On Tue, Mar 01, 2022 at 09:43:54AM +0100, Igor Mammedov wrote:
> On Mon, 28 Feb 2022 22:17:32 +0200
> Liav Albani <liav...@gmail.com> 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.
> >
> > This change only applies to the x86/q35 machine type, as it uses FACP
> > ACPI table with revision higher than 1, which should implement at least
> > ACPI 2.0 features within the table, hence it can also set the IA-PC boot
> > flags register according to the ACPI 2.0 specification.
> >
> > Signed-off-by: Liav Albani <liav...@gmail.com>
> > ---
> > hw/acpi/aml-build.c | 11 ++++++++++-
> > hw/i386/acpi-build.c | 9 +++++++++
> > hw/i386/acpi-microvm.c | 9 +++++++++
> commit message says it's q35 specific, so wy it touched microvm anc piix4?
>
> > include/hw/acpi/acpi-defs.h | 1 +
> > 4 files changed, 29 insertions(+), 1 deletion(-)
> >
> > diff --git a/hw/acpi/aml-build.c b/hw/acpi/aml-build.c
> > index 8966e16320..2085905b83 100644
> > --- a/hw/acpi/aml-build.c
> > +++ b/hw/acpi/aml-build.c
> > @@ -2152,7 +2152,16 @@ 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 */
> > + /*
> > + * This register is not defined in ACPI spec version 1.0, where the
> > FACP
> > + * revision == 1 also applies. Therefore, just ignore setting this
> > register.
> > + */
> > + if (f->rev == 1) {
> > + build_append_int_noprefix(tbl, 0, 2);
> > + } else {
> > + build_append_int_noprefix(tbl, f->iapc_boot_arch, 2);
> > + }
> > 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..c72c7bb9bb 100644
> > --- a/hw/i386/acpi-build.c
> > +++ b/hw/i386/acpi-build.c
> > @@ -38,6 +38,7 @@
> > #include "hw/nvram/fw_cfg.h"
> > #include "hw/acpi/bios-linker-loader.h"
> > #include "hw/isa/isa.h"
> > +#include "hw/input/i8042.h"
> > #include "hw/block/fdc.h"
> > #include "hw/acpi/memory_hotplug.h"
> > #include "sysemu/tpm.h"
> > @@ -192,6 +193,14 @@ 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 of the IAPC_BOOT_ARCH register indicates i8042
> > presence
> > + * or equivalent micro controller. See table 5-10 of APCI spec version
> > 2.0
> > + * (the earliest acpi revision that supports this).
>
> /* APCI spec version 2.0, Table 5-10 */
>
> is sufficient, the rest could be read from spec/
ACPI though, not APCI.
The comment can be shorter and more clearer, but I feel quoting spec
and including table name is a good idea actually, but pls quote verbatim:
/* ACPI spec version 2.0, Table 5-10: Fixed ACPI Description Table Boot
Architecture Flags */
/* Bit offset 1 - port 60 and 64 based keyboard controller, usually
implemented as an 8042 or equivalent micro-controller. */
>
> > + */
> > + fadt.iapc_boot_arch = object_resolve_path_type("", TYPE_I8042, NULL) ?
> > + 0x0002 : 0x0000;
and make it 0x1 << 1 - clearer that this is bit 1. Leading zeroes are
not helpful since compiler does not check there's a correct number of
these.
> > +
> > *data = fadt;
> > }
> >
> > diff --git a/hw/i386/acpi-microvm.c b/hw/i386/acpi-microvm.c
> > index 68ca7e7fc2..4bc72b1672 100644
> > --- a/hw/i386/acpi-microvm.c
> > +++ b/hw/i386/acpi-microvm.c
> > @@ -31,6 +31,7 @@
> > #include "hw/acpi/generic_event_device.h"
> > #include "hw/acpi/utils.h"
> > #include "hw/acpi/erst.h"
> > +#include "hw/input/i8042.h"
> > #include "hw/i386/fw_cfg.h"
> > #include "hw/i386/microvm.h"
> > #include "hw/pci/pci.h"
> > @@ -189,6 +190,14 @@ static void acpi_build_microvm(AcpiBuildTables *tables,
> > .reset_val = ACPI_GED_RESET_VALUE,
> > };
> >
> > + /*
> > + * second bit of 16 of the IAPC_BOOT_ARCH register indicates i8042
> > presence
> > + * or equivalent micro controller. See table 5-10 of APCI spec version
> > 2.0
> > + * (the earliest acpi revision that supports this).
> > + */
> > + pmfadt.iapc_boot_arch = object_resolve_path_type("", TYPE_I8042, NULL)
> > ?
> > + 0x0002 : 0x0000;
> > +
let's avoid code duplication pls.
> > 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 */
> >
> > /*
