在 2022/8/16 14:22, Michael S. Tsirkin 写道:
On Tue, Aug 16, 2022 at 02:15:57PM +0800, Xuan Zhuo wrote:
On Tue, 16 Aug 2022 02:14:10 -0400, "Michael S. Tsirkin" <m...@redhat.com>
wrote:
On Tue, Aug 16, 2022 at 09:06:12AM +0800, Kangjie Xu wrote:
The virtio queue reset function has already been defined in the virtio spec 1.2.
The relevant virtio spec information is here:
https://github.com/oasis-tcs/virtio-spec/issues/124
https://github.com/oasis-tcs/virtio-spec/issues/139
This patch set is to support this function in QEMU. It consists of several
parts:
1. Patches 1-7 are the basic interfaces for vq reset in virtio and virtio-pci.
2. Patches 8-12 support vq stop and vq restart for vhost-kernel.
3. Patches 13-19 support vq stop and vq restart for vhost-user.
4. Patches 20-22 support vq reset and re-enable for virtio-net.
5. Patches 23-24 enable the vq reset feature for vhost-kernel and vhost-user.
The process of virtqueue reset can be concluded as:
1. The virtqueue is disabled when VIRTIO_PCI_COMMON_Q_RESET is written.
2. Then the virtqueue can be optionally restarted(re-enabled).
Since this patch set involves multiple modules and seems a bit messy, we
briefly describe the
calling process for different modes below.
virtio-net:
1. VIRTIO_PCI_COMMON_Q_RESET is written [virtio-pci]
-> virtio_queue_reset() [virtio]
-> virtio_net_queue_reset() [virtio-net]
-> __virtio_queue_reset()
2. VIRTIO_PCI_COMMON_Q_ENABLE is written [virtio-pci]
-> set enabled, reset status of vq.
vhost-kernel:
1. VIRTIO_PCI_COMMON_Q_RESET is written [virtio-pci]
-> virtio_queue_reset() [virtio]
-> virtio_net_queue_reset() [virtio-net]
-> vhost_net_virtqueue_stop() [vhost-net]
-> vhost_net_set_backend() [vhost]
-> vhost_dev_virtqueue_stop()
-> vhost_virtqueue_unmap()
-> __virtio_queue_reset()
2. VIRTIO_PCI_COMMON_Q_ENABLE is written [virtio-pci]
-> virtio_queue_enable() [virtio]
-> virtio_net_queue_enable() [virtio-net]
-> vhost_net_virtqueue_restart() [vhost-net]
-> vhost_dev_virtqueue_restart() [vhost]
-> vhost_virtqueue_start()
-> vhost_net_set_backend()
-> set enabled, reset status of vq.
vhost-user:
1. VIRTIO_PCI_COMMON_Q_RESET is written [virtio-pci]
-> virtio_queue_reset() [virtio]
-> virtio_net_queue_reset() [virtio-net]
-> vhost_net_virtqueue_stop() [vhost-net]
-> vhost_dev_virtqueue_stop() [vhost]
-> vhost_user_reset_vring() [vhost-user]
-> send VHOST_USER_RESET_VRING to the device
-> vhost_virtqueue_unmap()
-> __virtio_queue_reset()
2. VIRTIO_PCI_COMMON_Q_ENABLE is written [virtio-pci]
-> virtio_queue_enable() [virtio]
-> virtio_net_queue_enable() [virtio-net]
-> vhost_net_virtqueue_restart() [vhost-net]
-> vhost_dev_virtqueue_restart() [vhost]
-> vhost_virtqueue_start()
-> vhost_user_set_single_vring_enable [vhost-user]
-> send VHOST_USER_SET_VRING_ENABLE to the device
-> set enabled, reset status of vq.
Test environment:
Host: 5.19.0-rc3 (With vq reset support)
Qemu: QEMU emulator version 7.0.50
Guest: 5.19.0-rc3 (With vq reset support)
DPDK: 22.07-rc1 (With vq reset support)
Test Cmd: ethtool -g eth1; ethtool -G eth1 rx $1 tx $2; ethtool -g eth1;
The drvier can resize the virtio queue, then virtio queue reset function
should
be triggered.
The default is split mode, modify Qemu virtio-net to add PACKED feature to
test packed mode.
legacy mode testing?
legacy does not support vq reset.
Thanks.
yes but did it break with all these code changes?
For pci legacy mode, we tested resizing the vq using 'ethtool -G', it
reported an error code -ENOENT because the transport did not support the
vq reset feature.
We also tested the connectivity and performance in pci legacy mode using
iperf 3.9. We placed a client in the host and a server in the guest, or
swapped the them.
In all the cases, the connectivity did not break down. The performance
was about the same with all our code changes.
Thanks.
Guest Kernel Patch:
https://lore.kernel.org/bpf/20220801063902.129329-1-xuanz...@linux.alibaba.com/
DPDK Patch:
https://github.com/middaywords/dpdk/compare/72206323a5dd3182b13f61b25a64abdddfee595c...eabadfac7953da66bc10ffb8284b490d09bb7ec7
Host Kernel Patch:
https://github.com/middaywords/linux/commit/19a91e0d7167b2031e46078c6215c213b89cb2c3
Looking forward to your review and comments. Thanks.
Kangjie Xu (19):
virtio: introduce virtio_queue_enable()
virtio: core: vq reset feature negotation support
virtio-pci: support queue enable
vhost: extract the logic of unmapping the vrings and desc
vhost: introduce vhost_dev_virtqueue_stop()
vhost: introduce vhost_dev_virtqueue_restart()
vhost-net: vhost-kernel: introduce vhost_net_virtqueue_stop()
vhost-net: vhost-kernel: introduce vhost_net_virtqueue_restart()
docs: vhost-user: add VHOST_USER_RESET_VRING message
vhost-user: introduce vhost_reset_vring() interface
vhost-user: add op to enable or disable a single vring
vhost: vhost-user: update vhost_dev_virtqueue_stop()
vhost: vhost-user: update vhost_dev_virtqueue_restart()
vhost-net: vhost-user: update vhost_net_virtqueue_stop()
vhost-net: vhost-user: update vhost_net_virtqueue_restart()
virtio-net: introduce flush_or_purge_queued_packets()
virtio-net: support queue_enable
vhost: vhost-kernel: enable vq reset feature
vhost: vhost-user: enable vq reset feature
Xuan Zhuo (5):
virtio: sync relevant definitions with linux
virtio: introduce __virtio_queue_reset()
virtio: introduce virtio_queue_reset()
virtio-pci: support queue reset
virtio-net: support queue reset
docs/interop/vhost-user.rst | 10 +++
hw/core/machine.c | 1 +
hw/net/vhost_net.c | 79 +++++++++++++++++++
hw/net/virtio-net.c | 58 ++++++++++++--
hw/virtio/vhost-user.c | 67 ++++++++++++++--
hw/virtio/vhost.c | 79 +++++++++++++++++--
hw/virtio/virtio-pci.c | 20 +++++
hw/virtio/virtio.c | 62 +++++++++++----
include/hw/virtio/vhost-backend.h | 6 ++
include/hw/virtio/vhost.h | 5 ++
include/hw/virtio/virtio-pci.h | 1 +
include/hw/virtio/virtio.h | 8 +-
include/net/vhost_net.h | 4 +
.../standard-headers/linux/virtio_config.h | 5 ++
include/standard-headers/linux/virtio_pci.h | 2 +
15 files changed, 371 insertions(+), 36 deletions(-)
--
2.32.0
