[libvirt PATCH] Adds e1000e/vmxnet3 Vnet_hdr suuport

[Patrick Magauran <patmagauran.j@xxxxxxxxx>]

Libvirt bases its decision about whether to apply the vnet_hdr flag to the tap interface on whether or not the selected model is VirtIO. Originally, VirtIO was the only model to support the vnet_hdr in QEMU; however, the e1000e & vmxnet3 adapters also support it(seemingly from introduction based on commits). This passes the whole packet to the host, reducing emulation overhead and improving performance.

Signed-off-by: Patrick Magauran <patmagauran.j@xxxxxxxxx>
---
 src/conf/domain_conf.c    | 8 +++++++-
 src/conf/domain_conf.h    | 1 +
 src/libvirt_private.syms  | 1 +
 src/qemu/qemu_interface.c | 8 ++++----
 4 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index 69e0439e7e..cb184110f7 100644
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -30981,7 +30981,13 @@ virDomainNetIsVirtioModel(const virDomainNetDef *net)
             net->model == VIR_DOMAIN_NET_MODEL_VIRTIO_TRANSITIONAL ||
             net->model == VIR_DOMAIN_NET_MODEL_VIRTIO_NON_TRANSITIONAL);
 }
-
+bool
+virDomainNetIsVnetCompatModel(const virDomainNetDef *net)
+{
+    return (virDomainNetIsVirtioModel(net) ||
+            net->model == VIR_DOMAIN_NET_MODEL_E1000E ||
+            net->model == VIR_DOMAIN_NET_MODEL_VMXNET3);
+}
 
 /* Return listens[i] from the appropriate union for the graphics
  * type, or NULL if this is an unsuitable type, or the index is out of
diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h
index 011bf66cb4..cbc46fdf78 100644
--- a/src/conf/domain_conf.h
+++ b/src/conf/domain_conf.h
@@ -3371,6 +3371,7 @@ const char *virDomainNetGetModelString(const virDomainNetDef *net);
 int virDomainNetSetModelString(virDomainNetDefPtr et,
                                const char *model);
 bool virDomainNetIsVirtioModel(const virDomainNetDef *net);
+bool virDomainNetIsVnetCompatModel(const virDomainNetDef *net);
 int virDomainNetAppendIPAddress(virDomainNetDefPtr def,
                                 const char *address,
                                 int family,
diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index 01c2e710cd..2b64042dd2 100644
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -525,6 +525,7 @@ virDomainNetGetActualVlan;
 virDomainNetGetModelString;
 virDomainNetInsert;
 virDomainNetIsVirtioModel;
+virDomainNetIsVnetCompatModel;
 virDomainNetModelTypeFromString;
 virDomainNetModelTypeToString;
 virDomainNetNotifyActualDevice;
diff --git a/src/qemu/qemu_interface.c b/src/qemu/qemu_interface.c
index ffec992596..8397ed8645 100644
--- a/src/qemu/qemu_interface.c
+++ b/src/qemu/qemu_interface.c
@@ -255,7 +255,7 @@ qemuInterfaceDirectConnect(virDomainDefPtr def,
     virQEMUDriverConfigPtr cfg = virQEMUDriverGetConfig(driver);
     unsigned int macvlan_create_flags = VIR_NETDEV_MACVLAN_CREATE_WITH_TAP;
 
-    if (virDomainNetIsVirtioModel(net))
+    if (virDomainNetIsVnetCompatModel(net))
         macvlan_create_flags |= VIR_NETDEV_MACVLAN_VNET_HDR;
 
     if (virNetDevMacVLanCreateWithVPortProfile(net->ifname,
@@ -417,7 +417,7 @@ qemuInterfaceEthernetConnect(virDomainDefPtr def,
         }
     }
 
-    if (virDomainNetIsVirtioModel(net))
+    if (virDomainNetIsVnetCompatModel(net))
         tap_create_flags |= VIR_NETDEV_TAP_CREATE_VNET_HDR;
 
     if (net->managed_tap == VIR_TRISTATE_BOOL_NO) {
@@ -436,7 +436,7 @@ qemuInterfaceEthernetConnect(virDomainDefPtr def,
             if (virNetDevMacVLanTapOpen(net->ifname, tapfd, tapfdSize) < 0)
                 goto cleanup;
             if (virNetDevMacVLanTapSetup(tapfd, tapfdSize,
-                                         virDomainNetIsVirtioModel(net)) < 0) {
+                                         virDomainNetIsVnetCompatModel(net)) < 0) {
                 goto cleanup;
             }
         } else {
@@ -559,7 +559,7 @@ qemuInterfaceBridgeConnect(virDomainDefPtr def,
         template_ifname = true;
     }
 
-    if (virDomainNetIsVirtioModel(net))
+    if (virDomainNetIsVnetCompatModel(net))
         tap_create_flags |= VIR_NETDEV_TAP_CREATE_VNET_HDR;
 
     if (driver->privileged) {
-- 
2.26.2