qemu-kvm/kvm-vhost-move-descriptor-translation-to-vhost_svq_vring.patch

From 2bdea90bfbce3b8d5bfa86178a942a470b85b835 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Eugenio=20P=C3=A9rez?= <eperezma@redhat.com>
Date: Thu, 21 Jul 2022 15:38:55 +0200
Subject: [PATCH 07/32] vhost: move descriptor translation to
 vhost_svq_vring_write_descs
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RH-Author: Eugenio Pérez <eperezma@redhat.com>
RH-MergeRequest: 108: Net Control Virtqueue shadow Support
RH-Commit: [7/27] 5533c72065e4ebf8ea7db966c976a3b29bdafb82 (eperezmartin/qemu-kvm)
RH-Bugzilla: 1939363
RH-Acked-by: Stefano Garzarella <sgarzare@redhat.com>
RH-Acked-by: Cindy Lu <lulu@redhat.com>
RH-Acked-by: Laurent Vivier <lvivier@redhat.com>

Bugzilla: https://bugzilla.redhat.com/1939363

Upstream Status: git://git.qemu.org/qemu.git

commit 009c2549bb9dc7f7061009eb87f2a53d4b364983
Author: Eugenio Pérez <eperezma@redhat.com>
Date:   Wed Jul 20 08:59:26 2022 +0200

    vhost: move descriptor translation to vhost_svq_vring_write_descs

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

    Acked-by: Jason Wang <jasowang@redhat.com>
    Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
    Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
    Signed-off-by: Jason Wang <jasowang@redhat.com>

Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
---
 hw/virtio/vhost-shadow-virtqueue.c | 38 +++++++++++++++++++++---------
 1 file changed, 27 insertions(+), 11 deletions(-)

diff --git a/hw/virtio/vhost-shadow-virtqueue.c b/hw/virtio/vhost-shadow-virtqueue.c
index 06d0bb39d9..3fbda1e3d4 100644
--- a/hw/virtio/vhost-shadow-virtqueue.c
+++ b/hw/virtio/vhost-shadow-virtqueue.c
@@ -122,17 +122,35 @@ 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)
+/**
+ * Write descriptors to SVQ vring
+ *
+ * @svq: The shadow virtqueue
+ * @sg: Cache for hwaddr
+ * @iovec: The iovec from the guest
+ * @num: iovec length
+ * @more_descs: True if more descriptors come in the chain
+ * @write: True if they are writeable descriptors
+ *
+ * Return true if success, false otherwise and print error.
+ */
+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 +168,7 @@ 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 +188,18 @@ 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).
-- 
2.31.1