Re: [Qemu-devel] [PATCH v4 10/20] hw/arm/virt-acpi-build: Generate RSDT table

[Igor Mammedov <imammedo@redhat.com>]

On Thu, 09 Apr 2015 13:50:52 +0100
Alex Bennée <alex.bennee@linaro.org> wrote:

> 
> Shannon Zhao <zhaoshenglong@huawei.com> writes:
> 
> > From: Shannon Zhao <shannon.zhao@linaro.org>
> >
> > RSDT points to other tables FADT, MADT, GTDT.
> >
> > Signed-off-by: Shannon Zhao <zhaoshenglong@huawei.com>
> > Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
> > ---
> >  hw/arm/virt-acpi-build.c | 27 +++++++++++++++++++++++++++
> >  1 file changed, 27 insertions(+)
> >
> > diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c
> > index a7aba75..85e84b1 100644
> > --- a/hw/arm/virt-acpi-build.c
> > +++ b/hw/arm/virt-acpi-build.c
> > @@ -176,6 +176,30 @@ static void acpi_dsdt_add_virtio(Aml *scope, const hwaddr *mmio_addrs,
> >      }
> >  }
> >  
> > +/* RSDT */
> > +static void
> > +build_rsdt(GArray *table_data, GArray *linker, GArray *table_offsets)
this function looks like exact copy of x86 impl.,
could you reuse that?

> > +{
> > +    AcpiRsdtDescriptorRev1 *rsdt;
> > +    size_t rsdt_len;
> > +    int i;
> > +
> > +    rsdt_len = sizeof(*rsdt) + sizeof(uint32_t) * table_offsets->len;
> 
> You should use explicit brackets to be unambiguous:
> 
>        rsdt_len = sizeof(*rsdt) + (sizeof(uint32_t) * table_offsets->len);
> 
> > +    rsdt = acpi_data_push(table_data, rsdt_len);
> > +    memcpy(rsdt->table_offset_entry, table_offsets->data,
> > +           sizeof(uint32_t) * table_offsets->len);
> 
> Or perhaps split the sizes:
> 
>    const int table_data_len = (sizeof(uint32_t) * table_offsets->len);
> 
>    rsdt_len = sizeof(*rsdt) + table_data_len;
>    rsdt = acpi_data_push(table_data, rsdt_len);
>    memcpy(rsdt->table_offset_entry, table_offsets->data, table_data_len)
> 
> Maybe?
> 
> > +    for (i = 0; i < table_offsets->len; ++i) {
> > +        /* rsdt->table_offset_entry to be filled by Guest linker */
> > +        bios_linker_loader_add_pointer(linker,
> > +                                       ACPI_BUILD_TABLE_FILE,
> > +                                       ACPI_BUILD_TABLE_FILE,
> > +                                       table_data, &rsdt->table_offset_entry[i],
> > +                                       sizeof(uint32_t));
> 
> Why are these pointers always 32 bit? Can they ever be 64 bit?
Laszlo, can you confirm that UEFI puts APCI tables below 4G address space?


> 
> > +    }
> > +    build_header(linker, table_data,
> > +                 (void *)rsdt, "RSDT", rsdt_len, 1);
> > +}
> > +
> >  /* GTDT */
> >  static void
> >  build_gtdt(GArray *table_data, GArray *linker, VirtGuestInfo *guest_info)
> > @@ -348,6 +372,9 @@ void virt_acpi_build(VirtGuestInfo *guest_info, AcpiBuildTables *tables)
> >      acpi_add_table(table_offsets, tables_blob);
> >      build_gtdt(tables_blob, tables->linker, guest_info);
> >  
> > +    /* RSDT is pointed to by RSDP */
> > +    build_rsdt(tables_blob, tables->linker, table_offsets);
> > +
> >      /* Cleanup memory that's no longer used. */
> >      g_array_free(table_offsets, true);
> >  }
>