hw: Drop superfluous special checks for orphaned -drive

We've traditionally rejected orphans here and there, but not
systematically.  For instance, the sun4m machines have an onboard SCSI
HBA (bus=0), and have always rejected bus>0.  Other machines with an
onboard SCSI HBA don't.

Commit a66c9dc7 made all orphans trigger a warning, and the previous
commit turned this into an error.  The checks "here and there" are now
redundant.  Drop them.

Note that the one in mips_jazz.c was wrong: it rejected bus > MAX_FD,
but MAX_FD is the number of floppy drives per bus.

Error messages change from

    $ qemu-system-x86_64 -drive if=ide,bus=2
    qemu-system-x86_64: Too many IDE buses defined (3 > 2)
    $ qemu-system-mips64 -M magnum,accel=qtest -drive if=floppy,bus=2,id=fd1
    qemu: too many floppy drives
    $ qemu-system-sparc -M LX -drive if=scsi,bus=1
    qemu: too many SCSI bus

to

    $ qemu-system-x86_64 -drive if=ide,bus=2
    qemu-system-x86_64: -drive if=ide,bus=2: machine type does not support if=ide,bus=2,unit=0
    $ qemu-system-mips64 -M magnum,accel=qtest -drive if=floppy,bus=2,id=fd1
    qemu-system-mips64: -drive if=floppy,bus=2,id=fd1: machine type does not support if=floppy,bus=2,unit=0
    $ qemu-system-sparc -M LX -drive if=scsi,bus=1
    qemu-system-sparc: -drive if=scsi,bus=1: machine type does not support if=scsi,bus=1,unit=0

Cc: John Snow <jsnow@redhat.com>
Cc: "Hervé Poussineau" <hpoussin@reactos.org>
Cc: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Message-Id: <1487153147-11530-9-git-send-email-armbru@redhat.com>
Reviewed-by: NJohn Snow <jsnow@redhat.com>

hw/ide/core.c

@@ -2840,23 +2840,6 @@ const VMStateDescription vmstate_ide_bus = {
 void ide_drive_get(DriveInfo **hd, int n)
 {
     int i;
-    int highest_bus = drive_get_max_bus(IF_IDE) + 1;
-    int max_devs = drive_get_max_devs(IF_IDE);
-    int n_buses = max_devs ? (n / max_devs) : n;
-
-    /*
-     * Note: The number of actual buses available is not known.
-     * We compute this based on the size of the DriveInfo* array, n.
-     * If it is less than max_devs * <num_real_buses>,
-     * We will stop looking for drives prematurely instead of overfilling
-     * the array.
-     */
-
-    if (highest_bus > n_buses) {
-        error_report("Too many IDE buses defined (%d > %d)",
-                     highest_bus, n_buses);
-        exit(1);
-    }
 
     for (i = 0; i < n; i++) {
         hd[i] = drive_get_by_index(IF_IDE, i);

hw/mips/mips_jazz.c

@@ -291,10 +291,6 @@ static void mips_jazz_init(MachineState *machine,
              qdev_get_gpio_in(rc4030, 5), &esp_reset, &dma_enable);
 
     /* Floppy */
-    if (drive_get_max_bus(IF_FLOPPY) >= MAX_FD) {
-        fprintf(stderr, "qemu: too many floppy drives\n");
-        exit(1);
-    }
     for (n = 0; n < MAX_FD; n++) {
         fds[n] = drive_get(IF_FLOPPY, 0, n);
     }

hw/sparc/sun4m.c

@@ -989,11 +989,6 @@ static void sun4m_hw_init(const struct sun4m_hwdef *hwdef,
     slavio_misc_init(hwdef->slavio_base, hwdef->aux1_base, hwdef->aux2_base,
                      slavio_irq[30], fdc_tc);
 
-    if (drive_get_max_bus(IF_SCSI) > 0) {
-        fprintf(stderr, "qemu: too many SCSI bus\n");
-        exit(1);
-    }
-
     esp_init(hwdef->esp_base, 2,
              espdma_memory_read, espdma_memory_write,
              espdma, espdma_irq, &esp_reset, &dma_enable);