s390: Add default support for SCLP console

The current s390 machine uses the virtio console as default console,
but this doesn't mean that we always want to keep it that way for new
machines.

This patch introduces a way for a machine type to specify that it wants
the default console to be an SCLP console, which is a lot closer to what
real hardware does.

Signed-off-by: Alexander Graf <agraf@suse.de>
Reviewed-by: Andreas Färber <afaerber@suse.de>

hw/boards.h

@@ -33,6 +33,7 @@ typedef struct QEMUMachine {
     unsigned int no_serial:1,
         no_parallel:1,
         use_virtcon:1,
+        use_sclp:1,
         no_floppy:1,
         no_cdrom:1,
         no_sdcard:1;

vl.c

@@ -176,6 +176,7 @@ int main(int argc, char **argv)
 #define DEFAULT_RAM_SIZE 128
 
 #define MAX_VIRTIO_CONSOLES 1
+#define MAX_SCLP_CONSOLES 1
 
 static const char *data_dir;
 const char *bios_name = NULL;
@@ -203,6 +204,7 @@ int no_quit = 0;
 CharDriverState *serial_hds[MAX_SERIAL_PORTS];
 CharDriverState *parallel_hds[MAX_PARALLEL_PORTS];
 CharDriverState *virtcon_hds[MAX_VIRTIO_CONSOLES];
+CharDriverState *sclp_hds[MAX_SCLP_CONSOLES];
 int win2k_install_hack = 0;
 int singlestep = 0;
 int smp_cpus = 1;
@@ -271,6 +273,7 @@ static int tcg_tb_size;
 static int default_serial = 1;
 static int default_parallel = 1;
 static int default_virtcon = 1;
+static int default_sclp = 1;
 static int default_monitor = 1;
 static int default_floppy = 1;
 static int default_cdrom = 1;
@@ -2340,6 +2343,7 @@ struct device_config {
         DEV_VIRTCON,   /* -virtioconsole */
         DEV_DEBUGCON,  /* -debugcon */
         DEV_GDB,       /* -gdb, -s */
+        DEV_SCLP,      /* s390 sclp */
     } type;
     const char *cmdline;
     Location loc;
@@ -2458,6 +2462,39 @@ static int virtcon_parse(const char *devname)
     return 0;
 }
 
+static int sclp_parse(const char *devname)
+{
+    QemuOptsList *device = qemu_find_opts("device");
+    static int index = 0;
+    char label[32];
+    QemuOpts *dev_opts;
+
+    if (strcmp(devname, "none") == 0) {
+        return 0;
+    }
+    if (index == MAX_SCLP_CONSOLES) {
+        fprintf(stderr, "qemu: too many sclp consoles\n");
+        exit(1);
+    }
+
+    assert(arch_type == QEMU_ARCH_S390X);
+
+    dev_opts = qemu_opts_create(device, NULL, 0, NULL);
+    qemu_opt_set(dev_opts, "driver", "sclpconsole");
+
+    snprintf(label, sizeof(label), "sclpcon%d", index);
+    sclp_hds[index] = qemu_chr_new(label, devname, NULL);
+    if (!sclp_hds[index]) {
+        fprintf(stderr, "qemu: could not connect sclp console"
+                " to character backend '%s'\n", devname);
+        return -1;
+    }
+    qemu_opt_set(dev_opts, "chardev", label);
+
+    index++;
+    return 0;
+}
+
 static int debugcon_parse(const char *devname)
 {   
     QemuOpts *opts;
@@ -3832,6 +3869,9 @@ int main(int argc, char **argv, char **envp)
     if (!machine->use_virtcon) {
         default_virtcon = 0;
     }
+    if (!machine->use_sclp) {
+        default_sclp = 0;
+    }
     if (machine->no_floppy) {
         default_floppy = 0;
     }
@@ -3873,11 +3913,16 @@ int main(int argc, char **argv, char **envp)
             add_device_config(DEV_SERIAL, "mon:stdio");
         } else if (default_virtcon && default_monitor) {
             add_device_config(DEV_VIRTCON, "mon:stdio");
+        } else if (default_sclp && default_monitor) {
+            add_device_config(DEV_SCLP, "mon:stdio");
         } else {
             if (default_serial)
                 add_device_config(DEV_SERIAL, "stdio");
             if (default_virtcon)
                 add_device_config(DEV_VIRTCON, "stdio");
+            if (default_sclp) {
+                add_device_config(DEV_SCLP, "stdio");
+            }
             if (default_monitor)
                 monitor_parse("stdio", "readline");
         }
@@ -3890,6 +3935,9 @@ int main(int argc, char **argv, char **envp)
             monitor_parse("vc:80Cx24C", "readline");
         if (default_virtcon)
             add_device_config(DEV_VIRTCON, "vc:80Cx24C");
+        if (default_sclp) {
+            add_device_config(DEV_SCLP, "vc:80Cx24C");
+        }
     }
 
     socket_init();
@@ -4060,6 +4108,9 @@ int main(int argc, char **argv, char **envp)
         exit(1);
     if (foreach_device_config(DEV_VIRTCON, virtcon_parse) < 0)
         exit(1);
+    if (foreach_device_config(DEV_SCLP, sclp_parse) < 0) {
+        exit(1);
+    }
     if (foreach_device_config(DEV_DEBUGCON, debugcon_parse) < 0)
         exit(1);