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" <mst@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?