On Fri, Nov 30, 2018 at 08:26:21AM +0100, Igor Mammedov wrote:
> On Thu, 29 Nov 2018 15:26:27 +0100
> Samuel Ortiz <sa...@linux.intel.com> wrote:
>
> > 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 <sa...@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).
> My guess would be that's for detecting an optional field and
> skipping setting it in build_rsdp(). But it's mostly for
> consistence with current code.
>
> >
> > > > +} 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
> then one would get random junk from the stack this variable is allocate from
> in this field.
Not when you initialize the structure with = { ... }. All uninitialized
pointers will be NULL and all uninitialized arithmetic types will be zero.
Of course explicitly setting it to NULL is fine too, which is why this is
only a "nit".
>
> > Unfortunately, yes.
> >
> > Cheers,
> > Samuel.
>
>
