e1000: PHY loopback mode support

The missing of loopback mode prevent the running of self diagnosis
program in guest. This patch adds this support.

After this patch, loopback test of ethtool were passed in guest.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 12 insertions, 2 deletions

diff --git a/hw/e1000.c b/hw/e1000.c
index 4e787bc2cf..4a09e39975 100644
--- a/hw/e1000.c
+++ b/hw/e1000.c
@@ -392,6 +392,16 @@ fcs_len(E1000State *s)
 }
 
 static void
+e1000_send_packet(E1000State *s, const uint8_t *buf, int size)
+{
+    if (s->phy_reg[PHY_CTRL] & MII_CR_LOOPBACK) {
+        s->nic->nc.info->receive(&s->nic->nc, buf, size);
+    } else {
+        qemu_send_packet(&s->nic->nc, buf, size);
+    }
+}
+
+static void
 xmit_seg(E1000State *s)
 {
     uint16_t len, *sp;
@@ -440,9 +450,9 @@ xmit_seg(E1000State *s)
         memmove(tp->vlan, tp->data, 4);
         memmove(tp->data, tp->data + 4, 8);
         memcpy(tp->data + 8, tp->vlan_header, 4);
-        qemu_send_packet(&s->nic->nc, tp->vlan, tp->size + 4);
+        e1000_send_packet(s, tp->vlan, tp->size + 4);
     } else
-        qemu_send_packet(&s->nic->nc, tp->data, tp->size);
+        e1000_send_packet(s, tp->data, tp->size);
     s->mac_reg[TPT]++;
     s->mac_reg[GPTC]++;
     n = s->mac_reg[TOTL];