Re: [RESEND PATCH v21 3/6] ACPI: Add APEI GHES table generation support

[Michael S. Tsirkin]

On Mon, Nov 18, 2019 at 09:18:01PM +0800, gengdongjiu wrote:
> On 2019/11/18 20:49, gengdongjiu wrote:
> >>> +     */
> >>> +    build_append_int_noprefix(table_data, source_id, 2);
> >>> +    /* Related Source Id */
> >>> +    build_append_int_noprefix(table_data, 0xffff, 2);
> >>> +    /* Flags */
> >>> +    build_append_int_noprefix(table_data, 0, 1);
> >>> +    /* Enabled */
> >>> +    build_append_int_noprefix(table_data, 1, 1);
> >>> +
> >>> +    /* Number of Records To Pre-allocate */
> >>> +    build_append_int_noprefix(table_data, 1, 4);
> >>> +    /* Max Sections Per Record */
> >>> +    build_append_int_noprefix(table_data, 1, 4);
> >>> +    /* Max Raw Data Length */
> >>> +    build_append_int_noprefix(table_data, ACPI_GHES_MAX_RAW_DATA_LENGTH, 
> >>> 4);
> >>> +
> >>> +    /* Error Status Address */
> >>> +    build_append_gas(table_data, AML_AS_SYSTEM_MEMORY, 0x40, 0,
> >>> +                     4 /* QWord access */, 0);
> >>> +    bios_linker_loader_add_pointer(linker, ACPI_BUILD_TABLE_FILE,
> >>> +        ACPI_GHES_ERROR_STATUS_ADDRESS_OFFSET(hest_start, source_id),
> >> it's fine only if GHESv2 is the only entries in HEST, but once
> >> other types are added this macro will silently fall apart and
> >> cause table corruption.
>    why  silently fall?
>    I think the acpi_ghes.c only support GHESv2 type, not support other type.
> 
> >>
> >> Instead of offset from hest_start, I suggest to use offset relative
> >> to GAS structure, here is an idea>>
> >> #define GAS_ADDR_OFFSET 4
> >>
> >>     off = table->len
> >>     build_append_gas()
> >>     bios_linker_loader_add_pointer(...,
> >>         off + GAS_ADDR_OFFSET, ...
> 
> If use offset relative to GAS structure, the code does not easily extend to 
> support more Generic Hardware Error Source.
> if use offset relative to hest_start, just use a loop, the code can support  
> more error source, for example:
> for (source_id = 0; i<n; source_id++)
> {
>    ......
>     bios_linker_loader_add_pointer(linker, ACPI_BUILD_TABLE_FILE,
>         ACPI_GHES_ERROR_STATUS_ADDRESS_OFFSET(hest_start, source_id),
>         sizeof(uint64_t), ACPI_GHES_ERRORS_FW_CFG_FILE,
>         source_id * sizeof(uint64_t));
>   .......
> }
> 
> My previous series patch support 2 error sources, but now only enable 'SEA' 
> type Error Source

I'd try to merge this, worry about extending things later.
This is at v21 and the simpler you can keep things,
the faster it'll go in.