[dpdk-dev] [PATCH] vhost: fix vhost interrupt support
Maxime Coquelin
maxime.coquelin at redhat.com
Mon Sep 10 09:22:00 CEST 2018
Hi Tiwei,
On 09/05/2018 01:55 AM, Tiwei Bie wrote:
> When VIRTIO_RING_F_EVENT_IDX is negotiated, we need to
> update the avail event to enable the notification.
>
> Fixes: 3f8ff12821e4 ("vhost: support interrupt mode")
> Cc: stable at dpdk.org
>
> Signed-off-by: Tiwei Bie <tiwei.bie at intel.com>
> ---
> lib/librte_vhost/Makefile | 1 +
> lib/librte_vhost/vhost.c | 18 ++++++++++++------
> lib/librte_vhost/vhost.h | 2 ++
> 3 files changed, 15 insertions(+), 6 deletions(-)
>
> diff --git a/lib/librte_vhost/Makefile b/lib/librte_vhost/Makefile
> index de431fbb7..531cf4832 100644
> --- a/lib/librte_vhost/Makefile
> +++ b/lib/librte_vhost/Makefile
> @@ -13,6 +13,7 @@ LIBABIVER := 4
> CFLAGS += -DALLOW_EXPERIMENTAL_API
> CFLAGS += $(WERROR_FLAGS) -I$(SRCDIR) -O3 -D_FILE_OFFSET_BITS=64
> CFLAGS += -I vhost_user
> +CFLAGS += -fno-strict-aliasing
I'm not clear why this is needed looking at the code below,
could you please explain?
> LDLIBS += -lpthread
>
> ifeq ($(CONFIG_RTE_LIBRTE_VHOST_NUMA),y)
> diff --git a/lib/librte_vhost/vhost.c b/lib/librte_vhost/vhost.c
> index 3c9be10a0..88b1781d5 100644
> --- a/lib/librte_vhost/vhost.c
> +++ b/lib/librte_vhost/vhost.c
> @@ -646,12 +646,18 @@ rte_vhost_avail_entries(int vid, uint16_t queue_id)
> }
>
> static inline void
> -vhost_enable_notify_split(struct vhost_virtqueue *vq, int enable)
> +vhost_enable_notify_split(struct virtio_net *dev,
> + struct vhost_virtqueue *vq, int enable)
> {
> - if (enable)
> - vq->used->flags &= ~VRING_USED_F_NO_NOTIFY;
> - else
> - vq->used->flags |= VRING_USED_F_NO_NOTIFY;
> + if (!(dev->features & (1ULL << VIRTIO_RING_F_EVENT_IDX))) {
> + if (enable)
> + vq->used->flags &= ~VRING_USED_F_NO_NOTIFY;
> + else
> + vq->used->flags |= VRING_USED_F_NO_NOTIFY;
> + } else {
> + if (enable)
> + vhost_avail_event(vq) = vq->last_avail_idx;
> + }
> }
>
> static inline void
> @@ -689,7 +695,7 @@ rte_vhost_enable_guest_notification(int vid, uint16_t queue_id, int enable)
> if (vq_is_packed(dev))
> vhost_enable_notify_packed(dev, vq, enable);
> else
> - vhost_enable_notify_split(vq, enable);
> + vhost_enable_notify_split(dev, vq, enable);
>
> return 0;
> }
> diff --git a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h
> index 760a09c0d..25ffd7614 100644
> --- a/lib/librte_vhost/vhost.h
> +++ b/lib/librte_vhost/vhost.h
> @@ -648,6 +648,8 @@ vhost_iova_to_vva(struct virtio_net *dev, struct vhost_virtqueue *vq,
> return __vhost_iova_to_vva(dev, vq, iova, len, perm);
> }
>
> +#define vhost_avail_event(vr) \
> + (*(volatile uint16_t*)&(vr)->used->ring[(vr)->size])
> #define vhost_used_event(vr) \
> (*(volatile uint16_t*)&(vr)->avail->ring[(vr)->size])
>
>
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