| Message ID | 20200115123620.250132-7-damien.hedde@greensocs.com |
|---|---|
| State | New |
| Headers | show |
| Series | Multi-phase reset mechanism | expand |
On 1/15/20 1:36 PM, Damien Hedde wrote: > 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 initializaing PREPPCIState/pci_dev typo "initializing" > + 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> > --- > > v6 update: there are now 3 more call sites (52 instead of 49). > + hw/isa/piix4.c > + hw/net/virtio-net.c > + hw/virtio/vhost-user-fs-pci.c (in list below) > > Exhaustive list of the 29 "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-fs-pci.c: VHostUserFSPCI/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 | 16 +++++++++++----- > 1 file changed, 11 insertions(+), 5 deletions(-) > > diff --git a/hw/core/qdev.c b/hw/core/qdev.c > index d431a020fc..310b87e25a 100644 > --- a/hw/core/qdev.c > +++ b/hw/core/qdev.c > @@ -96,25 +96,31 @@ 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, object_get_typename(OBJECT(dev)), > - dev->parent_bus, object_get_typename(OBJECT(dev->parent_bus)), > + old_parent_bus, object_get_typename(OBJECT(old_parent_bus)), > OBJECT(bus), object_get_typename(OBJECT(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)); > } > } >
diff --git a/hw/core/qdev.c b/hw/core/qdev.c index d431a020fc..310b87e25a 100644 --- a/hw/core/qdev.c +++ b/hw/core/qdev.c @@ -96,25 +96,31 @@ 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, object_get_typename(OBJECT(dev)), - dev->parent_bus, object_get_typename(OBJECT(dev->parent_bus)), + old_parent_bus, object_get_typename(OBJECT(old_parent_bus)), OBJECT(bus), object_get_typename(OBJECT(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)); } }
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 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 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> --- v6 update: there are now 3 more call sites (52 instead of 49). + hw/isa/piix4.c + hw/net/virtio-net.c + hw/virtio/vhost-user-fs-pci.c (in list below) Exhaustive list of the 29 "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-fs-pci.c: VHostUserFSPCI/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 | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-)