1 files changed, 41 insertions, 7 deletions

diff --git a/util/fifo8.c b/util/fifo8.c
index 4e01b532d9..1ffa19d900 100644
--- a/util/fifo8.c
+++ b/util/fifo8.c
@@ -16,12 +16,17 @@
 #include "migration/vmstate.h"
 #include "qemu/fifo8.h"
 
+void fifo8_reset(Fifo8 *fifo)
+{
+    fifo->num = 0;
+    fifo->head = 0;
+}
+
 void fifo8_create(Fifo8 *fifo, uint32_t capacity)
 {
     fifo->data = g_new(uint8_t, capacity);
     fifo->capacity = capacity;
-    fifo->head = 0;
-    fifo->num = 0;
+    fifo8_reset(fifo);
 }
 
 void fifo8_destroy(Fifo8 *fifo)
@@ -87,20 +92,49 @@ static const uint8_t *fifo8_peekpop_buf(Fifo8 *fifo, uint32_t max,
     return ret;
 }
 
-const uint8_t *fifo8_peek_buf(Fifo8 *fifo, uint32_t max, uint32_t *numptr)
+const uint8_t *fifo8_peek_bufptr(Fifo8 *fifo, uint32_t max, uint32_t *numptr)
 {
     return fifo8_peekpop_buf(fifo, max, numptr, false);
 }
 
-const uint8_t *fifo8_pop_buf(Fifo8 *fifo, uint32_t max, uint32_t *numptr)
+const uint8_t *fifo8_pop_bufptr(Fifo8 *fifo, uint32_t max, uint32_t *numptr)
 {
     return fifo8_peekpop_buf(fifo, max, numptr, true);
 }
 
-void fifo8_reset(Fifo8 *fifo)
+uint32_t fifo8_pop_buf(Fifo8 *fifo, uint8_t *dest, uint32_t destlen)
 {
-    fifo->num = 0;
-    fifo->head = 0;
+    const uint8_t *buf;
+    uint32_t n1, n2 = 0;
+    uint32_t len;
+
+    if (destlen == 0) {
+        return 0;
+    }
+
+    len = destlen;
+    buf = fifo8_pop_bufptr(fifo, len, &n1);
+    if (dest) {
+        memcpy(dest, buf, n1);
+    }
+
+    /* Add FIFO wraparound if needed */
+    len -= n1;
+    len = MIN(len, fifo8_num_used(fifo));
+    if (len) {
+        buf = fifo8_pop_bufptr(fifo, len, &n2);
+        if (dest) {
+            memcpy(&dest[n1], buf, n2);
+        }
+    }
+
+    return n1 + n2;
+}
+
+void fifo8_drop(Fifo8 *fifo, uint32_t len)
+{
+    len -= fifo8_pop_buf(fifo, NULL, len);
+    assert(len == 0);
 }
 
 bool fifo8_is_empty(Fifo8 *fifo)