Re: [Qemu-devel] [PATCH] hw/pxb-pcie: fix PCI Express hotplug support

[Michael S. Tsirkin]

On Fri, Feb 03, 2017 at 12:05:52AM +0200, Marcel Apfelbaum wrote:
> Add the missing osc method for pxb-pcie devices
> 
> Signed-off-by: Marcel Apfelbaum <address@hidden>
> ---
> 
> Note: The patch is based on the fact that Q35's osc method is quite generic.
> 
> Thanks,
> Marcel
> 
>  hw/i386/acpi-build.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
> index 1c928ab..555aab3 100644
> --- a/hw/i386/acpi-build.c
> +++ b/hw/i386/acpi-build.c
> @@ -1964,6 +1964,11 @@ build_dsdt(GArray *table_data, BIOSLinker *linker,
>              aml_append(dev, aml_name_decl("_UID", aml_int(bus_num)));
>              aml_append(dev, aml_name_decl("_HID", aml_eisaid("PNP0A03")));
>              aml_append(dev, aml_name_decl("_BBN", aml_int(bus_num)));
> +            if (pci_bus_is_express(bus)) {
> +                aml_append(dev, aml_name_decl("SUPP", aml_int(0)));
> +                aml_append(dev, aml_name_decl("CTRL", aml_int(0)));
> +                aml_append(dev, build_q35_osc_method());
> +            }

I think we want to move this stuff into build_q35_osc_method:
"SUPP" seems to be 0, CTRL should be a variable passed in.


>              if (numa_node != NUMA_NODE_UNASSIGNED) {
>                  aml_append(dev, aml_name_decl("_PXM", aml_int(numa_node)));


In fact build_q35_osc_method needs to be cleaned up.
It stores result in "CTRL" which should be documented.

"SUPP" seems to be unused.

A bunch of comments missing.

More importantly, its an unserialized method but it creates a bunch of
fields so attempts to run two of these in parallel will crash.
I see the same in ACPI spec which probably means it should be
revisited with a critical eye.


> -- 
> 2.5.5