When the physical device is probed it is existing but should not be able to do any operations since no driver is available until a guest is there. Hence the state is set to VFIO_CCW_STATE_NOT_OPER.
When the mediated device is created, nothing is changed for the device, it still stay not operational. When the guest is starting the state machine recieves the VFIO_CCW_EVENT_INIT event which statrts the fsm_init action to bring the state to VFIO_CCW_STATE_STANDBY. The VFIO_DEVICE_RESET command (not part of this patch) will bring the FSM state to VFIO_CCW_STATE_IDLE. Before the mediated device is opened by QEMU, the vfio_private structure is not completely initialized. Let's change the actions for the VFIO_CCW_STATE_NOT_OPER to fsm_nop when vfio_private is not initialized. Signed-off-by: Pierre Morel <[email protected]> --- drivers/s390/cio/vfio_ccw_drv.c | 22 ++++++---------------- drivers/s390/cio/vfio_ccw_fsm.c | 25 +++++++++++++++++++++++-- drivers/s390/cio/vfio_ccw_ops.c | 25 +++++++++++++------------ drivers/s390/cio/vfio_ccw_private.h | 1 + 4 files changed, 43 insertions(+), 30 deletions(-) diff --git a/drivers/s390/cio/vfio_ccw_drv.c b/drivers/s390/cio/vfio_ccw_drv.c index 98951d5..6fc7668 100644 --- a/drivers/s390/cio/vfio_ccw_drv.c +++ b/drivers/s390/cio/vfio_ccw_drv.c @@ -114,31 +114,21 @@ static int vfio_ccw_sch_probe(struct subchannel *sch) private = kzalloc(sizeof(*private), GFP_KERNEL | GFP_DMA); if (!private) return -ENOMEM; + + private->state = VFIO_CCW_STATE_NOT_OPER; private->sch = sch; dev_set_drvdata(&sch->dev, private); mutex_init(&private->state_mutex); - - spin_lock_irq(sch->lock); - private->state = VFIO_CCW_STATE_NOT_OPER; - sch->isc = VFIO_CCW_ISC; - ret = cio_enable_subchannel(sch, (u32)(unsigned long)sch); - spin_unlock_irq(sch->lock); - if (ret) - goto out_free; - - ret = vfio_ccw_mdev_reg(sch); - if (ret) - goto out_disable; - INIT_WORK(&private->io_work, vfio_ccw_sch_io_todo); INIT_WORK(&private->event_work, vfio_ccw_sch_event_todo); atomic_set(&private->avail, 1); - private->state = VFIO_CCW_STATE_STANDBY; + + ret = vfio_ccw_mdev_reg(sch); + if (ret) + goto out_free; return 0; -out_disable: - cio_disable_subchannel(sch); out_free: dev_set_drvdata(&sch->dev, NULL); kfree(private); diff --git a/drivers/s390/cio/vfio_ccw_fsm.c b/drivers/s390/cio/vfio_ccw_fsm.c index 077da23..20b909c 100644 --- a/drivers/s390/cio/vfio_ccw_fsm.c +++ b/drivers/s390/cio/vfio_ccw_fsm.c @@ -9,6 +9,7 @@ #include <linux/vfio.h> #include <linux/mdev.h> +#include <asm/isc.h> #include "ioasm.h" #include "vfio_ccw_private.h" @@ -174,35 +175,55 @@ static int fsm_sch_event(struct vfio_ccw_private *private) return ret; } +static int fsm_init(struct vfio_ccw_private *private) +{ + struct subchannel *sch = private->sch; + int ret = VFIO_CCW_STATE_STANDBY; + + spin_lock_irq(sch->lock); + sch->isc = VFIO_CCW_ISC; + if (cio_enable_subchannel(sch, (u32)(unsigned long)sch)) + ret = VFIO_CCW_STATE_NOT_OPER; + spin_unlock_irq(sch->lock); + + return ret; +} + + /* * Device statemachine */ fsm_func_t *vfio_ccw_jumptable[NR_VFIO_CCW_STATES][NR_VFIO_CCW_EVENTS] = { [VFIO_CCW_STATE_NOT_OPER] = { + [VFIO_CCW_EVENT_INIT] = fsm_init, [VFIO_CCW_EVENT_NOT_OPER] = fsm_nop, - [VFIO_CCW_EVENT_SSCH_REQ] = fsm_io_error, - [VFIO_CCW_EVENT_INTERRUPT] = fsm_disabled_irq, + [VFIO_CCW_EVENT_SSCH_REQ] = fsm_nop, + [VFIO_CCW_EVENT_INTERRUPT] = fsm_nop, [VFIO_CCW_EVENT_SCHIB_CHANGED] = fsm_nop, }, [VFIO_CCW_STATE_STANDBY] = { + [VFIO_CCW_EVENT_INIT] = fsm_nop, [VFIO_CCW_EVENT_NOT_OPER] = fsm_notoper, [VFIO_CCW_EVENT_SSCH_REQ] = fsm_io_error, [VFIO_CCW_EVENT_INTERRUPT] = fsm_irq, [VFIO_CCW_EVENT_SCHIB_CHANGED] = fsm_sch_event, }, [VFIO_CCW_STATE_IDLE] = { + [VFIO_CCW_EVENT_INIT] = fsm_nop, [VFIO_CCW_EVENT_NOT_OPER] = fsm_notoper, [VFIO_CCW_EVENT_SSCH_REQ] = fsm_io_request, [VFIO_CCW_EVENT_INTERRUPT] = fsm_irq, [VFIO_CCW_EVENT_SCHIB_CHANGED] = fsm_sch_event, }, [VFIO_CCW_STATE_BOXED] = { + [VFIO_CCW_EVENT_INIT] = fsm_nop, [VFIO_CCW_EVENT_NOT_OPER] = fsm_notoper, [VFIO_CCW_EVENT_SSCH_REQ] = fsm_io_busy, [VFIO_CCW_EVENT_INTERRUPT] = fsm_irq, [VFIO_CCW_EVENT_SCHIB_CHANGED] = fsm_sch_event, }, [VFIO_CCW_STATE_BUSY] = { + [VFIO_CCW_EVENT_INIT] = fsm_nop, [VFIO_CCW_EVENT_NOT_OPER] = fsm_notoper, [VFIO_CCW_EVENT_SSCH_REQ] = fsm_io_busy, [VFIO_CCW_EVENT_INTERRUPT] = fsm_irq, diff --git a/drivers/s390/cio/vfio_ccw_ops.c b/drivers/s390/cio/vfio_ccw_ops.c index 0206101..ea8fd64 100644 --- a/drivers/s390/cio/vfio_ccw_ops.c +++ b/drivers/s390/cio/vfio_ccw_ops.c @@ -111,14 +111,10 @@ static int vfio_ccw_mdev_create(struct kobject *kobj, struct mdev_device *mdev) struct vfio_ccw_private *private = dev_get_drvdata(mdev_parent_dev(mdev)); - if (private->state == VFIO_CCW_STATE_NOT_OPER) - return -ENODEV; - if (atomic_dec_if_positive(&private->avail) < 0) return -EPERM; private->mdev = mdev; - private->state = VFIO_CCW_STATE_IDLE; return 0; } @@ -128,13 +124,6 @@ static int vfio_ccw_mdev_remove(struct mdev_device *mdev) struct vfio_ccw_private *private = dev_get_drvdata(mdev_parent_dev(mdev)); - if ((private->state != VFIO_CCW_STATE_NOT_OPER) && - (private->state != VFIO_CCW_STATE_STANDBY)) { - if (!vfio_ccw_mdev_reset(mdev)) - private->state = VFIO_CCW_STATE_STANDBY; - /* The state will be NOT_OPER on error. */ - } - private->mdev = NULL; atomic_inc(&private->avail); @@ -146,11 +135,22 @@ static int vfio_ccw_mdev_open(struct mdev_device *mdev) struct vfio_ccw_private *private = dev_get_drvdata(mdev_parent_dev(mdev)); unsigned long events = VFIO_IOMMU_NOTIFY_DMA_UNMAP; + int ret; private->nb.notifier_call = vfio_ccw_mdev_notifier; - return vfio_register_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY, + ret = vfio_register_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY, &events, &private->nb); + if (ret) + return ret; + + vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_INIT); + if (private->state == VFIO_CCW_STATE_STANDBY) + return 0; + + vfio_unregister_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY, + &private->nb); + return -EFAULT; } static void vfio_ccw_mdev_release(struct mdev_device *mdev) @@ -158,6 +158,7 @@ static void vfio_ccw_mdev_release(struct mdev_device *mdev) struct vfio_ccw_private *private = dev_get_drvdata(mdev_parent_dev(mdev)); + vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_NOT_OPER); vfio_unregister_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY, &private->nb); } diff --git a/drivers/s390/cio/vfio_ccw_private.h b/drivers/s390/cio/vfio_ccw_private.h index 241176c..c5455a9 100644 --- a/drivers/s390/cio/vfio_ccw_private.h +++ b/drivers/s390/cio/vfio_ccw_private.h @@ -76,6 +76,7 @@ enum vfio_ccw_state { * Asynchronous events of the device statemachine. */ enum vfio_ccw_event { + VFIO_CCW_EVENT_INIT, VFIO_CCW_EVENT_NOT_OPER, VFIO_CCW_EVENT_SSCH_REQ, VFIO_CCW_EVENT_INTERRUPT, -- 2.7.4
