qemu-char: Call fe_claim / fe_release when not using qdev chr properties

chardev-frontends need to explictly check, increase and decrement the
avail_connections "property" of the chardev when they are not using a
qdev-chardev-property for the chardev.

This fixes things like:
qemu-kvm -chardev stdio,id=foo -device isa-serial,chardev=foo \
  -mon chardev=foo

Working, where they should fail. Most of the changes here are due to
old hardware emulation code which is using serial_hds directly rather then
a qdev-chardev-property.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Message-id: 1364412581-3672-3-git-send-email-hdegoede@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

7 files changed, 24 insertions, 6 deletions

diff --git a/hw/arm/pxa2xx.c b/hw/arm/pxa2xx.c
index 7467cca4f7..b7ca511d45 100644
--- a/hw/arm/pxa2xx.c
+++ b/hw/arm/pxa2xx.c
@@ -1981,9 +1981,11 @@ static PXA2xxFIrState *pxa2xx_fir_init(MemoryRegion *sysmem,
     memory_region_init_io(&s->iomem, &pxa2xx_fir_ops, s, "pxa2xx-fir", 0x1000);
     memory_region_add_subregion(sysmem, base, &s->iomem);
 
-    if (chr)
+    if (chr) {
+        qemu_chr_fe_claim_no_fail(chr);
         qemu_chr_add_handlers(chr, pxa2xx_fir_is_empty,
                         pxa2xx_fir_rx, pxa2xx_fir_event, s);
+    }
 
     register_savevm(NULL, "pxa2xx_fir", 0, 0, pxa2xx_fir_save,
                     pxa2xx_fir_load, s);
diff --git a/hw/bt-hci-csr.c b/hw/bt-hci-csr.c
index e4ada3c731..55c819b085 100644
--- a/hw/bt-hci-csr.c
+++ b/hw/bt-hci-csr.c
@@ -439,6 +439,7 @@ CharDriverState *uart_hci_init(qemu_irq wakeup)
     s->chr.opaque = s;
     s->chr.chr_write = csrhci_write;
     s->chr.chr_ioctl = csrhci_ioctl;
+    s->chr.avail_connections = 1;
 
     s->hci = qemu_next_hci();
     s->hci->opaque = s;
diff --git a/hw/ipoctal232.c b/hw/ipoctal232.c
index 1da6a99175..345efaecc9 100644
--- a/hw/ipoctal232.c
+++ b/hw/ipoctal232.c
@@ -556,6 +556,7 @@ static int ipoctal_init(IPackDevice *ip)
 
             if (ch->dev) {
                 index++;
+                qemu_chr_fe_claim_no_fail(ch->dev);
                 qemu_chr_add_handlers(ch->dev, hostdev_can_receive,
                                       hostdev_receive, hostdev_event, ch);
                 DPRINTF("Redirecting channel %u to %s (%s)\n",
diff --git a/hw/ivshmem.c b/hw/ivshmem.c
index 68a2cf2e69..af2789e9ac 100644
--- a/hw/ivshmem.c
+++ b/hw/ivshmem.c
@@ -292,6 +292,7 @@ static CharDriverState* create_eventfd_chr_device(void * opaque, EventNotifier *
         fprintf(stderr, "creating eventfd for eventfd %d failed\n", eventfd);
         exit(-1);
     }
+    qemu_chr_fe_claim_no_fail(chr);
 
     /* if MSI is supported we need multiple interrupts */
     if (ivshmem_has_feature(s, IVSHMEM_MSI)) {
diff --git a/hw/mcf_uart.c b/hw/mcf_uart.c
index aacf0f05ed..e5de801671 100644
--- a/hw/mcf_uart.c
+++ b/hw/mcf_uart.c
@@ -280,6 +280,7 @@ void *mcf_uart_init(qemu_irq irq, CharDriverState *chr)
     s->chr = chr;
     s->irq = irq;
     if (chr) {
+        qemu_chr_fe_claim_no_fail(chr);
         qemu_chr_add_handlers(chr, mcf_uart_can_receive, mcf_uart_receive,
                               mcf_uart_event, s);
     }
diff --git a/hw/sh_serial.c b/hw/sh_serial.c
index 40e797c5a2..462969557c 100644
--- a/hw/sh_serial.c
+++ b/hw/sh_serial.c
@@ -396,9 +396,11 @@ void sh_serial_init(MemoryRegion *sysmem,
 
     s->chr = chr;
 
-    if (chr)
+    if (chr) {
+        qemu_chr_fe_claim_no_fail(chr);
         qemu_chr_add_handlers(chr, sh_serial_can_receive1, sh_serial_receive1,
 			      sh_serial_event, s);
+    }
 
     s->eri = eri_source;
     s->rxi = rxi_source;
diff --git a/hw/xen_console.c b/hw/xen_console.c
index a8db6f8d8f..c56ef4737f 100644
--- a/hw/xen_console.c
+++ b/hw/xen_console.c
@@ -241,9 +241,17 @@ static int con_initialise(struct XenDevice *xendev)
 	return -1;
 
     xen_be_bind_evtchn(&con->xendev);
-    if (con->chr)
-        qemu_chr_add_handlers(con->chr, xencons_can_receive, xencons_receive,
-                              NULL, con);
+    if (con->chr) {
+        if (qemu_chr_fe_claim(con->chr) == 0) {
+            qemu_chr_add_handlers(con->chr, xencons_can_receive,
+                                  xencons_receive, NULL, con);
+        } else {
+            xen_be_printf(xendev, 0,
+                          "xen_console_init error chardev %s already used\n",
+                          con->chr->label);
+            con->chr = NULL;
+        }
+    }
 
     xen_be_printf(xendev, 1, "ring mfn %d, remote port %d, local port %d, limit %zd\n",
 		  con->ring_ref,
@@ -260,8 +268,10 @@ static void con_disconnect(struct XenDevice *xendev)
     if (!xendev->dev) {
         return;
     }
-    if (con->chr)
+    if (con->chr) {
         qemu_chr_add_handlers(con->chr, NULL, NULL, NULL, NULL);
+        qemu_chr_fe_release(con->chr);
+    }
     xen_be_unbind_evtchn(&con->xendev);
 
     if (con->sring) {