Messages in this thread | | | Date | Tue, 26 Apr 2022 11:45:15 +0800 | Subject | Re: [PATCH V3 7/9] virtio: allow to unbreak virtqueue | From | Jason Wang <> |
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在 2022/4/25 22:04, Michael S. Tsirkin 写道: > On Mon, Apr 25, 2022 at 02:44:06PM +0200, Cornelia Huck wrote: >> On Mon, Apr 25 2022, Jason Wang <jasowang@redhat.com> wrote: >> >>> This patch allows the virtio_break_device() to accept a boolean value >>> then we can unbreak the virtqueue. >>> >>> Signed-off-by: Jason Wang <jasowang@redhat.com> >>> --- >>> drivers/char/virtio_console.c | 2 +- >>> drivers/crypto/virtio/virtio_crypto_core.c | 2 +- >>> drivers/s390/virtio/virtio_ccw.c | 4 ++-- >>> drivers/virtio/virtio_pci_common.c | 2 +- >>> drivers/virtio/virtio_ring.c | 4 ++-- >>> include/linux/virtio.h | 2 +- >>> 6 files changed, 8 insertions(+), 8 deletions(-) >>> >>> diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c >>> index e3c430539a17..afede977f7b3 100644 >>> --- a/drivers/char/virtio_console.c >>> +++ b/drivers/char/virtio_console.c >>> @@ -1958,7 +1958,7 @@ static void virtcons_remove(struct virtio_device *vdev) >>> spin_unlock_irq(&pdrvdata_lock); >>> >>> /* Device is going away, exit any polling for buffers */ >>> - virtio_break_device(vdev); >>> + virtio_break_device(vdev, true); >>> if (use_multiport(portdev)) >>> flush_work(&portdev->control_work); >>> else >>> diff --git a/drivers/crypto/virtio/virtio_crypto_core.c b/drivers/crypto/virtio/virtio_crypto_core.c >>> index c6f482db0bc0..fd17f3f2e958 100644 >>> --- a/drivers/crypto/virtio/virtio_crypto_core.c >>> +++ b/drivers/crypto/virtio/virtio_crypto_core.c >>> @@ -215,7 +215,7 @@ static int virtcrypto_update_status(struct virtio_crypto *vcrypto) >>> dev_warn(&vcrypto->vdev->dev, >>> "Unknown status bits: 0x%x\n", status); >>> >>> - virtio_break_device(vcrypto->vdev); >>> + virtio_break_device(vcrypto->vdev, true); >>> return -EPERM; >>> } >>> >>> diff --git a/drivers/s390/virtio/virtio_ccw.c b/drivers/s390/virtio/virtio_ccw.c >>> index c19f07a82d62..9a963f5af5b5 100644 >>> --- a/drivers/s390/virtio/virtio_ccw.c >>> +++ b/drivers/s390/virtio/virtio_ccw.c >>> @@ -1211,7 +1211,7 @@ static void virtio_ccw_remove(struct ccw_device *cdev) >>> >>> if (vcdev && cdev->online) { >>> if (vcdev->device_lost) >>> - virtio_break_device(&vcdev->vdev); >>> + virtio_break_device(&vcdev->vdev, true); >>> unregister_virtio_device(&vcdev->vdev); >>> spin_lock_irqsave(get_ccwdev_lock(cdev), flags); >>> dev_set_drvdata(&cdev->dev, NULL); >>> @@ -1228,7 +1228,7 @@ static int virtio_ccw_offline(struct ccw_device *cdev) >>> if (!vcdev) >>> return 0; >>> if (vcdev->device_lost) >>> - virtio_break_device(&vcdev->vdev); >>> + virtio_break_device(&vcdev->vdev, true); >>> unregister_virtio_device(&vcdev->vdev); >>> spin_lock_irqsave(get_ccwdev_lock(cdev), flags); >>> dev_set_drvdata(&cdev->dev, NULL); >>> diff --git a/drivers/virtio/virtio_pci_common.c b/drivers/virtio/virtio_pci_common.c >>> index d724f676608b..39a711ddff30 100644 >>> --- a/drivers/virtio/virtio_pci_common.c >>> +++ b/drivers/virtio/virtio_pci_common.c >>> @@ -583,7 +583,7 @@ static void virtio_pci_remove(struct pci_dev *pci_dev) >>> * layers can abort any ongoing operation. >>> */ >>> if (!pci_device_is_present(pci_dev)) >>> - virtio_break_device(&vp_dev->vdev); >>> + virtio_break_device(&vp_dev->vdev, true); >>> >>> pci_disable_sriov(pci_dev); >>> >>> diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c >>> index cfb028ca238e..6da13495a70c 100644 >>> --- a/drivers/virtio/virtio_ring.c >>> +++ b/drivers/virtio/virtio_ring.c >>> @@ -2382,7 +2382,7 @@ EXPORT_SYMBOL_GPL(virtqueue_is_broken); >>> * This should prevent the device from being used, allowing drivers to >>> * recover. You may need to grab appropriate locks to flush. >>> */ >>> -void virtio_break_device(struct virtio_device *dev) >>> +void virtio_break_device(struct virtio_device *dev, bool broken) >> I think we need to be careful to say when it is safe to unset 'broken'. >> >> The current callers set all queues to broken in case of surprise removal >> (ccw, pci), removal (console), or the device behaving badly >> (crypto). There's also code setting individual queues to broken. We do >> not want to undo any of these, unless the device has gone through a >> reset in the meanwhile. Maybe add: >> >> "It is only safe to call this function to *remove* the broken flag for a >> device that is (re)transitioning to becoming usable; calling it that way >> during normal usage may have unpredictable consequences." >> >> (Not sure how to word this; especially if we consider future usage of >> queue reset.) > > Right. I would prefer __virtio_unbreak_device or something similar
Ok, so I think then we don't want it to be exported.
> with a bit comment explaining it's only safe to call during probe.
Will do.
Thanks
>
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