local2 == 0x04))
> +                    {
> +                        _LEN = 0x04000000
> +                    }
> +                }
> +
> +                Return (RBUF) /* \_SB_.DRAC.RBUF */
> +            }
> +        }
>      }
> 
>      Scope (_SB)
>      {
>          Device (HPET)
>          {
>              Name (_HID, EisaId ("PNP0103") /* HPET System Timer */)  // _HID: Hardware ID
>              Name (_UID, Zero)  // _UID: Unique ID
>              OperationRegion (HPTM, SystemMemory, 0xFED00000, 0x0400)
>              Field (HPTM, DWordAcc, Lock, Preserve)
>              {
>                  VEND,   32,
>                  PRD,    32
>              }
> 
>              Method (_STA, 0, NotSerialized)  // _STA: Status
> 
> Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
> Acked-by: Jiewen Yao <Jiewen.yao@intel.com>
> ---
>  hw/i386/acpi-build.c | 172 +++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 172 insertions(+)
> 
> diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
> index c2f11d95d8..bcb1f65c1d 100644
> --- a/hw/i386/acpi-build.c
> +++ b/hw/i386/acpi-build.c
> @@ -1066,6 +1066,177 @@ static void build_q35_pci0_int(Aml *table)
>      aml_append(table, sb_scope);
>  }
>  
> +static Aml *build_q35_dram_controller(void)
> +{
> +    /*
> +     * DSDT is created with revision 1 which means 32bit integer.
version 1, is kept for Windows XP sake which is EOLed long ago,
and it even will boot with v2 as long as AML doesn't contain non v1
terms or those are hidden behind dynamic method which are not evaluated.
Perhaps we should bump dsdt revision to v2.
And anyways with this patch XP probably will trip over, if it tries to parse
64bit CRS, but we probably don't care about XP on q35.

> +     * When the method of _CRS is called to determine MMCONFIG region,
> +     * only port io is allowed to access PCI configuration space.
> +     * It means qword access isn't allowed.
> +     *
> +     * Device(DRAC)
> +     * {
> +     *     Name(_HID, EisaId("PNP0C01"))
> +     *     OperationRegion(DRR0, PCI_Config, 0x0000000000000060, 0x8)
> +     *     Field(DRR0, DWordAcc, Lock, Preserve)
> +     *     {
> +     *         PEBL, 4,
> +     *         PEBH, 4
> +     *     }

why are you trying to fetch it dynamically?
what prevents you from getting MMCONFIG address in QEMU when building
ACPI tables and encode _CRS statically at that time?


> +     *     Name(RBUF, ResourceTemplate()
> +     *     {
> +     *         QWordMemory(ResourceConsumer,
> +     *                     PosDecode,
> +     *                     MinFixed,
> +     *                     MaxFixed,
> +     *                     NonCacheable,
> +     *                     ReadWrite,
> +     *                     0x0000000000000000, // Granularity
> +     *                     0x0000000000000000, // Range Minimum
> +     *                     0x0000000000000000, // Range Maxium
> +     *                     0x0000000000000000, // Translation Offset,
> +     *                     0x0000000000000000, // Length,
> +     *                     ,,
> +     *                     _MCF,
> +     *                     AddressRangeMemory,
> +     *                     TypeStatic
> +     *                     )
> +     *     })
> +     *     Method(_CRS, 0x0, NotSerialized)
> +     *     {
> +     *         CreateDWordField(RBUF, DRAC._MCF._MIN, MINL)
> +     *         CreateDWordField(RBUF, DRAC._MCF._MIN + 4, MINH)
> +     *         CreateDWordField(RBUF, DRAC._MCF._MAX, MAXL)
> +     *         CreateDWordField(RBUF, DRAC._MCF._MAX + 4, MAXH)
> +     *         CreateQWordField(RBUF, DRAC._MCF._LEN, _LEN)
> +     *
> +     *         Local0 = PEBL
> +     *         Local1 = Local0 & 0x1  // PCIEXBAR PCIEBAREN
> +     *         Local2 = Local0 & 0x6  // PCIEXBAR LENGTH
> +     *         Local3 = Local0 & ~0x7 // PCIEXBAR base address low 32bit
> +     *         Local4 = PEBH          // PCIEXBAR base address high 32bit
> +     *         If (Local1 == 1) {
> +     *             MINL = Local3
> +     *             MINH = Local4
> +     *             MAXL = Local3
> +     *             MAXH = Local4
> +     *
> +     *             If (Local2 == 0) {
> +     *                 _LEN = 256 * 1024 * 1024
> +     *             }
> +     *             If (Local2 == 0x2) {
> +     *                 _LEN = 128 * 1024 * 1024
> +     *             }
> +     *             If (Local2 == 0x4) {
> +     *                 _LEN = 64 * 1024 * 1024
> +     *             }
> +     *         }
> +     *         return (RBUF)
> +     *     }
> +     * }
> +     */
> +
> +    Aml *dev;
> +    Aml *field;
> +    Aml *rbuf;
> +    Aml *resource_template;
> +    Aml *crs;
> +
> +    /* DRAM controller */
> +    dev = aml_device("DRAC");
> +
> +    aml_append(dev, aml_name_decl("_HID", aml_string("PNP0C01")));
> +    /* 5.1.6 PCIEXBAR: Bus 0:Device 0:Function 0:offset 0x60 */
> +    aml_append(dev, aml_operation_region("DRR0", AML_PCI_CONFIG,
> +                                         aml_int(0x0000000000000060), 0x8));
> +    field = aml_field("DRR0", AML_DWORD_ACC, AML_NOLOCK, AML_PRESERVE);
> +    aml_append(field, aml_named_field("PEBL", 32));
> +    aml_append(field, aml_named_field("PEBH", 32));
> +    aml_append(dev, field);
> +
> +    resource_template = aml_resource_template();
> +    aml_append(resource_template, aml_qword_memory(AML_POS_DECODE,
> +                                                   AML_MIN_FIXED,
> +                                                   AML_MAX_FIXED,
> +                                                   AML_NON_CACHEABLE,
> +                                                   AML_READ_WRITE,
> +                                                   0x0000000000000000,
> +                                                   0x0000000000000000,
> +                                                   0x0000000000000000,
> +                                                   0x0000000000000000,
> +                                                   0x0000000000000000));
> +    rbuf = aml_name_decl("RBUF", resource_template);
> +    aml_append(dev, rbuf);
> +
> +    crs = aml_method("_CRS", 0, AML_SERIALIZED);
> +    {
> +        Aml *rbuf_name;
> +        Aml *local0;
> +        Aml *local1;
> +        Aml *local2;
> +        Aml *local3;
> +        Aml *local4;
> +        Aml *ifc;
> +
> +        rbuf_name = aml_name("RBUF");
> +        aml_append(crs, aml_create_dword_field(rbuf_name,
> +                                               aml_int(14), "MINL"));
> +        aml_append(crs, aml_create_dword_field(rbuf_name,
> +                                               aml_int(14 + 4), "MINH"));
> +        aml_append(crs, aml_create_dword_field(rbuf_name,
> +                                               aml_int(22), "MAXL"));
> +        aml_append(crs, aml_create_dword_field(rbuf_name,
> +                                               aml_int(22 + 4), "MAXH"));
> +        aml_append(crs, aml_create_qword_field(rbuf_name,
> +                                               aml_int(38), "_LEN"));
> +
> +        local0 = aml_local(0);
> +        aml_append(crs, aml_store(aml_name("PEBL"), local0));
> +        local1 = aml_local(1);
> +        aml_append(crs, aml_and(local0, aml_int(0x1), local1));
> +        local2 = aml_local(2);
> +        aml_append(crs, aml_and(local0, aml_int(0x6), local2));
> +        local3 = aml_local(3);
> +        aml_append(crs, aml_and(local0, aml_int((uint32_t)~0x7), local3));
> +        local4 = aml_local(4);
> +        aml_append(crs, aml_store(aml_name("PEBH"), local4));
> +
> +        ifc = aml_if(aml_equal(local1, aml_int(0x1)));
> +        {
> +            Aml *_len;
> +            Aml *ifc0;
> +            Aml *ifc2;
> +            Aml *ifc4;
> +
> +            aml_append(ifc, aml_store(local3, aml_name("MINL")));
> +            aml_append(ifc, aml_store(local4, aml_name("MINH")));
> +            aml_append(ifc, aml_store(local3, aml_name("MAXL")));
> +            aml_append(ifc, aml_store(local4, aml_name("MAXH")));
> +
> +            _len = aml_name("_LEN");
> +            ifc0 = aml_if(aml_equal(local2, aml_int(0x0)));
> +            aml_append(ifc0,
> +                       aml_store(aml_int(256 * 1024 * 1024), _len));
> +            aml_append(ifc, ifc0);
> +
> +            ifc2 = aml_if(aml_equal(local2, aml_int(0x2)));
> +            aml_append(ifc2,
> +                       aml_store(aml_int(128 * 1024 * 1024), _len));
> +            aml_append(ifc, ifc2);
> +
> +            ifc4 = aml_if(aml_equal(local2, aml_int(0x4)));
> +            aml_append(ifc4,
> +                       aml_store(aml_int(64 * 1024 * 1024), _len));
> +            aml_append(ifc, ifc4);
> +        }
> +        aml_append(crs, ifc);
> +        aml_append(crs, aml_return(rbuf_name));
> +    }
> +    aml_append(dev, crs);
> +
> +    return dev;
> +}
> +
>  static void build_q35_isa_bridge(Aml *table)
>  {
>      Aml *dev;
> @@ -1250,6 +1421,7 @@ build_dsdt(GArray *table_data, BIOSLinker *linker,
>          aml_append(dev, aml_name_decl("_UID", aml_int(0)));
>          aml_append(dev, build_q35_osc_method());
>          aml_append(sb_scope, dev);
> +        aml_append(sb_scope, build_q35_dram_controller());
>  
>          if (pm->smi_on_cpuhp) {
>              /* reserve SMI block resources, IO ports 0xB2, 0xB3 */