Boot up a Linux VM with 8 pci block devices which
are the 8 functions in one pci slot.
| # qemu-kvm ...
| -drive file=images/u0,if=none,id=drv0,format=qcow2,cache=none \
| -device virtio-blk-pci,drive=drv0,id=v0,multifunction=on,addr=0x03.0 \
| ....
| -drive file=images/u7,if=none,id=drv7,format=qcow2,cache=none \
| -device virtio-blk-pci,drive=drv7,id=v7,multifunction=on,addr=0x03.7 \
Check devices in guest.
| vm)# ls /dev/vd*
| vda vdb vdc vde vdf vdg vdh
| vm)# lspci |grep block
| 00:03.0 SCSI storage controller: Red Hat, Inc Virtio block device
| ...
| 00:03.7 SCSI storage controller: Red Hat, Inc Virtio block device
|
Func1~7 still exist in guest after hot-removing the whole slot
through qemu monitor.
| vm)# lspci |grep block (00:03.0 disappeared)
| 00:03.1 SCSI storage controller: Red Hat, Inc Virtio block device (rev ff)
| ...
| 00:03.7 SCSI storage controller: Red Hat, Inc Virtio block device (rev ff)
| vm)# ls /dev/vd* (vda disappeared)
| vdb vdc vde vdf vdg vdh
| vm)# mkfs /dev/vdb
| INFO: task mkfs.ext2:1784 blocked for more than 120 seconds. (task hung)
Currently only func0 is defined in ACPI DSDT table
of seabios, and only hot-adding func0 would cause
a ACPI event for notification. Other funcs except
func0 wouldn't be registered in linux pci driver.
(we can only found func0 in slot->funcs list of
pci driver).