On Thu, Aug 06, 2020 at 10:53:32PM -0400, Patrick Magauran wrote:
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(a)gmail.com>
---
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);
+}
Should really live in the qemu_inteface.c file, with
a qemuOnterfaceIsVnetCompatModel name, since the decision
is inherantly tied to QEMU, and inappropriate for other
virt drivers.
Regards,
Daniel
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