Hi Chenbo On 1/6/21 12:54 PM, Xia, Chenbo wrote: > Hi Maxime, > >> -----Original Message----- >> From: Maxime Coquelin <maxime.coque...@redhat.com> >> Sent: Monday, December 21, 2020 5:14 AM >> To: dev@dpdk.org; Xia, Chenbo <chenbo....@intel.com>; olivier.m...@6wind.com; >> amore...@redhat.com; david.march...@redhat.com >> Cc: Maxime Coquelin <maxime.coque...@redhat.com> >> Subject: [PATCH 25/40] net/virtio: add Virtio-user features ops >> >> This patch introduce new callbacks for getting > > s/introduce/introduces > >> and setting Virtio features, and implements them >> for the different backend types. >> >> Signed-off-by: Maxime Coquelin <maxime.coque...@redhat.com> >> --- >> drivers/net/virtio/virtio_user/vhost.h | 2 + >> drivers/net/virtio/virtio_user/vhost_kernel.c | 150 +++++++++--------- >> .../net/virtio/virtio_user/vhost_kernel_tap.c | 23 +++ >> .../net/virtio/virtio_user/vhost_kernel_tap.h | 1 + >> drivers/net/virtio/virtio_user/vhost_user.c | 63 +++++++- >> drivers/net/virtio/virtio_user/vhost_vdpa.c | 38 +++-- >> .../net/virtio/virtio_user/virtio_user_dev.c | 5 +- >> drivers/net/virtio/virtio_user_ethdev.c | 3 +- >> 8 files changed, 188 insertions(+), 97 deletions(-) >> >> diff --git a/drivers/net/virtio/virtio_user/vhost.h >> b/drivers/net/virtio/virtio_user/vhost.h >> index 8e819ecfb8..16978e27ed 100644 >> --- a/drivers/net/virtio/virtio_user/vhost.h >> +++ b/drivers/net/virtio/virtio_user/vhost.h >> @@ -102,6 +102,8 @@ struct virtio_user_dev; >> struct virtio_user_backend_ops { >> int (*setup)(struct virtio_user_dev *dev); >> int (*set_owner)(struct virtio_user_dev *dev); >> + int (*get_features)(struct virtio_user_dev *dev, uint64_t *features); >> + int (*set_features)(struct virtio_user_dev *dev, uint64_t features); >> int (*send_request)(struct virtio_user_dev *dev, >> enum vhost_user_request req, >> void *arg); >> diff --git a/drivers/net/virtio/virtio_user/vhost_kernel.c >> b/drivers/net/virtio/virtio_user/vhost_kernel.c >> index b79dcad179..f44df8ef1f 100644 >> --- a/drivers/net/virtio/virtio_user/vhost_kernel.c >> +++ b/drivers/net/virtio/virtio_user/vhost_kernel.c >> @@ -38,6 +38,28 @@ struct vhost_memory_kernel { >> #define VHOST_SET_VRING_ERR _IOW(VHOST_VIRTIO, 0x22, struct >> vhost_vring_file) >> #define VHOST_NET_SET_BACKEND _IOW(VHOST_VIRTIO, 0x30, struct >> vhost_vring_file) >> >> +/* with below features, vhost kernel does not need to do the checksum and >> TSO, >> + * these info will be passed to virtio_user through virtio net header. >> + */ >> +#define VHOST_KERNEL_GUEST_OFFLOADS_MASK \ >> + ((1ULL << VIRTIO_NET_F_GUEST_CSUM) | \ >> + (1ULL << VIRTIO_NET_F_GUEST_TSO4) | \ >> + (1ULL << VIRTIO_NET_F_GUEST_TSO6) | \ >> + (1ULL << VIRTIO_NET_F_GUEST_ECN) | \ >> + (1ULL << VIRTIO_NET_F_GUEST_UFO)) >> + >> +/* with below features, when flows from virtio_user to vhost kernel >> + * (1) if flows goes up through the kernel networking stack, it does not >> need >> + * to verify checksum, which can save CPU cycles; >> + * (2) if flows goes through a Linux bridge and outside from an interface >> + * (kernel driver), checksum and TSO will be done by GSO in kernel or even >> + * offloaded into real physical device. >> + */ >> +#define VHOST_KERNEL_HOST_OFFLOADS_MASK \ >> + ((1ULL << VIRTIO_NET_F_HOST_TSO4) | \ >> + (1ULL << VIRTIO_NET_F_HOST_TSO6) | \ >> + (1ULL << VIRTIO_NET_F_CSUM)) >> + >> static uint64_t max_regions = 64; >> >> static void >> @@ -77,10 +99,57 @@ vhost_kernel_set_owner(struct virtio_user_dev *dev) >> return vhost_kernel_ioctl(dev->vhostfds[0], VHOST_SET_OWNER, NULL); >> } >> >> +static int >> +vhost_kernel_get_features(struct virtio_user_dev *dev, uint64_t *features) >> +{ >> + int ret; >> + unsigned int tap_features; >> + >> + ret = vhost_kernel_ioctl(dev->vhostfds[0], VHOST_GET_FEATURES, >> features); >> + if (ret < 0) { >> + PMD_DRV_LOG(ERR, "Failed to get features"); >> + return -1; >> + } >> + >> + ret = tap_support_features(&tap_features); >> + if (ret < 0) { >> + PMD_DRV_LOG(ERR, "Failed to get TAP features)"); > > should delete ')' after 'features'? > >> + return -1; >> + } >> + >> + /* with tap as the backend, all these features are supported >> + * but not claimed by vhost-net, so we add them back when >> + * reporting to upper layer. >> + */ > > <snip> > >> .dma_map = vhost_vdpa_dma_map, >> diff --git a/drivers/net/virtio/virtio_user/virtio_user_dev.c >> b/drivers/net/virtio/virtio_user/virtio_user_dev.c >> index f8e4581951..0a85d058a8 100644 >> --- a/drivers/net/virtio/virtio_user/virtio_user_dev.c >> +++ b/drivers/net/virtio/virtio_user/virtio_user_dev.c >> @@ -141,7 +141,7 @@ virtio_user_dev_set_features(struct virtio_user_dev *dev) >> /* Strip VIRTIO_NET_F_CTRL_VQ, as devices do not really need to know */ >> features &= ~(1ull << VIRTIO_NET_F_CTRL_VQ); >> features &= ~(1ull << VIRTIO_NET_F_STATUS); >> - ret = dev->ops->send_request(dev, VHOST_USER_SET_FEATURES, &features); >> + ret = dev->ops->set_features(dev, features); > > I noticed that virtio_user_dev_set_features is called by > virtio_user_set_status. > The former may fail but the latter will ignore the failure. So this will > happen: > setting features already failed but virtio-user still continue to do things. > IMHO, > this is not very good (similar things may happen for > virtio_user_start_device). > What do you think? > You're right. Although set_status(features_ok) should be followed by get_status() to check if device has set feature_ok bit, the problem is that set_status is called on device initialization, which would happen even when the vhost backed is not yet connected (server-mode). Failing there would tear down the ethdev which would make the future "hotplug" fail. Hopefully this will all be fixed by Maxime's refactoring :) So +1 to reconsider improving error propagation here.
> Thanks, > Chenbo > >> if (ret < 0) >> goto error; >> PMD_DRV_LOG(INFO, "set features: %" PRIx64, features); >> @@ -488,8 +488,7 @@ virtio_user_dev_init(struct virtio_user_dev *dev, char >> *path, int queues, >> return -1; >> } >> >> - if (dev->ops->send_request(dev, VHOST_USER_GET_FEATURES, >> - &dev->device_features) < 0) { >> + if (dev->ops->get_features(dev, &dev->device_features) < 0) { >> PMD_INIT_LOG(ERR, "get_features failed: %s", >> strerror(errno)); >> return -1; >> diff --git a/drivers/net/virtio/virtio_user_ethdev.c >> b/drivers/net/virtio/virtio_user_ethdev.c >> index 283f5c7a36..4d2635c8aa 100644 >> --- a/drivers/net/virtio/virtio_user_ethdev.c >> +++ b/drivers/net/virtio/virtio_user_ethdev.c >> @@ -85,8 +85,7 @@ virtio_user_server_reconnect(struct virtio_user_dev *dev) >> >> virtio_set_status(hw, VIRTIO_CONFIG_STATUS_DRIVER); >> >> - if (dev->ops->send_request(dev, VHOST_USER_GET_FEATURES, >> - &dev->device_features) < 0) { >> + if (dev->ops->get_features(dev, &dev->device_features) < 0) { >> PMD_INIT_LOG(ERR, "get_features failed: %s", >> strerror(errno)); >> return -1; >> -- >> 2.29.2 > -- Adrián Moreno