[Qemu-devel] [PATCH v2] virtio dataplane: adapt dataplane for virtio Version 1

[Pierre Morel <pmorel@linux.vnet.ibm.com>]

Let dataplane allocate different region for the desc/avail/used
ring regions.

Signed-off-by: Pierre Morel <pmorel@linux.vnet.ibm.com>
Acked-by: Greg Kurz <gkurz@linux.vnet.ibm.com>
Tested-by: Greg Kurz <gkurz@linux.vnet.ibm.com>
---
 hw/virtio/dataplane/vring.c         | 48 ++++++++++++++++++++++++++-----------
 include/hw/virtio/dataplane/vring.h |  4 +++-
 2 files changed, 37 insertions(+), 15 deletions(-)

diff --git a/hw/virtio/dataplane/vring.c b/hw/virtio/dataplane/vring.c
index 07fd69c..ad86be5 100644
--- a/hw/virtio/dataplane/vring.c
+++ b/hw/virtio/dataplane/vring.c
@@ -65,24 +65,34 @@ static void vring_unmap(void *buffer, bool is_write)
 }
 
 /* Map the guest's vring to host memory */
+
+#define MAP_VRING_DESCRIPTOR(d) {                                       \
+        hwaddr addr;                                                    \
+        hwaddr size;                                                    \
+        void *ptr;                                                      \
+                                                                        \
+        addr = virtio_queue_get_##d##_addr(vdev, n);                    \
+        size = virtio_queue_get_##d## _size(vdev, n);                   \
+        ptr = vring_map(&vring->mr_##d, addr, size, true);              \
+        if (!ptr) {                                                     \
+            error_report("Failed to map vring "#d" "                    \
+                         "addr %#" HWADDR_PRIx " size %" HWADDR_PRIu,   \
+                         addr, size);                                   \
+            goto out_err_##d;                                           \
+        }                                                               \
+        vr->d = ptr;                                                    \
+    }
+
 bool vring_setup(Vring *vring, VirtIODevice *vdev, int n)
 {
-    hwaddr vring_addr = virtio_queue_get_ring_addr(vdev, n);
-    hwaddr vring_size = virtio_queue_get_ring_size(vdev, n);
-    void *vring_ptr;
+    struct vring *vr = &vring->vr;
 
     vring->broken = false;
+    vr->num = virtio_queue_get_num(vdev, n);
 
-    vring_ptr = vring_map(&vring->mr, vring_addr, vring_size, true);
-    if (!vring_ptr) {
-        error_report("Failed to map vring "
-                     "addr %#" HWADDR_PRIx " size %" HWADDR_PRIu,
-                     vring_addr, vring_size);
-        vring->broken = true;
-        return false;
-    }
-
-    vring_init(&vring->vr, virtio_queue_get_num(vdev, n), vring_ptr, 4096);
+    MAP_VRING_DESCRIPTOR(desc);
+    MAP_VRING_DESCRIPTOR(avail);
+    MAP_VRING_DESCRIPTOR(used);
 
     vring->last_avail_idx = virtio_queue_get_last_avail_idx(vdev, n);
     vring->last_used_idx = vring_get_used_idx(vdev, vring);
@@ -92,6 +102,14 @@ bool vring_setup(Vring *vring, VirtIODevice *vdev, int n)
     trace_vring_setup(virtio_queue_get_ring_addr(vdev, n),
                       vring->vr.desc, vring->vr.avail, vring->vr.used);
     return true;
+
+out_err_used:
+    memory_region_unref(vring->mr_avail);
+out_err_avail:
+    memory_region_unref(vring->mr_desc);
+out_err_desc:
+    vring->broken = true;
+    return false;
 }
 
 void vring_teardown(Vring *vring, VirtIODevice *vdev, int n)
@@ -99,7 +117,9 @@ void vring_teardown(Vring *vring, VirtIODevice *vdev, int n)
     virtio_queue_set_last_avail_idx(vdev, n, vring->last_avail_idx);
     virtio_queue_invalidate_signalled_used(vdev, n);
 
-    memory_region_unref(vring->mr);
+    memory_region_unref(vring->mr_desc);
+    memory_region_unref(vring->mr_avail);
+    memory_region_unref(vring->mr_used);
 }
 
 /* Disable guest->host notifies */
diff --git a/include/hw/virtio/dataplane/vring.h b/include/hw/virtio/dataplane/vring.h
index 8d97db9..a596e4c 100644
--- a/include/hw/virtio/dataplane/vring.h
+++ b/include/hw/virtio/dataplane/vring.h
@@ -22,7 +22,9 @@
 #include "hw/virtio/virtio.h"
 
 typedef struct {
-    MemoryRegion *mr;               /* memory region containing the vring */
+    MemoryRegion *mr_desc;          /* memory region for the vring desc */
+    MemoryRegion *mr_avail;         /* memory region for the vring avail */
+    MemoryRegion *mr_used;          /* memory region for the vring used */
     struct vring vr;                /* virtqueue vring mapped to host memory */
     uint16_t last_avail_idx;        /* last processed avail ring index */
     uint16_t last_used_idx;         /* last processed used ring index */
-- 
2.3.0