Re: [RFC PATCH v7 09/25] vhost: move descriptor translation to vhost_svq_vring_write_descs

[Jason Wang]

在 2022/4/14 00:31, Eugenio Pérez 写道:

It's done for both in and out descriptors so it's better placed here.

Signed-off-by: Eugenio Pérez <epere...@redhat.com>
---
  hw/virtio/vhost-shadow-virtqueue.c | 26 +++++++++++++++-----------
  1 file changed, 15 insertions(+), 11 deletions(-)

Acked-by: Jason Wang <jasow...@redhat.com>

diff --git a/hw/virtio/vhost-shadow-virtqueue.c 
b/hw/virtio/vhost-shadow-virtqueue.c
index a2531d5874..f874374651 100644
--- a/hw/virtio/vhost-shadow-virtqueue.c
+++ b/hw/virtio/vhost-shadow-virtqueue.c
@@ -122,17 +122,23 @@ static bool vhost_svq_translate_addr(const 
VhostShadowVirtqueue *svq,
      return true;
  }

-static void vhost_vring_write_descs(VhostShadowVirtqueue *svq, hwaddr *sg,

-                                    const struct iovec *iovec, size_t num,
-                                    bool more_descs, bool write)
+static bool vhost_svq_vring_write_descs(VhostShadowVirtqueue *svq, hwaddr *sg,
+                                        const struct iovec *iovec, size_t num,
+                                        bool more_descs, bool write)
  {
      uint16_t i = svq->free_head, last = svq->free_head;
      unsigned n;
      uint16_t flags = write ? cpu_to_le16(VRING_DESC_F_WRITE) : 0;
      vring_desc_t *descs = svq->vring.desc;
+    bool ok;

if (num == 0) {

-        return;
+        return true;
+    }
+
+    ok = vhost_svq_translate_addr(svq, sg, iovec, num);
+    if (unlikely(!ok)) {
+        return false;
      }

for (n = 0; n < num; n++) {

@@ -150,6 +156,7 @@ static void vhost_vring_write_descs(VhostShadowVirtqueue 
*svq, hwaddr *sg,
      }

svq->free_head = le16_to_cpu(svq->desc_next[last]);

+    return true;
  }

static bool vhost_svq_add_split(VhostShadowVirtqueue *svq,

@@ -169,21 +176,18 @@ static bool vhost_svq_add_split(VhostShadowVirtqueue *svq,
          return false;
      }

- ok = vhost_svq_translate_addr(svq, sgs, elem->out_sg, elem->out_num);

+    ok = vhost_svq_vring_write_descs(svq, sgs, elem->out_sg, elem->out_num,
+                                     elem->in_num > 0, false);
      if (unlikely(!ok)) {
          return false;
      }
-    vhost_vring_write_descs(svq, sgs, elem->out_sg, elem->out_num,
-                            elem->in_num > 0, false);

-

-    ok = vhost_svq_translate_addr(svq, sgs, elem->in_sg, elem->in_num);
+    ok = vhost_svq_vring_write_descs(svq, sgs, elem->in_sg, elem->in_num, 
false,
+                                     true);
      if (unlikely(!ok)) {
          return false;
      }

- vhost_vring_write_descs(svq, sgs, elem->in_sg, elem->in_num, false, true);

-
      /*
       * Put the entry in the available array (but don't update avail->idx until
       * they do sync).