Re: [PATCH v9 10/22] s390: vfio-ap: sysfs interfaces to configure adapters

2018-08-17 Thread Tony Krowiak

On 08/16/2018 03:30 AM, Cornelia Huck wrote:

On Wed, 15 Aug 2018 12:59:35 -0400
Tony Krowiak  wrote:


On 08/15/2018 05:52 AM, Cornelia Huck wrote:

On Mon, 13 Aug 2018 17:48:07 -0400
Tony Krowiak  wrote:

+/**
+ * unassign_adapter_store
+ *
+ * @dev: the matrix device
+ * @attr: a mediated matrix device attribute
+ * @buf: a buffer containing the adapter ID (APID) to be assigned
+ * @count: the number of bytes in @buf
+ *
+ * Parses the APID from @buf and unassigns it from the mediated matrix device.
+ * The APID must be a valid value

A valid value, but not necessarily assigned, right?

You are correct, if the APID is not assigned, then the corresponding bit
will be
cleared regardless. In a previous version, the functions failed if the
APID is
not assigned, but a colleague removed that check. I guess it makes sense
given
it really does not hurt anything to ask to unassign an APID that isn't
assigned
to begin with. Would you prefer I update the comment, or do you feel the
user
should be made aware of an attempt to unassign an APID that is not assigned?

I think the code is fine; updating the comment would be good.


Will do.







Re: [PATCH v9 10/22] s390: vfio-ap: sysfs interfaces to configure adapters

2018-08-17 Thread Tony Krowiak

On 08/16/2018 03:30 AM, Cornelia Huck wrote:

On Wed, 15 Aug 2018 12:59:35 -0400
Tony Krowiak  wrote:


On 08/15/2018 05:52 AM, Cornelia Huck wrote:

On Mon, 13 Aug 2018 17:48:07 -0400
Tony Krowiak  wrote:

+/**
+ * unassign_adapter_store
+ *
+ * @dev: the matrix device
+ * @attr: a mediated matrix device attribute
+ * @buf: a buffer containing the adapter ID (APID) to be assigned
+ * @count: the number of bytes in @buf
+ *
+ * Parses the APID from @buf and unassigns it from the mediated matrix device.
+ * The APID must be a valid value

A valid value, but not necessarily assigned, right?

You are correct, if the APID is not assigned, then the corresponding bit
will be
cleared regardless. In a previous version, the functions failed if the
APID is
not assigned, but a colleague removed that check. I guess it makes sense
given
it really does not hurt anything to ask to unassign an APID that isn't
assigned
to begin with. Would you prefer I update the comment, or do you feel the
user
should be made aware of an attempt to unassign an APID that is not assigned?

I think the code is fine; updating the comment would be good.


Will do.







Re: [PATCH v9 10/22] s390: vfio-ap: sysfs interfaces to configure adapters

2018-08-16 Thread Cornelia Huck
On Wed, 15 Aug 2018 12:59:35 -0400
Tony Krowiak  wrote:

> On 08/15/2018 05:52 AM, Cornelia Huck wrote:
> > On Mon, 13 Aug 2018 17:48:07 -0400
> > Tony Krowiak  wrote:

> >> +/**
> >> + * unassign_adapter_store
> >> + *
> >> + * @dev: the matrix device
> >> + * @attr: a mediated matrix device attribute
> >> + * @buf: a buffer containing the adapter ID (APID) to be assigned
> >> + * @count: the number of bytes in @buf
> >> + *
> >> + * Parses the APID from @buf and unassigns it from the mediated matrix 
> >> device.
> >> + * The APID must be a valid value  
> > A valid value, but not necessarily assigned, right?  
> 
> You are correct, if the APID is not assigned, then the corresponding bit 
> will be
> cleared regardless. In a previous version, the functions failed if the 
> APID is
> not assigned, but a colleague removed that check. I guess it makes sense 
> given
> it really does not hurt anything to ask to unassign an APID that isn't 
> assigned
> to begin with. Would you prefer I update the comment, or do you feel the 
> user
> should be made aware of an attempt to unassign an APID that is not assigned?

I think the code is fine; updating the comment would be good.


Re: [PATCH v9 10/22] s390: vfio-ap: sysfs interfaces to configure adapters

2018-08-16 Thread Cornelia Huck
On Wed, 15 Aug 2018 12:59:35 -0400
Tony Krowiak  wrote:

> On 08/15/2018 05:52 AM, Cornelia Huck wrote:
> > On Mon, 13 Aug 2018 17:48:07 -0400
> > Tony Krowiak  wrote:

> >> +/**
> >> + * unassign_adapter_store
> >> + *
> >> + * @dev: the matrix device
> >> + * @attr: a mediated matrix device attribute
> >> + * @buf: a buffer containing the adapter ID (APID) to be assigned
> >> + * @count: the number of bytes in @buf
> >> + *
> >> + * Parses the APID from @buf and unassigns it from the mediated matrix 
> >> device.
> >> + * The APID must be a valid value  
> > A valid value, but not necessarily assigned, right?  
> 
> You are correct, if the APID is not assigned, then the corresponding bit 
> will be
> cleared regardless. In a previous version, the functions failed if the 
> APID is
> not assigned, but a colleague removed that check. I guess it makes sense 
> given
> it really does not hurt anything to ask to unassign an APID that isn't 
> assigned
> to begin with. Would you prefer I update the comment, or do you feel the 
> user
> should be made aware of an attempt to unassign an APID that is not assigned?

I think the code is fine; updating the comment would be good.


Re: [PATCH v9 10/22] s390: vfio-ap: sysfs interfaces to configure adapters

2018-08-15 Thread Tony Krowiak

On 08/15/2018 05:52 AM, Cornelia Huck wrote:

On Mon, 13 Aug 2018 17:48:07 -0400
Tony Krowiak  wrote:


+/**
+ * assign_adapter_store
+ *
+ * @dev: the matrix device
+ * @attr: a mediated matrix device attribute
+ * @buf: a buffer containing the adapter ID (APID) to be assigned
+ * @count: the number of bytes in @buf
+ *
+ * Parses the APID from @buf and assigns it to the mediated matrix device.
+ *
+ * Returns the number of bytes processed if the APID is valid; otherwise 
returns
+ * an error.
+ */
+static ssize_t assign_adapter_store(struct device *dev,
+   struct device_attribute *attr,
+   const char *buf, size_t count)
+{
+   int ret = 0;

You don't need to initialize this to 0, as kstrtoul will set it in any
case.


Right you are! Will change it.




+   unsigned long apid;
+   struct mdev_device *mdev = mdev_from_dev(dev);
+   struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);
+   unsigned long max_apid = matrix_mdev->matrix.apm_max;
+
+   ret = kstrtoul(buf, 0, );
+   if (ret)
+   return ret;
+   if (apid > max_apid)
+   return -EINVAL;
+
+   /* Set the bit in the AP mask (APM) corresponding to the AP adapter
+* number (APID). The bits in the mask, from most significant to least
+* significant bit, correspond to APIDs 0-255.
+*/
+   mutex_lock(_dev.lock);
+
+   ret = vfio_ap_mdev_verify_queues_reserved_for_apid(matrix_mdev, apid);

That function name really is a mouthful :) I don't have any better
suggestions, though.


It is, but I think it describes exactly what the function does.




+   if (ret)
+   goto done;
+
+   set_bit_inv(apid, matrix_mdev->matrix.apm);
+
+   ret = vfio_ap_mdev_verify_no_sharing(matrix_mdev);
+   if (ret)
+   goto share_err;
+
+   ret = count;
+   goto done;
+
+share_err:
+   clear_bit_inv(apid, matrix_mdev->matrix.apm);
+done:
+   mutex_unlock(_dev.lock);
+
+   return ret;
+}
+static DEVICE_ATTR_WO(assign_adapter);
+
+/**
+ * unassign_adapter_store
+ *
+ * @dev: the matrix device
+ * @attr: a mediated matrix device attribute
+ * @buf: a buffer containing the adapter ID (APID) to be assigned
+ * @count: the number of bytes in @buf
+ *
+ * Parses the APID from @buf and unassigns it from the mediated matrix device.
+ * The APID must be a valid value

A valid value, but not necessarily assigned, right?


You are correct, if the APID is not assigned, then the corresponding bit 
will be
cleared regardless. In a previous version, the functions failed if the 
APID is
not assigned, but a colleague removed that check. I guess it makes sense 
given
it really does not hurt anything to ask to unassign an APID that isn't 
assigned
to begin with. Would you prefer I update the comment, or do you feel the 
user

should be made aware of an attempt to unassign an APID that is not assigned?




+ *
+ * Returns the number of bytes processed if the APID is valid; otherwise 
returns
+ * an error.
+ */
+static ssize_t unassign_adapter_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+   int ret;
+   unsigned long apid;
+   struct mdev_device *mdev = mdev_from_dev(dev);
+   struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);
+
+   ret = kstrtoul(buf, 0, );
+   if (ret)
+   return ret;
+
+   if (apid > matrix_mdev->matrix.apm_max)
+   return -EINVAL;
+
+   mutex_lock(_dev.lock);
+   clear_bit_inv((unsigned long)apid, matrix_mdev->matrix.apm);
+   mutex_unlock(_dev.lock);
+
+   return count;
+}
+DEVICE_ATTR_WO(unassign_adapter);

In general, looks good to me.


That is good news indeed.







Re: [PATCH v9 10/22] s390: vfio-ap: sysfs interfaces to configure adapters

2018-08-15 Thread Tony Krowiak

On 08/15/2018 05:52 AM, Cornelia Huck wrote:

On Mon, 13 Aug 2018 17:48:07 -0400
Tony Krowiak  wrote:


+/**
+ * assign_adapter_store
+ *
+ * @dev: the matrix device
+ * @attr: a mediated matrix device attribute
+ * @buf: a buffer containing the adapter ID (APID) to be assigned
+ * @count: the number of bytes in @buf
+ *
+ * Parses the APID from @buf and assigns it to the mediated matrix device.
+ *
+ * Returns the number of bytes processed if the APID is valid; otherwise 
returns
+ * an error.
+ */
+static ssize_t assign_adapter_store(struct device *dev,
+   struct device_attribute *attr,
+   const char *buf, size_t count)
+{
+   int ret = 0;

You don't need to initialize this to 0, as kstrtoul will set it in any
case.


Right you are! Will change it.




+   unsigned long apid;
+   struct mdev_device *mdev = mdev_from_dev(dev);
+   struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);
+   unsigned long max_apid = matrix_mdev->matrix.apm_max;
+
+   ret = kstrtoul(buf, 0, );
+   if (ret)
+   return ret;
+   if (apid > max_apid)
+   return -EINVAL;
+
+   /* Set the bit in the AP mask (APM) corresponding to the AP adapter
+* number (APID). The bits in the mask, from most significant to least
+* significant bit, correspond to APIDs 0-255.
+*/
+   mutex_lock(_dev.lock);
+
+   ret = vfio_ap_mdev_verify_queues_reserved_for_apid(matrix_mdev, apid);

That function name really is a mouthful :) I don't have any better
suggestions, though.


It is, but I think it describes exactly what the function does.




+   if (ret)
+   goto done;
+
+   set_bit_inv(apid, matrix_mdev->matrix.apm);
+
+   ret = vfio_ap_mdev_verify_no_sharing(matrix_mdev);
+   if (ret)
+   goto share_err;
+
+   ret = count;
+   goto done;
+
+share_err:
+   clear_bit_inv(apid, matrix_mdev->matrix.apm);
+done:
+   mutex_unlock(_dev.lock);
+
+   return ret;
+}
+static DEVICE_ATTR_WO(assign_adapter);
+
+/**
+ * unassign_adapter_store
+ *
+ * @dev: the matrix device
+ * @attr: a mediated matrix device attribute
+ * @buf: a buffer containing the adapter ID (APID) to be assigned
+ * @count: the number of bytes in @buf
+ *
+ * Parses the APID from @buf and unassigns it from the mediated matrix device.
+ * The APID must be a valid value

A valid value, but not necessarily assigned, right?


You are correct, if the APID is not assigned, then the corresponding bit 
will be
cleared regardless. In a previous version, the functions failed if the 
APID is
not assigned, but a colleague removed that check. I guess it makes sense 
given
it really does not hurt anything to ask to unassign an APID that isn't 
assigned
to begin with. Would you prefer I update the comment, or do you feel the 
user

should be made aware of an attempt to unassign an APID that is not assigned?




+ *
+ * Returns the number of bytes processed if the APID is valid; otherwise 
returns
+ * an error.
+ */
+static ssize_t unassign_adapter_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+   int ret;
+   unsigned long apid;
+   struct mdev_device *mdev = mdev_from_dev(dev);
+   struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);
+
+   ret = kstrtoul(buf, 0, );
+   if (ret)
+   return ret;
+
+   if (apid > matrix_mdev->matrix.apm_max)
+   return -EINVAL;
+
+   mutex_lock(_dev.lock);
+   clear_bit_inv((unsigned long)apid, matrix_mdev->matrix.apm);
+   mutex_unlock(_dev.lock);
+
+   return count;
+}
+DEVICE_ATTR_WO(unassign_adapter);

In general, looks good to me.


That is good news indeed.







Re: [PATCH v9 10/22] s390: vfio-ap: sysfs interfaces to configure adapters

2018-08-15 Thread Cornelia Huck
On Mon, 13 Aug 2018 17:48:07 -0400
Tony Krowiak  wrote:

> +/**
> + * assign_adapter_store
> + *
> + * @dev: the matrix device
> + * @attr: a mediated matrix device attribute
> + * @buf: a buffer containing the adapter ID (APID) to be assigned
> + * @count: the number of bytes in @buf
> + *
> + * Parses the APID from @buf and assigns it to the mediated matrix device.
> + *
> + * Returns the number of bytes processed if the APID is valid; otherwise 
> returns
> + * an error.
> + */
> +static ssize_t assign_adapter_store(struct device *dev,
> + struct device_attribute *attr,
> + const char *buf, size_t count)
> +{
> + int ret = 0;

You don't need to initialize this to 0, as kstrtoul will set it in any
case.

> + unsigned long apid;
> + struct mdev_device *mdev = mdev_from_dev(dev);
> + struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);
> + unsigned long max_apid = matrix_mdev->matrix.apm_max;
> +
> + ret = kstrtoul(buf, 0, );
> + if (ret)
> + return ret;
> + if (apid > max_apid)
> + return -EINVAL;
> +
> + /* Set the bit in the AP mask (APM) corresponding to the AP adapter
> +  * number (APID). The bits in the mask, from most significant to least
> +  * significant bit, correspond to APIDs 0-255.
> +  */
> + mutex_lock(_dev.lock);
> +
> + ret = vfio_ap_mdev_verify_queues_reserved_for_apid(matrix_mdev, apid);

That function name really is a mouthful :) I don't have any better
suggestions, though.

> + if (ret)
> + goto done;
> +
> + set_bit_inv(apid, matrix_mdev->matrix.apm);
> +
> + ret = vfio_ap_mdev_verify_no_sharing(matrix_mdev);
> + if (ret)
> + goto share_err;
> +
> + ret = count;
> + goto done;
> +
> +share_err:
> + clear_bit_inv(apid, matrix_mdev->matrix.apm);
> +done:
> + mutex_unlock(_dev.lock);
> +
> + return ret;
> +}
> +static DEVICE_ATTR_WO(assign_adapter);
> +
> +/**
> + * unassign_adapter_store
> + *
> + * @dev: the matrix device
> + * @attr: a mediated matrix device attribute
> + * @buf: a buffer containing the adapter ID (APID) to be assigned
> + * @count: the number of bytes in @buf
> + *
> + * Parses the APID from @buf and unassigns it from the mediated matrix 
> device.
> + * The APID must be a valid value

A valid value, but not necessarily assigned, right?

> + *
> + * Returns the number of bytes processed if the APID is valid; otherwise 
> returns
> + * an error.
> + */
> +static ssize_t unassign_adapter_store(struct device *dev,
> +   struct device_attribute *attr,
> +   const char *buf, size_t count)
> +{
> + int ret;
> + unsigned long apid;
> + struct mdev_device *mdev = mdev_from_dev(dev);
> + struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);
> +
> + ret = kstrtoul(buf, 0, );
> + if (ret)
> + return ret;
> +
> + if (apid > matrix_mdev->matrix.apm_max)
> + return -EINVAL;
> +
> + mutex_lock(_dev.lock);
> + clear_bit_inv((unsigned long)apid, matrix_mdev->matrix.apm);
> + mutex_unlock(_dev.lock);
> +
> + return count;
> +}
> +DEVICE_ATTR_WO(unassign_adapter);

In general, looks good to me.


Re: [PATCH v9 10/22] s390: vfio-ap: sysfs interfaces to configure adapters

2018-08-15 Thread Cornelia Huck
On Mon, 13 Aug 2018 17:48:07 -0400
Tony Krowiak  wrote:

> +/**
> + * assign_adapter_store
> + *
> + * @dev: the matrix device
> + * @attr: a mediated matrix device attribute
> + * @buf: a buffer containing the adapter ID (APID) to be assigned
> + * @count: the number of bytes in @buf
> + *
> + * Parses the APID from @buf and assigns it to the mediated matrix device.
> + *
> + * Returns the number of bytes processed if the APID is valid; otherwise 
> returns
> + * an error.
> + */
> +static ssize_t assign_adapter_store(struct device *dev,
> + struct device_attribute *attr,
> + const char *buf, size_t count)
> +{
> + int ret = 0;

You don't need to initialize this to 0, as kstrtoul will set it in any
case.

> + unsigned long apid;
> + struct mdev_device *mdev = mdev_from_dev(dev);
> + struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);
> + unsigned long max_apid = matrix_mdev->matrix.apm_max;
> +
> + ret = kstrtoul(buf, 0, );
> + if (ret)
> + return ret;
> + if (apid > max_apid)
> + return -EINVAL;
> +
> + /* Set the bit in the AP mask (APM) corresponding to the AP adapter
> +  * number (APID). The bits in the mask, from most significant to least
> +  * significant bit, correspond to APIDs 0-255.
> +  */
> + mutex_lock(_dev.lock);
> +
> + ret = vfio_ap_mdev_verify_queues_reserved_for_apid(matrix_mdev, apid);

That function name really is a mouthful :) I don't have any better
suggestions, though.

> + if (ret)
> + goto done;
> +
> + set_bit_inv(apid, matrix_mdev->matrix.apm);
> +
> + ret = vfio_ap_mdev_verify_no_sharing(matrix_mdev);
> + if (ret)
> + goto share_err;
> +
> + ret = count;
> + goto done;
> +
> +share_err:
> + clear_bit_inv(apid, matrix_mdev->matrix.apm);
> +done:
> + mutex_unlock(_dev.lock);
> +
> + return ret;
> +}
> +static DEVICE_ATTR_WO(assign_adapter);
> +
> +/**
> + * unassign_adapter_store
> + *
> + * @dev: the matrix device
> + * @attr: a mediated matrix device attribute
> + * @buf: a buffer containing the adapter ID (APID) to be assigned
> + * @count: the number of bytes in @buf
> + *
> + * Parses the APID from @buf and unassigns it from the mediated matrix 
> device.
> + * The APID must be a valid value

A valid value, but not necessarily assigned, right?

> + *
> + * Returns the number of bytes processed if the APID is valid; otherwise 
> returns
> + * an error.
> + */
> +static ssize_t unassign_adapter_store(struct device *dev,
> +   struct device_attribute *attr,
> +   const char *buf, size_t count)
> +{
> + int ret;
> + unsigned long apid;
> + struct mdev_device *mdev = mdev_from_dev(dev);
> + struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);
> +
> + ret = kstrtoul(buf, 0, );
> + if (ret)
> + return ret;
> +
> + if (apid > matrix_mdev->matrix.apm_max)
> + return -EINVAL;
> +
> + mutex_lock(_dev.lock);
> + clear_bit_inv((unsigned long)apid, matrix_mdev->matrix.apm);
> + mutex_unlock(_dev.lock);
> +
> + return count;
> +}
> +DEVICE_ATTR_WO(unassign_adapter);

In general, looks good to me.