On 1/13/21 2:43 PM, Adrian Moreno wrote:
> 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.
Yes, makes sense.
Sorry for not replying earlier, I'm rebasing the series and than will
look at all your comments one by one.
Thanks,
Maxime
>> 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
>>
>
