Re: [Qemu-devel] [PATCH v2 4/8] hw: arm: Carry RSDP specific data through AcpiRsdpData

[Samuel Ortiz <sameo@linux.intel.com>]

On Thu, Nov 29, 2018 at 03:09:32PM +0100, Andrew Jones wrote:
> On Thu, Nov 29, 2018 at 02:24:24PM +0100, Samuel Ortiz wrote:
> > That will allow us to generalize the ARM build_rsdp() routine to support
> > both legacy RSDP (The current i386 implementation) and extended RSDP
> > (The ARM implementation).
> > 
> > Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
> > ---
> >  include/hw/acpi/acpi-defs.h |  8 ++++++++
> >  hw/arm/virt-acpi-build.c    | 18 +++++++++++++-----
> >  2 files changed, 21 insertions(+), 5 deletions(-)
> > 
> > diff --git a/include/hw/acpi/acpi-defs.h b/include/hw/acpi/acpi-defs.h
> > index af8e023968..8425ecb8c6 100644
> > --- a/include/hw/acpi/acpi-defs.h
> > +++ b/include/hw/acpi/acpi-defs.h
> > @@ -53,6 +53,14 @@ struct AcpiRsdpDescriptor {        /* Root System Descriptor Pointer */
> >  } QEMU_PACKED;
> >  typedef struct AcpiRsdpDescriptor AcpiRsdpDescriptor;
> >  
> > +typedef struct AcpiRsdpData {
> > +    uint8_t oem_id[6]; /* OEM identification */
> > +    uint8_t revision;  /* Must be 0 for 1.0, 2 for 2.0 */
> > +
> > +    unsigned *rsdt_tbl_offset;
> > +    unsigned *xsdt_tbl_offset;
> 
> Why use pointers?
Mostly to be consistent with the FADT data structure (AcpiFadtData).


> > +} AcpiRsdpData;
> > +
> >  /* Table structure from Linux kernel (the ACPI tables are under the
> >     BSD license) */
> >  
> > diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c
> > index 0835900052..ce8bfa5a37 100644
> > --- a/hw/arm/virt-acpi-build.c
> > +++ b/hw/arm/virt-acpi-build.c
> > @@ -368,7 +368,7 @@ static void acpi_dsdt_add_power_button(Aml *scope)
> >  
> >  /* RSDP */
> >  static void
> > -build_rsdp(GArray *rsdp_table, BIOSLinker *linker, unsigned xsdt_tbl_offset)
> > +build_rsdp(GArray *rsdp_table, BIOSLinker *linker, AcpiRsdpData *rsdp_data)
> >  {
> >      AcpiRsdpDescriptor *rsdp = acpi_data_push(rsdp_table, sizeof *rsdp);
> >      unsigned xsdt_pa_size = sizeof(rsdp->xsdt_physical_address);
> > @@ -379,14 +379,14 @@ build_rsdp(GArray *rsdp_table, BIOSLinker *linker, unsigned xsdt_tbl_offset)
> >                               true /* fseg memory */);
> >  
> >      memcpy(&rsdp->signature, "RSD PTR ", sizeof(rsdp->signature));
> > -    memcpy(rsdp->oem_id, ACPI_BUILD_APPNAME6, sizeof(rsdp->oem_id));
> > +    memcpy(rsdp->oem_id, rsdp_data->oem_id, sizeof(rsdp->oem_id));
> 
> sizeof(rsdp_data->oem_id)
Which is the same thing. Note that this piece of code eventually gets
removed later in the serie.



> >      rsdp->length = cpu_to_le32(sizeof(*rsdp));
> > -    rsdp->revision = 0x02;
> > +    rsdp->revision = rsdp_data->revision;
> >  
> >      /* Address to be filled by Guest linker */
> >      bios_linker_loader_add_pointer(linker,
> >          ACPI_BUILD_RSDP_FILE, xsdt_pa_offset, xsdt_pa_size,
> > -        ACPI_BUILD_TABLE_FILE, xsdt_tbl_offset);
> > +        ACPI_BUILD_TABLE_FILE, *rsdp_data->xsdt_tbl_offset);
> >  
> >      /* Checksum to be filled by Guest linker */
> >      bios_linker_loader_add_checksum(linker, ACPI_BUILD_RSDP_FILE,
> > @@ -857,7 +857,15 @@ void virt_acpi_build(VirtMachineState *vms, AcpiBuildTables *tables)
> >      build_xsdt(tables_blob, tables->linker, table_offsets, NULL, NULL);
> >  
> >      /* RSDP is in FSEG memory, so allocate it separately */
> > -    build_rsdp(tables->rsdp, tables->linker, xsdt);
> > +    {
> > +        AcpiRsdpData rsdp_data = {
> > +            .revision = 2,
> > +            .oem_id = ACPI_BUILD_APPNAME6,
> > +            .xsdt_tbl_offset = &xsdt,
> > +            .rsdt_tbl_offset = NULL,
> 
> nit: no need for this explicit NULLing
Unfortunately, yes.

Cheers,
Samuel.