From: Tiwei Bie <tiwei.bie@intel.com>
To: Maxime Coquelin <maxime.coquelin@redhat.com>
Cc: zhihong.wang@intel.com, jfreimann@redhat.com, dev@dpdk.org,
mst@redhat.com, jasowang@redhat.com, wexu@redhat.com
Subject: Re: [dpdk-dev] [PATCH v7 14/15] vhost: add notification for packed ring
Date: Thu, 5 Jul 2018 13:12:41 +0800 [thread overview]
Message-ID: <20180705051241.GA20322@debian> (raw)
In-Reply-To: <20180704215438.5579-15-maxime.coquelin@redhat.com>
On Wed, Jul 04, 2018 at 11:54:37PM +0200, Maxime Coquelin wrote:
[...]
> @@ -225,6 +231,15 @@ struct vring_desc_packed {
> uint16_t index;
> uint16_t flags;
> };
> +
> +#define VRING_EVENT_F_ENABLE 0x0
> +#define VRING_EVENT_F_DISABLE 0x1
> +#define VRING_EVENT_F_DESC 0x2
> +
> +struct vring_packed_desc_event {
> + uint16_t desc_event_off_wrap;
> + uint16_t desc_event_flags;
> +};
As all above types (including struct vring_desc_packed)
and macros are being protected by VIRTIO_F_RING_PACKED,
and they won't be defined if VIRTIO_F_RING_PACKED is
defined in kernel header. We may want to unify the names.
For the types, we may have below types defined in
linux uapi:
struct vring_packed;
struct vring_packed_desc;
struct vring_packed_desc_event;
They can also be named as:
struct vring_packed;
struct vring_desc_packed;
struct vring_packed_desc_event;
We need to choose one of them or something else.
For the `struct vring_packed_desc_event`, it can
be defined as:
struct vring_packed_desc_event {
uint16_t off_wrap;
uint16_t flags;
};
or
struct vring_packed_desc_event {
uint16_t desc_event_off_wrap;
uint16_t desc_event_flags;
};
We need to choose one of them or something else.
For the `struct vring_packed_desc`, it can be
defined as:
struct vring_packed_desc {
uint64_t addr;
uint32_t len;
uint16_t index;
uint16_t flags;
};
or
struct vring_packed_desc {
uint64_t addr;
uint32_t len;
uint16_t id; // index -> id
uint16_t flags;
};
We need to choose one of them or something else.
> #endif
>
[...]
> +static __rte_always_inline void
> +vhost_vring_call_packed(struct virtio_net *dev, struct vhost_virtqueue *vq)
> +{
> + uint16_t old, new, off, off_wrap;
> + bool kick = false;
> +
> + /* Flush used desc update. */
> + rte_smp_mb();
> +
> + if (!(dev->features & (1ULL << VIRTIO_RING_F_EVENT_IDX))) {
> + if (vq->driver_event->desc_event_flags !=
> + VRING_EVENT_F_DISABLE)
> + kick = true;
> + goto kick;
> + }
> +
> + old = vq->signalled_used;
We also need to check whether vq->signalled_used is valid?
> + new = vq->last_used_idx;
> + vq->signalled_used = new;
> +
> + if (vq->driver_event->desc_event_flags != VRING_EVENT_F_DESC) {
> + if (vq->driver_event->desc_event_flags !=
> + VRING_EVENT_F_DISABLE)
> + kick = true;
> + goto kick;
> + }
> +
> + rte_smp_rmb();
> +
> + off_wrap = vq->driver_event->desc_event_off_wrap;
> + off = off_wrap & ~(1 << 15);
> +
> + if (vq->used_wrap_counter != off_wrap >> 15)
> + off -= vq->size;
> +
> + if (vhost_need_event(off, new, old))
> + kick = true;
If new <= old, old needs to -= vq->size?
> +kick:
> + if (kick)
> + eventfd_write(vq->callfd, (eventfd_t)1);
> +}
> +
[...]
next prev parent reply other threads:[~2018-07-05 5:12 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-04 21:54 [dpdk-dev] [PATCH v7 00/15] Vhost: add support to packed ring layout Maxime Coquelin
2018-07-04 21:54 ` [dpdk-dev] [PATCH v7 01/15] vhost: add virtio packed virtqueue defines Maxime Coquelin
2018-07-04 21:54 ` [dpdk-dev] [PATCH v7 02/15] vhost: add helpers for packed virtqueues Maxime Coquelin
2018-07-04 21:54 ` [dpdk-dev] [PATCH v7 03/15] vhost: vring address setup for packed queues Maxime Coquelin
2018-07-04 21:54 ` [dpdk-dev] [PATCH v7 04/15] vhost: clear shadow used table index at flush time Maxime Coquelin
2018-07-04 21:54 ` [dpdk-dev] [PATCH v7 05/15] vhost: make indirect desc table copy desc type agnostic Maxime Coquelin
2018-07-04 21:54 ` [dpdk-dev] [PATCH v7 06/15] vhost: clear batch copy index at copy time Maxime Coquelin
2018-07-04 21:54 ` [dpdk-dev] [PATCH v7 07/15] vhost: extract split ring handling from Rx and Tx functions Maxime Coquelin
2018-07-04 21:54 ` [dpdk-dev] [PATCH v7 08/15] vhost: append shadow used ring function names with split Maxime Coquelin
2018-07-04 21:54 ` [dpdk-dev] [PATCH v7 09/15] vhost: add shadow used ring support for packed rings Maxime Coquelin
2018-07-05 7:15 ` Tiwei Bie
2018-07-05 12:49 ` Maxime Coquelin
2018-07-05 14:03 ` Tiwei Bie
2018-07-05 14:28 ` Maxime Coquelin
2018-07-05 14:36 ` Tiwei Bie
2018-07-04 21:54 ` [dpdk-dev] [PATCH v7 10/15] vhost: create descriptor mapping function Maxime Coquelin
2018-07-04 21:54 ` [dpdk-dev] [PATCH v7 11/15] vhost: add vector filling support for packed ring Maxime Coquelin
2018-07-04 21:54 ` [dpdk-dev] [PATCH v7 12/15] vhost: add Rx " Maxime Coquelin
2018-07-04 21:54 ` [dpdk-dev] [PATCH v7 13/15] vhost: add Tx " Maxime Coquelin
2018-07-04 21:54 ` [dpdk-dev] [PATCH v7 14/15] vhost: add notification " Maxime Coquelin
2018-07-05 5:12 ` Tiwei Bie [this message]
2018-07-05 7:20 ` Maxime Coquelin
2018-07-04 21:54 ` [dpdk-dev] [PATCH v7 15/15] vhost: advertize packed ring layout support Maxime Coquelin
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