3 files changed, 20 insertions, 6 deletions

diff --git a/hw/char/sclpconsole-lm.c b/hw/char/sclpconsole-lm.c
index 80dd0a9e13..a9f5e62f24 100644
--- a/hw/char/sclpconsole-lm.c
+++ b/hw/char/sclpconsole-lm.c
@@ -52,7 +52,8 @@ typedef struct SCLPConsoleLM {
  * event_pending is set when a newline character is encountered
  *
  * The maximum command line length is limited by the maximum
- * space available in an SCCB
+ * space available in an SCCB. Line mode console input is sent
+ * truncated to the guest in case it doesn't fit into the SCCB.
  */
 
 static int chr_can_read(void *opaque)
@@ -61,10 +62,8 @@ static int chr_can_read(void *opaque)
 
     if (scon->event.event_pending) {
         return 0;
-    } else if (SIZE_CONSOLE_BUFFER - scon->length) {
-        return 1;
     }
-    return 0;
+    return 1;
 }
 
 static void chr_read(void *opaque, const uint8_t *buf, int size)
@@ -78,6 +77,10 @@ static void chr_read(void *opaque, const uint8_t *buf, int size)
         sclp_service_interrupt(0);
         return;
     }
+    if (scon->length == SIZE_CONSOLE_BUFFER) {
+        /* Eat the character, but still process CR and LF.  */
+        return;
+    }
     scon->buf[scon->length] = *buf;
     scon->length += 1;
     if (scon->echo) {
@@ -125,6 +128,7 @@ static int get_console_data(SCLPEvent *event, uint8_t *buf, size_t *size,
     cons->length = 0;
     /* data provided and no more data pending */
     event->event_pending = false;
+    qemu_notify_event();
     return 0;
 }
 
diff --git a/hw/char/sclpconsole.c b/hw/char/sclpconsole.c
index fca105db4e..79891dfc58 100644
--- a/hw/char/sclpconsole.c
+++ b/hw/char/sclpconsole.c
@@ -36,6 +36,7 @@ typedef struct SCLPConsole {
     uint32_t iov_bs;        /* offset in buf for char layer read operation */
     uint32_t iov_data_len;  /* length of byte stream in buffer             */
     uint32_t iov_sclp_rest; /* length of byte stream not read via SCLP     */
+    bool notify;            /* qemu_notify_event() req'd if true           */
 } SCLPConsole;
 
 /* character layer call-back functions */
@@ -44,8 +45,12 @@ typedef struct SCLPConsole {
 static int chr_can_read(void *opaque)
 {
     SCLPConsole *scon = opaque;
+    int avail = SIZE_BUFFER_VT220 - scon->iov_data_len;
 
-    return SIZE_BUFFER_VT220 - scon->iov_data_len;
+    if (avail == 0) {
+        scon->notify = true;
+    }
+    return avail;
 }
 
 /* Send data from a char device over to the guest */
@@ -113,6 +118,10 @@ static void get_console_data(SCLPEvent *event, uint8_t *buf, size_t *size,
         cons->iov_sclp += avail;
         /* more data pending */
     }
+    if (cons->notify) {
+        cons->notify = false;
+        qemu_notify_event();
+    }
 }
 
 static int read_event_data(SCLPEvent *event, EventBufferHeader *evt_buf_hdr,
@@ -229,6 +238,7 @@ static void console_reset(DeviceState *dev)
    scon->iov_bs = 0;
    scon->iov_data_len = 0;
    scon->iov_sclp_rest = 0;
+   scon->notify = false;
 }
 
 static int console_exit(SCLPEvent *event)
diff --git a/hw/char/virtio-serial-bus.c b/hw/char/virtio-serial-bus.c
index c6870f19e1..a7b1b68984 100644
--- a/hw/char/virtio-serial-bus.c
+++ b/hw/char/virtio-serial-bus.c
@@ -871,7 +871,7 @@ static void virtser_port_device_realize(DeviceState *dev, Error **errp)
         return;
     }
 
-    if (find_port_by_name(port->name)) {
+    if (port->name != NULL && find_port_by_name(port->name)) {
         error_setg(errp, "virtio-serial-bus: A port already exists by name %s",
                    port->name);
         return;