[libvirt] [PATCH 1/4] util: fixing wrong assumption that PF has to have netdev assigned

[Radoslaw Biernacki]

libvirt wrongly assumes that VF netdev has to have the
netdev assigned to PF. There is no such requirement in SRIOV standard.
This patch change the virNetDevSwitchdevFeature() function to deal
with SRIOV devices which does not have netdev on PF. Also removes
one comment about PF netdev assumption.

One example of such devices is ThunderX VNIC.
By applying this change, VF device is used for virNetlinkCommand() as
it is the only netdev assigned to VNIC.

Signed-off-by: Radoslaw Biernacki <radoslaw.biernacki at linaro.org>
---
 src/util/virnetdev.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/src/util/virnetdev.c b/src/util/virnetdev.c
index 5867977df4..e55c538a29 100644
--- a/src/util/virnetdev.c
+++ b/src/util/virnetdev.c
@@ -1359,9 +1359,6 @@ virNetDevGetPhysicalFunction(const char *ifname, char **pfname)
     }
 
     if (!*pfname) {
-        /* this shouldn't be possible. A VF can't exist unless its
-         * PF device is bound to a network driver
-         */
         virReportError(VIR_ERR_INTERNAL_ERROR,
                        _("The PF device for VF %s has no network device name"),
                        ifname);
@@ -3182,8 +3179,11 @@ virNetDevSwitchdevFeature(const char *ifname,
     if ((is_vf = virNetDevIsVirtualFunction(ifname)) < 0)
         return ret;
 
-    if (is_vf == 1 && virNetDevGetPhysicalFunction(ifname, &pfname) < 0)
-        goto cleanup;
+    if (is_vf == 1) {
+        /* ignore error if PF does noto have netdev assigned
+         * in that case pfname == NULL */
+        ignore_value(virNetDevGetPhysicalFunction(ifname, &pfname));
+    }
 
     pci_device_ptr = pfname ? virNetDevGetPCIDevice(pfname) :
                               virNetDevGetPCIDevice(ifname);
-- 
2.14.1