Re: [Qemu-devel] [PATCH v4 6/6] acpi: pci: use build_append_foo() API to construct MCFG

[Philippe Mathieu-Daudé]

On 5/15/19 3:10 AM, Michael S. Tsirkin wrote:
> On Fri, Apr 19, 2019 at 08:30:53AM +0800, Wei Yang wrote:
>> build_append_foo() API doesn't need explicit endianness conversions
>> which eliminates a source of errors and it makes build_mcfg() look like
>> declarative definition of MCFG table in ACPI spec, which makes it easy
>> to review.
>>
>> Signed-off-by: Wei Yang <address@hidden>
>> Suggested-by: Igor Mammedov <address@hidden>
>> Reviewed-by: Igor Mammedov <address@hidden>
>> Reviewed-by: Philippe Mathieu-Daudé <address@hidden>
> 
> Causes a regression with an invalid MCFG produced.
> Dropped.
> 
>> ---
>>  hw/acpi/pci.c               | 33 +++++++++++++++++++++------------
>>  include/hw/acpi/acpi-defs.h | 18 ------------------
>>  2 files changed, 21 insertions(+), 30 deletions(-)
>>
>> diff --git a/hw/acpi/pci.c b/hw/acpi/pci.c
>> index fa0fa30bb9..341805e786 100644
>> --- a/hw/acpi/pci.c
>> +++ b/hw/acpi/pci.c
>> @@ -30,17 +30,26 @@
>>  
>>  void build_mcfg(GArray *table_data, BIOSLinker *linker, AcpiMcfgInfo *info)
>>  {
>> -    AcpiTableMcfg *mcfg;
>> -    int len = sizeof(*mcfg) + sizeof(mcfg->allocation[0]);
>> -
>> -    mcfg = acpi_data_push(table_data, len);
>> -    mcfg->allocation[0].address = cpu_to_le64(info->base);
>> -
>> -    /* Only a single allocation so no need to play with segments */
>> -    mcfg->allocation[0].pci_segment = cpu_to_le16(0);
>> -    mcfg->allocation[0].start_bus_number = 0;
>> -    mcfg->allocation[0].end_bus_number = PCIE_MMCFG_BUS(info->size - 1);
>> -
>> -    build_header(linker, table_data, (void *)mcfg, "MCFG", len, 1, NULL, 
>> NULL);
>> +    int mcfg_start = table_data->len;
>> +
>> +    acpi_data_push(table_data, sizeof(AcpiTableHeader));

Ah, it seems we missed AcpiTableMcfg.reserved[8]...:

        build_append_int_noprefix(table_data, 0, 8);

>> +
>> +    /*
>> +     * PCI Firmware Specification, Revision 3.0
>> +     * 4.1.2 MCFG Table Description.
>> +     */
>> +    /* Base address, processor-relative */
>> +    build_append_int_noprefix(table_data, info->base, 8);
>> +    /* PCI segment group number */
>> +    build_append_int_noprefix(table_data, 0, 2);
>> +    /* Starting PCI Bus number */
>> +    build_append_int_noprefix(table_data, 0, 1);
>> +    /* Final PCI Bus number */
>> +    build_append_int_noprefix(table_data, PCIE_MMCFG_BUS(info->size - 1), 
>> 1);
>> +    /* Reserved */
>> +    build_append_int_noprefix(table_data, 0, 4);
>> +
>> +    build_header(linker, table_data, (void *)(table_data->data + 
>> mcfg_start),
>> +                 "MCFG", table_data->len - mcfg_start, 1, NULL, NULL);
>>  }
>>  
>> diff --git a/include/hw/acpi/acpi-defs.h b/include/hw/acpi/acpi-defs.h
>> index f9aa4bd398..57a3f58b0c 100644
>> --- a/include/hw/acpi/acpi-defs.h
>> +++ b/include/hw/acpi/acpi-defs.h
>> @@ -449,24 +449,6 @@ struct AcpiSratProcessorGiccAffinity {
>>  
>>  typedef struct AcpiSratProcessorGiccAffinity AcpiSratProcessorGiccAffinity;
>>  
>> -/* PCI fw r3.0 MCFG table. */
>> -/* Subtable */
>> -struct AcpiMcfgAllocation {
>> -    uint64_t address;                /* Base address, processor-relative */
>> -    uint16_t pci_segment;            /* PCI segment group number */
>> -    uint8_t start_bus_number;       /* Starting PCI Bus number */
>> -    uint8_t end_bus_number;         /* Final PCI Bus number */
>> -    uint32_t reserved;
>> -} QEMU_PACKED;
>> -typedef struct AcpiMcfgAllocation AcpiMcfgAllocation;
>> -
>> -struct AcpiTableMcfg {
>> -    ACPI_TABLE_HEADER_DEF;
>> -    uint8_t reserved[8];

           --------^

Thanks Michael for testing...

Wei, can you add a MCFG test in tests/bios-tables-test.c?

Regards,

Phil.

>> -    AcpiMcfgAllocation allocation[0];
>> -} QEMU_PACKED;
>> -typedef struct AcpiTableMcfg AcpiTableMcfg;
>> -
>>  /*
>>   * TCPA Description Table
>>   *
>> -- 
>> 2.19.1