On 08/05/2019 11:52, Cornelia Huck wrote:
On Tue, 7 May 2019 15:44:54 -0400
Farhan Ali <alifm@xxxxxxxxxxxxx> 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@xxxxxxxxxxxxx>
---
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;
--
Pierre Morel
Linux/KVM/QEMU in Böblingen - Germany
