Re: [Qemu-devel] [PATCH v2] pc: acpi: force FADT rev1 for 440fx based machine types

["Michael S. Tsirkin" <mst@redhat.com>]

On Wed, Jul 26, 2017 at 04:09:37PM +0200, Igor Mammedov wrote:
> On Tue, 25 Jul 2017 16:36:06 +0300
> "Michael S. Tsirkin" <mst@redhat.com> wrote:
> 
> > On Mon, Jul 24, 2017 at 03:50:20PM +0200, Igor Mammedov wrote:
> > > w2k used to boot on QEMU until revision of FADT has
> > > been bumped to rev3
> > > (commit 77af8a2b hw/i386: Use Rev3 FADT (ACPI 2.0) instead of Rev1 to improve guest OS support.)
> > > 
> > > Keep PC machine at rev1 to remain compatible and Q35
> > > at rev3 where w2k isn't supported anyway so OSX could
> > > run as well.
> > > 
> > > Signed-off-by: Igor Mammedov <imammedo@redhat.com>
> > > ---
> > > v2:
> > >    - make pc rev1 and q35 rev3.
> > >        "Michael S. Tsirkin" <mst@redhat.com>
> > > 
> > > PS:
> > > Only compile tested.
> > > 
> > > 
> > > CC: Programmingkid <programmingkidx@gmail.com>
> > > CC: Phil Dennis-Jordan <lists@philjordan.eu>
> > > CC: "Michael S. Tsirkin" <mst@redhat.com>
> > > 
> > > ---
> > >  hw/i386/acpi-build.c | 22 ++++++++++++++++++----
> > >  1 file changed, 18 insertions(+), 4 deletions(-)
> > > 
> > > diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
> > > index 6b7bade..b9c245c 100644
> > > --- a/hw/i386/acpi-build.c
> > > +++ b/hw/i386/acpi-build.c
> > > @@ -90,6 +90,7 @@ typedef struct AcpiMcfgInfo {
> > >  } AcpiMcfgInfo;
> > >  
> > >  typedef struct AcpiPmInfo {
> > > +    bool force_rev1_fadt;
> > >      bool s3_disabled;
> > >      bool s4_disabled;
> > >      bool pcihp_bridge_en;
> > > @@ -129,10 +130,13 @@ static void acpi_get_pm_info(AcpiPmInfo *pm)
> > >      Object *obj = NULL;
> > >      QObject *o;
> > >  
> > > +    pm->force_rev1_fadt = false;
> > >      pm->cpu_hp_io_base = 0;
> > >      pm->pcihp_io_base = 0;
> > >      pm->pcihp_io_len = 0;
> > >      if (piix) {
> > > +        /* w2k requires FADT(rev1) or it won't boot, keep PC compatible */
> > > +        pm->force_rev1_fadt = true;
> > >          obj = piix;
> > >          pm->cpu_hp_io_base = PIIX4_CPU_HOTPLUG_IO_BASE;
> > >          pm->pcihp_io_base =
> > > @@ -304,6 +308,9 @@ static void fadt_setup(AcpiFadtDescriptorRev3 *fadt, AcpiPmInfo *pm)
> > >          fadt->flags |= cpu_to_le32(1 << ACPI_FADT_F_FORCE_APIC_CLUSTER_MODEL);
> > >      }
> > >      fadt->century = RTC_CENTURY;
> > > +    if (pm->force_rev1_fadt) {
> > > +        return;
> > > +    }
> > >  
> > >      fadt->flags |= cpu_to_le32(1 << ACPI_FADT_F_RESET_REG_SUP);
> > >      fadt->reset_value = 0xf;
> > > @@ -342,6 +349,8 @@ build_fadt(GArray *table_data, BIOSLinker *linker, AcpiPmInfo *pm,
> > >      unsigned fw_ctrl_offset = (char *)&fadt->firmware_ctrl - table_data->data;
> > >      unsigned dsdt_entry_offset = (char *)&fadt->dsdt - table_data->data;
> > >      unsigned xdsdt_entry_offset = (char *)&fadt->x_dsdt - table_data->data;
> > > +    int fadt_size = sizeof(*fadt);
> > > +    int rev = 3;
> > >  
> > >      /* FACS address to be filled by Guest linker */
> > >      bios_linker_loader_add_pointer(linker,
> > > @@ -353,12 +362,17 @@ build_fadt(GArray *table_data, BIOSLinker *linker, AcpiPmInfo *pm,
> > >      bios_linker_loader_add_pointer(linker,
> > >          ACPI_BUILD_TABLE_FILE, dsdt_entry_offset, sizeof(fadt->dsdt),
> > >          ACPI_BUILD_TABLE_FILE, dsdt_tbl_offset);
> > > -    bios_linker_loader_add_pointer(linker,
> > > -        ACPI_BUILD_TABLE_FILE, xdsdt_entry_offset, sizeof(fadt->x_dsdt),
> > > -        ACPI_BUILD_TABLE_FILE, dsdt_tbl_offset);
> > > +    if (pm->force_rev1_fadt) {
> > > +        rev = 1;
> > > +        fadt_size = offsetof(typeof(*fadt), reset_register);  
> > 
> > I don't really like it that we are using structs to format fields - I
> > would prefer build_append_int_noprefix based APIs - but since we do,
> > let's add a proper structure for FADT rev 1 instead of this hack.
> I'll do it.
> 
> > 
> > While we are at it, maybe we should replace macro hacks like
> > ACPI_FADT_COMMON_DEF with simple sub-structures (unless you see a reason
> > not to).
> that would be rewriting every user that touches fields,
> I'd ratter slowly /one table at time/ switch to build_append_int_noprefix() API
> instead of amending legacy approach.

Fine with me.

> > 
> > 
> > > +    } else {
> > > +        bios_linker_loader_add_pointer(linker,
> > > +            ACPI_BUILD_TABLE_FILE, xdsdt_entry_offset, sizeof(fadt->x_dsdt),
> > > +            ACPI_BUILD_TABLE_FILE, dsdt_tbl_offset);
> > > +    }
> > >  
> > >      build_header(linker, table_data,
> > > -                 (void *)fadt, "FACP", sizeof(*fadt), 3, oem_id, oem_table_id);
> > > +                 (void *)fadt, "FACP", fadt_size, rev, oem_id, oem_table_id);
> > >  }
> > >  
> > >  void pc_madt_cpu_entry(AcpiDeviceIf *adev, int uid,
> > > -- 
> > > 2.7.4  
> >