Re: [PATCH 3/6] pcie: add power indicator blink check

["Michael S. Tsirkin" <mst@redhat.com>]

On Mon, Oct 11, 2021 at 02:05:01PM +0200, Gerd Hoffmann wrote:
> Refuse to push the attention button in case the guest is busy with some
> hotplug operation (as indicated by the power indicator blinking).
> 
> Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

Can't we do better and press the button later after
indicator stops blinking?

> ---
>  hw/pci/pcie.c | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/hw/pci/pcie.c b/hw/pci/pcie.c
> index 4a52c250615e..c455f92e16bf 100644
> --- a/hw/pci/pcie.c
> +++ b/hw/pci/pcie.c
> @@ -506,6 +506,7 @@ void pcie_cap_slot_unplug_request_cb(HotplugHandler *hotplug_dev,
>      PCIDevice *hotplug_pdev = PCI_DEVICE(hotplug_dev);
>      uint8_t *exp_cap = hotplug_pdev->config + hotplug_pdev->exp.exp_cap;
>      uint32_t sltcap = pci_get_word(exp_cap + PCI_EXP_SLTCAP);
> +    uint16_t sltctl = pci_get_word(exp_cap + PCI_EXP_SLTCTL);
>  
>      /* Check if hot-unplug is disabled on the slot */
>      if ((sltcap & PCI_EXP_SLTCAP_HPC) == 0) {
> @@ -521,6 +522,12 @@ void pcie_cap_slot_unplug_request_cb(HotplugHandler *hotplug_dev,
>          return;
>      }
>  
> +    if ((sltctl & PCI_EXP_SLTCTL_PIC) == PCI_EXP_SLTCTL_PWR_IND_BLINK) {
> +        error_setg(errp, "Hot-unplug failed: "
> +                   "guest is busy (power indicator blinking)");
> +        return;
> +    }
> +
>      dev->pending_deleted_event = true;
>  
>      /* In case user cancel the operation of multi-function hot-add,
> -- 
> 2.31.1