qemu-e2k/hw
Paul Durrant 3809f7583b xen: perform XenDevice clean-up in XenBus watch handler
Cleaning up offline XenDevice objects directly in
xen_device_backend_changed() is dangerous as xen_device_unrealize() will
modify the watch list that is being walked. Even the QLIST_FOREACH_SAFE()
used in notifier_list_notify() is insufficient as *two* notifiers (for
the frontend and backend watches) are removed, thus potentially rendering
the 'next' pointer unsafe.

The solution is to use the XenBus backend_watch handler to do the clean-up
instead, as it is invoked whilst walking a separate watch list.

This patch therefore adds a new 'inactive_devices' list to XenBus, to which
offline devices are added by xen_device_backend_changed(). The XenBus
backend_watch registration is also changed to not only invoke
xen_bus_enumerate() but also a new xen_bus_cleanup() function, which will
walk 'inactive_devices' and perform the necessary actions.
For safety an extra 'online' check is also added to xen_bus_type_enumerate()
to make sure that no attempt is made to create a new XenDevice object for a
backend that is offline.

NOTE: This patch also includes some cosmetic changes:
      - substitute the local variable name 'backend_state'
        in xen_bus_type_enumerate() with 'state', since there
        is no ambiguity with any other state in that context.
      - change xen_device_state_is_active() to
        xen_device_frontend_is_active() (and pass a XenDevice directly)
        since the state tests contained therein only apply to a frontend.
      - use 'state' rather then 'xendev->backend_state' in
        xen_device_backend_changed() to shorten the code.

Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
Message-Id: <20190913082159.31338-4-paul.durrant@citrix.com>
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
2019-09-24 12:18:47 +01:00
..
9pfs 9p: simplify source file selection 2019-08-20 17:26:19 +02:00
acpi ipmi: Fix SSIF ACPI handling to use the right CRS 2019-09-20 14:08:10 -05:00
adc
alpha Clean up inclusion of sysemu/sysemu.h 2019-08-16 13:31:53 +02:00
arm aspeed/scu: Introduce per-SoC SCU types 2019-09-13 16:05:01 +01:00
audio audio: remove audio_MIN, audio_MAX 2019-08-21 09:13:37 +02:00
block vhost-user-blk: prevent using uninitialized vqs 2019-09-16 06:27:35 -04:00
bt
char escc: introduce a selector for the register bit 2019-09-07 08:32:12 +02:00
core Pull request 2019-09-19 13:27:11 +01:00
cpu hw/core: Move cpu.c, cpu.h from qom/ to hw/core/ 2019-08-21 13:24:01 +02:00
cris
display ati: use vga_read_byte in ati_cursor_define 2019-09-19 10:37:46 +02:00
dma hw/dma/xilinx_axi: Use object_initialize_child for correct ref. counting 2019-09-03 16:20:34 +01:00
gpio hw/gpio: Add basic Aspeed GPIO model for AST2400 and AST2500 2019-09-13 16:05:00 +01:00
hppa Clean up inclusion of sysemu/sysemu.h 2019-08-16 13:31:53 +02:00
hyperv Include hw/qdev-properties.h less 2019-08-16 13:31:53 +02:00
i2c Clean up inclusion of sysemu/sysemu.h 2019-08-16 13:31:53 +02:00
i386 pc: Add an SMB0 ACPI device to q35 2019-09-20 14:09:24 -05:00
ide hw/ide/atapi: Use the ldst API 2019-08-16 19:14:04 -04:00
input sysemu: Split sysemu/runstate.h off sysemu/sysemu.h 2019-08-16 13:37:36 +02:00
intc s390x/kvm: Officially require at least kernel 3.15 2019-09-23 09:15:03 +02:00
ipack Include hw/qdev-properties.h less 2019-08-16 13:31:53 +02:00
ipmi ipmi: Add an SMBus IPMI interface 2019-09-20 14:08:10 -05:00
isa hw/core: Move cpu.c, cpu.h from qom/ to hw/core/ 2019-08-21 13:24:01 +02:00
lm32 Include hw/qdev-properties.h less 2019-08-16 13:31:53 +02:00
m68k m68k: Add serial controller to the NeXTcube machine 2019-09-07 08:32:34 +02:00
mem numa: move numa global variable nb_numa_nodes into MachineState 2019-09-03 11:26:55 -03:00
microblaze hw/misc: Add a config switch for the "unimplemented" device 2019-08-20 09:11:17 +02:00
mips hw/mips/mips_jazz: Remove no-longer-necessary override of do_unassigned_access 2019-09-12 18:25:34 +02:00
misc trace: Remove trailing newline in events 2019-09-18 10:19:47 +01:00
moxie
net hw/net/vmxnet3: Fix leftover unregister_savevm 2019-09-12 11:13:55 +01:00
nios2 Clean up inclusion of sysemu/sysemu.h 2019-08-16 13:31:53 +02:00
nvram sysemu: Split sysemu/runstate.h off sysemu/sysemu.h 2019-08-16 13:37:36 +02:00
openrisc Include hw/qdev-properties.h less 2019-08-16 13:31:53 +02:00
pci Include sysemu/sysemu.h a lot less 2019-08-16 13:31:53 +02:00
pci-bridge numa: move numa global variable nb_numa_nodes into MachineState 2019-09-03 11:26:55 -03:00
pci-host hw/core: Add a config switch for the "or-irq" device 2019-08-20 09:11:17 +02:00
pcmcia
ppc migration: register_savevm_live doesn't need dev 2019-09-12 11:15:03 +01:00
rdma sysemu: Split sysemu/runstate.h off sysemu/sysemu.h 2019-08-16 13:37:36 +02:00
riscv riscv: sifive_u: Update model and compatible strings in device tree 2019-09-17 08:42:49 -07:00
s390x migration: register_savevm_live doesn't need dev 2019-09-12 11:15:03 +01:00
scsi trace: Remove trailing newline in events 2019-09-18 10:19:47 +01:00
sd trace: Remove trailing newline in events 2019-09-18 10:19:47 +01:00
semihosting Clean up inclusion of sysemu/sysemu.h 2019-08-16 13:31:53 +02:00
sh4 sysemu: Split sysemu/runstate.h off sysemu/sysemu.h 2019-08-16 13:37:36 +02:00
smbios smbios:ipmi: Ignore IPMI devices with no fwinfo function 2019-09-20 14:08:10 -05:00
sparc sysemu: Split sysemu/runstate.h off sysemu/sysemu.h 2019-08-16 13:37:36 +02:00
sparc64 hw/misc: Add a config switch for the "unimplemented" device 2019-08-20 09:11:17 +02:00
ssi aspeed/smc: Calculate checksum on normal DMA 2019-09-13 16:05:01 +01:00
timer aspeed/scu: Introduce a aspeed_scu_get_apb_freq() routine 2019-09-13 16:05:01 +01:00
tpm Include hw/qdev-properties.h less 2019-08-16 13:31:53 +02:00
tricore Clean up inclusion of sysemu/sysemu.h 2019-08-16 13:31:53 +02:00
unicore32
usb usb-mtp: add sanity checks on rootdir 2019-08-29 07:31:12 +02:00
vfio vfio: fix a typo 2019-09-19 11:50:37 +02:00
virtio virtio-mmio: implement modern (v2) personality (virtio-1) 2019-09-16 11:17:06 -04:00
watchdog sysemu: Split sysemu/runstate.h off sysemu/sysemu.h 2019-08-16 13:37:36 +02:00
xen xen: perform XenDevice clean-up in XenBus watch handler 2019-09-24 12:18:47 +01:00
xenpv Include sysemu/sysemu.h a lot less 2019-08-16 13:31:53 +02:00
xtensa sysemu: Split sysemu/runstate.h off sysemu/sysemu.h 2019-08-16 13:37:36 +02:00
Kconfig hw/core: Add a config switch for the "register" device 2019-08-20 09:11:05 +02:00
Makefile.objs