virtio: various cleanup

Signed-off-by: Ivan-Velickovic <[email protected]>
au-ts · Nov 7, 2024 · 9420943 · 9420943
1 parent 4a18c5b
commit 9420943
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Showing 3 changed files with 20 additions and 21 deletions.
diff --git a/include/libvmm/virtio/block.h b/include/libvmm/virtio/block.h
@@ -150,8 +150,6 @@ struct virtio_blk_outhdr {
  * virtio response from sddf response.
  */
 typedef struct reqbk {
-    // /* For writing response byte in virtio descriptor */
-    // uint8_t *virtio_resp_byte;
     /* Descriptor head of the virtio request */
     uint16_t virtio_desc_head;
     /* For enqueuing sddf req/resp */

diff --git a/src/virtio/block.c b/src/virtio/block.c
@@ -244,7 +244,9 @@ static bool virtio_blk_mmio_queue_notify(struct virtio_device *dev)
         uint32_t curr_desc_bytes_read = 0;
 
         /* There are three parts with each block request. The header, body (which
-         * contains the data) and reply. */
+         * contains the data) and footer. */
+
+        /* First read the header */
         uint32_t header_bytes_read = 0;
         struct virtio_blk_outhdr virtio_req_header;
         for (; header_bytes_read < sizeof(struct virtio_blk_outhdr);
@@ -254,21 +256,20 @@ static bool virtio_blk_mmio_queue_notify(struct virtio_device *dev)
             /* We can guarantee existence of next descriptor as footer is write only
              */
             assert(virtq->desc[curr_desc].flags & VIRTQ_DESC_F_NEXT);
-            if (header_bytes_read + virtq->desc[curr_desc].len >
-                sizeof(struct virtio_blk_outhdr)) {
-                memcpy(&virtio_req_header, (void *)virtq->desc[curr_desc].addr,
-                       sizeof(struct virtio_blk_outhdr) - header_bytes_read);
-                curr_desc_bytes_read =
-                    sizeof(struct virtio_blk_outhdr) - header_bytes_read;
-                header_bytes_read +=
-                        sizeof(struct virtio_blk_outhdr) - header_bytes_read;
+
+            void *desc_addr = (void *)virtq->desc[curr_desc].addr;
+            uint32_t desc_len = virtq->desc[curr_desc].len;
+
+            if (header_bytes_read + desc_len > sizeof(struct virtio_blk_outhdr)) {
+                memcpy(&virtio_req_header, desc_addr, sizeof(struct virtio_blk_outhdr) - header_bytes_read);
+                curr_desc_bytes_read = sizeof(struct virtio_blk_outhdr) - header_bytes_read;
+                header_bytes_read += sizeof(struct virtio_blk_outhdr) - header_bytes_read;
                 /* Don't go to the next descriptor yet, we're not done processing with
                  * current one */
                 break;
             } else {
-                memcpy(&virtio_req_header, (void *)virtq->desc[curr_desc].addr,
-                       virtq->desc[curr_desc].len);
-                header_bytes_read += virtq->desc[curr_desc].len;
+                memcpy(&virtio_req_header, desc_addr, desc_len);
+                header_bytes_read += desc_len;
             }
         }
 

diff --git a/vmm.mk b/vmm.mk
@@ -43,13 +43,13 @@ CFLAGS += -I${LIBVMM_DIR}/include
 endif
 
 ARCH_INDEP_FILES := src/util/printf.c \
-		    src/util/util.c \
-		    src/virtio/block.c \
-		    src/virtio/console.c \
-		    src/virtio/mmio.c \
-		    src/virtio/net.c \
-		    src/virtio/sound.c \
-		    src/guest.c \
+			src/util/util.c \
+			src/virtio/block.c \
+			src/virtio/console.c \
+			src/virtio/mmio.c \
+			src/virtio/net.c \
+			src/virtio/sound.c \
+			src/guest.c \
 			src/uio/uio.c \
 
 CFILES := ${AARCH64_FILES} ${ARCH_INDEP_FILES}