Note: some other unwanted block devices are tracked separately: bug 903914 (usb-uas), bug 903918 (lsi53c895a am53c974 dc390 esp megasas pvscsi), bug 994642 (vhost-scsi vhost-scsi-pci).

Another one to disable:
name "SUNW,fdtwo", bus System

Fix included in qemu-kvm-1.5.3-15.el7

Verify this bug:
Version-Release number of selected component (if applicable):
qemu-kvm-rhev-1.5.3-21.el7.x86_64
---
# /usr/libexec/qemu-kvm -device ?
Controller/Bridge/Hub devices:
name "i82801b11-bridge", bus PCI
name "ioh3420", bus PCI, desc "Intel IOH device id 3420 PCIE Root Port"
name "pci-bridge", bus PCI, desc "Standard PCI Bridge"
name "usb-host", bus usb-bus
name "usb-hub", bus usb-bus
name "x3130-upstream", bus PCI, desc "TI X3130 Upstream Port of PCI Express Switch"
name "xio3130-downstream", bus PCI, desc "TI X3130 Downstream Port of PCI Express Switch"

USB devices:
name "ich9-usb-ehci1", bus PCI
name "ich9-usb-ehci2", bus PCI
name "ich9-usb-uhci1", bus PCI
name "ich9-usb-uhci2", bus PCI
name "ich9-usb-uhci3", bus PCI
name "ich9-usb-uhci4", bus PCI
name "ich9-usb-uhci5", bus PCI
name "ich9-usb-uhci6", bus PCI
name "nec-usb-xhci", bus PCI
name "piix3-usb-uhci", bus PCI
name "piix4-usb-uhci", bus PCI
name "usb-ehci", bus PCI
name "vt82c686b-usb-uhci", bus PCI

Storage devices:
name "ich9-ahci", bus PCI, alias "ahci"
name "ide-cd", bus IDE, desc "virtual IDE CD-ROM"
name "ide-drive", bus IDE, desc "virtual IDE disk or CD-ROM (legacy)"
name "ide-hd", bus IDE, desc "virtual IDE disk"
name "scsi-block", bus SCSI, desc "SCSI block device passthrough"
name "scsi-cd", bus SCSI, desc "virtual SCSI CD-ROM"
name "scsi-disk", bus SCSI, desc "virtual SCSI disk or CD-ROM (legacy)"
name "scsi-generic", bus SCSI, desc "pass through generic scsi device (/dev/sg*)"
name "scsi-hd", bus SCSI, desc "virtual SCSI disk"
name "usb-bot", bus usb-bus
name "usb-storage", bus usb-bus
name "virtio-blk-device", bus virtio-bus
name "virtio-blk-pci", bus PCI, alias "virtio-blk"
name "virtio-scsi-device", bus virtio-bus
name "virtio-scsi-pci", bus PCI

Network devices:
name "e1000", bus PCI, desc "Intel Gigabit Ethernet"
name "rtl8139", bus PCI
name "virtio-net-device", bus virtio-bus
name "virtio-net-pci", bus PCI, alias "virtio-net"

Input devices:
name "ccid-card-passthru", bus ccid-bus, desc "passthrough smartcard"
name "isa-serial", bus ISA
name "pci-serial", bus PCI
name "usb-ccid", bus usb-bus, desc "CCID Rev 1.1 smartcard reader"
name "usb-kbd", bus usb-bus
name "usb-mouse", bus usb-bus
name "virtconsole", bus virtio-serial-bus
name "virtio-serial-device", bus virtio-bus
name "virtio-serial-pci", bus PCI, alias "virtio-serial"
name "virtserialport", bus virtio-serial-bus

Display devices:
name "cirrus-vga", bus PCI, desc "Cirrus CLGD 54xx VGA"
name "qxl", bus PCI, desc "Spice QXL GPU (secondary)"
name "qxl-vga", bus PCI, desc "Spice QXL GPU (primary, vga compatible)"
name "sga", bus ISA, desc "Serial Graphics Adapter"
name "VGA", bus PCI

Sound devices:
name "AC97", bus PCI, desc "Intel 82801AA AC97 Audio"
name "hda-duplex", bus HDA, desc "HDA Audio Codec, duplex (line-out, line-in)"
name "hda-micro", bus HDA, desc "HDA Audio Codec, duplex (speaker, microphone)"
name "hda-output", bus HDA, desc "HDA Audio Codec, output-only (line-out)"
name "ich9-intel-hda", bus PCI, desc "Intel HD Audio Controller (ich9)"
name "intel-hda", bus PCI, desc "Intel HD Audio Controller (ich6)"

Misc devices:
name "i6300esb", bus PCI
name "ib700", bus ISA
name "isa-debug-exit", bus ISA
name "isa-debugcon", bus ISA
name "kvm-pci-assign", bus PCI, alias "pci-assign", desc "KVM-based PCI passthrough"
name "pc-testdev", bus ISA
name "pci-testdev", bus PCI, desc "PCI Test Device"
name "smbus-eeprom", bus i2c-bus
name "usb-redir", bus usb-bus
name "usb-tablet", bus usb-bus
name "vfio-pci", bus PCI, desc "VFIO-based PCI device assignment"
name "virtio-balloon-device", bus virtio-bus
name "virtio-balloon-pci", bus PCI, alias "virtio-balloon"
name "virtio-rng-device", bus virtio-bus
name "virtio-rng-pci", bus PCI

Uncategorized devices:
name "pvpanic", bus ISA
---
# /usr/libexec/qemu-kvm -device X,?
qemu-kvm: -device X,?: Parameter 'driver' expects device type
---
Based on above test, this bug has been verified.

qemu-kvm-1.5.3-21.el7.x86_64 got the same results as comments 6.

Based on comment 6, the following block devices(comment 0 described) have been removed or made unavailable with -device / device_add:
name "cfi.pflash01", bus System
name "isa-ide", bus ISA
name "piix3-ide-xen", bus PCI, no-user
name "piix4-ide", bus PCI, no-user
name "sysbus-ahci", bus System
name "sysbus-fdc", bus System

This request was resolved in Red Hat Enterprise Linux 7.0.

Contact your manager or support representative in case you have further questions about the request.