Merge remote-tracking branch 'mjt/mjt-iov2' into staging

[qemu.git] / hw / rtl8139.c

diff --git a/hw/rtl8139.c b/hw/rtl8139.c
index 8128b64a0fefbfd6b2b8438c5ffb9732bafd7e2e..436b015c645e7832f15bb56ef03c13a8f206424c 100644 (file)
--- a/hw/rtl8139.c
+++ b/hw/rtl8139.c
@@ -781,6 +781,13 @@ static inline dma_addr_t rtl8139_addr64(uint32_t low, uint32_t high)
 #endif
 }
 
+/* Workaround for buggy guest driver such as linux who allocates rx
+ * rings after the receiver were enabled. */
+static bool rtl8139_cp_rx_valid(RTL8139State *s)
+{
+    return !(s->RxRingAddrLO == 0 && s->RxRingAddrHI == 0);
+}
+
 static int rtl8139_can_receive(VLANClientState *nc)
 {
     RTL8139State *s = DO_UPCAST(NICState, nc, nc)->opaque;
@@ -791,18 +798,15 @@ static int rtl8139_can_receive(VLANClientState *nc)
       return 1;
     if (!rtl8139_receiver_enabled(s))
       return 1;
-    /* network/host communication happens only in normal mode */
-    if ((s->Cfg9346 & Chip9346_op_mask) != Cfg9346_Normal)
-       return 0;
 
-    if (rtl8139_cp_receiver_enabled(s)) {
+    if (rtl8139_cp_receiver_enabled(s) && rtl8139_cp_rx_valid(s)) {
         /* ??? Flow control not implemented in c+ mode.
            This is a hack to work around slirp deficiencies anyway.  */
         return 1;
     } else {
         avail = MOD2(s->RxBufferSize + s->RxBufPtr - s->RxBufAddr,
                      s->RxBufferSize);
-        return (avail == 0 || avail >= 1514);
+        return (avail == 0 || avail >= 1514 || (s->IntrMask & RxOverflow));
     }
 }
 
@@ -836,12 +840,6 @@ static ssize_t rtl8139_do_receive(VLANClientState *nc, const uint8_t *buf, size_
         return -1;
     }
 
-    /* check whether we are in normal mode */
-    if ((s->Cfg9346 & Chip9346_op_mask) != Cfg9346_Normal) {
-        DPRINTF("not in normal op mode\n");
-        return -1;
-    }
-
     /* XXX: check this */
     if (s->RxConfig & AcceptAllPhys) {
         /* promiscuous: receive all */
@@ -946,6 +944,10 @@ static ssize_t rtl8139_do_receive(VLANClientState *nc, const uint8_t *buf, size_
 
     if (rtl8139_cp_receiver_enabled(s))
     {
+        if (!rtl8139_cp_rx_valid(s)) {
+            return size;
+        }
+
         DPRINTF("in C+ Rx mode ================\n");
 
         /* begin C+ receiver mode */