generate notification of new console ring data

diff -r 80ccadd3cd47 tools/libxc/xc_misc.c
@@ -31,6 +31,20 @@ int xc_readconsolering(int xc_handle,
     unlock_pages(buffer, nr_chars);
 
     return ret;
+}
+
+int xc_set_conring_notify(int xc_handle, int enable)
+{
+    int ret;
+    DECLARE_SYSCTL;
+
+    sysctl.cmd = XEN_SYSCTL_conring_notify;
+    sysctl.u.conring_notify.enable = enable;
+
+    if ( (ret = do_sysctl(xc_handle, &sysctl)) != 0 )
+        return ret;
+
+    return 0;
 }
 
 int xc_physinfo(int xc_handle,

diff -r 80ccadd3cd47 tools/libxc/xenctrl.h
@@ -465,6 +465,7 @@ int xc_readconsolering(int xc_handle,
                        unsigned int *pnr_chars,
                        int clear);
 
+int xc_set_conring_notify(int xc_handle, int enable);
 typedef xen_sysctl_physinfo_t xc_physinfo_t;
 int xc_physinfo(int xc_handle,
                 xc_physinfo_t *info);

diff -r 80ccadd3cd47 xen/common/sysctl.c
@@ -128,6 +128,13 @@ long do_sysctl(XEN_GUEST_HANDLE(xen_sysc
     break;
 #endif
 
+    case XEN_SYSCTL_conring_notify:
+    {
+        ret = set_conring_notify(op->u.conring_notify.enable);
+    }
+
+    break;
+
     default:
         ret = arch_do_sysctl(op, u_sysctl);
         break;

diff -r 80ccadd3cd47 xen/drivers/char/console.c
@@ -52,6 +52,7 @@ boolean_param("sync_console", opt_sync_c
 #define CONRING_IDX_MASK(i) ((i)&(CONRING_SIZE-1))
 static char conring[CONRING_SIZE];
 static unsigned int conringc, conringp;
+static int conring_notify = 0;
 
 static char printk_prefix[16] = "";
 

@@ -173,6 +174,12 @@ static void putchar_console_ring(int c)
         conringc = conringp - CONRING_SIZE;
 }
 
+int set_conring_notify(int enable)
+{
+    conring_notify = enable;
+    return 0;
+}
+
 long read_console_ring(XEN_GUEST_HANDLE(char) str, u32 *pcount, int clear)
 {
     unsigned int idx, len, max, sofar, c;

@@ -328,8 +335,13 @@ static long guest_console_write(XEN_GUES
 
         sercon_puts(kbuf);
 
-        for ( kptr = kbuf; *kptr != '\0'; kptr++ )
+        for ( kptr = kbuf; *kptr != '\0'; kptr++ ) {
             vga_putchar(*kptr);
+            putchar_console_ring(*kptr);
+        }
+
+        if (conring_notify)
+            send_guest_global_virq(dom0, VIRQ_CON_RING);
 
         guest_handle_add_offset(buffer, kcount);
         count -= kcount;

@@ -399,6 +411,10 @@ static void __putstr(const char *str)
         vga_putchar(c);
         putchar_console_ring(c);
     }
+
+    if (conring_notify)
+        send_guest_global_virq(dom0, VIRQ_CON_RING);
+
 }
 
 static int printk_prefix_check(char *p, char **pp)

diff -r 80ccadd3cd47 xen/include/public/sysctl.h
@@ -140,6 +140,14 @@ typedef struct xen_sysctl_getdomaininfol
 typedef struct xen_sysctl_getdomaininfolist xen_sysctl_getdomaininfolist_t;
 DEFINE_XEN_GUEST_HANDLE(xen_sysctl_getdomaininfolist_t);
 
+#define XEN_SYSCTL_conring_notify 7
+struct xen_sysctl_conring_notify {
+    /* IN variables. */
+    uint32_t              enable;
+};
+typedef struct xen_sysctl_conring_notify xen_sysctl_conring_notify_t;
+DEFINE_XEN_GUEST_HANDLE(xen_sysctl_conring_notify_t);
+
 struct xen_sysctl {
     uint32_t cmd;
     uint32_t interface_version; /* XEN_SYSCTL_INTERFACE_VERSION */

@@ -150,6 +158,7 @@ struct xen_sysctl {
         struct xen_sysctl_sched_id          sched_id;
         struct xen_sysctl_perfc_op          perfc_op;
         struct xen_sysctl_getdomaininfolist getdomaininfolist;
+        struct xen_sysctl_conring_notify    conring_notify;
         uint8_t                             pad[128];
     } u;
 };

diff -r 80ccadd3cd47 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

diff -r 80ccadd3cd47 xen/include/xen/console.h
@@ -14,6 +14,7 @@ void set_printk_prefix(const char *prefi
 void set_printk_prefix(const char *prefix);
 
 long read_console_ring(XEN_GUEST_HANDLE(char), u32 *, int);
+int set_conring_notify(int enable);
 
 void init_console(void);
 void console_endboot(void);