dev: Correctly transform packets into responses

The VirtIO devices didn't correctly set the response flags in memory
packets. This changeset adds the required Packet::makeResponse()
calls.

src/dev/virtio/base.cc

@@ -426,6 +426,7 @@ VirtIODeviceBase::readConfigBlob(PacketPtr pkt, Addr cfgOffset, const uint8_t *c
     if (cfgOffset + size > configSize)
         panic("Config read out of bounds.\n");
 
+    pkt->makeResponse();
     pkt->setData(const_cast<uint8_t *>(cfg) + cfgOffset);
 }
 
@@ -437,6 +438,7 @@ VirtIODeviceBase::writeConfigBlob(PacketPtr pkt, Addr cfgOffset, uint8_t *cfg)
     if (cfgOffset + size > configSize)
         panic("Config write out of bounds.\n");
 
+    pkt->makeResponse();
     pkt->writeData((uint8_t *)cfg + cfgOffset);
 }
 

src/dev/virtio/pci.cc

@@ -75,6 +75,8 @@ PciVirtIO::read(PacketPtr pkt)
         return 0;
     }
 
+    pkt->makeResponse();
+
     switch(offset) {
       case OFF_DEVICE_FEATURES:
         DPRINTF(VIOPci, "   DEVICE_FEATURES request\n");
@@ -151,6 +153,8 @@ PciVirtIO::write(PacketPtr pkt)
         return 0;
     }
 
+    pkt->makeResponse();
+
     switch(offset) {
       case OFF_DEVICE_FEATURES:
         warn("Guest tried to write device features.");