On Wed, Dec 8, 2021 at 1:20 PM Longpeng(Mike) <longpe...@huawei.com> wrote: > > From: Longpeng <longpe...@huawei.com> > > Hi guys, > > This patch introduces vhost-vdpa-net device, which is inspired > by vhost-user-blk and the proposal of vhost-vdpa-blk device [1]. > > I've tested this patch on Huawei's offload card: > ./x86_64-softmmu/qemu-system-x86_64 \ > -device vhost-vdpa-net-pci,vdpa-dev=/dev/vhost-vdpa-0 > > For virtio hardware offloading, the most important requirement for us > is to support live migration between offloading cards from different > vendors, the combination of netdev and virtio-net seems too heavy, we > prefer a lightweight way.
Could you elaborate more on this? It's mainly the control path when using with netdev, and it provides a lot of other benefits: - decouple the transport specific stuff out of the vhost abstraction, mmio device is supported with 0 line of code - migration compatibility, reuse the migration stream that is already supported by Qemu virtio-net, this will allow migration among different vhost backends. - software mediation facility, not all the virtqueues are assigned to guests directly. One example is the virtio-net cvq, qemu may want to intercept and record the device state for migration. Reusing the current virtio-net codes simplifies a lot of codes. - transparent failover (in the future), the nic model can choose to switch between vhost backends etc. > > Maybe we could support both in the future ? For the net, we need to figure out the advantages of this approach first. Note that we didn't have vhost-user-net-pci or vhost-pci in the past. For the block, I will leave Stefan and Stefano to comment. > Such as: > > * Lightweight > Net: vhost-vdpa-net > Storage: vhost-vdpa-blk > > * Heavy but more powerful > Net: netdev + virtio-net + vhost-vdpa > Storage: bdrv + virtio-blk + vhost-vdpa > > [1] https://www.mail-archive.com/qemu-devel@nongnu.org/msg797569.html > > Signed-off-by: Longpeng(Mike) <longpe...@huawei.com> > --- > hw/net/meson.build | 1 + > hw/net/vhost-vdpa-net.c | 338 > +++++++++++++++++++++++++++++++++++++ > hw/virtio/Kconfig | 5 + > hw/virtio/meson.build | 1 + > hw/virtio/vhost-vdpa-net-pci.c | 118 +++++++++++++ I'd expect there's no device type specific code in this approach and any kind of vDPA devices could be used with a general pci device. Any reason for having net specific types here? > include/hw/virtio/vhost-vdpa-net.h | 31 ++++ > include/net/vhost-vdpa.h | 2 + > net/vhost-vdpa.c | 2 +- > 8 files changed, 497 insertions(+), 1 deletion(-) > create mode 100644 hw/net/vhost-vdpa-net.c > create mode 100644 hw/virtio/vhost-vdpa-net-pci.c > create mode 100644 include/hw/virtio/vhost-vdpa-net.h > > diff --git a/hw/net/meson.build b/hw/net/meson.build > index bdf71f1..139ebc4 100644 > --- a/hw/net/meson.build > +++ b/hw/net/meson.build > @@ -44,6 +44,7 @@ specific_ss.add(when: 'CONFIG_XILINX_ETHLITE', if_true: > files('xilinx_ethlite.c' > > softmmu_ss.add(when: 'CONFIG_VIRTIO_NET', if_true: files('net_rx_pkt.c')) > specific_ss.add(when: 'CONFIG_VIRTIO_NET', if_true: files('virtio-net.c')) > +specific_ss.add(when: 'CONFIG_VHOST_VDPA_NET', if_true: > files('vhost-vdpa-net.c')) > > softmmu_ss.add(when: ['CONFIG_VIRTIO_NET', 'CONFIG_VHOST_NET'], if_true: > files('vhost_net.c'), if_false: files('vhost_net-stub.c')) > softmmu_ss.add(when: 'CONFIG_ALL', if_true: files('vhost_net-stub.c')) > diff --git a/hw/net/vhost-vdpa-net.c b/hw/net/vhost-vdpa-net.c > new file mode 100644 > index 0000000..48b99f9 > --- /dev/null > +++ b/hw/net/vhost-vdpa-net.c > @@ -0,0 +1,338 @@ > +#include "qemu/osdep.h" > +#include "qapi/error.h" > +#include "qemu/error-report.h" > +#include "qemu/cutils.h" > +#include "hw/qdev-core.h" > +#include "hw/qdev-properties.h" > +#include "hw/qdev-properties-system.h" > +#include "hw/virtio/vhost.h" > +#include "hw/virtio/vhost-vdpa-net.h" > +#include "hw/virtio/virtio.h" > +#include "hw/virtio/virtio-bus.h" > +#include "hw/virtio/virtio-access.h" > +#include "sysemu/sysemu.h" > +#include "sysemu/runstate.h" > +#include "net/vhost-vdpa.h" > + > +static void vhost_vdpa_net_get_config(VirtIODevice *vdev, uint8_t *config) > +{ > + VHostVdpaNet *s = VHOST_VDPA_NET(vdev); > + > + memcpy(config, &s->netcfg, sizeof(struct virtio_net_config)); > +} > + > +static void vhost_vdpa_net_set_config(VirtIODevice *vdev, const uint8_t > *config) > +{ > + VHostVdpaNet *s = VHOST_VDPA_NET(vdev); > + struct virtio_net_config *netcfg = (struct virtio_net_config *)config; > + int ret; > + > + ret = vhost_dev_set_config(&s->dev, (uint8_t *)netcfg, 0, > sizeof(*netcfg), > + VHOST_SET_CONFIG_TYPE_MASTER); > + if (ret) { > + error_report("set device config space failed"); > + return; > + } > +} > + > +static uint64_t vhost_vdpa_net_get_features(VirtIODevice *vdev, > + uint64_t features, > + Error **errp) > +{ > + VHostVdpaNet *s = VHOST_VDPA_NET(vdev); > + > + virtio_add_feature(&features, VIRTIO_NET_F_CSUM); > + virtio_add_feature(&features, VIRTIO_NET_F_GUEST_CSUM); > + virtio_add_feature(&features, VIRTIO_NET_F_MAC); > + virtio_add_feature(&features, VIRTIO_NET_F_GSO); > + virtio_add_feature(&features, VIRTIO_NET_F_GUEST_TSO4); > + virtio_add_feature(&features, VIRTIO_NET_F_GUEST_TSO6); > + virtio_add_feature(&features, VIRTIO_NET_F_GUEST_ECN); > + virtio_add_feature(&features, VIRTIO_NET_F_GUEST_UFO); > + virtio_add_feature(&features, VIRTIO_NET_F_GUEST_ANNOUNCE); > + virtio_add_feature(&features, VIRTIO_NET_F_HOST_TSO4); > + virtio_add_feature(&features, VIRTIO_NET_F_HOST_TSO6); > + virtio_add_feature(&features, VIRTIO_NET_F_HOST_ECN); > + virtio_add_feature(&features, VIRTIO_NET_F_HOST_UFO); > + virtio_add_feature(&features, VIRTIO_NET_F_MRG_RXBUF); > + virtio_add_feature(&features, VIRTIO_NET_F_STATUS); > + virtio_add_feature(&features, VIRTIO_NET_F_CTRL_VQ); > + virtio_add_feature(&features, VIRTIO_NET_F_CTRL_RX); > + virtio_add_feature(&features, VIRTIO_NET_F_CTRL_VLAN); > + virtio_add_feature(&features, VIRTIO_NET_F_CTRL_RX_EXTRA); > + virtio_add_feature(&features, VIRTIO_NET_F_CTRL_MAC_ADDR); > + virtio_add_feature(&features, VIRTIO_NET_F_MQ); Any reason for those hand crafted features? > + > + return vhost_get_features(&s->dev, vdpa_feature_bits, features); > +} > + > +static int vhost_vdpa_net_start(VirtIODevice *vdev, Error **errp) > +{ > + VHostVdpaNet *s = VHOST_VDPA_NET(vdev); > + BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); > + VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); > + int i, ret; > + > + if (!k->set_guest_notifiers) { > + error_setg(errp, "binding does not support guest notifiers"); > + return -ENOSYS; > + } > + > + ret = vhost_dev_enable_notifiers(&s->dev, vdev); > + if (ret < 0) { > + error_setg_errno(errp, -ret, "Error enabling host notifiers"); > + return ret; > + } > + > + ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, true); > + if (ret < 0) { > + error_setg_errno(errp, -ret, "Error binding guest notifier"); > + goto err_host_notifiers; > + } > + > + s->dev.acked_features = vdev->guest_features; > + > + ret = vhost_dev_start(&s->dev, vdev); > + if (ret < 0) { > + error_setg_errno(errp, -ret, "Error starting vhost"); > + goto err_guest_notifiers; > + } > + s->started = true; > + > + /* guest_notifier_mask/pending not used yet, so just unmask > + * everything here. virtio-pci will do the right thing by > + * enabling/disabling irqfd. > + */ > + for (i = 0; i < s->dev.nvqs; i++) { > + vhost_virtqueue_mask(&s->dev, vdev, i, false); > + } > + > + return ret; > + > +err_guest_notifiers: > + k->set_guest_notifiers(qbus->parent, s->dev.nvqs, false); > +err_host_notifiers: > + vhost_dev_disable_notifiers(&s->dev, vdev); > + return ret; > +} > + > +static void vhost_vdpa_net_handle_output(VirtIODevice *vdev, VirtQueue *vq) > +{ > + VHostVdpaNet *s = VHOST_VDPA_NET(vdev); > + Error *local_err = NULL; > + int i, ret; > + > + if (!vdev->start_on_kick) { > + return; > + } > + > + if (s->dev.started) { > + return; > + } > + > + /* Some guests kick before setting VIRTIO_CONFIG_S_DRIVER_OK so start > + * vhost here instead of waiting for .set_status(). > + */ > + ret = vhost_vdpa_net_start(vdev, &local_err); > + if (ret < 0) { > + error_reportf_err(local_err, "vhost-vdpa-net: start failed: "); > + return; > + } > + > + /* Kick right away to begin processing requests already in vring */ > + for (i = 0; i < s->dev.nvqs; i++) { > + VirtQueue *kick_vq = virtio_get_queue(vdev, i); > + > + if (!virtio_queue_get_desc_addr(vdev, i)) { > + continue; > + } > + event_notifier_set(virtio_queue_get_host_notifier(kick_vq)); > + } > +} > + > +static void vhost_vdpa_net_stop(VirtIODevice *vdev) > +{ > + VHostVdpaNet *s = VHOST_VDPA_NET(vdev); > + BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); > + VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); > + int ret; > + > + if (!s->started) { > + return; > + } > + s->started = false; > + > + if (!k->set_guest_notifiers) { > + return; > + } > + > + vhost_dev_stop(&s->dev, vdev); > + > + ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, false); > + if (ret < 0) { > + error_report("vhost guest notifier cleanup failed: %d", ret); > + return; > + } > + > + vhost_dev_disable_notifiers(&s->dev, vdev); > +} > + > +static void vhost_vdpa_net_set_status(VirtIODevice *vdev, uint8_t status) > +{ > + VHostVdpaNet *s = VHOST_VDPA_NET(vdev); > + bool should_start = virtio_device_started(vdev, status); > + Error *local_err = NULL; > + int ret; > + > + if (!vdev->vm_running) { > + should_start = false; > + } > + > + if (s->started == should_start) { > + return; > + } > + > + if (should_start) { > + ret = vhost_vdpa_net_start(vdev, &local_err); > + if (ret < 0) { > + error_reportf_err(local_err, "vhost-vdpa-net: start failed: "); > + } > + } else { > + vhost_vdpa_net_stop(vdev); > + } > +} > + > +static void vhost_vdpa_net_unrealize(VHostVdpaNet *s) > +{ > + VirtIODevice *vdev = VIRTIO_DEVICE(s); > + int i; > + > + for (i = 0; i < s->queue_pairs * 2; i++) { > + virtio_delete_queue(s->virtqs[i]); > + } > + /* ctrl vq */ > + virtio_delete_queue(s->virtqs[i]); > + > + g_free(s->virtqs); > + virtio_cleanup(vdev); > +} > + > +static void vhost_vdpa_net_device_realize(DeviceState *dev, Error **errp) > +{ > + VirtIODevice *vdev = VIRTIO_DEVICE(dev); > + VHostVdpaNet *s = VHOST_VDPA_NET(vdev); > + int i, ret; > + > + s->vdpa.device_fd = qemu_open_old(s->vdpa_dev, O_RDWR); > + if (s->vdpa.device_fd == -1) { > + error_setg(errp, "vhost-vdpa-net: open %s failed: %s", > + s->vdpa_dev, strerror(errno)); > + return; > + } > + > + virtio_init(vdev, "virtio-net", VIRTIO_ID_NET, > + sizeof(struct virtio_net_config)); > + > + s->dev.nvqs = s->queue_pairs * 2 + 1; > + s->dev.vqs = g_new0(struct vhost_virtqueue, s->dev.nvqs); > + s->dev.vq_index = 0; > + s->dev.vq_index_end = s->dev.nvqs; > + s->dev.backend_features = 0; > + s->started = false; > + > + s->virtqs = g_new0(VirtQueue *, s->dev.nvqs); > + for (i = 0; i < s->dev.nvqs; i++) { > + s->virtqs[i] = virtio_add_queue(vdev, s->queue_size, > + vhost_vdpa_net_handle_output); We should check whether MQ is negotiated since the index varies depending on that. > + } > + > + ret = vhost_dev_init(&s->dev, &s->vdpa, VHOST_BACKEND_TYPE_VDPA, 0, > NULL); > + if (ret < 0) { > + error_setg(errp, "vhost-vdpa-net: vhost initialization failed: %s", > + strerror(-ret)); > + goto init_err; > + } > + > + ret = vhost_dev_get_config(&s->dev, (uint8_t *)&s->netcfg, > + sizeof(struct virtio_net_config), NULL); > + if (ret < 0) { > + error_setg(errp, "vhost-vdpa-net: get network config failed"); > + goto config_err; > + } > + > + return; > +config_err: > + vhost_dev_cleanup(&s->dev); > +init_err: > + vhost_vdpa_net_unrealize(s); > + close(s->vdpa.device_fd); > +} > + > +static void vhost_vdpa_net_device_unrealize(DeviceState *dev) > +{ > + VirtIODevice *vdev = VIRTIO_DEVICE(dev); > + VHostVdpaNet *s = VHOST_VDPA_NET(vdev); > + > + virtio_set_status(vdev, 0); > + vhost_dev_cleanup(&s->dev); > + vhost_vdpa_net_unrealize(s); > + close(s->vdpa.device_fd); > +} > + > +static const VMStateDescription vmstate_vhost_vdpa_net = { > + .name = "vhost-vdpa-net", > + .minimum_version_id = 1, > + .version_id = 1, > + .fields = (VMStateField[]) { > + VMSTATE_VIRTIO_DEVICE, > + VMSTATE_END_OF_LIST() > + }, > +}; > + > +static void vhost_vdpa_net_instance_init(Object *obj) > +{ > + VHostVdpaNet *s = VHOST_VDPA_NET(obj); > + > + device_add_bootindex_property(obj, &s->bootindex, "bootindex", > + "/ethernet-phy@0,0", DEVICE(obj)); > +} > + > +static Property vhost_vdpa_net_properties[] = { > + DEFINE_PROP_STRING("vdpa-dev", VHostVdpaNet, vdpa_dev), > + DEFINE_PROP_UINT16("queue-pairs", VHostVdpaNet, queue_pairs, > + VHOST_VDPA_NET_AUTO_QUEUE_PAIRS), Any reason that we need the queue pairs parameter? Note that it is expected to be provisioned by the netlink for the management device. Thanks
