vga: improve VGA logic

Improve VGA selection logic, push check for device availabilty to vl.c.
Create the devices at board level unconditionally.

Remove now unused pci_try_create*() functions.

Make PCI VGA devices optional.

Reviewed-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>

hw/alpha_pci.c

@@ -121,11 +121,9 @@ void alpha_pci_vga_setup(PCIBus *pci_bus)
         pci_cirrus_vga_init(pci_bus);
         return;
     case VGA_VMWARE:
-        if (pci_vmsvga_init(pci_bus)) {
+        pci_vmsvga_init(pci_bus);
         return;
     }
-        break;
-    }
     /* If VGA is enabled at all, and one of the above didn't work, then
        fallback to Standard VGA.  */
     if (vga_interface_type != VGA_NONE) {

hw/boards.h

@@ -22,7 +22,6 @@ typedef struct QEMUMachine {
     unsigned int no_serial:1,
         no_parallel:1,
         use_virtcon:1,
-        no_vga:1,
         no_floppy:1,
         no_cdrom:1,
         no_sdcard:1;

hw/mips_malta.c

@@ -996,11 +996,7 @@ void mips_malta_init (ram_addr_t ram_size,
     if (cirrus_vga_enabled) {
         pci_cirrus_vga_init(pci_bus);
     } else if (vmsvga_enabled) {
-        if (!pci_vmsvga_init(pci_bus)) {
+        pci_vmsvga_init(pci_bus);
-            fprintf(stderr, "Warning: vmware_vga not available,"
-                    " using standard VGA instead\n");
-            pci_vga_init(pci_bus);
-        }
     } else if (std_vga_enabled) {
         pci_vga_init(pci_bus);
     }

hw/pc.c

@@ -1085,11 +1085,6 @@ DeviceState *pc_vga_init(ISABus *isa_bus, PCIBus *pci_bus)
     } else if (vmsvga_enabled) {
         if (pci_bus) {
             dev = pci_vmsvga_init(pci_bus);
-            if (!dev) {
-                fprintf(stderr, "Warning: vmware_vga not available,"
-                        " using standard VGA instead\n");
-                dev = pci_vga_init(pci_bus);
-            }
         } else {
             fprintf(stderr, "%s: vmware_vga: no PCI bus\n", __FUNCTION__);
         }

hw/pci.c

@@ -1572,21 +1572,6 @@ PCIDevice *pci_create_multifunction(PCIBus *bus, int devfn, bool multifunction,
     return DO_UPCAST(PCIDevice, qdev, dev);
 }
 
-PCIDevice *pci_try_create_multifunction(PCIBus *bus, int devfn,
-                                        bool multifunction,
-                                        const char *name)
-{
-    DeviceState *dev;
-
-    dev = qdev_try_create(&bus->qbus, name);
-    if (!dev) {
-        return NULL;
-    }
-    qdev_prop_set_uint32(dev, "addr", devfn);
-    qdev_prop_set_bit(dev, "multifunction", multifunction);
-    return DO_UPCAST(PCIDevice, qdev, dev);
-}
-
 PCIDevice *pci_create_simple_multifunction(PCIBus *bus, int devfn,
                                            bool multifunction,
                                            const char *name)
@@ -1606,11 +1591,6 @@ PCIDevice *pci_create_simple(PCIBus *bus, int devfn, const char *name)
     return pci_create_simple_multifunction(bus, devfn, false, name);
 }
 
-PCIDevice *pci_try_create(PCIBus *bus, int devfn, const char *name)
-{
-    return pci_try_create_multifunction(bus, devfn, false, name);
-}
-
 static int pci_find_space(PCIDevice *pdev, uint8_t size)
 {
     int config_size = pci_config_size(pdev);

hw/pci.h

@@ -469,12 +469,8 @@ PCIDevice *pci_create_multifunction(PCIBus *bus, int devfn, bool multifunction,
 PCIDevice *pci_create_simple_multifunction(PCIBus *bus, int devfn,
                                            bool multifunction,
                                            const char *name);
-PCIDevice *pci_try_create_multifunction(PCIBus *bus, int devfn,
-                                        bool multifunction,
-                                        const char *name);
 PCIDevice *pci_create(PCIBus *bus, int devfn, const char *name);
 PCIDevice *pci_create_simple(PCIBus *bus, int devfn, const char *name);
-PCIDevice *pci_try_create(PCIBus *bus, int devfn, const char *name);
 
 static inline int pci_is_express(const PCIDevice *d)
 {

hw/qdev.c

@@ -80,6 +80,10 @@ static DeviceInfo *qdev_find_info(BusInfo *bus_info, const char *name)
     return NULL;
 }
 
+bool qdev_exists(const char *name)
+{
+    return !!qdev_find_info(NULL, name);
+}
 static void qdev_property_add_legacy(DeviceState *dev, Property *prop,
                                      Error **errp);
 

hw/qdev.h

@@ -179,6 +179,7 @@ typedef struct GlobalProperty {
 
 DeviceState *qdev_create(BusState *bus, const char *name);
 DeviceState *qdev_try_create(BusState *bus, const char *name);
+bool qdev_exists(const char *name);
 int qdev_device_help(QemuOpts *opts);
 DeviceState *qdev_device_add(QemuOpts *opts);
 int qdev_init(DeviceState *dev) QEMU_WARN_UNUSED_RESULT;

hw/s390-virtio.c

@@ -317,7 +317,6 @@ static QEMUMachine s390_machine = {
     .no_serial = 1,
     .no_parallel = 1,
     .use_virtcon = 1,
-    .no_vga = 1,
     .max_cpus = 255,
     .is_default = 1,
 };

hw/spapr.c

@@ -740,7 +740,6 @@ static QEMUMachine spapr_machine = {
     .desc = "pSeries Logical Partition (PAPR compliant)",
     .init = ppc_spapr_init,
     .max_cpus = MAX_CPUS,
-    .no_vga = 1,
     .no_parallel = 1,
     .use_scsi = 1,
 };

hw/vmware_vga.h

@@ -8,12 +8,8 @@ static inline DeviceState *pci_vmsvga_init(PCIBus *bus)
 {
     PCIDevice *dev;
 
-    dev = pci_try_create(bus, -1, "vmware-svga");
+    dev = pci_create_simple(bus, -1, "vmware-svga");
-    if (!dev || qdev_init(&dev->qdev) < 0) {
-        return NULL;
-    } else {
     return &dev->qdev;
-    }
 }
 
 #endif

vl.c

@@ -271,7 +271,6 @@ static int default_serial = 1;
 static int default_parallel = 1;
 static int default_virtcon = 1;
 static int default_monitor = 1;
-static int default_vga = 1;
 static int default_floppy = 1;
 static int default_cdrom = 1;
 static int default_sdcard = 1;
@@ -290,11 +289,6 @@ static struct {
     { .driver = "virtio-serial-pci",    .flag = &default_virtcon   },
     { .driver = "virtio-serial-s390",   .flag = &default_virtcon   },
     { .driver = "virtio-serial",        .flag = &default_virtcon   },
-    { .driver = "VGA",                  .flag = &default_vga       },
-    { .driver = "cirrus-vga",           .flag = &default_vga       },
-    { .driver = "vmware-svga",          .flag = &default_vga       },
-    { .driver = "isa-vga",              .flag = &default_vga       },
-    { .driver = "qxl-vga",              .flag = &default_vga       },
 };
 
 static void res_free(void)
@@ -1525,18 +1519,48 @@ static const QEMUOption qemu_options[] = {
 #include "qemu-options-wrapper.h"
     { NULL },
 };
+
+static bool vga_available(void)
+{
+    return qdev_exists("VGA") || qdev_exists("isa-vga");
+}
+
+static bool cirrus_vga_available(void)
+{
+    return qdev_exists("cirrus-vga") || qdev_exists("isa-cirrus-vga");
+}
+
+static bool vmware_vga_available(void)
+{
+    return qdev_exists("vmware-svga");
+}
+
 static void select_vgahw (const char *p)
 {
     const char *opts;
 
-    default_vga = 0;
     vga_interface_type = VGA_NONE;
     if (strstart(p, "std", &opts)) {
+        if (vga_available()) {
             vga_interface_type = VGA_STD;
+        } else {
+            fprintf(stderr, "Error: standard VGA not available\n");
+            exit(0);
+        }
     } else if (strstart(p, "cirrus", &opts)) {
+        if (cirrus_vga_available()) {
             vga_interface_type = VGA_CIRRUS;
+        } else {
+            fprintf(stderr, "Error: Cirrus VGA not available\n");
+            exit(0);
+        }
     } else if (strstart(p, "vmware", &opts)) {
+        if (vmware_vga_available()) {
             vga_interface_type = VGA_VMWARE;
+        } else {
+            fprintf(stderr, "Error: VMWare SVGA not available\n");
+            exit(0);
+        }
     } else if (strstart(p, "xenfb", &opts)) {
         vga_interface_type = VGA_XENFB;
     } else if (strstart(p, "qxl", &opts)) {
@@ -2155,6 +2179,7 @@ int main(int argc, char **argv, char **envp)
     const char *loadvm = NULL;
     QEMUMachine *machine;
     const char *cpu_model;
+    const char *vga_model = NULL;
     const char *pid_file = NULL;
     const char *incoming = NULL;
 #ifdef CONFIG_VNC
@@ -2581,7 +2606,7 @@ int main(int argc, char **argv, char **envp)
                 rtc_utc = 0;
                 break;
             case QEMU_OPTION_vga:
-                select_vgahw (optarg);
+                vga_model = optarg;
                 break;
             case QEMU_OPTION_g:
                 {
@@ -2978,7 +3003,6 @@ int main(int argc, char **argv, char **envp)
                 default_parallel = 0;
                 default_virtcon = 0;
                 default_monitor = 0;
-                default_vga = 0;
                 default_net = 0;
                 default_floppy = 0;
                 default_cdrom = 0;
@@ -3140,9 +3164,6 @@ int main(int argc, char **argv, char **envp)
     if (!machine->use_virtcon) {
         default_virtcon = 0;
     }
-    if (machine->no_vga) {
-        default_vga = 0;
-    }
     if (machine->no_floppy) {
         default_floppy = 0;
     }
@@ -3178,8 +3199,6 @@ int main(int argc, char **argv, char **envp)
         if (default_virtcon)
             add_device_config(DEV_VIRTCON, "vc:80Cx24C");
     }
-    if (default_vga)
-        vga_interface_type = VGA_CIRRUS;
 
     socket_init();
 
@@ -3330,6 +3349,15 @@ int main(int argc, char **argv, char **envp)
 
     module_call_init(MODULE_INIT_DEVICE);
 
+    /* must be after qdev registration but before machine init */
+    if (vga_model) {
+        select_vgahw(vga_model);
+    } else if (cirrus_vga_available()) {
+        select_vgahw("cirrus");
+    } else {
+        select_vgahw("none");
+    }
+
     if (qemu_opts_foreach(qemu_find_opts("device"), device_help_func, NULL, 0) != 0)
         exit(0);