Re: [PATCH 02/11] pci: add option for net failover

[Alex Williamson <alex.williamson@redhat.com>]

On Fri, 18 Oct 2019 22:20:31 +0200
Jens Freimann <jfreimann@redhat.com> wrote:

> This patch adds a net_failover_pair_id property to PCIDev which is
> used to link the primary device in a failover pair (the PCI dev) to
> a standby (a virtio-net-pci) device.
> 
> It only supports ethernet devices. Also currently it only supports
> PCIe devices. QEMU will exit with an error message otherwise.

Doesn't the PCIe device also need to be hotpluggable?  We can have PCIe
devices attached to the root bus where we don't currently support
hotplug.  Thanks,

Alex
 
> Signed-off-by: Jens Freimann <jfreimann@redhat.com>
> ---
>  hw/pci/pci.c         | 17 +++++++++++++++++
>  include/hw/pci/pci.h |  3 +++
>  2 files changed, 20 insertions(+)
> 
> diff --git a/hw/pci/pci.c b/hw/pci/pci.c
> index aa05c2b9b2..fa9b5219f8 100644
> --- a/hw/pci/pci.c
> +++ b/hw/pci/pci.c
> @@ -75,6 +75,8 @@ static Property pci_props[] = {
>                      QEMU_PCIE_LNKSTA_DLLLA_BITNR, true),
>      DEFINE_PROP_BIT("x-pcie-extcap-init", PCIDevice, cap_present,
>                      QEMU_PCIE_EXTCAP_INIT_BITNR, true),
> +    DEFINE_PROP_STRING("net_failover_pair_id", PCIDevice,
> +            net_failover_pair_id),
>      DEFINE_PROP_END_OF_LIST()
>  };
>  
> @@ -2077,6 +2079,7 @@ static void pci_qdev_realize(DeviceState *qdev, Error **errp)
>      ObjectClass *klass = OBJECT_CLASS(pc);
>      Error *local_err = NULL;
>      bool is_default_rom;
> +    uint16_t class_id;
>  
>      /* initialize cap_present for pci_is_express() and pci_config_size(),
>       * Note that hybrid PCIs are not set automatically and need to manage
> @@ -2101,6 +2104,20 @@ static void pci_qdev_realize(DeviceState *qdev, Error **errp)
>          }
>      }
>  
> +    if (pci_dev->net_failover_pair_id) {
> +        if (!pci_is_express(pci_dev)) {
> +            error_setg(errp, "failover device is not a PCIExpress device");
> +            error_propagate(errp, local_err);
> +            return;
> +        }
> +        class_id = pci_get_word(pci_dev->config + PCI_CLASS_DEVICE);
> +        if (class_id != PCI_CLASS_NETWORK_ETHERNET) {
> +            error_setg(errp, "failover device is not an Ethernet device");
> +            error_propagate(errp, local_err);
> +            return;
> +        }
> +    }
> +
>      /* rom loading */
>      is_default_rom = false;
>      if (pci_dev->romfile == NULL && pc->romfile != NULL) {
> diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h
> index f3f0ffd5fb..def5435685 100644
> --- a/include/hw/pci/pci.h
> +++ b/include/hw/pci/pci.h
> @@ -352,6 +352,9 @@ struct PCIDevice {
>      MSIVectorUseNotifier msix_vector_use_notifier;
>      MSIVectorReleaseNotifier msix_vector_release_notifier;
>      MSIVectorPollNotifier msix_vector_poll_notifier;
> +
> +    /* ID of standby device in net_failover pair */
> +    char *net_failover_pair_id;
>  };
>  
>  void pci_register_bar(PCIDevice *pci_dev, int region_num,