lan9118: log and ignore access to invalid registers, rather than aborting

With this change, access to invalid/unimplemented device registers are
logged as a "guest error" rather than aborting qemu with
hw_error. This enables drivers for similar devices (e.g. SMSC 9221),
by simply ignoring the unimplemented writes. It's also closer to what
real hardware does.

Signed-off-by: Andrew Baumann <Andrew.Baumann@microsoft.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>

1 files changed, 8 insertions, 4 deletions

diff --git a/hw/net/lan9118.c b/hw/net/lan9118.c
index 133fd3d226..1734b5276d 100644
--- a/hw/net/lan9118.c
+++ b/hw/net/lan9118.c
@@ -904,7 +904,8 @@ static void do_mac_write(lan9118_state *s, int reg, uint32_t val)
          */
         break;
     default:
-        hw_error("lan9118: Unimplemented MAC register write: %d = 0x%x\n",
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "lan9118: Unimplemented MAC register write: %d = 0x%x\n",
                  s->mac_cmd & 0xf, val);
     }
 }
@@ -932,8 +933,10 @@ static uint32_t do_mac_read(lan9118_state *s, int reg)
     case MAC_FLOW:
         return s->mac_flow;
     default:
-        hw_error("lan9118: Unimplemented MAC register read: %d\n",
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "lan9118: Unimplemented MAC register read: %d\n",
                  s->mac_cmd & 0xf);
+        return 0;
     }
 }
 
@@ -1130,7 +1133,8 @@ static void lan9118_writel(void *opaque, hwaddr offset,
         break;
 
     default:
-        hw_error("lan9118_write: Bad reg 0x%x = %x\n", (int)offset, (int)val);
+        qemu_log_mask(LOG_GUEST_ERROR, "lan9118_write: Bad reg 0x%x = %x\n",
+                      (int)offset, (int)val);
         break;
     }
     lan9118_update(s);
@@ -1248,7 +1252,7 @@ static uint64_t lan9118_readl(void *opaque, hwaddr offset,
     case CSR_E2P_DATA:
         return s->e2p_data;
     }
-    hw_error("lan9118_read: Bad reg 0x%x\n", (int)offset);
+    qemu_log_mask(LOG_GUEST_ERROR, "lan9118_read: Bad reg 0x%x\n", (int)offset);
     return 0;
 }