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

[Michael S. Tsirkin]

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.

> +        return;
> +    }
> +
>      pcie_cap_slot_push_attention_button(hotplug_pdev);
>  }
>  
> -- 
> 2.31.1