qemu/hw/core
Damien Hedde a7c3a4f986 hw/core/qdev: handle parent bus change regarding resettable
In qdev_set_parent_bus(), when changing the parent bus of a
realized device, if the source and destination buses are not in the
same reset state, some adaptations are required. This patch adds
needed call to resettable_change_parent() to make sure a device reset
state stays coherent with its parent bus.

The addition is a no-op if:
1. the device being parented is not realized.
2. the device is realized, but both buses are not under reset.

Case 2 means that as long as qdev_set_parent_bus() is called
during the machine realization procedure (which is before the
machine reset so nothing is in reset), it is a no op.

There are 52 call sites of qdev_set_parent_bus(). All but one fall
into the no-op case:
+ 29 trivial calls related to virtio (in hw/{s390x,display,virtio}/
  {vhost,virtio}-xxx.c) to set a vdev(or vgpu) composing device
  parent bus just before realizing the same vdev(vgpu).
+ hw/core/qdev.c: when creating a device in qdev_try_create()
+ hw/core/sysbus.c: when initializing a device in the sysbus
+ hw/i386/amd_iommu.c: before realizing AMDVIState/pci
+ hw/isa/piix4.c: before realizing PIIX4State/rtc
+ hw/misc/auxbus.c: when creating an AUXBus
+ hw/misc/auxbus.c: when creating an AUXBus child
+ hw/misc/macio/macio.c: when initializing a MACIOState child
+ hw/misc/macio/macio.c: before realizing NewWorldMacIOState/pmu
+ hw/misc/macio/macio.c: before realizing NewWorldMacIOState/cuda
+ hw/net/virtio-net.c: Used for migration when using the failover
                       mechanism to migration a vfio-pci/net. It is
                       a no-op because at this point the device is
                       already on the bus.
+ hw/pci-host/designware.c: before realizing DesignwarePCIEHost/root
+ hw/pci-host/gpex.c: before realizing GPEXHost/root
+ hw/pci-host/prep.c: when initialiazing PREPPCIState/pci_dev
+ hw/pci-host/q35.c: before realizing Q35PCIHost/mch
+ hw/pci-host/versatile.c: when initializing PCIVPBState/pci_dev
+ hw/pci-host/xilinx-pcie.c: before realizing XilinxPCIEHost/root
+ hw/s390x/event-facility.c: when creating SCLPEventFacility/
                             TYPE_SCLP_QUIESCE
+ hw/s390x/event-facility.c: ditto with SCLPEventFacility/
                             TYPE_SCLP_CPU_HOTPLUG
+ hw/s390x/sclp.c: Not trivial because it is called on a SLCPDevice
  just after realizing it. Ok because at this point the destination
  bus (sysbus) is not in reset; the realize step is before the
  machine reset.
+ hw/sd/core.c: Not OK. Used in sdbus_reparent_card(). See below.
+ hw/ssi/ssi.c: Used to put spi slave on spi bus and connect the cs
  line in ssi_auto_connect_slave(). Ok because this function is only
  used in realize step in hw/ssi/aspeed_smc.ci, hw/ssi/imx_spi.c,
  hw/ssi/mss-spi.c, hw/ssi/xilinx_spi.c and hw/ssi/xilinx_spips.c.
+ hw/xen/xen-legacy-backend.c: when creating a XenLegacyDevice device
+ qdev-monitor.c: in device hotplug creation procedure before realize

Note that this commit alone will have no effect, right now there is no
use of resettable API to reset anything. So a bus will never be tagged
as in-reset by this same API.

The one place where side-effect will occurs is in hw/sd/core.c in
sdbus_reparent_card(). This function is only used in the raspi machines,
including during the sysbus reset procedure. This case will be
carrefully handled when doing the multiple phase reset transition.

Signed-off-by: Damien Hedde <damien.hedde@greensocs.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20200123132823.1117486-7-damien.hedde@greensocs.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2020-01-30 16:02:04 +00:00
..
bus.c hw/core: add Resettable support to BusClass and DeviceClass 2020-01-30 16:02:04 +00:00
cpu.c qdev: set properties with device_class_set_props() 2020-01-24 20:59:15 +01:00
empty_slot.c Include hw/hw.h exactly where needed 2019-08-16 13:31:52 +02:00
fw-path-provider.c Include qemu/module.h where needed, drop it from qemu-common.h 2019-06-12 13:18:33 +02:00
generic-loader.c hw/core/loader: Let load_elf() populate a field with CPU-specific flags 2020-01-29 19:28:52 +01:00
hotplug.c call HotplugHandler->plug() as the last step in device realization 2018-10-19 13:44:12 +02:00
irq.c Revert "irq: introduce qemu_irq_proxy()" 2019-11-05 23:33:12 +01:00
Kconfig hw/core: Add a config switch for the generic loader device 2019-08-20 09:11:17 +02:00
loader-fit.c hw/core: Fix fit_load_fdt() error API violations 2019-12-18 08:36:15 +01:00
loader.c hw/core/loader: Let load_elf() populate a field with CPU-specific flags 2020-01-29 19:28:52 +01:00
machine-hmp-cmds.c hmp: drop Error pointer indirection in hmp_handle_error 2019-12-18 08:36:16 +01:00
machine-qmp-cmds.c qapi: report the default CPU type for each machine 2019-09-03 14:39:46 -03:00
machine.c usb-redir: remove 'remote wakeup' flag from configuration descriptor 2020-01-13 09:17:31 +01:00
Makefile.objs hw/core: create Resettable QOM interface 2020-01-30 16:02:03 +00:00
nmi.c Include qemu/module.h where needed, drop it from qemu-common.h 2019-06-12 13:18:33 +02:00
null-machine.c hw/core: Move cpu.c, cpu.h from qom/ to hw/core/ 2019-08-21 13:24:01 +02:00
numa.c virtio, pci, pc: fixes, features 2020-01-07 16:25:00 +00:00
or-irq.c hw/core/or-irq: Fix incorrect assert forbidding num-lines == MAX_OR_LINES 2020-01-30 16:02:01 +00:00
platform-bus.c qdev: set properties with device_class_set_props() 2020-01-24 20:59:15 +01:00
ptimer.c ptimer: Remove old ptimer_init_with_bh() API 2019-11-11 13:44:16 +00:00
qdev-fw.c Include hw/qdev-properties.h less 2019-08-16 13:31:53 +02:00
qdev-properties-system.c audio: add audiodev properties to frontends 2019-08-21 09:13:37 +02:00
qdev-properties.c qdev: register properties as class properties 2020-01-24 20:59:16 +01:00
qdev.c hw/core/qdev: handle parent bus change regarding resettable 2020-01-30 16:02:04 +00:00
register.c Include hw/qdev-properties.h less 2019-08-16 13:31:53 +02:00
reset.c qemu/queue.h: leave head structs anonymous unless necessary 2019-01-11 15:46:55 +01:00
resettable.c hw/core/resettable: add support for changing parent 2020-01-30 16:02:04 +00:00
split-irq.c qdev: set properties with device_class_set_props() 2020-01-24 20:59:15 +01:00
stream.c Include qemu/module.h where needed, drop it from qemu-common.h 2019-06-12 13:18:33 +02:00
sysbus.c sysbus: remove unused sysbus_try_create* 2020-01-07 16:06:59 +04:00
trace-events hw/core/resettable: add support for changing parent 2020-01-30 16:02:04 +00:00
uboot_image.h Support u-boot noload images for arm as used by, NetBSD/evbarm GENERIC kernel. 2019-01-07 15:46:20 +00:00
vm-change-state-handler.c sysemu: Split sysemu/runstate.h off sysemu/sysemu.h 2019-08-16 13:37:36 +02:00
vmstate-if.c vmstate: add qom interface to get id 2020-01-06 18:41:32 +04:00