Re: [QEMU][PATCH v1 1/7] xen: when unplugging emulated devices skip virtio devices

[Stefano Stabellini]

On Thu, 5 Oct 2023, Vikram Garhwal wrote:
> From: Juergen Gross <jgross@suse.com>
> 
> Virtio devices should never be unplugged at boot time, as they are
> similar to pci passthrough devices.
> 
> Signed-off-by: Juergen Gross <jgross@suse.com>
> Signed-off-by: Vikram Garhwal <vikram.garhwal@amd.com>
> ---
>  hw/i386/xen/xen_platform.c | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/hw/i386/xen/xen_platform.c b/hw/i386/xen/xen_platform.c
> index 17457ff3de..3560eaf8c8 100644
> --- a/hw/i386/xen/xen_platform.c
> +++ b/hw/i386/xen/xen_platform.c
> @@ -28,6 +28,7 @@
>  #include "hw/ide/pci.h"
>  #include "hw/pci/pci.h"
>  #include "migration/vmstate.h"
> +#include "hw/virtio/virtio-bus.h"
>  #include "net/net.h"
>  #include "trace.h"
>  #include "sysemu/xen.h"
> @@ -132,7 +133,8 @@ static void unplug_nic(PCIBus *b, PCIDevice *d, void *o)
>      /* We have to ignore passthrough devices */
>      if (pci_get_word(d->config + PCI_CLASS_DEVICE) ==
>              PCI_CLASS_NETWORK_ETHERNET
> -            && !pci_device_is_passthrough(d)) {
> +            && !pci_device_is_passthrough(d)
> +            && !qdev_get_child_bus(&d->qdev, TYPE_VIRTIO_BUS)) {

Please update the in-code comment above to say "ignore passthrough
devices and virtio devices"


>          object_unparent(OBJECT(d));
>      }
>  }
> @@ -208,6 +210,10 @@ static void unplug_disks(PCIBus *b, PCIDevice *d, void 
> *opaque)
>      /* We have to ignore passthrough devices */
>      if (pci_device_is_passthrough(d))
>          return;
> +    /* Ignore virtio devices */
> +    if (qdev_get_child_bus(&d->qdev, TYPE_VIRTIO_BUS)) {
> +        return;
> +    }
>  
>      switch (pci_get_word(d->config + PCI_CLASS_DEVICE)) {
>      case PCI_CLASS_STORAGE_IDE:
> -- 
> 2.17.1
>