我的问题是我的设备树中的网络设备不是很稳定，所以我认为在 qemu 和主机系统之间共享文件夹的最佳方法是在两侧挂载相同的没有缓存的 img，但是 qemu 上的 -hda 选项不会使 hd 在 /dev/ 中可用。
这是我运行的命令。
./qemu-xilinx/arm-softmmu/qemu-system-arm -M xilinx-zynq-a9 -m 1024 -serial null -serial mon:stdio -dtb resources/devicetree.dtb -kernel resources/zImage -initrd resources.qemu/ramdisk.img -nographic -s
所以问题是：有没有办法可以避免联网，但在 qemu 和主机之间仍有共享目录？
编辑：我用
./configure --target-list="arm-softmmu,microblazeel-softmmu" --enable-fdt --disable-kvm --enable-virtfs
这应该可以启用所需的一切。但是当我运行
./qemu-xilinx/arm-softmmu/qemu-system-arm -M xilinx-zynq-a9 -m 1024 -serial null -serial mon:stdio -dtb /homes/cperivol/Sandbox/xilinx-zynq-bootstrap/resources/devicetree.dtb -kernel /homes/cperivol/Sandbox/xilinx-zynq-bootstrap/resources/zImage -initrd /homes/cperivol/Sandbox/xilinx-zynq-bootstrap/resources.qemu/ramdisk.img -nographic -s -fsdev local,path=/homes/cperivol/Sandbox/xilinx-zynq-bootstrap/qemu-sandbox/,security_model=passthrough,id=host0 -device virtio-9p-pci,fsdev=host0,mount_tag=host_tag0
或者
./qemu-xilinx/arm-softmmu/qemu-system-arm -M xilinx-zynq-a9 -m 1024 -serial null -serial mon:stdio -dtb resources/devicetree.dtb -kernel resources/zImage -initrd resources.qemu/ramdisk.img -nographic -s -virtfs local,path=/homes/cperivol/Sandbox/xilinx-zynq-bootstrap/qemu-sandbox/,mount_tag=host0,security_model=passthrough,id=host0
我明白了
No 'PCI' bus found for device 'virtio-9p-pci'
也许我还应该提一下，那里arm-softmmu/config-devices.mak有CONFIG_PCI=y，而且 pci 的目标文件肯定在那里hw/pci。
编辑2：查看 qemu 转储的设备树，模拟系统不包含 PCI 总线。
(qemu) info qtree
bus: main-system-bus
type System
dev: xlnx.ps7-dev-cfg, id ""
irq 1
mmio 00000000f8007000/000000000000011c
dev: pl330, id ""
gpio-in 32
num_chnls = 8
num_periph_req = 4
num_events = 16
mgr_ns_at_rst = 0
i-cache_len = 4
num_i-cache_lines = 8
boot_addr = 0
INS = 0
PNS = 0
data_width = 64
wr_cap = 8
wr_q_dep = 16
rd_cap = 8
rd_q_dep = 16
data_buffer_dep = 256
irq 17
mmio 00000000f8003000/0000000000001000
dev: generic-sdhci, id ""
capareg = 0x5780080
maxcurr = 0x0
irq 1
mmio 00000000e0101000/0000000000000100
dev: generic-sdhci, id ""
capareg = 0x5780080
maxcurr = 0x0
irq 1
mmio 00000000e0100000/0000000000000100
dev: cadence_gem, id ""
mac = 52:54:00:12:34:56
vlan = 0
netdev = hub0port0
bootindex = -1
irq 1
mmio 00000000e000b000/0000000000000640
dev: cadence_ttc, id ""
irq 3
mmio 00000000f8002000/0000000000001000
dev: cadence_ttc, id ""
irq 3
mmio 00000000f8001000/0000000000001000
dev: cadence_uart, id ""
irq 1
mmio 00000000e0001000/0000000000001000
dev: cadence_uart, id ""
irq 1
mmio 00000000e0000000/0000000000001000
dev: xlnx.ps7-qspi, id ""
num-busses = 2
num-ss-bits = 1
num-txrx-bytes = 4
irq 3
mmio 00000000e000d000/0000000000000100
mmio 00000000fc000000/0000000002000000
bus: spi1
type SSI
dev: n25q128, id ""
gpio-in 1
bus: spi0
type SSI
dev: n25q128, id ""
gpio-in 1
dev: xlnx.ps7-spi, id ""
num-busses = 1
num-ss-bits = 4
num-txrx-bytes = 1
irq 5
mmio 00000000e0007000/0000000000000100
bus: spi0
type SSI
dev: n25q128, id ""
gpio-in 1
dev: n25q128, id ""
gpio-in 1
dev: n25q128, id ""
gpio-in 1
dev: n25q128, id ""
gpio-in 1
dev: xlnx.ps7-spi, id ""
num-busses = 1
num-ss-bits = 4
num-txrx-bytes = 1
irq 5
mmio 00000000e0006000/0000000000000100
bus: spi0
type SSI
dev: n25q128, id ""
gpio-in 1
dev: n25q128, id ""
gpio-in 1
dev: n25q128, id ""
gpio-in 1
dev: n25q128, id ""
gpio-in 1
dev: xlnx,ps7-usb, id "zynq-usb-1"
maxframes = 128
irq 1
mmio 00000000e0003000/0000000000001000
bus: zynq-usb-1.0
type usb-bus
dev: xlnx,ps7-usb, id "zynq-usb-0"
maxframes = 128
irq 1
mmio 00000000e0002000/0000000000001000
bus: zynq-usb-0.0
type usb-bus
dev: xlnx.ps7-i2c, id ""
irq 1
mmio 00000000e0005000/000000000000002c
bus: i2c
type i2c-bus
dev: pca9548, id ""
chip-enable = 0
address = 0
address-range = 128
reg = 0
bus: i2c@7
type i2c-bus
bus: i2c@6
type i2c-bus
bus: i2c@5
type i2c-bus
bus: i2c@4
type i2c-bus
bus: i2c@3
type i2c-bus
dev: at.24c08, id ""
size = 1024
address = 84
address-range = 4
reg = 84
dev: at.24c08, id ""
size = 1024
address = 80
address-range = 4
reg = 80
bus: i2c@2
type i2c-bus
dev: at.24c08, id ""
size = 1024
address = 84
address-range = 4
reg = 84
dev: at.24c08, id ""
size = 1024
address = 80
address-range = 4
reg = 80
bus: i2c@1
type i2c-bus
bus: i2c@0
type i2c-bus
dev: xlnx.ps7-i2c, id ""
irq 1
mmio 00000000e0004000/000000000000002c
bus: i2c
type i2c-bus
dev: pca9548, id ""
chip-enable = 0
address = 0
address-range = 128
reg = 0
bus: i2c@7
type i2c-bus
bus: i2c@6
type i2c-bus
bus: i2c@5
type i2c-bus
bus: i2c@4
type i2c-bus
bus: i2c@3
type i2c-bus
dev: at.24c08, id ""
size = 1024
address = 84
address-range = 4
reg = 84
dev: at.24c08, id ""
size = 1024
address = 80
address-range = 4
reg = 80
bus: i2c@2
type i2c-bus
dev: at.24c08, id ""
size = 1024
address = 84
address-range = 4
reg = 84
dev: at.24c08, id ""
size = 1024
address = 80
address-range = 4
reg = 80
bus: i2c@1
type i2c-bus
bus: i2c@0
type i2c-bus
dev: arm_mptimer, id ""
num-cpu = 1
irq 1
mmio ffffffffffffffff/0000000000000020
mmio ffffffffffffffff/0000000000000020
dev: arm_mptimer, id ""
num-cpu = 1
irq 1
mmio ffffffffffffffff/0000000000000020
mmio ffffffffffffffff/0000000000000020
dev: a9-scu, id ""
num-cpu = 1
irq 0
mmio ffffffffffffffff/0000000000000100
dev: arm_gic, id ""
gpio-in 96
num-cpu = 1
num-irq = 96
revision = 1
irq 1
mmio ffffffffffffffff/0000000000001000
mmio ffffffffffffffff/0000000000000100
mmio ffffffffffffffff/0000000000000100
dev: a9mpcore_priv, id ""
gpio-in 64
num-cpu = 1
num-irq = 96
irq 1
mmio 00000000f8f00000/0000000000002000
dev: xilinx,zynq_slcr, id ""
irq 0
mmio 00000000f8000000/0000000000001000
dev: nand, id ""
manufacturer_id = 32
chip_id = 170
drive = <null>
irq 0
dev: cfi.pflash02, id ""
drive = <null>
num-blocks = 512
sector-length = 131072
width = 1
mappings = 1
big-endian = 0
id0 = 102
id1 = 34
id2 = 0
id3 = 0
unlock-addr0 = 2730
unlock-addr1 = 1365
name = "pl353.pflash"
irq 0
mmio ffffffffffffffff/0000000004000000
dev: arm.pl35x, id ""
x = 3
irq 0
mmio 00000000e000e000/0000000000001000
mmio 00000000e2000000/0000000001000000
mmio 00000000e1000000/0000000001000000
答案1
如果客户机具有 9p 支持（例如 Linux，或者当然是 Plan 9）和 virtio，请尝试添加以下开关。
-virtfs local,path=/path/to/share,mount_tag=host0,security_model=passthrough,id=host0
您可能需要更改 security_model 参数。有关详细信息，请参阅手册页 qemu(1)。如果我记得没错的话，mount_tag 是客人看到的，而 id 则是一个虚拟的。
如果你正在 chrooting，请确保路径在 chroot 下。它是主机上的目录的路径。
客户机上的 fstab 条目应如下所示。
host0 /wherever 9p trans=virtio,version=9p2000.L 0 0
将其添加到您的 fstab，或者手动调用适当的命令或使用您的 init 系统，无论它是什么。
答案2
适用于 x86_64、arm 和 aarch64 的极简 9P Buildroot 设置
我已经创建了一个高度自动化的 Buildroot 工作设置这可能会帮助你找出你的方法不起作用的原因。
主要成分有：
内核设置：
CONFIG_9P_FS=y CONFIG_9P_FS_POSIX_ACL=y CONFIG_9P_FS_SECURITY=y CONFIG_NETWORK_FILESYSTEMS=y CONFIG_NET_9P=y CONFIG_NET_9P_DEBUG=y CONFIG_NET_9P_VIRTIO=y对于 aarch64，还添加：
CONFIG_PCI=y CONFIG_PCI_HOST_COMMON=y CONFIG_PCI_HOST_GENERIC=y CONFIG_VIRTIO_PCI=y CONFIG_VIRTIO_BLK=y CONFIG_VIRTIO_NET=y如果您忘记添加 aarch64 配置，并
mount失败：mount: mounting host0 on /mnt/my9p failed: Invalid argument并且 dmesg 抱怨：
9pnet_virtio: no channels available for device我的 fstab 条目和 QEMU 命令与以下解释完全一致：https://superuser.com/a/628381/128124
手动挂载命令是：
mkdir /mnt/my9p mount -t 9p -o trans=virtio,version=9p2000.L host0 /mnt/my9phost0QEMU CLI 上指定的标签在哪里。作为参考，我的完整 QEMU 命令行是：x86：
./buildroot/output.x86_64~/host/usr/bin/qemu-system-x86_64 \ -m 128M \ -monitor telnet::45454,server,nowait \ -netdev user,hostfwd=tcp::45455-:45455,id=net0 \ -smp 1 \ -virtfs local,path=/host/path/to/share,mount_tag=host0,security_model=mapped,id=host0 \ -M pc \ -append 'root=/dev/vda nopat nokaslr norandmaps printk.devkmsg=on printk.time=y' \ -device edu \ -device lkmc_pci_min \ -device virtio-net-pci,netdev=net0 \ -kernel ./buildroot/output.x86_64~/images/bzImage \ -drive file='./buildroot/output.x86_64~/images/rootfs.ext2.qcow2,if=virtio,format=qcow2'手臂：
./buildroot/output.arm~/host/usr/bin/qemu-system-arm -m 128M -monitor telnet::45454,server,nowait -netdev user,hostfwd=tcp::45455-:45455,id=net0 -smp 1 -virtfs local,path=/host/path/to/share,mount_tag=host0,security_model=mapped,id=host0 -M versatilepb -append 'root=/dev/sda nokaslr norandmaps printk.devkmsg=on printk.time=y' -device rtl8139,netdev=net0 -dtb ./buildroot/output.arm~/images/versatile-pb.dtb -kernel ./buildroot/output.arm~/images/zImage -serial stdio -drive file='./buildroot/output.arm~/images/rootfs.ext2.qcow2,if=scsi,format=qcow2'aarch64：
./buildroot/output.aarch64~/host/usr/bin/qemu-system-aarch64 -m 128M -monitor telnet::45454,server,nowait -netdev user,hostfwd=tcp::45455-:45455,id=net0 -smp 1 -virtfs local,path=/host/path/to/share,mount_tag=host0,security_model=mapped,id=host0 -M virt -append 'root=/dev/sda nokaslr norandmaps printk.devkmsg=on printk.time=y' -cpu cortex-a57 -device virtio-net-device,netdev=net0 -kernel ./buildroot/output.aarch64~/images/Image -nographic -serial stdio确保 QEMU 构建有：
./configure --enable-virtfs
在 QEMU 2.11 和客户 Linux 内核 4.15 上进行了测试。
然后我也在 Ubuntu 18.04 上进行了测试，并且成功了：https://askubuntu.com/questions/884534/how-to-run-ubuntu-desktop-on-qemu/1046792#1046792