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[Qemu-devel] [PATCH v2 0/2] virtio: Move host features to backends
From: |
shannon . zhao |
Subject: |
[Qemu-devel] [PATCH v2 0/2] virtio: Move host features to backends |
Date: |
Mon, 20 Apr 2015 16:19:59 +0800 |
From: Shannon Zhao <address@hidden>
The reason to do this is that the virtio-net-device can't expose host
features to guest while using virtio-mmio. So the performance is low.
The virtio-*-pci, virtio-*-s390, and virtio-*-ccw already have the ability
to forward property accesses to the backend child, by calling
*_virtio_*_instance_init -> qdev_alias_all_properties. So if we move the
host features to backends, it doesn't break the backwards compatibility
for virtio-*-pci, virtio-*-s390, and virtio-*-ccw.
Here we move the host features to backends, involving
DEFINE_VIRTIO_NET_FEATURES, DEFINE_VIRTIO_SCSI_FEATURES. So the virtio-mmio
devices could have the host freatures, and this has a great performance
improvement to virtio-mmio, especially to virtio-net-device.
changes since v1:
* drop unnecessary change of adding device_plugged hook for
virtio-ccw and s390-virtio-bus (Cornelia)
Shannon Zhao (2):
hw/net/virtio-net: Move DEFINE_VIRTIO_NET_FEATURES to virtio-net
virtio-scsi: Move DEFINE_VIRTIO_SCSI_FEATURES to virtio-scsi
hw/net/virtio-net.c | 4 ++++
hw/s390x/s390-virtio-bus.c | 2 --
hw/s390x/virtio-ccw.c | 2 --
hw/scsi/virtio-scsi.c | 5 +++++
hw/virtio/virtio-pci.c | 2 --
include/hw/virtio/virtio-net.h | 1 +
include/hw/virtio/virtio-scsi.h | 1 +
7 files changed, 11 insertions(+), 6 deletions(-)
--
2.0.4