From: Damien Hedde <damien.hedde@greensocs.com>
To: qemu-devel@nongnu.org
Cc: Damien Hedde <damien.hedde@greensocs.com>,
peter.maydell@linaro.org, berrange@redhat.com,
ehabkost@redhat.com, cohuck@redhat.com,
mark.burton@greensocs.com, qemu-s390x@nongnu.org,
edgari@xilinx.com, qemu-arm@nongnu.org, pbonzini@redhat.com,
philmd@redhat.com, david@gibson.dropbear.id.au
Subject: [PATCH v5 06/13] hw/core/qdev: handle parent bus change regarding resettable
Date: Fri, 18 Oct 2019 17:06:23 +0200 [thread overview]
Message-ID: <20191018150630.31099-7-damien.hedde@greensocs.com> (raw)
In-Reply-To: <20191018150630.31099-1-damien.hedde@greensocs.com>
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 adaptation 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 49 call sites of qdev_set_parent_bus(). All but one fall
into the no-op case:
+ 28 calls related to virtio (in hw/{s390x,display,virtio}/
{vhost,virtio}-xxx.c) to set a _vdev_/_vgpu_ composing device
parent bus just before realizing the _vdev_/_vgpu_.
+ hw/qdev.c: when creating a device in qdev_try_create()
+ hw/sysbus.c: when initializing a device in the sysbus
+ hw/display/virtio-gpu-pci.c: before realizing VirtIOGPUPCIBase/vgpu
+ hw/display/virtio-vga.c: before realizing VirtIOVGABase/vgpu
+ hw/i386/amd_iommu.c: before realizing AMDVIState/pci
+ 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/pci-host/designware.c: before realizing DesignwarePCIEHost/root
+ hw/pci-host/gpex.c: before realizing GPEXHost/root
+ hw/pci-host/prep.c: when initializaing 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 fixed by
a following commit before globally enabling resettable API for sysbus
reset.
Signed-off-by: Damien Hedde <damien.hedde@greensocs.com>
---
Exhaustive list of the 28 virtio caller to qdev_set_parent_bus():
+ hw/display/virtio-gpu-pci.c -> VirtIOGPUPCIBase/vgpu realize
+ hw/display_virtio-vga.c -> VirtIOVGABase/vgpu realize
+ hw/s390x/vhost-vsock-ccw.c -> VHostVSockCCWState/vdev realize
+ hw/s390x/virtio-ccw-9p.c -> V9fsCCWState/vdev realize
+ hw/s390x/virtio-ccw-balloon.c -> VirtIOBalloonCcw/vdev realize
+ hw/s390x/virtio-ccw-blk.c -> VirtIOBlkCcw/vdev realize
+ hw/s390x/virtio-ccw-crypto.c -> VirtIOCryptoCcw/vdev realize
+ hw/s390x/virtio-ccw-gpu.c -> VirtIOGPUCcw/vdev realize
+ hw/s390x/virtio-ccw-input.c -> VirtIOInputCcw/vdev realize
+ hw/s390x/virtio-ccw-net.c -> VirtIONetCcw/vdev realize
+ hw/s390x/virtio-ccw-rng.c -> VirtIORNGCcw/vdev realize
+ hw/s390x/virtio-ccw-scsi.c -> VirtIOSCSICcw/vdev realize
+ hw/s390x/virtio-ccw-scsi.c -> VHostSCSICcw/vdev realize
+ hw/s390x/virtio-ccw-serial.c -> VirtioSerialCcw/vdev realize
+ hw/virtio/vhost-scsi-pci.c -> VHostSCSIPCI/vdev realize
+ hw/virtio/vhost-user-blk-pci.c -> VHostUserBlkPCI/vdev realize
+ hw/virtio/vhost-user-scsi-pci.c -> VHostUserSCSIPCI/vdev realize
+ hw/virtio/vhost-vsock-pci.c -> VHostVSockPCI/vdev realize
+ hw/virtio/virtio-9p-pci.c -> V9fsPCIState/vdev realize
+ hw/virtio/virtio-balloon-pci.c -> VirtIOBalloonPCI/vdev realize
+ hw/virtio/virtio-blk-pci.c -> VirtIOBlkPCI/vdev realize
+ hw/virtio/virtio-crypto-pci.c -> VirtIOCryptoPCI/vdev realize
+ hw/virtio/virtio-input-pci.c -> VirtIOInputPCI/vdev realize
+ hw/virtio/virtio-net-pci.c -> VirtIONetPCI/vdev realize
+ hw/virtio/virtio-pmem-pci.c -> VirtIOPMEMPCI/vdev realize
+ hw/virtio/virtio-rng-pci.c -> VirtIORngPCI/vdev realize
+ hw/virtio/virtio-scsi-pci.c -> VirtIOSCSIPCI/vdev realize
+ hw/virtio/virtio-serial-pci.c -> VirtIOSerialPCI/vdev realize
---
hw/core/qdev.c | 14 ++++++++++----
1 file changed, 10 insertions(+), 4 deletions(-)
diff --git a/hw/core/qdev.c b/hw/core/qdev.c
index 81784c73fb..3933f62d0c 100644
--- a/hw/core/qdev.c
+++ b/hw/core/qdev.c
@@ -96,23 +96,29 @@ static void bus_add_child(BusState *bus, DeviceState *child)
void qdev_set_parent_bus(DeviceState *dev, BusState *bus)
{
- bool replugging = dev->parent_bus != NULL;
+ BusState *old_parent_bus = dev->parent_bus;
- if (replugging) {
+ if (old_parent_bus) {
trace_qdev_update_parent_bus(dev, dev->parent_bus, bus);
/*
* Keep a reference to the device while it's not plugged into
* any bus, to avoid it potentially evaporating when it is
* dereffed in bus_remove_child().
+ * Also keep the ref of the parent bus until the end, so that
+ * we can safely call resettable_change_parent() below.
*/
object_ref(OBJECT(dev));
bus_remove_child(dev->parent_bus, dev);
- object_unref(OBJECT(dev->parent_bus));
}
dev->parent_bus = bus;
object_ref(OBJECT(bus));
bus_add_child(bus, dev);
- if (replugging) {
+ if (dev->realized) {
+ resettable_change_parent(OBJECT(dev), OBJECT(bus),
+ OBJECT(old_parent_bus));
+ }
+ if (old_parent_bus) {
+ object_unref(OBJECT(old_parent_bus));
object_unref(OBJECT(dev));
}
}
--
2.23.0
next prev parent reply other threads:[~2019-10-18 15:18 UTC|newest]
Thread overview: 57+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-18 15:06 [PATCH v5 00/13] Multi-phase reset mechanism Damien Hedde
2019-10-18 15:06 ` [PATCH v5 01/13] add device_legacy_reset function to prepare for reset api change Damien Hedde
2019-10-19 17:35 ` Richard Henderson
2019-12-03 10:55 ` Cornelia Huck
2019-10-18 15:06 ` [PATCH v5 02/13] hw/core/qdev: add trace events to help with resettable transition Damien Hedde
2019-10-19 17:44 ` Richard Henderson
2019-10-31 23:23 ` Philippe Mathieu-Daudé
2019-11-04 12:16 ` Damien Hedde
2019-11-04 14:33 ` Philippe Mathieu-Daudé
2019-12-03 10:57 ` Cornelia Huck
2019-10-18 15:06 ` [PATCH v5 03/13] hw/core: create Resettable QOM interface Damien Hedde
2019-11-29 18:32 ` Peter Maydell
2019-12-02 11:07 ` Damien Hedde
2019-12-02 11:14 ` Peter Maydell
2019-12-03 11:16 ` Cornelia Huck
2019-10-18 15:06 ` [PATCH v5 04/13] hw/core: add Resettable support to BusClass and DeviceClass Damien Hedde
2019-10-19 18:49 ` Richard Henderson
2019-11-29 18:36 ` Peter Maydell
2019-12-02 11:38 ` Damien Hedde
2019-10-18 15:06 ` [PATCH v5 05/13] hw/core/resettable: add support for changing parent Damien Hedde
2019-11-29 18:38 ` Peter Maydell
2019-12-02 11:43 ` Damien Hedde
2019-10-18 15:06 ` Damien Hedde [this message]
2019-11-29 18:41 ` [PATCH v5 06/13] hw/core/qdev: handle parent bus change regarding resettable Peter Maydell
2019-12-03 11:37 ` Cornelia Huck
2019-10-18 15:06 ` [PATCH v5 07/13] hw/core/qdev: update hotplug reset " Damien Hedde
2019-11-08 15:14 ` Damien Hedde
2019-10-18 15:06 ` [PATCH v5 08/13] hw/core: deprecate old reset functions and introduce new ones Damien Hedde
2019-10-31 23:35 ` Philippe Mathieu-Daudé
2019-11-04 12:01 ` Damien Hedde
2019-11-04 15:42 ` Philippe Mathieu-Daudé
2019-11-29 18:42 ` Peter Maydell
2019-10-18 15:06 ` [PATCH v5 09/13] docs/devel/reset.txt: add doc about Resettable interface Damien Hedde
2019-11-29 19:00 ` Peter Maydell
2019-12-06 15:40 ` Damien Hedde
2019-12-06 16:21 ` Damien Hedde
2019-10-18 15:06 ` [PATCH v5 10/13] vl: replace deprecated qbus_reset_all registration Damien Hedde
2019-11-29 19:01 ` Peter Maydell
2019-10-18 15:06 ` [PATCH v5 11/13] hw/s390x/ipl: replace deprecated qdev_reset_all registration Damien Hedde
2019-10-31 23:38 ` Philippe Mathieu-Daudé
2019-11-29 19:02 ` Peter Maydell
2019-12-03 11:41 ` Cornelia Huck
2019-10-18 15:06 ` [PATCH v5 12/13] hw/gpio/bcm2835_gpio: Isolate sdbus reparenting Damien Hedde
2019-11-29 19:05 ` Peter Maydell
2019-12-02 12:27 ` Damien Hedde
2019-12-02 12:33 ` Peter Maydell
2019-12-02 13:05 ` Damien Hedde
2019-12-02 13:10 ` Peter Maydell
2019-10-18 15:06 ` [PATCH v5 13/13] hw/gpio/bcm2835_gpio: Update to resettable Damien Hedde
2019-11-29 19:02 ` Peter Maydell
2019-10-19 9:01 ` [PATCH v5 00/13] Multi-phase reset mechanism no-reply
2019-10-29 15:53 ` Damien Hedde
2019-11-08 15:26 ` Damien Hedde
2019-11-08 15:28 ` Peter Maydell
2019-11-08 15:58 ` Damien Hedde
2019-11-29 19:07 ` Peter Maydell
2019-12-03 11:44 ` Cornelia Huck
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