When vfio device is reset(encounter FLR, or bus reset), if need to do
bus reset(vfio_pci_hot_reset_one is called), vfio_pci_pre_reset &
vfio_pci_post_reset will be called twice.

Signed-off-by: Cao jin <caoj.f...@cn.fujitsu.com>
Also has a little question on vfio_pci_reset. it will be called when encounter
bus reset, or FLR. The reset method's priority in this function now is:

    1. If has "device specific reset function", then do it
    2. If has FLR, then do it.
    3. If it can do bus reset(only 1 affected device), then do it
    4. If has pm_reset, then do it

The question is: why pm reset has low priority than bus reset(if it does
can do a bus reset)? why bus reset is not the last choice? In PCI driver
of kernel, pls see __pci_dev_reset, we can see, if device support pm reset,
it won't do bus reset.

 hw/vfio/pci.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
index cce3024..ca4d1c1 100644
--- a/hw/vfio/pci.c
+++ b/hw/vfio/pci.c
@@ -1930,7 +1930,9 @@ static int vfio_pci_hot_reset(VFIOPCIDevice *vdev, bool 
     trace_vfio_pci_hot_reset(vdev->vbasedev.name, single ? "one" : "multi");
-    vfio_pci_pre_reset(vdev);
+    if (!single) {
+        vfio_pci_pre_reset(vdev);
+    }
     vdev->vbasedev.needs_reset = false;
     info = g_malloc0(sizeof(*info));
@@ -2088,7 +2090,9 @@ out:
-    vfio_pci_post_reset(vdev);
+    if (!single) {
+        vfio_pci_post_reset(vdev);
+    }
     return ret;

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