From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Pierre Morel Subject: [PATCH v1 1/2] vfio-ccw: Set subchannel state STANDBY on open Date: Mon, 6 May 2019 15:11:09 +0200 In-Reply-To: <1557148270-19901-1-git-send-email-pmorel@linux.ibm.com> References: <1557148270-19901-1-git-send-email-pmorel@linux.ibm.com> Message-Id: <1557148270-19901-2-git-send-email-pmorel@linux.ibm.com> Sender: kvm-owner@vger.kernel.org List-Archive: List-Post: To: cohuck@redhat.com Cc: pasic@linux.vnet.ibm.com, farman@linux.ibm.com, alifm@linux.ibm.com, linux-s390@vger.kernel.org, kvm@vger.kernel.org List-ID: 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 --- 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; + 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; -- 2.7.4