Re: [PATCH v3 3/4] hw/acpi: add indication for i8042 in IA-PC boot flags of the FADT table

[Liav Albani <liavalb@gmail.com>]

On 2/27/22 08:56, Ani Sinha wrote:
>
> On Sat, 26 Feb 2022, Liav Albani wrote:
>
>> This can allow the guest OS to determine more easily if i8042 controller
>> is present in the system or not, so it doesn't need to do probing of the
>> controller, but just initialize it immediately, before enumerating the
>> ACPI AML namespace.
>>
>> Signed-off-by: Liav Albani <liavalb@gmail.com>
>> ---
>>   hw/acpi/aml-build.c         | 7 ++++++-
>>   hw/i386/acpi-build.c        | 8 ++++++++
>>   hw/i386/acpi-microvm.c      | 9 +++++++++
>>   include/hw/acpi/acpi-defs.h | 1 +
>>   4 files changed, 24 insertions(+), 1 deletion(-)
>>
>> diff --git a/hw/acpi/aml-build.c b/hw/acpi/aml-build.c
>> index 8966e16320..ef5f4cad87 100644
>> --- a/hw/acpi/aml-build.c
>> +++ b/hw/acpi/aml-build.c
>> @@ -2152,7 +2152,12 @@ void build_fadt(GArray *tbl, BIOSLinker *linker, const AcpiFadtData *f,
>>       build_append_int_noprefix(tbl, 0, 1); /* DAY_ALRM */
>>       build_append_int_noprefix(tbl, 0, 1); /* MON_ALRM */
>>       build_append_int_noprefix(tbl, f->rtc_century, 1); /* CENTURY */
>> -    build_append_int_noprefix(tbl, 0, 2); /* IAPC_BOOT_ARCH */
>> +    /* IAPC_BOOT_ARCH */
>> +    if (f->rev == 1) {
>> +        build_append_int_noprefix(tbl, 0, 2);
>> +    } else {
>> +        build_append_int_noprefix(tbl, f->iapc_boot_arch, 2);
>> +    }
> Like a suggested in the previous iteration, please add a comment here to
> specify why you are adding this only for rev !=1 . Also please mention
> that your change only affects q35 machines since i440fx uses rev 1 (ref to
> acpi_get_pm_info()).
>
>
>>       build_append_int_noprefix(tbl, 0, 1); /* Reserved */
>>       build_append_int_noprefix(tbl, f->flags, 4); /* Flags */
>>
>> diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
>> index ebd47aa26f..65dbc1ec36 100644
>> --- a/hw/i386/acpi-build.c
>> +++ b/hw/i386/acpi-build.c
>> @@ -192,6 +192,14 @@ static void init_common_fadt_data(MachineState *ms, Object *o,
>>               .address = object_property_get_uint(o, ACPI_PM_PROP_GPE0_BLK, NULL)
>>           },
>>       };
>> +    /*
>> +     * second bit of 16 but
> wow, you even retained my typo here! :-)

Yeah, I figured this after I sent the patch series, sorry for that mistake!

>
>> IAPC_BOOT_ARCH indicates presence of 8042 or
>> +     * equivalent micro controller. See table 5-10 of APCI spec version 2.0
>> +     * (the earliest acpi revision that supports this).
>> +     */
>> +
>> +    fadt.iapc_boot_arch = isa_check_device_existence("i8042") ? 0x0002 : 0x0000;
>> +
>>       *data = fadt;
>>   }
>>
>> diff --git a/hw/i386/acpi-microvm.c b/hw/i386/acpi-microvm.c
>> index 68ca7e7fc2..e5f89164be 100644
>> --- a/hw/i386/acpi-microvm.c
>> +++ b/hw/i386/acpi-microvm.c
>> @@ -189,6 +189,15 @@ static void acpi_build_microvm(AcpiBuildTables *tables,
>>           .reset_val = ACPI_GED_RESET_VALUE,
>>       };
>>
>> +    /*
>> +     * second bit of 16 but IAPC_BOOT_ARCH indicates presence of 8042 or
>>
> ditto as above.
No problem, I'll send a v4 soon :)
>
>   +     * equivalent micro controller. See table 5-10 of APCI spec version 2.0
>> +     * (the earliest acpi revision that supports this).
>> +     */
>> +
>> +    pmfadt.iapc_boot_arch = isa_check_device_existence("i8042") ? 0x0002
>> +                            : 0x0000;
>> +
>>       table_offsets = g_array_new(false, true /* clear */,
>>                                           sizeof(uint32_t));
>>       bios_linker_loader_alloc(tables->linker,
>> diff --git a/include/hw/acpi/acpi-defs.h b/include/hw/acpi/acpi-defs.h
>> index c97e8633ad..2b42e4192b 100644
>> --- a/include/hw/acpi/acpi-defs.h
>> +++ b/include/hw/acpi/acpi-defs.h
>> @@ -77,6 +77,7 @@ typedef struct AcpiFadtData {
>>       uint16_t plvl2_lat;        /* P_LVL2_LAT */
>>       uint16_t plvl3_lat;        /* P_LVL3_LAT */
>>       uint16_t arm_boot_arch;    /* ARM_BOOT_ARCH */
>> +    uint16_t iapc_boot_arch;   /* IAPC_BOOT_ARCH */
>>       uint8_t minor_ver;         /* FADT Minor Version */
>>
>>       /*
>> --
>> 2.35.1
>>
>>