On Wed, Aug 10, 2022 at 1:39 AM Eugenio Pérez <epere...@redhat.com> wrote:
>
> As this series will reuse them to restore the device state at the end of
> a migration (or a device start), let's allocate only once at the device
> start so we don't duplicate their map and unmap.
>
> Signed-off-by: Eugenio Pérez <epere...@redhat.com>
Acked-by: Jason Wang <jasow...@redhat.com>
> ---
> net/vhost-vdpa.c | 123 ++++++++++++++++++++++-------------------------
> 1 file changed, 58 insertions(+), 65 deletions(-)
>
> diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c
> index 55e8a39a56..5254b58bdc 100644
> --- a/net/vhost-vdpa.c
> +++ b/net/vhost-vdpa.c
> @@ -263,29 +263,20 @@ static size_t vhost_vdpa_net_cvq_cmd_page_len(void)
> return ROUND_UP(vhost_vdpa_net_cvq_cmd_len(),
> qemu_real_host_page_size());
> }
>
> -/** Copy and map a guest buffer. */
> -static bool vhost_vdpa_cvq_map_buf(struct vhost_vdpa *v,
> - const struct iovec *out_data,
> - size_t out_num, size_t data_len, void
> *buf,
> - size_t *written, bool write)
> +/** Map CVQ buffer. */
> +static int vhost_vdpa_cvq_map_buf(struct vhost_vdpa *v, void *buf, size_t
> size,
> + bool write)
> {
> DMAMap map = {};
> int r;
>
> - if (unlikely(!data_len)) {
> - qemu_log_mask(LOG_GUEST_ERROR, "%s: invalid legnth of %s buffer\n",
> - __func__, write ? "in" : "out");
> - return false;
> - }
> -
> - *written = iov_to_buf(out_data, out_num, 0, buf, data_len);
> map.translated_addr = (hwaddr)(uintptr_t)buf;
> - map.size = vhost_vdpa_net_cvq_cmd_page_len() - 1;
> + map.size = size - 1;
> map.perm = write ? IOMMU_RW : IOMMU_RO,
> r = vhost_iova_tree_map_alloc(v->iova_tree, &map);
> if (unlikely(r != IOVA_OK)) {
> error_report("Cannot map injected element");
> - return false;
> + return r;
> }
>
> r = vhost_vdpa_dma_map(v, map.iova, vhost_vdpa_net_cvq_cmd_page_len(),
> buf,
> @@ -294,50 +285,58 @@ static bool vhost_vdpa_cvq_map_buf(struct vhost_vdpa *v,
> goto dma_map_err;
> }
>
> - return true;
> + return 0;
>
> dma_map_err:
> vhost_iova_tree_remove(v->iova_tree, &map);
> - return false;
> + return r;
> }
>
> -/**
> - * Copy the guest element into a dedicated buffer suitable to be sent to NIC
> - *
> - * @iov: [0] is the out buffer, [1] is the in one
> - */
> -static bool vhost_vdpa_net_cvq_map_elem(VhostVDPAState *s,
> - VirtQueueElement *elem,
> - struct iovec *iov)
> +static int vhost_vdpa_net_cvq_start(NetClientState *nc)
> {
> - size_t in_copied;
> - bool ok;
> + VhostVDPAState *s;
> + int r;
>
> - iov[0].iov_base = s->cvq_cmd_out_buffer;
> - ok = vhost_vdpa_cvq_map_buf(&s->vhost_vdpa, elem->out_sg, elem->out_num,
> - vhost_vdpa_net_cvq_cmd_len(),
> iov[0].iov_base,
> - &iov[0].iov_len, false);
> - if (unlikely(!ok)) {
> - return false;
> + assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_VDPA);
> +
> + s = DO_UPCAST(VhostVDPAState, nc, nc);
> + if (!s->vhost_vdpa.shadow_vqs_enabled) {
> + return 0;
> }
>
> - iov[1].iov_base = s->cvq_cmd_in_buffer;
> - ok = vhost_vdpa_cvq_map_buf(&s->vhost_vdpa, NULL, 0,
> - sizeof(virtio_net_ctrl_ack), iov[1].iov_base,
> - &in_copied, true);
> - if (unlikely(!ok)) {
> + r = vhost_vdpa_cvq_map_buf(&s->vhost_vdpa, s->cvq_cmd_out_buffer,
> + vhost_vdpa_net_cvq_cmd_page_len(), false);
> + if (unlikely(r < 0)) {
> + return r;
> + }
> +
> + r = vhost_vdpa_cvq_map_buf(&s->vhost_vdpa, s->cvq_cmd_in_buffer,
> + vhost_vdpa_net_cvq_cmd_page_len(), true);
> + if (unlikely(r < 0)) {
> vhost_vdpa_cvq_unmap_buf(&s->vhost_vdpa, s->cvq_cmd_out_buffer);
> - return false;
> }
>
> - iov[1].iov_len = sizeof(virtio_net_ctrl_ack);
> - return true;
> + return r;
> +}
> +
> +static void vhost_vdpa_net_cvq_stop(NetClientState *nc)
> +{
> + VhostVDPAState *s = DO_UPCAST(VhostVDPAState, nc, nc);
> +
> + assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_VDPA);
> +
> + if (s->vhost_vdpa.shadow_vqs_enabled) {
> + vhost_vdpa_cvq_unmap_buf(&s->vhost_vdpa, s->cvq_cmd_out_buffer);
> + vhost_vdpa_cvq_unmap_buf(&s->vhost_vdpa, s->cvq_cmd_in_buffer);
> + }
> }
>
> static NetClientInfo net_vhost_vdpa_cvq_info = {
> .type = NET_CLIENT_DRIVER_VHOST_VDPA,
> .size = sizeof(VhostVDPAState),
> .receive = vhost_vdpa_receive,
> + .start = vhost_vdpa_net_cvq_start,
> + .stop = vhost_vdpa_net_cvq_stop,
> .cleanup = vhost_vdpa_cleanup,
> .has_vnet_hdr = vhost_vdpa_has_vnet_hdr,
> .has_ufo = vhost_vdpa_has_ufo,
> @@ -348,19 +347,17 @@ static NetClientInfo net_vhost_vdpa_cvq_info = {
> * Do not forward commands not supported by SVQ. Otherwise, the device could
> * accept it and qemu would not know how to update the device model.
> */
> -static bool vhost_vdpa_net_cvq_validate_cmd(const struct iovec *out,
> - size_t out_num)
> +static bool vhost_vdpa_net_cvq_validate_cmd(const void *out_buf, size_t len)
> {
> struct virtio_net_ctrl_hdr ctrl;
> - size_t n;
>
> - n = iov_to_buf(out, out_num, 0, &ctrl, sizeof(ctrl));
> - if (unlikely(n < sizeof(ctrl))) {
> + if (unlikely(len < sizeof(ctrl))) {
> qemu_log_mask(LOG_GUEST_ERROR,
> - "%s: invalid legnth of out buffer %zu\n", __func__, n);
> + "%s: invalid legnth of out buffer %zu\n", __func__,
> len);
> return false;
> }
>
> + memcpy(&ctrl, out_buf, sizeof(ctrl));
> switch (ctrl.class) {
> case VIRTIO_NET_CTRL_MAC:
> switch (ctrl.cmd) {
> @@ -392,10 +389,14 @@ static int
> vhost_vdpa_net_handle_ctrl_avail(VhostShadowVirtqueue *svq,
> VhostVDPAState *s = opaque;
> size_t in_len, dev_written;
> virtio_net_ctrl_ack status = VIRTIO_NET_ERR;
> - /* out and in buffers sent to the device */
> - struct iovec dev_buffers[2] = {
> - { .iov_base = s->cvq_cmd_out_buffer },
> - { .iov_base = s->cvq_cmd_in_buffer },
> + /* Out buffer sent to both the vdpa device and the device model */
> + struct iovec out = {
> + .iov_base = s->cvq_cmd_out_buffer,
> + };
> + /* In buffer sent to the device */
> + const struct iovec dev_in = {
> + .iov_base = s->cvq_cmd_in_buffer,
> + .iov_len = sizeof(virtio_net_ctrl_ack),
> };
> /* in buffer used for device model */
> const struct iovec in = {
> @@ -405,17 +406,15 @@ static int
> vhost_vdpa_net_handle_ctrl_avail(VhostShadowVirtqueue *svq,
> int r = -EINVAL;
> bool ok;
>
> - ok = vhost_vdpa_net_cvq_map_elem(s, elem, dev_buffers);
> - if (unlikely(!ok)) {
> - goto out;
> - }
> -
> - ok = vhost_vdpa_net_cvq_validate_cmd(&dev_buffers[0], 1);
> + out.iov_len = iov_to_buf(elem->out_sg, elem->out_num, 0,
> + s->cvq_cmd_out_buffer,
> + vhost_vdpa_net_cvq_cmd_len());
> + ok = vhost_vdpa_net_cvq_validate_cmd(s->cvq_cmd_out_buffer, out.iov_len);
> if (unlikely(!ok)) {
> goto out;
> }
>
> - r = vhost_svq_add(svq, &dev_buffers[0], 1, &dev_buffers[1], 1, elem);
> + r = vhost_svq_add(svq, &out, 1, &dev_in, 1, elem);
> if (unlikely(r != 0)) {
> if (unlikely(r == -ENOSPC)) {
> qemu_log_mask(LOG_GUEST_ERROR, "%s: No space on device queue\n",
> @@ -435,13 +434,13 @@ static int
> vhost_vdpa_net_handle_ctrl_avail(VhostShadowVirtqueue *svq,
> goto out;
> }
>
> - memcpy(&status, dev_buffers[1].iov_base, sizeof(status));
> + memcpy(&status, s->cvq_cmd_in_buffer, sizeof(status));
> if (status != VIRTIO_NET_OK) {
> goto out;
> }
>
> status = VIRTIO_NET_ERR;
> - virtio_net_handle_ctrl_iov(svq->vdev, &in, 1, dev_buffers, 1);
> + virtio_net_handle_ctrl_iov(svq->vdev, &in, 1, &out, 1);
> if (status != VIRTIO_NET_OK) {
> error_report("Bad CVQ processing in model");
> }
> @@ -454,12 +453,6 @@ out:
> }
> vhost_svq_push_elem(svq, elem, MIN(in_len, sizeof(status)));
> g_free(elem);
> - if (dev_buffers[0].iov_base) {
> - vhost_vdpa_cvq_unmap_buf(&s->vhost_vdpa, dev_buffers[0].iov_base);
> - }
> - if (dev_buffers[1].iov_base) {
> - vhost_vdpa_cvq_unmap_buf(&s->vhost_vdpa, dev_buffers[1].iov_base);
> - }
> return r;
> }
>
> --
> 2.31.1
>
