Re: [PATCH 5/6] pcie: fast unplug when slot power is off

[Gerd Hoffmann]

On Tue, Oct 12, 2021 at 01:56:31AM -0400, Michael S. Tsirkin wrote:
> On Mon, Oct 11, 2021 at 02:05:03PM +0200, Gerd Hoffmann wrote:
> > In case the slot is powered off (and the power indicator turned off too)
> > we can unplug right away, without round-trip to the guest.
> > 
> > Also clear pending attention button press, there is nothing to care
> > about any more.
> > 
> > Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
> > ---
> >  hw/pci/pcie.c | 10 ++++++++++
> >  1 file changed, 10 insertions(+)
> > 
> > diff --git a/hw/pci/pcie.c b/hw/pci/pcie.c
> > index 70fc11ba4c7d..f3ac04399969 100644
> > --- a/hw/pci/pcie.c
> > +++ b/hw/pci/pcie.c
> > @@ -561,6 +561,16 @@ void pcie_cap_slot_unplug_request_cb(HotplugHandler 
> > *hotplug_dev,
> >          return;
> >      }
> >  
> > +    if (((sltctl & PCI_EXP_SLTCTL_PIC) == PCI_EXP_SLTCTL_PWR_IND_OFF) &&
> > +        ((sltctl & PCI_EXP_SLTCTL_PCC) == PCI_EXP_SLTCTL_PWR_OFF)) {
> > +        /* slot is powered off -> unplug without round-trip to the guest */
> > +        pcie_cap_slot_do_unplug(hotplug_pdev);
> > +        hotplug_event_notify(hotplug_pdev);
> > +        pci_word_test_and_clear_mask(exp_cap + PCI_EXP_SLTSTA,
> > +                                     PCI_EXP_SLTSTA_ABP);
> 
> Does this handle all the things including link status etc btw?
> I don't remember off-hand.

Yes.  See patch #4 which moves the relevant code to the new
pcie_cap_slot_do_unplug() helper.

take care,
  Gerd