pcnet: Add link state support

Update lnkst on link state changes so that guests can obtain this
information via reading back the LED output pin. Works for Linux but
not for guests that depend on the missing PHY.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/hw/pcnet.c b/hw/pcnet.c
index add3ec2559..cba253ba7b 100644
--- a/hw/pcnet.c
+++ b/hw/pcnet.c
@@ -1197,6 +1197,13 @@ ssize_t pcnet_receive(VLANClientState *nc, const uint8_t *buf, size_t size_)
     return size_;
 }
 
+void pcnet_set_link_status(VLANClientState *nc)
+{
+    PCNetState *d = DO_UPCAST(NICState, nc, nc)->opaque;
+
+    d->lnkst = nc->link_down ? 0 : 0x40;
+}
+
 static void pcnet_transmit(PCNetState *s)
 {
     target_phys_addr_t xmit_cxda = 0;