Re: [Qemu-devel] [PATCH v4 3/5] acpi: pc: add fw_cfg device node to ssdt

[Gabriel L. Somlo]

On Tue, Sep 29, 2015 at 12:33:40PM +0200, Laszlo Ersek wrote:
> On 09/27/15 23:29, Gabriel L. Somlo wrote:
> > Add a fw_cfg device node to the ACPI SSDT, on machine types
> > pc-*-2.5 and up. While the guest-side BIOS can't utilize
> > this information (since it has to access the hard-coded
> > fw_cfg device to extract ACPI tables to begin with), having
> > fw_cfg listed in ACPI will help the guest kernel keep a more
> > accurate inventory of in-use IO port regions.
> > 
> > Signed-off-by: Gabriel Somlo <address@hidden>
> > ---
> >  hw/i386/acpi-build.c | 23 +++++++++++++++++++++++
> >  hw/i386/pc_piix.c    |  1 +
> >  hw/i386/pc_q35.c     |  1 +
> >  include/hw/i386/pc.h |  1 +
> >  4 files changed, 26 insertions(+)
> > 
> > diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
> > index 95e0c65..ece2710 100644
> > --- a/hw/i386/acpi-build.c
> > +++ b/hw/i386/acpi-build.c
> > @@ -906,6 +906,7 @@ build_ssdt(GArray *table_data, GArray *linker,
> >             PcPciInfo *pci, PcGuestInfo *guest_info)
> >  {
> >      MachineState *machine = MACHINE(qdev_get_machine());
> > +    PCMachineClass *pcmc = PC_MACHINE_GET_CLASS(machine);
> >      uint32_t nr_mem = machine->ram_slots;
> >      unsigned acpi_cpus = guest_info->apic_id_limit;
> >      Aml *ssdt, *sb_scope, *scope, *pkg, *dev, *method, *crs, *field, 
> > *ifctx;
> > @@ -1071,6 +1072,28 @@ build_ssdt(GArray *table_data, GArray *linker,
> >      aml_append(scope, aml_name_decl("_S5", pkg));
> >      aml_append(ssdt, scope);
> >  
> > +    if (!pcmc->acpi_no_fw_cfg_node) {
> > +        scope = aml_scope("\\_SB");
> > +        dev = aml_device("FWCF");
> > +
> > +        aml_append(dev, aml_name_decl("_HID", aml_string("QEMU0002")));
> > +        /* device present, functioning, decoding, not shown in UI */
> > +        aml_append(dev, aml_name_decl("_STA", aml_int(0xB)));
> > +
> > +        crs = aml_resource_template();
> > +        /* when using port i/o, the 8-bit data register *always* overlaps
> > +         * with half of the 16-bit control register. Hence, the total size
> > +         * of the i/o region used is FW_CFG_CTL_SIZE */
> > +        aml_append(crs,
> > +            aml_io(AML_DECODE16, FW_CFG_IO_BASE, FW_CFG_IO_BASE,
> > +                   0x01, FW_CFG_CTL_SIZE)
> > +        );
> 
> I think "aml_io" should be indented so that it lines up with "crs" above it.

There are a few other nodes being added in if() {...} bloks
immediately following the fw_cfg one. They *all* indent it this way, I
just made mine look similar. That said, I have no problem indenting
mine differently, if you still want me to... :)

> 
> Other than that:
> 
> Reviewed-by: Laszlo Ersek <address@hidden>
> 
> What Windows guests did you test this with? ("Testing" meant as "looked
> at Device Manager".) I can help with Windows 7, 8, and 10, if you'd like
> that.

I tested on winddows 7. After re-adding _STA set to 0x08, it no longer
complains about not being able to find a driver for it :)

Thanks,
--Gabriel

> 
> > +        aml_append(dev, aml_name_decl("_CRS", crs));
> > +
> > +        aml_append(scope, dev);
> > +        aml_append(ssdt, scope);
> > +    }
> > +
> >      if (misc->applesmc_io_base) {
> >          scope = aml_scope("\\_SB.PCI0.ISA");
> >          dev = aml_device("SMC");
> > diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
> > index 3ffb05f..7f5e5d9 100644
> > --- a/hw/i386/pc_piix.c
> > +++ b/hw/i386/pc_piix.c
> > @@ -482,6 +482,7 @@ static void pc_i440fx_2_4_machine_options(MachineClass 
> > *m)
> >      m->alias = NULL;
> >      m->is_default = 0;
> >      pcmc->broken_reserved_end = true;
> > +    pcmc->acpi_no_fw_cfg_node = true;
> >      SET_MACHINE_COMPAT(m, PC_COMPAT_2_4);
> >  }
> >  
> > diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c
> > index 1b7d3b6..7180ca3 100644
> > --- a/hw/i386/pc_q35.c
> > +++ b/hw/i386/pc_q35.c
> > @@ -385,6 +385,7 @@ static void pc_q35_2_4_machine_options(MachineClass *m)
> >      pc_q35_2_5_machine_options(m);
> >      m->alias = NULL;
> >      pcmc->broken_reserved_end = true;
> > +    pcmc->acpi_no_fw_cfg_node = true;
> >      SET_MACHINE_COMPAT(m, PC_COMPAT_2_4);
> >  }
> >  
> > diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h
> > index 86007e3..6d0f1bd 100644
> > --- a/include/hw/i386/pc.h
> > +++ b/include/hw/i386/pc.h
> > @@ -62,6 +62,7 @@ struct PCMachineClass {
> >      bool broken_reserved_end;
> >      HotplugHandler *(*get_hotplug_handler)(MachineState *machine,
> >                                             DeviceState *dev);
> > +    bool acpi_no_fw_cfg_node;
> >  };
> >  
> >  #define TYPE_PC_MACHINE "generic-pc-machine"
> > 
>