virtio: introduce packed ring interface

Added placeholder for packed ring implementation and procedures
for getting sizes of allocations for split and packed ring.

Signed-off-by: Yuri Benditovich <yuri.benditovich@daynix.com>

VirtIO/VirtIORing-Packed.c

@@ -0,0 +1,61 @@
+/*
+ * Packed virtio ring manipulation routines
+ *
+ * Copyright 2019 Red Hat, Inc.
+ *
+ * Authors:
+ *  Yuri Benditovich <ybendito@redhat.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met :
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and / or other materials provided with the distribution.
+ * 3. Neither the names of the copyright holders nor the names of their contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include "osdep.h"
+#include "virtio_pci.h"
+#include "virtio.h"
+#include "kdebugprint.h"
+#include "virtio_ring.h"
+#include "windows\virtio_ring_allocation.h"
+
+unsigned int vring_control_block_size_packed(u16 qsize)
+{
+    return sizeof(struct virtqueue);
+}
+
+unsigned long vring_size_packed(unsigned int num, unsigned long align)
+{
+    return 4096;
+}
+
+/* Initializes a new virtqueue using already allocated memory */
+struct virtqueue *vring_new_virtqueue_packed(
+    unsigned int index,                 /* virtqueue index */
+    unsigned int num,                   /* virtqueue size (always a power of 2) */
+    unsigned int vring_align,           /* vring alignment requirement */
+    VirtIODevice *vdev,                 /* the virtio device owning the queue */
+    void *pages,                        /* vring memory */
+    void(*notify)(struct virtqueue *), /* notification callback */
+    void *control)                      /* virtqueue memory */
+{
+    return NULL;
+}

VirtIO/VirtIORing.c

@@ -473,7 +473,11 @@ static void *virtqueue_detach_unused_buf_split(struct virtqueue *_vq)
  * additional size for per-descriptor data */
 unsigned int vring_control_block_size(u16 qsize, bool packed)
 {
-    unsigned int res = sizeof(struct virtqueue_split);
+    unsigned int res;
+    if (packed) {
+        return vring_control_block_size_packed(qsize);
+    }
+    res = sizeof(struct virtqueue_split);
     res += sizeof(void *) * qsize;
     return res;
 }
@@ -551,7 +555,7 @@ u32 virtio_get_indirect_page_capacity()
 unsigned long vring_size(unsigned int num, unsigned long align, bool packed)
 {
     if (packed) {
-        return vring_size_split(num, align);
+        return vring_size_packed(num, align);
     } else {
         return vring_size_split(num, align);
     }

VirtIO/VirtioLib.vcxproj

@@ -66,6 +66,7 @@
     <ClCompile Include="VirtIOPCICommon.c" />
     <ClCompile Include="VirtIOPCILegacy.c" />
     <ClCompile Include="VirtIOPCIModern.c" />
+    <ClCompile Include="VirtIORing-Packed.c" />
     <ClCompile Include="VirtIORing.c" />
   </ItemGroup>
   <ItemGroup>

VirtIO/VirtioLib.vcxproj.filters

@@ -13,6 +13,9 @@
     <ClCompile Include="VirtIORing.c">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="VirtIORing-Packed.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="linux\types.h">

VirtIO/windows/virtio_ring_allocation.h

@@ -10,5 +10,7 @@ struct virtqueue *vring_new_virtqueue(unsigned int index,
     void *control);
 
 unsigned int vring_control_block_size(u16 qsize, bool packed);
+unsigned int vring_control_block_size_packed(u16 qsize);
+unsigned long vring_size_packed(unsigned int num, unsigned long align);
 
 #endif /* _VIRTIO_RING_ALLOCATION_H */