Re: [PATCH 2/2] virtio reset support

Avi Kivity wrote:

Rusty Russell wrote:

quoted

+
+static void vp_reset(struct virtio_device *vdev)
+{
+    struct virtio_pci_device *vp_dev = to_vp_device(vdev);
+    /* 0 status means a reset. */
+    return iowrite8(0, vp_dev->ioaddr + VIRTIO_PCI_STATUS);
 }
  

pci has something called FLR for function-level reset.  If we use that 
as the reset mechanism, then reset can be initiated from outside the 
virtio layer, if the guest OS supports that.

PCI-e has a common reset concept (warm and cold).  I've been looking 
around and I can't seem to find any common reset mechanism for PCI.  Is 
FLR something that is per-device or a standard PCI mechanism?  If it's 
the former, than we've basically implemented FLR using this bit in the 
config space.

Regards,

Anthony Liguori