Re: [Qemu-devel] [RFC PATCH] pci: deassert intx when pci device unrealize

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

On Mon, Apr 24, 2017 at 09:12:29PM +0800, Herongguang (Stephen) wrote:
> If a pci device is not reset by VM (by writing into config space)
> and unplugged by VM, after that when VM reboots, qemu may assert:
> pcibus_reset: Assertion `bus->irq_count[i] == 0' failed
> 
> Signed-off-by: herongguang <herongguang.he@huawei.com>

Good grief, I can't believe we have had this bug for so long.
Thanks a lot for finding this.

Pls Cc stable on this patch.

> ---
> 
> Is there need to call pci_do_device_reset()?

I don't think so, why?

> ---
>  hw/pci/pci.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/hw/pci/pci.c b/hw/pci/pci.c
> index 259483b..afe6397 100644
> --- a/hw/pci/pci.c
> +++ b/hw/pci/pci.c
> @@ -1078,6 +1078,7 @@ static void pci_qdev_unrealize(DeviceState *dev, Error **errp)
> 
>      pci_unregister_io_regions(pci_dev);
>      pci_del_option_rom(pci_dev);
> +    pci_device_deassert_intx(pci_dev);

I think the right place to call this is after class exit
when we know no one will try to assert the interrupt.

> 
>      if (pc->exit) {
>          pc->exit(pci_dev);
> --
> 1.7.12.4