Merge pull request #57 from shengwen-tw/packed

Introduce PACKED macro

Author: jserv

common.h

@@ -25,3 +25,12 @@ static inline int ilog2(int x)
  */
 #define RANGE_CHECK(x, minx, size) \
     ((int32_t) ((x - minx) | (minx + size - 1 - x)) >= 0)
+
+/* Packed macro */
+#if defined(__GNUC__) || defined(__clang__)
+#define PACKED(name) name __attribute__((packed))
+#elif defined(_MSC_VER)
+#define PACKED(name) __pragma(pack(push, 1)) name __pragma(pack(pop))
+#else /* unsupported compilers */
+#define PACKED(name)
+#endif

virtio-blk.c

@@ -26,7 +26,7 @@
 
 #define PRIV(x) ((struct virtio_blk_config *) x->priv)
 
-struct virtio_blk_config {
+PACKED(struct virtio_blk_config {
     uint64_t capacity;
     uint32_t size_max;
     uint32_t seg_max;
@@ -55,14 +55,14 @@ struct virtio_blk_config {
     uint32_t max_write_zeroes_seg;
     uint8_t write_zeroes_may_unmap;
     uint8_t unused1[3];
-} __attribute__((packed));
+});
 
-struct vblk_req_header {
+PACKED(struct vblk_req_header {
     uint32_t type;
     uint32_t reserved;
     uint64_t sector;
     uint8_t status;
-} __attribute__((packed));
+});
 
 static struct virtio_blk_config vblk_configs[VBLK_DEV_CNT_MAX];
 static int vblk_dev_cnt = 0;

virtio-net.c

@@ -30,12 +30,12 @@
 
 enum { VNET_QUEUE_RX = 0, VNET_QUEUE_TX = 1 };
 
-struct virtio_net_config {
+PACKED(struct virtio_net_config {
     uint8_t mac[6];
     uint16_t status;
     uint16_t max_virtqueue_pairs;
     uint16_t mtu;
-} __attribute__((packed));
+});
 
 static struct virtio_net_config vnet_configs[VNET_DEV_CNT_MAX];
 static int vnet_dev_cnt = 0;