updated virtio block device to partially handle non-aligned IO requests

[palacios.git] / palacios / src / devices / lnx_virtio_blk.c

diff --git a/palacios/src/devices/lnx_virtio_blk.c b/palacios/src/devices/lnx_virtio_blk.c
index d47243a..fd9ec61 100644 (file)
--- a/palacios/src/devices/lnx_virtio_blk.c
+++ b/palacios/src/devices/lnx_virtio_blk.c
@@ -407,38 +407,44 @@ static int virtio_io_read(struct guest_info * core, uint16_t port, void * dst, u
     PrintDebug("VIRTIO BLOCK Read  for port %d (index =%d), length=%d\n", 
               port, port_idx, length);
 
+
     switch (port_idx) {
        case HOST_FEATURES_PORT:
-           if (length != 4) {
-               PrintError("Illegal read length for host features\n");
+       case HOST_FEATURES_PORT + 1:
+       case HOST_FEATURES_PORT + 2:
+       case HOST_FEATURES_PORT + 3:
+           if (port_idx + length > HOST_FEATURES_PORT + 4) {
+               PrintError("Illegal read length for host features (len=%d)\n", length);
                return -1;
            }
 
-           *(uint32_t *)dst = blk_state->virtio_cfg.host_features;
-       
+           memcpy(dst, &(blk_state->virtio_cfg.host_features), length);
            break;
        case VRING_PG_NUM_PORT:
-           if (length != 4) {
-               PrintError("Illegal read length for page frame number\n");
+       case VRING_PG_NUM_PORT + 1:
+       case VRING_PG_NUM_PORT + 2:
+       case VRING_PG_NUM_PORT + 3:
+           if (port_idx + length > VRING_PG_NUM_PORT + 4) {
+               PrintError("Illegal read length for vring pg num (len=%d)\n", length);
                return -1;
            }
 
-           *(uint32_t *)dst = blk_state->queue.pfn;
-
+           memcpy(dst, &(blk_state->queue.pfn), length);
            break;
        case VRING_SIZE_PORT:
-           if (length != 2) {
-               PrintError("Illegal read length for vring size\n");
+       case VRING_SIZE_PORT + 1:
+           if (length > 2) {
+               PrintError("Illegal read length for vring size (len=%d)\n", length);
                return -1;
            }
-               
-           *(uint16_t *)dst = blk_state->queue.queue_size;
+           
+           memcpy(dst, &(blk_state->queue.queue_size), length);
 
            break;
 
        case VIRTIO_STATUS_PORT:
            if (length != 1) {
-               PrintError("Illegal read length for status\n");
+               PrintError("Illegal read length for status (len=%d)\n", length);
                return -1;
            }