This patch adds two capabilities flags to deal with various aspects
of supporting SG_IO commands on virtio-blk-pci devices:
QEMU_CAPS_VIRTIO_BLK_SCSI
set if -device virtio-blk-pci accepts the scsi="on|off" option
When present, this is on by default, but can be set to off to disable
SG_IO functions.
QEMU_CAPS_VIRTIO_BLK_SG_IO
set if SG_IO commands are supported in the virtio-blk-pci driver
(present since qemu 0.11 according to a qemu developer, if I
understood correctly)
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