Support default block interfaces per QEMUMachine

There are QEMUMachines that have neither IF_IDE nor IF_SCSI as a
default/standard interface to their block devices / drives. Therefore,
this patch introduces a new field default_block_type per QEMUMachine
struct. The prior use_scsi field becomes thereby obsolete and is
replaced through .default_block_type = IF_SCSI.

This patch also changes the default for s390x to IF_VIRTIO and
removes an early hack that converts IF_IDE drives.
Other parties have already claimed interest (e.g. IF_SD for exynos)

To create a sane default, for machines that dont specify a
default_block_type, this patch makes IF_IDE = 0 and IF_NONE = 1.
I checked all users of IF_NONE (blockdev.c and ww/device-hotplug.c)
as well as IF_IDE and it seems that it is ok to change the defines -
in other words, I found no obvious (to me) assumption in the code
regarding IF_NONE==0. IF_NONE is only set if there is an
explicit if=none. Without if=* the interface becomes IF_DEFAULT.

I would suggest to have some additional care, e.g. by letting
this patch sit some days in the block tree.

Based on an initial patch from Einar Lueck <elelueck@de.ibm.com>

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
CC: Igor Mitsyanko <i.mitsyanko@samsung.com>
CC: Markus Armbruster <armbru@redhat.com>
CC: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Alexander Graf <agraf@suse.de>
Acked-by: Igor Mitsyanko <i.mitsyanko@samsung.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

blockdev.c

@@ -275,7 +275,7 @@ static bool do_check_io_limits(BlockIOLimit *io_limits)
     return true;
 }
 
-DriveInfo *drive_init(QemuOpts *opts, int default_to_scsi)
+DriveInfo *drive_init(QemuOpts *opts, BlockInterfaceType block_default_type)
 {
     const char *buf;
     const char *file = NULL;
@@ -325,7 +325,7 @@ DriveInfo *drive_init(QemuOpts *opts, int default_to_scsi)
             return NULL;
 	}
     } else {
-        type = default_to_scsi ? IF_SCSI : IF_IDE;
+        type = block_default_type;
     }
 
     max_devs = if_max_devs[type];

blockdev.h

@@ -19,8 +19,13 @@ void blockdev_auto_del(BlockDriverState *bs);
 
 typedef enum {
     IF_DEFAULT = -1,            /* for use with drive_add() only */
+    /*
+     * IF_IDE must be zero, because we want QEMUMachine member
+     * block_default_type to default-initialize to IF_IDE
+     */
+    IF_IDE = 0,
     IF_NONE,
-    IF_IDE, IF_SCSI, IF_FLOPPY, IF_PFLASH, IF_MTD, IF_SD, IF_VIRTIO, IF_XEN,
+    IF_SCSI, IF_FLOPPY, IF_PFLASH, IF_MTD, IF_SD, IF_VIRTIO, IF_XEN,
     IF_COUNT
 } BlockInterfaceType;
 
@@ -51,7 +56,7 @@ DriveInfo *drive_get_by_blockdev(BlockDriverState *bs);
 QemuOpts *drive_def(const char *optstr);
 QemuOpts *drive_add(BlockInterfaceType type, int index, const char *file,
                     const char *optstr);
-DriveInfo *drive_init(QemuOpts *arg, int default_to_scsi);
+DriveInfo *drive_init(QemuOpts *arg, BlockInterfaceType block_default_type);
 
 /* device-hotplug */
 

hw/boards.h

@@ -3,6 +3,7 @@
 #ifndef HW_BOARDS_H
 #define HW_BOARDS_H
 
+#include "blockdev.h"
 #include "qdev.h"
 
 typedef struct QEMUMachineInitArgs {
@@ -24,7 +25,7 @@ typedef struct QEMUMachine {
     const char *desc;
     QEMUMachineInitFunc *init;
     QEMUMachineResetFunc *reset;
-    int use_scsi;
+    BlockInterfaceType block_default_type;
     int max_cpus;
     unsigned int no_serial:1,
         no_parallel:1,

hw/device-hotplug.c

@@ -39,7 +39,7 @@ DriveInfo *add_init_drive(const char *optstr)
     if (!opts)
         return NULL;
 
-    dinfo = drive_init(opts, current_machine->use_scsi);
+    dinfo = drive_init(opts, current_machine->block_default_type);
     if (!dinfo) {
         qemu_opts_del(opts);
         return NULL;

hw/highbank.c

@@ -326,7 +326,7 @@ static QEMUMachine highbank_machine = {
     .name = "highbank",
     .desc = "Calxeda Highbank (ECX-1000)",
     .init = highbank_init,
-    .use_scsi = 1,
+    .block_default_type = IF_SCSI,
     .max_cpus = 4,
 };
 

hw/leon3.c

@@ -212,7 +212,6 @@ static QEMUMachine leon3_generic_machine = {
     .name     = "leon3_generic",
     .desc     = "Leon-3 generic",
     .init     = leon3_generic_hw_init,
-    .use_scsi = 0,
 };
 
 static void leon3_machine_init(void)

hw/mips_jazz.c

@@ -324,14 +324,14 @@ static QEMUMachine mips_magnum_machine = {
     .name = "magnum",
     .desc = "MIPS Magnum",
     .init = mips_magnum_init,
-    .use_scsi = 1,
+    .block_default_type = IF_SCSI,
 };
 
 static QEMUMachine mips_pica61_machine = {
     .name = "pica61",
     .desc = "Acer Pica 61",
     .init = mips_pica61_init,
-    .use_scsi = 1,
+    .block_default_type = IF_SCSI,
 };
 
 static void mips_jazz_machine_init(void)

hw/pc_sysfw.c

@@ -98,7 +98,7 @@ static void pc_fw_add_pflash_drv(void)
       return;
     }
 
-    if (!drive_init(opts, machine->use_scsi)) {
+    if (!drive_init(opts, machine->block_default_type)) {
         qemu_opts_del(opts);
     }
 }

hw/puv3.c

@@ -122,7 +122,6 @@ static QEMUMachine puv3_machine = {
     .desc = "PKUnity Version-3 based on UniCore32",
     .init = puv3_init,
     .is_default = 1,
-    .use_scsi = 0,
 };
 
 static void puv3_machine_init(void)

hw/realview.c

@@ -364,14 +364,14 @@ static QEMUMachine realview_eb_machine = {
     .name = "realview-eb",
     .desc = "ARM RealView Emulation Baseboard (ARM926EJ-S)",
     .init = realview_eb_init,
-    .use_scsi = 1,
+    .block_default_type = IF_SCSI,
 };
 
 static QEMUMachine realview_eb_mpcore_machine = {
     .name = "realview-eb-mpcore",
     .desc = "ARM RealView Emulation Baseboard (ARM11MPCore)",
     .init = realview_eb_mpcore_init,
-    .use_scsi = 1,
+    .block_default_type = IF_SCSI,
     .max_cpus = 4,
 };
 
@@ -385,7 +385,7 @@ static QEMUMachine realview_pbx_a9_machine = {
     .name = "realview-pbx-a9",
     .desc = "ARM RealView Platform Baseboard Explore for Cortex-A9",
     .init = realview_pbx_a9_init,
-    .use_scsi = 1,
+    .block_default_type = IF_SCSI,
     .max_cpus = 4,
 };
 

hw/s390-virtio.c

@@ -314,21 +314,6 @@ static void s390_init(QEMUMachineInitArgs *args)
         qdev_set_nic_properties(dev, nd);
         qdev_init_nofail(dev);
     }
-
-    /* Create VirtIO disk drives */
-    for(i = 0; i < MAX_BLK_DEVS; i++) {
-        DriveInfo *dinfo;
-        DeviceState *dev;
-
-        dinfo = drive_get(IF_IDE, 0, i);
-        if (!dinfo) {
-            continue;
-        }
-
-        dev = qdev_create((BusState *)s390_bus, "virtio-blk-s390");
-        qdev_prop_set_drive_nofail(dev, "drive", dinfo->bdrv);
-        qdev_init_nofail(dev);
-    }
 }
 
 static QEMUMachine s390_machine = {
@@ -336,6 +321,7 @@ static QEMUMachine s390_machine = {
     .alias = "s390",
     .desc = "VirtIO based S390 machine",
     .init = s390_init,
+    .block_default_type = IF_VIRTIO,
     .no_cdrom = 1,
     .no_floppy = 1,
     .no_serial = 1,
@@ -352,3 +338,4 @@ static void s390_machine_init(void)
 }
 
 machine_init(s390_machine_init);
+

hw/spapr.c

@@ -924,9 +924,9 @@ static QEMUMachine spapr_machine = {
     .desc = "pSeries Logical Partition (PAPR compliant)",
     .init = ppc_spapr_init,
     .reset = ppc_spapr_reset,
+    .block_default_type = IF_SCSI,
     .max_cpus = MAX_CPUS,
     .no_parallel = 1,
-    .use_scsi = 1,
 };
 
 static void spapr_machine_init(void)

hw/sun4m.c

@@ -1426,7 +1426,7 @@ static QEMUMachine ss5_machine = {
     .name = "SS-5",
     .desc = "Sun4m platform, SPARCstation 5",
     .init = ss5_init,
-    .use_scsi = 1,
+    .block_default_type = IF_SCSI,
     .is_default = 1,
 };
 
@@ -1434,7 +1434,7 @@ static QEMUMachine ss10_machine = {
     .name = "SS-10",
     .desc = "Sun4m platform, SPARCstation 10",
     .init = ss10_init,
-    .use_scsi = 1,
+    .block_default_type = IF_SCSI,
     .max_cpus = 4,
 };
 
@@ -1442,7 +1442,7 @@ static QEMUMachine ss600mp_machine = {
     .name = "SS-600MP",
     .desc = "Sun4m platform, SPARCserver 600MP",
     .init = ss600mp_init,
-    .use_scsi = 1,
+    .block_default_type = IF_SCSI,
     .max_cpus = 4,
 };
 
@@ -1450,7 +1450,7 @@ static QEMUMachine ss20_machine = {
     .name = "SS-20",
     .desc = "Sun4m platform, SPARCstation 20",
     .init = ss20_init,
-    .use_scsi = 1,
+    .block_default_type = IF_SCSI,
     .max_cpus = 4,
 };
 
@@ -1458,35 +1458,35 @@ static QEMUMachine voyager_machine = {
     .name = "Voyager",
     .desc = "Sun4m platform, SPARCstation Voyager",
     .init = vger_init,
-    .use_scsi = 1,
+    .block_default_type = IF_SCSI,
 };
 
 static QEMUMachine ss_lx_machine = {
     .name = "LX",
     .desc = "Sun4m platform, SPARCstation LX",
     .init = ss_lx_init,
-    .use_scsi = 1,
+    .block_default_type = IF_SCSI,
 };
 
 static QEMUMachine ss4_machine = {
     .name = "SS-4",
     .desc = "Sun4m platform, SPARCstation 4",
     .init = ss4_init,
-    .use_scsi = 1,
+    .block_default_type = IF_SCSI,
 };
 
 static QEMUMachine scls_machine = {
     .name = "SPARCClassic",
     .desc = "Sun4m platform, SPARCClassic",
     .init = scls_init,
-    .use_scsi = 1,
+    .block_default_type = IF_SCSI,
 };
 
 static QEMUMachine sbook_machine = {
     .name = "SPARCbook",
     .desc = "Sun4m platform, SPARCbook",
     .init = sbook_init,
-    .use_scsi = 1,
+    .block_default_type = IF_SCSI,
 };
 
 static const struct sun4d_hwdef sun4d_hwdefs[] = {
@@ -1709,7 +1709,7 @@ static QEMUMachine ss1000_machine = {
     .name = "SS-1000",
     .desc = "Sun4d platform, SPARCserver 1000",
     .init = ss1000_init,
-    .use_scsi = 1,
+    .block_default_type = IF_SCSI,
     .max_cpus = 8,
 };
 
@@ -1717,7 +1717,7 @@ static QEMUMachine ss2000_machine = {
     .name = "SS-2000",
     .desc = "Sun4d platform, SPARCcenter 2000",
     .init = ss2000_init,
-    .use_scsi = 1,
+    .block_default_type = IF_SCSI,
     .max_cpus = 20,
 };
 
@@ -1896,7 +1896,7 @@ static QEMUMachine ss2_machine = {
     .name = "SS-2",
     .desc = "Sun4c platform, SPARCstation 2",
     .init = ss2_init,
-    .use_scsi = 1,
+    .block_default_type = IF_SCSI,
 };
 
 static void sun4m_register_types(void)

hw/versatilepb.c

@@ -358,14 +358,14 @@ static QEMUMachine versatilepb_machine = {
     .name = "versatilepb",
     .desc = "ARM Versatile/PB (ARM926EJ-S)",
     .init = vpb_init,
-    .use_scsi = 1,
+    .block_default_type = IF_SCSI,
 };
 
 static QEMUMachine versatileab_machine = {
     .name = "versatileab",
     .desc = "ARM Versatile/AB (ARM926EJ-S)",
     .init = vab_init,
-    .use_scsi = 1,
+    .block_default_type = IF_SCSI,
 };
 
 static void versatile_machine_init(void)

hw/vexpress.c

@@ -477,7 +477,7 @@ static QEMUMachine vexpress_a9_machine = {
     .name = "vexpress-a9",
     .desc = "ARM Versatile Express for Cortex-A9",
     .init = vexpress_a9_init,
-    .use_scsi = 1,
+    .block_default_type = IF_SCSI,
     .max_cpus = 4,
 };
 
@@ -485,7 +485,7 @@ static QEMUMachine vexpress_a15_machine = {
     .name = "vexpress-a15",
     .desc = "ARM Versatile Express for Cortex-A15",
     .init = vexpress_a15_init,
-    .use_scsi = 1,
+    .block_default_type = IF_SCSI,
     .max_cpus = 4,
 };
 

hw/xilinx_zynq.c

@@ -200,7 +200,7 @@ static QEMUMachine zynq_machine = {
     .name = "xilinx-zynq-a9",
     .desc = "Xilinx Zynq Platform Baseboard for Cortex-A9",
     .init = zynq_init,
-    .use_scsi = 1,
+    .block_default_type = IF_SCSI,
     .max_cpus = 1,
     .no_sdcard = 1
 };

vl.c

@@ -886,9 +886,9 @@ static int cleanup_add_fd(QemuOpts *opts, void *opaque)
 
 static int drive_init_func(QemuOpts *opts, void *opaque)
 {
-    int *use_scsi = opaque;
+    BlockInterfaceType *block_default_type = opaque;
 
-    return drive_init(opts, *use_scsi) == NULL;
+    return drive_init(opts, *block_default_type) == NULL;
 }
 
 static int drive_enable_snapshot(QemuOpts *opts, void *opaque)
@@ -899,14 +899,15 @@ static int drive_enable_snapshot(QemuOpts *opts, void *opaque)
     return 0;
 }
 
-static void default_drive(int enable, int snapshot, int use_scsi,
+static void default_drive(int enable, int snapshot,
+                          BlockInterfaceType block_default_type,
                           BlockInterfaceType type, int index,
                           const char *optstr)
 {
     QemuOpts *opts;
 
     if (type == IF_DEFAULT) {
-        type = use_scsi ? IF_SCSI : IF_IDE;
+        type = block_default_type;
     }
 
     if (!enable || drive_get_by_index(type, index)) {
@@ -917,7 +918,7 @@ static void default_drive(int enable, int snapshot, int use_scsi,
     if (snapshot) {
         drive_enable_snapshot(opts, NULL);
     }
-    if (!drive_init(opts, use_scsi)) {
+    if (!drive_init(opts, type)) {
         exit(1);
     }
 }
@@ -3770,14 +3771,16 @@ int main(int argc, char **argv, char **envp)
     /* open the virtual block devices */
     if (snapshot)
         qemu_opts_foreach(qemu_find_opts("drive"), drive_enable_snapshot, NULL, 0);
-    if (qemu_opts_foreach(qemu_find_opts("drive"), drive_init_func, &machine->use_scsi, 1) != 0)
+    if (qemu_opts_foreach(qemu_find_opts("drive"), drive_init_func,
+                          &machine->block_default_type, 1) != 0) {
         exit(1);
+    }
 
-    default_drive(default_cdrom, snapshot, machine->use_scsi,
+    default_drive(default_cdrom, snapshot, machine->block_default_type,
                   IF_DEFAULT, 2, CDROM_OPTS);
-    default_drive(default_floppy, snapshot, machine->use_scsi,
+    default_drive(default_floppy, snapshot, machine->block_default_type,
                   IF_FLOPPY, 0, FD_OPTS);
-    default_drive(default_sdcard, snapshot, machine->use_scsi,
+    default_drive(default_sdcard, snapshot, machine->block_default_type,
                   IF_SD, 0, SD_OPTS);
 
     register_savevm_live(NULL, "ram", 0, 4, &savevm_ram_handlers, NULL);