| Message ID | 1557148270-19901-2-git-send-email-pmorel@linux.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | New state handling for VFIO CCW | expand |
On 05/06/2019 09:11 AM, Pierre Morel wrote: > When no guest is associated with the mediated device, > i.e. the mediated device is not opened, the state of > the mediated device is VFIO_CCW_STATE_NOT_OPER. > > The subchannel enablement and the according setting to the > VFIO_CCW_STATE_STANDBY state should only be done when all > parts of the VFIO mediated device have been initialized > i.e. after the mediated device has been successfully opened. > > Let's stay in VFIO_CCW_STATE_NOT_OPER until the mediated > device has been opened. > > When the mediated device is closed, disable the sub channel > by calling vfio_ccw_sch_quiesce() no reset needs to be done > the mediated devce will be enable on next open. s/devce/device > > Signed-off-by: Pierre Morel <pmorel@linux.ibm.com> > --- > drivers/s390/cio/vfio_ccw_drv.c | 10 +--------- > drivers/s390/cio/vfio_ccw_ops.c | 36 ++++++++++++++++++------------------ > 2 files changed, 19 insertions(+), 27 deletions(-) > > diff --git a/drivers/s390/cio/vfio_ccw_drv.c b/drivers/s390/cio/vfio_ccw_drv.c > index ee8767f..a95b6c7 100644 > --- a/drivers/s390/cio/vfio_ccw_drv.c > +++ b/drivers/s390/cio/vfio_ccw_drv.c > @@ -143,26 +143,18 @@ static int vfio_ccw_sch_probe(struct subchannel *sch) > dev_set_drvdata(&sch->dev, private); > mutex_init(&private->io_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; > > INIT_WORK(&private->io_work, vfio_ccw_sch_io_todo); > atomic_set(&private->avail, 1); > - private->state = VFIO_CCW_STATE_STANDBY; > > ret = vfio_ccw_mdev_reg(sch); > if (ret) > - goto out_disable; > + goto out_free; > > return 0; > > -out_disable: > - cio_disable_subchannel(sch); > out_free: > dev_set_drvdata(&sch->dev, NULL); > if (private->cmd_region) > diff --git a/drivers/s390/cio/vfio_ccw_ops.c b/drivers/s390/cio/vfio_ccw_ops.c > index 5eb6111..497419c 100644 > --- a/drivers/s390/cio/vfio_ccw_ops.c > +++ b/drivers/s390/cio/vfio_ccw_ops.c > @@ -115,14 +115,10 @@ 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; > } > @@ -132,12 +128,7 @@ 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_sch_quiesce(private->sch)) > - private->state = VFIO_CCW_STATE_STANDBY; > - /* The state will be NOT_OPER on error. */ > - } > + vfio_ccw_sch_quiesce(private->sch); > > cp_free(&private->cp); > private->mdev = NULL; > @@ -151,6 +142,7 @@ 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; > + struct subchannel *sch = private->sch; > int ret; > > private->nb.notifier_call = vfio_ccw_mdev_notifier; > @@ -165,6 +157,20 @@ static int vfio_ccw_mdev_open(struct mdev_device *mdev) > vfio_unregister_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY, > &private->nb); > return ret; > + > + spin_lock_irq(private->sch->lock); > + if (cio_enable_subchannel(sch, (u32)(unsigned long)sch)) > + goto error; > + > + private->state = VFIO_CCW_STATE_STANDBY; I don't think we should set the state to STANDBY here, because with just this patch applied, any VFIO_CCW_EVENT_IO_REQ will return an error (due to fsm_io_error). It might be safe to set it to IDLE in this patch. > + spin_unlock_irq(sch->lock); > + return 0; > + > +error: > + spin_unlock_irq(sch->lock); > + vfio_unregister_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY, > + &private->nb); > + return -EFAULT; > } > > static void vfio_ccw_mdev_release(struct mdev_device *mdev) > @@ -173,20 +179,14 @@ static void vfio_ccw_mdev_release(struct mdev_device *mdev) > dev_get_drvdata(mdev_parent_dev(mdev)); > int i; > > - 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. */ > - } > - > - cp_free(&private->cp); > + vfio_ccw_sch_quiesce(private->sch); > vfio_unregister_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY, > &private->nb); > > for (i = 0; i < private->num_regions; i++) > private->region[i].ops->release(private, &private->region[i]); > > + cp_free(&private->cp); > private->num_regions = 0; > kfree(private->region); > private->region = NULL; >
On Tue, 7 May 2019 15:44:54 -0400 Farhan Ali <alifm@linux.ibm.com> wrote: > On 05/06/2019 09:11 AM, Pierre Morel wrote: > > When no guest is associated with the mediated device, > > i.e. the mediated device is not opened, the state of > > the mediated device is VFIO_CCW_STATE_NOT_OPER. > > > > The subchannel enablement and the according setting to the > > VFIO_CCW_STATE_STANDBY state should only be done when all > > parts of the VFIO mediated device have been initialized > > i.e. after the mediated device has been successfully opened. > > > > Let's stay in VFIO_CCW_STATE_NOT_OPER until the mediated > > device has been opened. > > > > When the mediated device is closed, disable the sub channel > > by calling vfio_ccw_sch_quiesce() no reset needs to be done > > the mediated devce will be enable on next open. > > s/devce/device > > > > > Signed-off-by: Pierre Morel <pmorel@linux.ibm.com> > > --- > > drivers/s390/cio/vfio_ccw_drv.c | 10 +--------- > > drivers/s390/cio/vfio_ccw_ops.c | 36 ++++++++++++++++++------------------ > > 2 files changed, 19 insertions(+), 27 deletions(-) > > (...) > > diff --git a/drivers/s390/cio/vfio_ccw_ops.c b/drivers/s390/cio/vfio_ccw_ops.c > > index 5eb6111..497419c 100644 > > --- a/drivers/s390/cio/vfio_ccw_ops.c > > +++ b/drivers/s390/cio/vfio_ccw_ops.c > > @@ -115,14 +115,10 @@ 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; > > } > > @@ -132,12 +128,7 @@ 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_sch_quiesce(private->sch)) > > - private->state = VFIO_CCW_STATE_STANDBY; > > - /* The state will be NOT_OPER on error. */ > > - } > > + vfio_ccw_sch_quiesce(private->sch); > > > > cp_free(&private->cp); > > private->mdev = NULL; > > @@ -151,6 +142,7 @@ 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; > > + struct subchannel *sch = private->sch; > > int ret; > > > > private->nb.notifier_call = vfio_ccw_mdev_notifier; > > @@ -165,6 +157,20 @@ static int vfio_ccw_mdev_open(struct mdev_device *mdev) > > vfio_unregister_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY, > > &private->nb); > > return ret; I think this "return ret;" needs to go into the if branch above it; otherwise, the code below won't be reached :) > > + > > + spin_lock_irq(private->sch->lock); > > + if (cio_enable_subchannel(sch, (u32)(unsigned long)sch)) > > + goto error; > > + > > + private->state = VFIO_CCW_STATE_STANDBY; > > I don't think we should set the state to STANDBY here, because with just > this patch applied, any VFIO_CCW_EVENT_IO_REQ will return an error (due > to fsm_io_error). > > It might be safe to set it to IDLE in this patch. Agreed, this should be IDLE; otherwise, I don't see how a device might move into IDLE state? (That change happens in the next patch anyway.) > > > > + spin_unlock_irq(sch->lock); > > + return 0; > > + > > +error: > > + spin_unlock_irq(sch->lock); > > + vfio_unregister_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY, > > + &private->nb); > > + return -EFAULT; > > } > > > > static void vfio_ccw_mdev_release(struct mdev_device *mdev) > > @@ -173,20 +179,14 @@ static void vfio_ccw_mdev_release(struct mdev_device *mdev) > > dev_get_drvdata(mdev_parent_dev(mdev)); > > int i; > > > > - 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. */ > > - } > > - > > - cp_free(&private->cp); > > + vfio_ccw_sch_quiesce(private->sch); > > vfio_unregister_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY, > > &private->nb); > > > > for (i = 0; i < private->num_regions; i++) > > private->region[i].ops->release(private, &private->region[i]); > > > > + cp_free(&private->cp); I'm wondering why this cp_free is moved -- there should not be any activity related to it after quiesce, should there? > > private->num_regions = 0; > > kfree(private->region); > > private->region = NULL; > > >
On 08/05/2019 11:52, Cornelia Huck wrote: > On Tue, 7 May 2019 15:44:54 -0400 > Farhan Ali <alifm@linux.ibm.com> wrote: > >> On 05/06/2019 09:11 AM, Pierre Morel wrote: >>> When no guest is associated with the mediated device, >>> i.e. the mediated device is not opened, the state of >>> the mediated device is VFIO_CCW_STATE_NOT_OPER. >>> >>> The subchannel enablement and the according setting to the >>> VFIO_CCW_STATE_STANDBY state should only be done when all >>> parts of the VFIO mediated device have been initialized >>> i.e. after the mediated device has been successfully opened. >>> >>> Let's stay in VFIO_CCW_STATE_NOT_OPER until the mediated >>> device has been opened. >>> >>> When the mediated device is closed, disable the sub channel >>> by calling vfio_ccw_sch_quiesce() no reset needs to be done >>> the mediated devce will be enable on next open. >> >> s/devce/device >> >>> >>> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com> >>> --- >>> drivers/s390/cio/vfio_ccw_drv.c | 10 +--------- >>> drivers/s390/cio/vfio_ccw_ops.c | 36 ++++++++++++++++++------------------ >>> 2 files changed, 19 insertions(+), 27 deletions(-) >>> > (...) >>> diff --git a/drivers/s390/cio/vfio_ccw_ops.c b/drivers/s390/cio/vfio_ccw_ops.c >>> index 5eb6111..497419c 100644 >>> --- a/drivers/s390/cio/vfio_ccw_ops.c >>> +++ b/drivers/s390/cio/vfio_ccw_ops.c >>> @@ -115,14 +115,10 @@ 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; >>> } >>> @@ -132,12 +128,7 @@ 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_sch_quiesce(private->sch)) >>> - private->state = VFIO_CCW_STATE_STANDBY; >>> - /* The state will be NOT_OPER on error. */ >>> - } >>> + vfio_ccw_sch_quiesce(private->sch); >>> >>> cp_free(&private->cp); >>> private->mdev = NULL; >>> @@ -151,6 +142,7 @@ 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; >>> + struct subchannel *sch = private->sch; >>> int ret; >>> >>> private->nb.notifier_call = vfio_ccw_mdev_notifier; >>> @@ -165,6 +157,20 @@ static int vfio_ccw_mdev_open(struct mdev_device *mdev) >>> vfio_unregister_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY, >>> &private->nb); >>> return ret; > > I think this "return ret;" needs to go into the if branch above it; > otherwise, the code below won't be reached :) > >>> + >>> + spin_lock_irq(private->sch->lock); >>> + if (cio_enable_subchannel(sch, (u32)(unsigned long)sch)) >>> + goto error; >>> + >>> + private->state = VFIO_CCW_STATE_STANDBY; >> >> I don't think we should set the state to STANDBY here, because with just >> this patch applied, any VFIO_CCW_EVENT_IO_REQ will return an error (due >> to fsm_io_error). >> >> It might be safe to set it to IDLE in this patch. > > Agreed, this should be IDLE; otherwise, I don't see how a device might > move into IDLE state? > > (That change happens in the next patch anyway.) > >> >> >>> + spin_unlock_irq(sch->lock); >>> + return 0; >>> + >>> +error: >>> + spin_unlock_irq(sch->lock); >>> + vfio_unregister_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY, >>> + &private->nb); >>> + return -EFAULT; >>> } >>> >>> static void vfio_ccw_mdev_release(struct mdev_device *mdev) >>> @@ -173,20 +179,14 @@ static void vfio_ccw_mdev_release(struct mdev_device *mdev) >>> dev_get_drvdata(mdev_parent_dev(mdev)); >>> int i; >>> >>> - 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. */ >>> - } >>> - >>> - cp_free(&private->cp); >>> + vfio_ccw_sch_quiesce(private->sch); >>> vfio_unregister_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY, >>> &private->nb); >>> >>> for (i = 0; i < private->num_regions; i++) >>> private->region[i].ops->release(private, &private->region[i]); >>> >>> + cp_free(&private->cp); > > I'm wondering why this cp_free is moved -- there should not be any > activity related to it after quiesce, should there? Yes there should. I will let it where it was. > >>> private->num_regions = 0; >>> kfree(private->region); >>> private->region = NULL; >>> >> >
diff --git a/drivers/s390/cio/vfio_ccw_drv.c b/drivers/s390/cio/vfio_ccw_drv.c index ee8767f..a95b6c7 100644 --- a/drivers/s390/cio/vfio_ccw_drv.c +++ b/drivers/s390/cio/vfio_ccw_drv.c @@ -143,26 +143,18 @@ static int vfio_ccw_sch_probe(struct subchannel *sch) dev_set_drvdata(&sch->dev, private); mutex_init(&private->io_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; INIT_WORK(&private->io_work, vfio_ccw_sch_io_todo); atomic_set(&private->avail, 1); - private->state = VFIO_CCW_STATE_STANDBY; ret = vfio_ccw_mdev_reg(sch); if (ret) - goto out_disable; + goto out_free; return 0; -out_disable: - cio_disable_subchannel(sch); out_free: dev_set_drvdata(&sch->dev, NULL); if (private->cmd_region) diff --git a/drivers/s390/cio/vfio_ccw_ops.c b/drivers/s390/cio/vfio_ccw_ops.c index 5eb6111..497419c 100644 --- a/drivers/s390/cio/vfio_ccw_ops.c +++ b/drivers/s390/cio/vfio_ccw_ops.c @@ -115,14 +115,10 @@ 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; } @@ -132,12 +128,7 @@ 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_sch_quiesce(private->sch)) - private->state = VFIO_CCW_STATE_STANDBY; - /* The state will be NOT_OPER on error. */ - } + vfio_ccw_sch_quiesce(private->sch); cp_free(&private->cp); private->mdev = NULL; @@ -151,6 +142,7 @@ 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; + struct subchannel *sch = private->sch; int ret; private->nb.notifier_call = vfio_ccw_mdev_notifier; @@ -165,6 +157,20 @@ static int vfio_ccw_mdev_open(struct mdev_device *mdev) vfio_unregister_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY, &private->nb); return ret; + + spin_lock_irq(private->sch->lock); + if (cio_enable_subchannel(sch, (u32)(unsigned long)sch)) + goto error; + + private->state = VFIO_CCW_STATE_STANDBY; + spin_unlock_irq(sch->lock); + return 0; + +error: + spin_unlock_irq(sch->lock); + vfio_unregister_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY, + &private->nb); + return -EFAULT; } static void vfio_ccw_mdev_release(struct mdev_device *mdev) @@ -173,20 +179,14 @@ static void vfio_ccw_mdev_release(struct mdev_device *mdev) dev_get_drvdata(mdev_parent_dev(mdev)); int i; - 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. */ - } - - cp_free(&private->cp); + vfio_ccw_sch_quiesce(private->sch); vfio_unregister_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY, &private->nb); for (i = 0; i < private->num_regions; i++) private->region[i].ops->release(private, &private->region[i]); + cp_free(&private->cp); private->num_regions = 0; kfree(private->region); private->region = NULL;
When no guest is associated with the mediated device, i.e. the mediated device is not opened, the state of the mediated device is VFIO_CCW_STATE_NOT_OPER. The subchannel enablement and the according setting to the VFIO_CCW_STATE_STANDBY state should only be done when all parts of the VFIO mediated device have been initialized i.e. after the mediated device has been successfully opened. Let's stay in VFIO_CCW_STATE_NOT_OPER until the mediated device has been opened. When the mediated device is closed, disable the sub channel by calling vfio_ccw_sch_quiesce() no reset needs to be done the mediated devce will be enable on next open. Signed-off-by: Pierre Morel <pmorel@linux.ibm.com> --- drivers/s390/cio/vfio_ccw_drv.c | 10 +--------- drivers/s390/cio/vfio_ccw_ops.c | 36 ++++++++++++++++++------------------ 2 files changed, 19 insertions(+), 27 deletions(-)