From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:42630) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fQHJq-0002FZ-7q for qemu-devel@nongnu.org; Tue, 05 Jun 2018 15:08:35 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fQHJl-00038b-AD for qemu-devel@nongnu.org; Tue, 05 Jun 2018 15:08:34 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:50274 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fQHJl-00038A-3x for qemu-devel@nongnu.org; Tue, 05 Jun 2018 15:08:29 -0400 From: wexu@redhat.com Date: Tue, 5 Jun 2018 15:08:01 -0400 Message-Id: <1528225683-11413-7-git-send-email-wexu@redhat.com> In-Reply-To: <1528225683-11413-1-git-send-email-wexu@redhat.com> References: <1528225683-11413-1-git-send-email-wexu@redhat.com> Subject: [Qemu-devel] [RFC v2 6/8] virtio: flush/push for packed ring List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: jasowang@redhat.com, tiwei.bie@intel.com, mst@redhat.com, wexu@redhat.com, jfreimann@redhat.com From: Wei Xu Signed-off-by: Wei Xu Signed-off-by: Wei Xu --- hw/virtio/virtio.c | 109 ++++++++++++++++++++++++++++++++++++++++++++++------- 1 file changed, 96 insertions(+), 13 deletions(-) diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c index 0160d03..6f2da83 100644 --- a/hw/virtio/virtio.c +++ b/hw/virtio/virtio.c @@ -371,6 +371,21 @@ static void vring_packed_desc_read(VirtIODevice *vdev, VRingDescPacked *desc, virtio_tswap16s(vdev, &desc->flags); } +static void vring_packed_desc_write(VirtIODevice *vdev, VRingDescPacked *desc, + MemoryRegionCache *cache, int i) +{ + virtio_tswap64s(vdev, &desc->addr); + virtio_tswap32s(vdev, &desc->len); + virtio_tswap16s(vdev, &desc->id); + virtio_tswap16s(vdev, &desc->flags); + address_space_write_cached(cache, + sizeof(VRingDescPacked) * i, desc, + sizeof(VRingDescPacked)); + address_space_cache_invalidate(cache, + sizeof(VRingDescPacked) * i, + sizeof(VRingDescPacked)); +} + static inline bool is_desc_avail(struct VRingDescPacked *desc) { return !!(desc->flags & AVAIL_DESC_PACKED(1)) != @@ -526,19 +541,11 @@ bool virtqueue_rewind(VirtQueue *vq, unsigned int num) } /* Called within rcu_read_lock(). */ -void virtqueue_fill(VirtQueue *vq, const VirtQueueElement *elem, +static void virtqueue_split_fill(VirtQueue *vq, const VirtQueueElement *elem, unsigned int len, unsigned int idx) { VRingUsedElem uelem; - trace_virtqueue_fill(vq, elem, len, idx); - - virtqueue_unmap_sg(vq, elem, len); - - if (unlikely(vq->vdev->broken)) { - return; - } - if (unlikely(!vq->vring.used)) { return; } @@ -550,16 +557,64 @@ void virtqueue_fill(VirtQueue *vq, const VirtQueueElement *elem, vring_used_write(vq, &uelem, idx); } -/* Called within rcu_read_lock(). */ -void virtqueue_flush(VirtQueue *vq, unsigned int count) +static void virtqueue_packed_fill(VirtQueue *vq, const VirtQueueElement *elem, + unsigned int len, unsigned int idx) { - uint16_t old, new; + uint16_t w, head; + VRingMemoryRegionCaches *caches; + VRingDescPacked desc = { + .addr = 0, + .flags = 0, + }; + + if (unlikely(!vq->vring.desc)) { + return; + } + + caches = vring_get_region_caches(vq); + head = vq->used_idx + idx; + head = head >= vq->vring.num ? (head - vq->vring.num) : head; + vring_packed_desc_read(vq->vdev, &desc, &caches->desc, head); + + w = (desc.flags & AVAIL_DESC_PACKED(1)) >> 7; + desc.flags &= ~(AVAIL_DESC_PACKED(1) | USED_DESC_PACKED(1)); + desc.flags |= AVAIL_DESC_PACKED(w) | USED_DESC_PACKED(w); + if (!(desc.flags & VRING_DESC_F_INDIRECT)) { + if (!(desc.flags & VRING_DESC_F_WRITE)) { + desc.len = 0; + } else { + desc.len = len; + } + } + vring_packed_desc_write(vq->vdev, &desc, &caches->desc, head); + + /* Make sure flags has been updated */ + smp_mb(); +} + +void virtqueue_fill(VirtQueue *vq, const VirtQueueElement *elem, + unsigned int len, unsigned int idx) +{ + trace_virtqueue_fill(vq, elem, len, idx); + + virtqueue_unmap_sg(vq, elem, len); if (unlikely(vq->vdev->broken)) { - vq->inuse -= count; return; } + if (virtio_vdev_has_feature(vq->vdev, VIRTIO_F_RING_PACKED)) { + virtqueue_packed_fill(vq, elem, len, idx); + } else { + virtqueue_split_fill(vq, elem, len, idx); + } +} + +/* Called within rcu_read_lock(). */ +static void virtqueue_split_flush(VirtQueue *vq, unsigned int count) +{ + uint16_t old, new; + if (unlikely(!vq->vring.used)) { return; } @@ -575,6 +630,34 @@ void virtqueue_flush(VirtQueue *vq, unsigned int count) vq->signalled_used_valid = false; } +static void virtqueue_packed_flush(VirtQueue *vq, unsigned int count) +{ + if (unlikely(!vq->vring.desc)) { + return; + } + + vq->inuse -= count; + vq->used_idx += count; + if (vq->used_idx >= vq->vring.num) { + vq->used_idx -= vq->vring.num; + vq->used_wrap_counter = !vq->used_wrap_counter; + } +} + +void virtqueue_flush(VirtQueue *vq, unsigned int count) +{ + if (unlikely(vq->vdev->broken)) { + vq->inuse -= count; + return; + } + + if (virtio_vdev_has_feature(vq->vdev, VIRTIO_F_RING_PACKED)) { + virtqueue_packed_flush(vq, count); + } else { + virtqueue_split_flush(vq, count); + } +} + void virtqueue_push(VirtQueue *vq, const VirtQueueElement *elem, unsigned int len) { -- 1.8.3.1