QEmu `eject` 抱怨设备在那里时找不到

Question

我需要从 QEmu3.0 监视器中弹出软盘，但是该命令出人意料地失败了，抱怨没有找到该设备，而它确实在那里。

设备列表：

(qemu) info block
fda: dos-6-22/Dos622-1.img (raw)
    Attached to:      /machine/unattached/device[11]
    Removable device: not locked, tray closed
    Cache mode:       writeback

hda: hda.img (raw)
    Attached to:      /machine/peripheral-anon/device[1]
    Cache mode:       writeback

弹出命令结果：

(qemu) eject fda
Device 'fda' not found

虽然本文档说这是我必须这样做的：https://www.linux-kvm.org/page/Change_cdrom（只是我想弹出软盘而不是 CD-ROM）。

change 命令同样报错：

(qemu) change fda dos-6-22/Dos622-2.img raw
Device 'fda' not found

这是一个错误还是我做错了什么？

我尝试使用不同的节点名称，结果总是相同。

更新：

我很确定没有正确答案，这是一个错误，我刚刚提交了：https://bugs.launchpad.net/qemu/+bug/1799766。

Answer 1

我将发布作为答案，但我不确定。我只能说，如果我理解正确的话，这是一个错误。

答案分为两部分。

第一部分，是一个精简的失败调用：

qemu-system-i386 \
   -monitor stdio \
   -machine type=isapc,vmport=off \
   -blockdev driver=file,node-name=fda-img,filename=fda.img \
   -blockdev driver=raw,node-name=fda,file=fda-img \
   -global isa-fdc.driveA=fda

(qemu) info block
ide1-cd0: [not inserted]
    Attached to:      /machine/unattached/device[19]
    Removable device: not locked, tray closed

sd0: [not inserted]
    Removable device: not locked, tray closed

fda: fda.img (raw)
    Attached to:      /machine/unattached/device[13]
    Removable device: not locked, tray closed
    Cache mode:       writeback
(qemu) eject fda
Device 'fda' not found

第二部分，同样没有最后一个参数-global isa-fdc.driveA=fda：

qemu-system-i386 \
   -monitor stdio \
   -machine type=isapc,vmport=off \
   -blockdev driver=file,node-name=fda-img,filename=fda.img \
   -blockdev driver=raw,node-name=fda,file=fda-img

(qemu) info block
ide1-cd0: [not inserted]
    Attached to:      /machine/unattached/device[19]
    Removable device: not locked, tray closed

floppy0: [not inserted]
    Attached to:      /machine/unattached/device[13]
    Removable device: not locked, tray closed

sd0: [not inserted]
    Removable device: not locked, tray closed
(qemu) eject floppy0

删除-global isa-fdc.driveA=fda 时会出现更多错误。但是，文档说：

-全局驱动程序=驱动程序，属性=属性，值=值 将 driver 的属性 prop 的默认值设置为 value，例如：

qemu-system-i386 -global ide-hd.physical_block_size=4096 disk-image.img 特别是，您可以使用它来设置由机器型号自动创建的设备的驱动程序属性。要创建非自动创建的设备并为其设置属性，请使用 -device。

-global driver.prop=value 是 -global driver=driver,property=prop,value=value 的简写。即使驱动程序包含点，速记语法也有效。

我在引用中强调的是，表明我没有滥用-global，这很可能是一个错误。

更新详情：

似乎使用-drive而不是-device和driveA赋值，结果不一样，虽然RedHat文档建议使用-device而不是-drive和QEmu3.0文档说-drive本质上是-device 的快捷方式（“本质上”，没有说明区别）。

下面，两个案例，除了info block 和info qtree 的摘录。

有了这个，eject floppy0 工作：

qemu-system-i386 \
   -monitor stdio \
   -machine type=isapc,vmport=off \
   -drive format=raw,if=floppy,media=disk,file=fda.img \
   -device isa-vga,vgamem_mb=1 \
   -serial msmouse

[…]

floppy0 (#block156): fda.img (raw)
    Attached to:      /machine/unattached/device[12]
    Removable device: not locked, tray closed
    Cache mode:       writeback

[…]

  dev: isa-fdc, id ""
    iobase = 1008 (0x3f0)
    irq = 6 (0x6)
    dma = 2 (0x2)
    driveA = ""
    driveB = ""
    check_media_rate = true
    fdtypeA = "auto"
    fdtypeB = "auto"
    fallback = "288"
    isa irq 6
    bus: floppy-bus.0
      type floppy-bus
      dev: floppy, id ""
        unit = 0 (0x0)
        drive = "floppy0"
        logical_block_size = 512 (0x200)
        physical_block_size = 512 (0x200)
        min_io_size = 0 (0x0)
        opt_io_size = 0 (0x0)
        discard_granularity = 4294967295 (0xffffffff)
        write-cache = "auto"
        share-rw = false
        drive-type = "144"

有了这个，eject fda 就不行了：

qemu-system-i386 \
   -monitor stdio \
   -machine type=isapc,vmport=off \
   -blockdev driver=file,node-name=fda-img,filename=fda.img \
   -blockdev driver=raw,node-name=fda,file=fda-img \
   -global isa-fdc.driveA=fda \
   -device isa-vga,vgamem_mb=1 \
   -serial msmouse

[…]

fda: fda.img (raw)
    Attached to:      /machine/unattached/device[12]
    Removable device: not locked, tray closed
    Cache mode:       writeback

[…]

  dev: isa-fdc, id ""
    iobase = 1008 (0x3f0)
    irq = 6 (0x6)
    dma = 2 (0x2)
    driveA = ""
    driveB = ""
    check_media_rate = true
    fdtypeA = "auto"
    fdtypeB = "auto"
    fallback = "288"
    isa irq 6
    bus: floppy-bus.0
      type floppy-bus
      dev: floppy, id ""
        unit = 0 (0x0)
        drive = "fda"
        logical_block_size = 512 (0x200)
        physical_block_size = 512 (0x200)
        min_io_size = 0 (0x0)
        opt_io_size = 0 (0x0)
        discard_granularity = 4294967295 (0xffffffff)
        write-cache = "auto"
        share-rw = false
        drive-type = "144"