Re: [Qemu-devel] [PATCH 2/4] hw/virtio: fix error enabling flags in Device Control register

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

On Wed, Jan 04, 2017 at 09:57:16PM +0200, Marcel Apfelbaum wrote:
> When the virtio devices are PCI Express, make error-enabling flags
> writable to respect the PCIe spec.
> 
> Signed-off-by: Marcel Apfelbaum <marcel@redhat.com>

If guest writes there, it won't be able to migrate.
So I think this needs a compat flag.

> ---
>  hw/virtio/virtio-pci.c | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
> index 21c2b9d..da2124f 100644
> --- a/hw/virtio/virtio-pci.c
> +++ b/hw/virtio/virtio-pci.c
> @@ -1802,6 +1802,8 @@ static void virtio_pci_realize(PCIDevice *pci_dev, Error **errp)
>           * PCI Power Management Interface Specification.
>           */
>          pci_set_word(pci_dev->config + pos + PCI_PM_PMC, 0x3);
> +        /* Init error enabling flags */
> +        pcie_cap_deverr_init(pci_dev);
>      } else {
>          /*
>           * make future invocations of pci_is_express() return false
> @@ -1828,6 +1830,7 @@ static void virtio_pci_reset(DeviceState *qdev)
>  {
>      VirtIOPCIProxy *proxy = VIRTIO_PCI(qdev);
>      VirtioBusState *bus = VIRTIO_BUS(&proxy->bus);
> +    PCIDevice *dev = PCI_DEVICE(qdev);
>      int i;
>  
>      virtio_pci_stop_ioeventfd(proxy);
> @@ -1837,6 +1840,10 @@ static void virtio_pci_reset(DeviceState *qdev)
>      for (i = 0; i < VIRTIO_QUEUE_MAX; i++) {
>          proxy->vqs[i].enabled = 0;
>      }
> +
> +    if (pci_is_express(dev)) {
> +        pcie_cap_deverr_reset(dev);
> +    }
>  }
>  
>  static Property virtio_pci_properties[] = {
> -- 
> 2.5.5