xen: Provide notification of console updates via VIRQ.

The readconsolering capabilities provide the opportunity to
provide console output to other clients (remote systems,
logging systems, etc). This patchs adds the ability to generate
a notification of a change in the console buffer.

Signed-off-by: Ben Thomas <ben@virtualiron.com>
Signed-off-by: Keir Fraser <keir@xensource.com>

diff --git a/xen/common/event_channel.c b/xen/common/event_channel.c
index 2b361f501e9bd6e701e6cb090376e64e2e85fb34..6054527286e75a8ab2d8b08dd696d3798f51dc13 100644 (file)
--- a/xen/common/event_channel.c
+++ b/xen/common/event_channel.c
@@ -560,6 +560,9 @@ void send_guest_global_virq(struct domain *d, int virq)
 
     ASSERT(virq_is_global(virq));
 
+    if ( unlikely(d == NULL) )
+        return;
+
     v = d->vcpu[0];
     if ( unlikely(v == NULL) )
         return;

diff --git a/xen/drivers/char/console.c b/xen/drivers/char/console.c
index 03045963c9d2b1314f3bf2472c689c31f3caada4..927b47112f565cd775d10df6bab65b4d7ec8de2f 100644 (file)
--- a/xen/drivers/char/console.c
+++ b/xen/drivers/char/console.c
@@ -399,6 +399,8 @@ static void __putstr(const char *str)
         vga_putchar(c);
         putchar_console_ring(c);
     }
+
+    send_guest_global_virq(dom0, VIRQ_CON_RING);
 }
 
 static int printk_prefix_check(char *p, char **pp)

diff --git a/xen/include/public/xen.h b/xen/include/public/xen.h
index 3b6e4a8b2b68442e5ac3b512a533d1fecd748fa1..cf00a62e7ac24cddd762e0ab38a3f01353e38bee 100644 (file)
--- a/xen/include/public/xen.h
+++ b/xen/include/public/xen.h
@@ -131,6 +131,7 @@
 #define VIRQ_TBUF       4  /* G. (DOM0) Trace buffer has records available.  */
 #define VIRQ_DEBUGGER   6  /* G. (DOM0) A domain has paused for debugging.   */
 #define VIRQ_XENOPROF   7  /* V. XenOprofile interrupt: new sample available */
+#define VIRQ_CON_RING   8  /* G. (DOM0) Bytes received on console            */
 
 /* Architecture-specific VIRQ definitions. */
 #define VIRQ_ARCH_0    16