Hi Maxime,
> -----Original Message-----
> From: Maxime Coquelin <maxime.coque...@redhat.com>
> Sent: Wednesday, July 29, 2020 8:54 PM
> To: dev@dpdk.org; ma...@mellanox.com; Xia, Chenbo
> <chenbo....@intel.com>; Liu, Yong <yong....@intel.com>; Wang, Yinan
> <yinan.w...@intel.com>
> Cc: tho...@monjalon.net; Yigit, Ferruh <ferruh.yi...@intel.com>;
> david.march...@redhat.com
> Subject: Re: [PATCH v3 3/3] net/vhost: fix interrupt mode
>
>
>
> On 7/29/20 11:20 AM, Maxime Coquelin wrote:
> > At .new_device() time, only the first vring pair is now ready, other
> > vrings are consfigured later.
> >
> > Problem is that when application will setup and enable interrupts,
> > only the first queue pair Rx interrupt will be enabled.
> >
> > This patches fixes the issue by setting the number of max interrupts
> > to the number of Rx queues that will be later initialized. Then, as
> > soon as a Rx vring is ready and interrupt enabled by the application,
> > it removes the corresponding uninitialized epoll event, and install a
> > new one with the valid FD.
> >
> > Fixes: 604052ae5395 ("net/vhost: support queue update")
> >
> > Signed-off-by: Maxime Coquelin <maxime.coque...@redhat.com>
> > ---
> > drivers/net/vhost/rte_eth_vhost.c | 75
> > +++++++++++++++++++++++++++----
> > 1 file changed, 66 insertions(+), 9 deletions(-)
> >
> > diff --git a/drivers/net/vhost/rte_eth_vhost.c
> > b/drivers/net/vhost/rte_eth_vhost.c
> > index 951929c663..237785dd66 100644
> > --- a/drivers/net/vhost/rte_eth_vhost.c
> > +++ b/drivers/net/vhost/rte_eth_vhost.c
> > @@ -5,6 +5,7 @@
> > #include <unistd.h>
> > #include <pthread.h>
> > #include <stdbool.h>
> > +#include <sys/epoll.h>
> >
> > #include <rte_mbuf.h>
> > #include <rte_ethdev_driver.h>
> > @@ -95,6 +96,8 @@ struct vhost_queue {
> > uint16_t port;
> > uint16_t virtqueue_id;
> > struct vhost_stats stats;
> > + int intr_enable;
> > + rte_spinlock_t intr_lock;
> > };
> >
> > struct pmd_internal {
> > @@ -524,6 +527,45 @@ find_internal_resource(char *ifname)
> > return list;
> > }
> >
> > +static int
> > +eth_vhost_update_intr(struct rte_eth_dev *eth_dev, uint16_t rxq_idx)
> > +{
> > + struct rte_intr_handle *handle = eth_dev->intr_handle;
> > + struct rte_epoll_event rev;
> > + int epfd, ret;
> > +
>
> Chenbo reported that we can have a NULL pointer dereference on handle when
> using Virtio-user on the other end and quitting.
To clarity the root cause, it's because 'destroy_device' calls
'eth_vhost_uninstall_intr'
when connection lost but l3fwd-power APP are still enabling intr.
Thanks,
Chenbo
>
>
>
> > + if (handle->efds[rxq_idx] == handle->elist[rxq_idx].fd)
> > + return 0;
> > +
> > + VHOST_LOG(INFO, "kickfd for rxq-%d was changed, updating
> handler.\n",
> > + rxq_idx);
> > +
> > + /*
> > + * First remove invalid epoll event, and then isntall
> > + * the new one. May be solved with a proper API in the
> > + * future.
> > + */
> > + epfd = handle->elist[rxq_idx].epfd;
> > + rev = handle->elist[rxq_idx];
> > + ret = rte_epoll_ctl(epfd, EPOLL_CTL_DEL, rev.fd,
> > + &handle->elist[rxq_idx]);
> > + if (ret) {
> > + VHOST_LOG(ERR, "Delete epoll event failed.\n");
> > + return ret;
> > + }
> > +
> > + rev.fd = handle->efds[rxq_idx];
> > + handle->elist[rxq_idx] = rev;
> > + ret = rte_epoll_ctl(epfd, EPOLL_CTL_ADD, rev.fd,
> > + &handle->elist[rxq_idx]);
> > + if (ret) {
> > + VHOST_LOG(ERR, "Add epoll event failed.\n");
> > + return ret;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > static int
> > eth_rxq_intr_enable(struct rte_eth_dev *dev, uint16_t qid) { @@
> > -537,6 +579,11 @@ eth_rxq_intr_enable(struct rte_eth_dev *dev, uint16_t qid)
> > return -1;
> > }
> >
> > + rte_spinlock_lock(&vq->intr_lock);
> > + vq->intr_enable = 1;
> > + ret = eth_vhost_update_intr(dev, qid);
> > + rte_spinlock_unlock(&vq->intr_lock);
> > +
>
> I missed to check ret value here, will add it in v4.
>
> > ret = rte_vhost_get_vhost_vring(vq->vid, (qid << 1) + 1, &vring);
> > if (ret < 0) {
> > VHOST_LOG(ERR, "Failed to get rxq%d's vring\n", qid);
