Add a fw_cfg device node to the ACPI SSDT, on machine types
pc-*-2.5 and up. While the guest-side BIOS 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>
---
hw/i386/acpi-build.c | 23 +++++++++++++++++++++++
hw/i386/pc_piix.c | 1 +
hw/i386/pc_q35.c | 1 +
include/hw/i386/pc.h | 1 +
4 files changed, 26 insertions(+)
diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
index 95e0c65..ece2710 100644
--- a/hw/i386/acpi-build.c
+++ b/hw/i386/acpi-build.c
@@ -906,6 +906,7 @@ build_ssdt(GArray *table_data, GArray *linker,
PcPciInfo *pci, PcGuestInfo *guest_info)
{
MachineState *machine = MACHINE(qdev_get_machine());
+ PCMachineClass *pcmc = PC_MACHINE_GET_CLASS(machine);
uint32_t nr_mem = machine->ram_slots;
unsigned acpi_cpus = guest_info->apic_id_limit;
Aml *ssdt, *sb_scope, *scope, *pkg, *dev, *method, *crs, *field, *ifctx;
@@ -1071,6 +1072,28 @@ build_ssdt(GArray *table_data, GArray *linker,
aml_append(scope, aml_name_decl("_S5", pkg));
aml_append(ssdt, scope);
+ if (!pcmc->acpi_no_fw_cfg_node) {
+ scope = aml_scope("\\_SB");
+ 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();
+ /* 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 */
+ aml_append(crs,
+ aml_io(AML_DECODE16, FW_CFG_IO_BASE, FW_CFG_IO_BASE,
+ 0x01, FW_CFG_CTL_SIZE)
+ );
+ aml_append(dev, aml_name_decl("_CRS", crs));
+
+ aml_append(scope, dev);
+ aml_append(ssdt, scope);
+ }
+
if (misc->applesmc_io_base) {
scope = aml_scope("\\_SB.PCI0.ISA");
dev = aml_device("SMC");
diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
index 3ffb05f..7f5e5d9 100644
--- a/hw/i386/pc_piix.c
+++ b/hw/i386/pc_piix.c
@@ -482,6 +482,7 @@ static void pc_i440fx_2_4_machine_options(MachineClass *m)
m->alias = NULL;
m->is_default = 0;
pcmc->broken_reserved_end = true;
+ pcmc->acpi_no_fw_cfg_node = true;
SET_MACHINE_COMPAT(m, PC_COMPAT_2_4);
}
diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c
index 1b7d3b6..7180ca3 100644
--- a/hw/i386/pc_q35.c
+++ b/hw/i386/pc_q35.c
@@ -385,6 +385,7 @@ static void pc_q35_2_4_machine_options(MachineClass *m)
pc_q35_2_5_machine_options(m);
m->alias = NULL;
pcmc->broken_reserved_end = true;
+ pcmc->acpi_no_fw_cfg_node = true;
SET_MACHINE_COMPAT(m, PC_COMPAT_2_4);
}
diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h
index 86007e3..6d0f1bd 100644
--- a/include/hw/i386/pc.h
+++ b/include/hw/i386/pc.h
@@ -62,6 +62,7 @@ struct PCMachineClass {
bool broken_reserved_end;
HotplugHandler *(*get_hotplug_handler)(MachineState *machine,
DeviceState *dev);
+ bool acpi_no_fw_cfg_node;
};
#define TYPE_PC_MACHINE "generic-pc-machine"
--
2.4.3
