Changes from Original:
Moved Comparison to qemuInterfaceIsVnetCompatModel in qemu_interface.c per the recommendation of Daniel Berrangé
-----
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/qemu/qemu_interface.c | 15 +++++++++++----
src/qemu/qemu_interface.h | 1 +
2 files changed, 12 insertions(+), 4 deletions(-)
diff --git a/src/qemu/qemu_interface.c b/src/qemu/qemu_interface.c
index ffec992596..229bb299aa 100644
--- a/src/qemu/qemu_interface.c
+++ b/src/qemu/qemu_interface.c
@@ -230,6 +230,13 @@ qemuInterfaceStopDevices(virDomainDefPtr def)
return 0;
}
+bool qemuInterfaceIsVnetCompatModel(const virDomainNetDef *net)
+{
+ return (virDomainNetIsVirtioModel(net) ||
+ net->model == VIR_DOMAIN_NET_MODEL_E1000E ||
+ net->model == VIR_DOMAIN_NET_MODEL_VMXNET3);
+}
+
/**
* qemuInterfaceDirectConnect:
@@ -255,7 +262,7 @@ qemuInterfaceDirectConnect(virDomainDefPtr def,
virQEMUDriverConfigPtr cfg = virQEMUDriverGetConfig(driver);
unsigned int macvlan_create_flags = VIR_NETDEV_MACVLAN_CREATE_WITH_TAP;
- if (virDomainNetIsVirtioModel(net))
+ if (qemuInterfaceIsVnetCompatModel(net))
macvlan_create_flags |= VIR_NETDEV_MACVLAN_VNET_HDR;
if (virNetDevMacVLanCreateWithVPortProfile(net->ifname,
@@ -417,7 +424,7 @@ qemuInterfaceEthernetConnect(virDomainDefPtr def,
}
}
- if (virDomainNetIsVirtioModel(net))
+ if (qemuInterfaceIsVnetCompatModel(net))
tap_create_flags |= VIR_NETDEV_TAP_CREATE_VNET_HDR;
if (net->managed_tap == VIR_TRISTATE_BOOL_NO) {
@@ -436,7 +443,7 @@ qemuInterfaceEthernetConnect(virDomainDefPtr def,
if (virNetDevMacVLanTapOpen(net->ifname, tapfd, tapfdSize) < 0)
goto cleanup;
if (virNetDevMacVLanTapSetup(tapfd, tapfdSize,
- virDomainNetIsVirtioModel(net)) < 0) {
+ qemuInterfaceIsVnetCompatModel(net)) < 0) {
goto cleanup;
}
} else {
@@ -559,7 +566,7 @@ qemuInterfaceBridgeConnect(virDomainDefPtr def,
template_ifname = true;
}
- if (virDomainNetIsVirtioModel(net))
+ if (qemuInterfaceIsVnetCompatModel(net))
tap_create_flags |= VIR_NETDEV_TAP_CREATE_VNET_HDR;
if (driver->privileged) {
diff --git a/src/qemu/qemu_interface.h b/src/qemu/qemu_interface.h
index 0464b903d7..9e3f61e8e0 100644
--- a/src/qemu/qemu_interface.h
+++ b/src/qemu/qemu_interface.h
@@ -58,3 +58,4 @@ int qemuInterfaceOpenVhostNet(virDomainDefPtr def,
qemuSlirpPtr qemuInterfacePrepareSlirp(virQEMUDriverPtr driver,
virDomainNetDefPtr net);
+bool qemuInterfaceIsVnetCompatModel(const virDomainNetDef *net);
--
2.26.2
