On Thu, Oct 01, 2015 at 01:52:59PM +0200, Laszlo Ersek wrote:
> On 10/01/15 13:33, Igor Mammedov wrote:
> > On Thu, 1 Oct 2015 10:27:15 +0200
> > Laszlo Ersek <ler...@redhat.com> wrote:
> >
> >> On 10/01/15 09:02, Igor Mammedov wrote:
> >>> On Sun, 27 Sep 2015 17:29:00 -0400
> >>> "Gabriel L. Somlo" <so...@cmu.edu> wrote:
> >>>
> >>>> 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) {
> >>> we don't really care about SSDT size changes since during
> >>> migration ACPI blobs will be migrated from source, so
> >>> machine compat bloat is excessive here. It would be better
> >>> to just remove it.
> >>
> >> This was Eduardo's suggestion, if I recall correctly:
> >>
> >> http://thread.gmane.org/gmane.comp.emulators.qemu/361930/focus=361983
> >>
> >> The idea being, if you move a guest from older QEMU to newer QEMU, but
> >> keep the machine type (or more precisely, the full machine config, like
> >> the domain XML) intact, the ACPI device node should not appear out of
> >> the blue.
> > This ACPI device is an always used resource declaration regardless
> > of machine type so it makes sense to tell guest about used resource.
> >
> > The only reason for machine compat code would be if guest suddenly
> > started to ask for a driver but as Gabriel showed with _STA(0xB)
> > it doesn't, so I'm trying to keep ACPI code machine compat agnostic
> > as much as possible.
>
> Fine by me, but I think Eduardo should agree (or disagree) as well,
> because it was his point originally.
I have no problem taking the compat logic back out, if Eduardo agrees
that's an OK thing to do.
> >>>> + 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)
> >>>> + );
> >>> could you check/dump this _CRS and PCI0._CRS to see if they are
> >>> intersecting
> >>> in any way?
On bot PIIX and Q35, there's no _CRS under PCI0 in the dsdt.
All I could find was
Scope (\_SB.PCI0)
{
Name (_CRS, ...)
IO (Decode16,
0x0CF8, // Range Minimum
0x0CF8, // Range Maximum
0x01, // Alignment
0x08, // Length
)
...
So that does not overlap with fw_cfg.
In fact, I searched for all "IO (Decode..." occurrences, and nothing
in either DSDT or SSDT has any overlap with [ 0x510 .. 0x512 ].
Thanks,
-- Gabriel
> >>>
> >>>
> >>>> + 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"
> >>>
> >>
> >
>
