On Tue, Nov 16, 2021 at 08:26:41PM +0100, Igor Mammedov wrote:
> On Tue, 16 Nov 2021 10:04:33 +0100
> Gerd Hoffmann <kra...@redhat.com> wrote:
>
> > Disable power control for pcie slots in case acpi hotplug is enabled
> > (6.2+ only for compatibility reasons). This makes sure we don't get
> > unpleasant surprises with pci devices not being functional due to slot
> > power being turned off.
> >
> > Signed-off-by: Gerd Hoffmann <kra...@redhat.com>
> > ---
> > hw/i386/pc_q35.c | 13 ++++++++++---
> > 1 file changed, 10 insertions(+), 3 deletions(-)
> >
> > diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c
> > index e1e100316d93..869ca4c130f0 100644
> > --- a/hw/i386/pc_q35.c
> > +++ b/hw/i386/pc_q35.c
> > @@ -247,9 +247,16 @@ static void pc_q35_init(MachineState *machine)
> > "x-keep-pci-slot-hpc",
> > NULL);
> >
> > - if (!keep_pci_slot_hpc && acpi_pcihp) {
> > - object_register_sugar_prop(TYPE_PCIE_SLOT, "x-native-hotplug",
> > - "false", true);
> > + if (acpi_pcihp) {
> > + if (keep_pci_slot_hpc) {
> > + /* 6.2+ default: acpi-hotplug=on native-hotplug=on
> > power-ctrl=off */
> > + object_register_sugar_prop(TYPE_PCIE_SLOT, COMPAT_PROP_PCP,
> > + "false", true);
>
> that will also turn off COMPAT_PROP_PCP on ports attached to PXBs,
> where ACPI hotplug is not used and native one is active.
Oh, wasn't aware of that detail.
> So question is if it's expected behavior?
Nope. When native hotplug is used slot power control should be enabled.
Not sure how to handle that best though ...
take care,
Gerd
