On Fri, 19 Feb 2016 13:20:27 -0500
"Gabriel L. Somlo" <so...@cmu.edu> wrote:
> Add a fw_cfg device node to the ACPI DSDT. While the guest-side
> firmware 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 <so...@cmu.edu>
> Reviewed-by: Laszlo Ersek <ler...@redhat.com>
> Reviewed-by: Marc Marí <mar...@redhat.com>
Reviewed-by: Igor Mammedov <imamm...@redhat.com>
> ---
> hw/i386/acpi-build.c | 29 +++++++++++++++++++++++++++++
> 1 file changed, 29 insertions(+)
>
> diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
> index 4554eb8..915fddd 100644
> --- a/hw/i386/acpi-build.c
> +++ b/hw/i386/acpi-build.c
> @@ -2190,6 +2190,35 @@ build_dsdt(GArray *table_data, GArray *linker,
> aml_append(scope, aml_name_decl("_S5", pkg));
> aml_append(dsdt, scope);
>
> + /* create fw_cfg node, unconditionally */
> + {
> + /* 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; when using DMA, the
> + * DMA control register is located at FW_CFG_DMA_IO_BASE + 4 */
> + uint8_t io_size = object_property_get_bool(OBJECT(pcms->fw_cfg),
> + "dma_enabled", NULL) ?
> + ROUND_UP(FW_CFG_CTL_SIZE, 4) + sizeof(dma_addr_t) :
> + FW_CFG_CTL_SIZE;
> +
> + scope = aml_scope("\\_SB.PCI0");
> + 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();
> + aml_append(crs,
> + aml_io(AML_DECODE16, FW_CFG_IO_BASE, FW_CFG_IO_BASE, 0x01,
> io_size)
> + );
> + aml_append(dev, aml_name_decl("_CRS", crs));
> +
> + aml_append(scope, dev);
> + aml_append(dsdt, scope);
> + }
> +
> if (misc->applesmc_io_base) {
> scope = aml_scope("\\_SB.PCI0.ISA");
> dev = aml_device("SMC");
