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

[Liav Albani]

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