[Qemu-devel] [PATCH v5 0/8] modify boot order of guest, and take effect after rebooting

[arei.gonglei]

From: Gonglei <address@hidden>

Sometimes, we want to modify boot order of a guest, but no need to
shutdown it. We can call dynamic changing bootindex of a guest, which
can be assured taking effect just after the guest rebooting.

For example, in P2V scene, we boot a guest and then attach a
new system disk, for copying some thing. We want to assign the
new disk as the booting disk, which means its bootindex=1.

Different nics can be assigen different bootindex dynamically
also make sense.

The patchsets add one qmp interface, and add an fw_cfg_machine_reset()
to achieve it.

Steps of testing:

./qemu-system-x86_64 -enable-kvm -m 4096 -smp 4 -name redhat6.2 -drive \
file=/home/redhat6.2.img,if=none,id=drive-ide0-0-0 \
-device ide-hd,bus=ide.0,unit=0,drive=drive-ide0-0-0,id=ide0-0-0,bootindex=1 \
-drive file=/home/RH-DVD1.iso,if=none,id=drive-ide0-0-1 \
-device ide-cd,bus=ide.0,unit=1,drive=drive-ide0-0-1,id=ide0-0-1,bootindex=4 \
-vnc 0.0.0.0:10 -netdev type=user,id=net0 \
-device virtio-net-pci,netdev=net0,bootindex=3,id=nic1 \
-netdev type=user,id=net1 -device e1000,netdev=net1,bootindex=2,id=nic2 \
-drive file=/home/virtio-disk.vfd,if=none,id=drive-fdc0-0-0,format=raw \
-device isa-fdc,driveA=drive-fdc0-0-0,id=floppy1,bootindexA=5 -monitor stdio
QEMU 2.0.93 monitor - type 'help' for more information
(qemu) info bootindex
id       bootindex       suffix
"floppy1"        5      "/address@hidden"
"ide0-0-1"       4      "/address@hidden"
"nic1"   3      "/address@hidden"
"nic2"   2      "/address@hidden"
"ide0-0-0"       1      "/address@hidden"
(qemu) set-bootindex ide0-0-1 1
The bootindex 1 has already been used
(qemu) set-bootindex ide0-0-1 6 "/address@hidden"
(qemu) set-bootindex ide0-0-1 0
(qemu) system_reset
(qemu) set-bootindex ide0-0-1 1
The bootindex 1 has already been used
(qemu) set-bootindex nic1 0
The bootindex 0 has already been used
(qemu) set-bootindex ide0-0-1 -1
(qemu) set-bootindex nic1 0
(qemu) info bootindex
id       bootindex       suffix
"floppy1"        5      "/address@hidden"
"nic2"   2      "/address@hidden"
"ide0-0-0"       1      "/address@hidden"
"nic1"   0      "/address@hidden"
(qemu) system_reset
(qemu)


Changes since v4:
 - using error_setg() instead of qerror_report() in patch 1/8.
 - call del_boot_device_path() from device_finalize() instead
  of placing it into each individual device in patch 4/8.

Changes since v3:
 - rework del_* and modify_* function, because of virtio devices' specialation.
   For example, virtio-net's id is NULL, and its parent virtio-net-pci's id was 
assigned.
   Though the global fw_boot_order stored the virtio-net device.
 - call dell_boot_device_path in each individual device avoiding waste resouce.
 - introduce qmp "query-bootindex" command
 - introcude hmp "info bootindex" command
 - Fixes by Eric's reviewing comments, thanks.

Changes since v2:
 *address Gerd's reviewing suggestion:
 - use the old entry's suffix, if the caller do not pass it in.
 - call del_boot_device_path() from device_finalize() instead
   of placing it into each individual device.

  Thanks Gerd.

Changes since v1:
 *rework by Gerd's suggestion:
 - split modify and del fw_boot_order for single function.
 - change modify bootindex's realization which simply lookup
   the device and modify the bootindex. if the new bootindex
   has already used by another device just throw an error.
 - change to del_boot_device_path(DeviceState *dev) and simply delete all
   entries belonging to the device.

Gonglei (8):
  bootindex: add modify_boot_device_path function
  bootindex: add del_boot_device_path function
  fw_cfg: add fw_cfg_machine_reset function
  bootindex: delete bootindex when device is removed
  qmp: add set-bootindex command
  qemu-monitor: HMP set-bootindex wrapper
  qmp: add query-bootindex command
  qemu-monitor: add HMP "info-bootindex" command

 hmp-commands.hx           |  17 +++++++
 hmp.c                     |  33 +++++++++++++
 hmp.h                     |   2 +
 hw/core/qdev.c            |   4 ++
 hw/nvram/fw_cfg.c         |  54 ++++++++++++++++++---
 include/hw/nvram/fw_cfg.h |   2 +
 include/sysemu/sysemu.h   |   3 ++
 monitor.c                 |   7 +++
 qapi-schema.json          |  46 ++++++++++++++++++
 qmp-commands.hx           |  66 ++++++++++++++++++++++++++
 qmp.c                     |  17 +++++++
 vl.c                      | 117 ++++++++++++++++++++++++++++++++++++++++++++++
 12 files changed, 361 insertions(+), 7 deletions(-)

-- 
1.7.12.4