Michael S. Tsirkin
2022-Jul-29 09:39 UTC
[PATCH V3 6/6] vDPA: fix 'cast to restricted le16' warnings in vdpa.c
On Fri, Jul 29, 2022 at 05:35:09PM +0800, Zhu, Lingshan wrote:> > > On 7/29/2022 5:23 PM, Michael S. Tsirkin wrote: > > On Fri, Jul 29, 2022 at 05:20:17PM +0800, Zhu, Lingshan wrote: > > > > > > On 7/29/2022 5:17 PM, Michael S. Tsirkin wrote: > > > > On Fri, Jul 29, 2022 at 05:07:11PM +0800, Zhu, Lingshan wrote: > > > > > On 7/29/2022 4:53 PM, Michael S. Tsirkin wrote: > > > > > > On Fri, Jul 01, 2022 at 09:28:26PM +0800, Zhu Lingshan wrote: > > > > > > > This commit fixes spars warnings: cast to restricted __le16 > > > > > > > in function vdpa_dev_net_config_fill() and > > > > > > > vdpa_fill_stats_rec() > > > > > > > > > > > > > > Signed-off-by: Zhu Lingshan <lingshan.zhu at intel.com> > > > > > > > --- > > > > > > > drivers/vdpa/vdpa.c | 6 +++--- > > > > > > > 1 file changed, 3 insertions(+), 3 deletions(-) > > > > > > > > > > > > > > diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c > > > > > > > index 846dd37f3549..ed49fe46a79e 100644 > > > > > > > --- a/drivers/vdpa/vdpa.c > > > > > > > +++ b/drivers/vdpa/vdpa.c > > > > > > > @@ -825,11 +825,11 @@ static int vdpa_dev_net_config_fill(struct vdpa_device *vdev, struct sk_buff *ms > > > > > > > config.mac)) > > > > > > > return -EMSGSIZE; > > > > > > > - val_u16 = le16_to_cpu(config.status); > > > > > > > + val_u16 = __virtio16_to_cpu(true, config.status); > > > > > > > if (nla_put_u16(msg, VDPA_ATTR_DEV_NET_STATUS, val_u16)) > > > > > > > return -EMSGSIZE; > > > > > > > - val_u16 = le16_to_cpu(config.mtu); > > > > > > > + val_u16 = __virtio16_to_cpu(true, config.mtu); > > > > > > > if (nla_put_u16(msg, VDPA_ATTR_DEV_NET_CFG_MTU, val_u16)) > > > > > > > return -EMSGSIZE; > > > > > > Wrong on BE platforms with legacy interface, isn't it? > > > > > > We generally don't handle legacy properly in VDPA so it's > > > > > > not a huge deal, but maybe add a comment at least? > > > > > Sure, I can add a comment here: this is for modern devices only. > > > > > > > > > > Thanks, > > > > > Zhu Lingshan > > > > Hmm. what "this" is for modern devices only here? > > > this cast, for LE modern devices. > > I think status existed in legacy for sure, and it's possible that > > some legacy devices backported mtu and max_virtqueue_pairs otherwise > > we would have these fields as __le not as __virtio, right? > yes, that's the reason why it is virtio_16 than just le16. > > I may find a better solution to detect whether it is LE, or BE without a > virtio_dev structure. > Check whether vdpa_device->get_device_features() has VIRTIO_F_VERISON_1. If > the device offers _F_VERSION_1, then it is a LE device, > or it is a BE device, then we use __virtio16_to_cpu(false, config.status). > > Does this look good?No since the question is can be a legacy driver with a transitional device. I don't have a good idea yet. vhost has VHOST_SET_VRING_ENDIAN and maybe we need something like this for config as well?> > > > > > > > > @@ -911,7 +911,7 @@ static int vdpa_fill_stats_rec(struct vdpa_device *vdev, struct sk_buff *msg, > > > > > > > } > > > > > > > vdpa_get_config_unlocked(vdev, 0, &config, sizeof(config)); > > > > > > > - max_vqp = le16_to_cpu(config.max_virtqueue_pairs); > > > > > > > + max_vqp = __virtio16_to_cpu(true, config.max_virtqueue_pairs); > > > > > > > if (nla_put_u16(msg, VDPA_ATTR_DEV_NET_CFG_MAX_VQP, max_vqp)) > > > > > > > return -EMSGSIZE; > > > > > > > -- > > > > > > > 2.31.1
Jason Wang
2022-Aug-01 04:33 UTC
[PATCH V3 6/6] vDPA: fix 'cast to restricted le16' warnings in vdpa.c
? 2022/7/29 17:39, Michael S. Tsirkin ??:> On Fri, Jul 29, 2022 at 05:35:09PM +0800, Zhu, Lingshan wrote: >> >> On 7/29/2022 5:23 PM, Michael S. Tsirkin wrote: >>> On Fri, Jul 29, 2022 at 05:20:17PM +0800, Zhu, Lingshan wrote: >>>> On 7/29/2022 5:17 PM, Michael S. Tsirkin wrote: >>>>> On Fri, Jul 29, 2022 at 05:07:11PM +0800, Zhu, Lingshan wrote: >>>>>> On 7/29/2022 4:53 PM, Michael S. Tsirkin wrote: >>>>>>> On Fri, Jul 01, 2022 at 09:28:26PM +0800, Zhu Lingshan wrote: >>>>>>>> This commit fixes spars warnings: cast to restricted __le16 >>>>>>>> in function vdpa_dev_net_config_fill() and >>>>>>>> vdpa_fill_stats_rec() >>>>>>>> >>>>>>>> Signed-off-by: Zhu Lingshan <lingshan.zhu at intel.com> >>>>>>>> --- >>>>>>>> drivers/vdpa/vdpa.c | 6 +++--- >>>>>>>> 1 file changed, 3 insertions(+), 3 deletions(-) >>>>>>>> >>>>>>>> diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c >>>>>>>> index 846dd37f3549..ed49fe46a79e 100644 >>>>>>>> --- a/drivers/vdpa/vdpa.c >>>>>>>> +++ b/drivers/vdpa/vdpa.c >>>>>>>> @@ -825,11 +825,11 @@ static int vdpa_dev_net_config_fill(struct vdpa_device *vdev, struct sk_buff *ms >>>>>>>> config.mac)) >>>>>>>> return -EMSGSIZE; >>>>>>>> - val_u16 = le16_to_cpu(config.status); >>>>>>>> + val_u16 = __virtio16_to_cpu(true, config.status); >>>>>>>> if (nla_put_u16(msg, VDPA_ATTR_DEV_NET_STATUS, val_u16)) >>>>>>>> return -EMSGSIZE; >>>>>>>> - val_u16 = le16_to_cpu(config.mtu); >>>>>>>> + val_u16 = __virtio16_to_cpu(true, config.mtu); >>>>>>>> if (nla_put_u16(msg, VDPA_ATTR_DEV_NET_CFG_MTU, val_u16)) >>>>>>>> return -EMSGSIZE; >>>>>>> Wrong on BE platforms with legacy interface, isn't it? >>>>>>> We generally don't handle legacy properly in VDPA so it's >>>>>>> not a huge deal, but maybe add a comment at least? >>>>>> Sure, I can add a comment here: this is for modern devices only. >>>>>> >>>>>> Thanks, >>>>>> Zhu Lingshan >>>>> Hmm. what "this" is for modern devices only here? >>>> this cast, for LE modern devices. >>> I think status existed in legacy for sure, and it's possible that >>> some legacy devices backported mtu and max_virtqueue_pairs otherwise >>> we would have these fields as __le not as __virtio, right? >> yes, that's the reason why it is virtio_16 than just le16. >> >> I may find a better solution to detect whether it is LE, or BE without a >> virtio_dev structure. >> Check whether vdpa_device->get_device_features() has VIRTIO_F_VERISON_1. If >> the device offers _F_VERSION_1, then it is a LE device, >> or it is a BE device, then we use __virtio16_to_cpu(false, config.status). >> >> Does this look good? > No since the question is can be a legacy driver with a transitional > device. I don't have a good idea yet. vhost has VHOST_SET_VRING_ENDIAN > and maybe we need something like this for config as well?Not sure, and even if we had this, the query could happen before VHOST_SET_VRING_ENDIAN. Actually, the patch should be fine itself, since the issue exist even before the patch (which assumes a le). Thanks> >>>>>>>> @@ -911,7 +911,7 @@ static int vdpa_fill_stats_rec(struct vdpa_device *vdev, struct sk_buff *msg, >>>>>>>> } >>>>>>>> vdpa_get_config_unlocked(vdev, 0, &config, sizeof(config)); >>>>>>>> - max_vqp = le16_to_cpu(config.max_virtqueue_pairs); >>>>>>>> + max_vqp = __virtio16_to_cpu(true, config.max_virtqueue_pairs); >>>>>>>> if (nla_put_u16(msg, VDPA_ATTR_DEV_NET_CFG_MAX_VQP, max_vqp)) >>>>>>>> return -EMSGSIZE; >>>>>>>> -- >>>>>>>> 2.31.1