diff mbox series

[v10,14/16] s390/vfio-ap: handle AP bus scan completed notification

Message ID 20200821195616.13554-15-akrowiak@linux.ibm.com (mailing list archive)
State New, archived
Headers show
Series s390/vfio-ap: dynamic configuration support | expand

Commit Message

Anthony Krowiak Aug. 21, 2020, 7:56 p.m. UTC
Implements the driver callback invoked by the AP bus when the AP bus
scan has completed. Since this callback is invoked after binding the newly
added devices to their respective device drivers, the vfio_ap driver will
attempt to plug the adapters, domains and control domains into each guest
using a matrix mdev to which they are assigned. Keep in mind that an
adapter or domain can be plugged in only if each APQN with the APID of the
adapter or the APQI of the domain references a queue device bound to the
vfio_ap device driver. Consequently, not all newly added adapters and
domains will necessarily get hot plugged.

Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
---
 drivers/s390/crypto/vfio_ap_drv.c     |   1 +
 drivers/s390/crypto/vfio_ap_ops.c     | 110 +++++++++++++++++++++++++-
 drivers/s390/crypto/vfio_ap_private.h |   2 +
 3 files changed, 110 insertions(+), 3 deletions(-)

Comments

Halil Pasic Sept. 28, 2020, 2:11 a.m. UTC | #1
On Fri, 21 Aug 2020 15:56:14 -0400
Tony Krowiak <akrowiak@linux.ibm.com> wrote:

> Implements the driver callback invoked by the AP bus when the AP bus
> scan has completed. Since this callback is invoked after binding the newly
> added devices to their respective device drivers, the vfio_ap driver will
> attempt to plug the adapters, domains and control domains into each guest
> using a matrix mdev to which they are assigned. Keep in mind that an
> adapter or domain can be plugged in only if each APQN with the APID of the
> adapter or the APQI of the domain references a queue device bound to the
> vfio_ap device driver. Consequently, not all newly added adapters and
> domains will necessarily get hot plugged.
> 
> Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
> ---
>  drivers/s390/crypto/vfio_ap_drv.c     |   1 +
>  drivers/s390/crypto/vfio_ap_ops.c     | 110 +++++++++++++++++++++++++-
>  drivers/s390/crypto/vfio_ap_private.h |   2 +
>  3 files changed, 110 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/s390/crypto/vfio_ap_drv.c b/drivers/s390/crypto/vfio_ap_drv.c
> index ea0a7603e886..21bfae928be5 100644
> --- a/drivers/s390/crypto/vfio_ap_drv.c
> +++ b/drivers/s390/crypto/vfio_ap_drv.c
> @@ -180,6 +180,7 @@ static int __init vfio_ap_init(void)
>  	vfio_ap_drv.in_use = vfio_ap_mdev_resource_in_use;
>  	vfio_ap_drv.ids = ap_queue_ids;
>  	vfio_ap_drv.on_config_changed = vfio_ap_on_cfg_changed;
> +	vfio_ap_drv.on_scan_complete = vfio_ap_on_scan_complete;
>  
>  	ret = ap_driver_register(&vfio_ap_drv, THIS_MODULE, VFIO_AP_DRV_NAME);
>  	if (ret) {
> diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
> index e002d556abab..e6480f31a42b 100644
> --- a/drivers/s390/crypto/vfio_ap_ops.c
> +++ b/drivers/s390/crypto/vfio_ap_ops.c
> @@ -616,14 +616,13 @@ static bool vfio_ap_mdev_config_shadow_apcb(struct ap_matrix_mdev *matrix_mdev)
>  		 * CRYCB after filtering, then try filtering the APQIs.
>  		 */
>  		if (napm == 0) {
> -			naqm = vfio_ap_mdev_filter_matrix(matrix_mdev,
> -							  &shadow_apcb, false);
> -
>  			/*
>  			 * If there are no APQNs that can be assigned to the
>  			 * matrix mdev after filtering the APQIs, then no APQNs
>  			 * shall be assigned to the guest's CRYCB.
>  			 */
> +			naqm = vfio_ap_mdev_filter_matrix(matrix_mdev,
> +							  &shadow_apcb, false);

Here you just moved the thing around the comment, or?

>  			if (naqm == 0) {
>  				bitmap_clear(shadow_apcb.apm, 0, AP_DEVICES);
>  				bitmap_clear(shadow_apcb.aqm, 0, AP_DOMAINS);
> @@ -1758,6 +1757,16 @@ static bool vfio_ap_mdev_unassign_apids(struct ap_matrix_mdev *matrix_mdev,
>  	for_each_set_bit_inv(apid, apm_unassign, AP_DEVICES) {
>  		unassigned |= vfio_ap_mdev_unassign_guest_apid(matrix_mdev,
>  							       apid);
> +		/*
> +		 * If the APID is not assigned to the matrix mdev's shadow
> +		 * CRYCB, continue with the next APID.
> +		 */
> +		if (!test_bit_inv(apid, matrix_mdev->shadow_apcb.apm))
> +			continue;
> +
> +		/* Unassign the APID from the matrix mdev's shadow CRYCB */
> +		clear_bit_inv(apid, matrix_mdev->shadow_apcb.apm);
> +		unassigned = true;

I don't understand this at all. This patch is supposed to be about
assign and not unassign, or?

>  	}
>  
>  	return unassigned;
> @@ -1791,6 +1800,17 @@ static bool vfio_ap_mdev_unassign_apqis(struct ap_matrix_mdev *matrix_mdev,
>  	for_each_set_bit_inv(apqi, aqm_unassign, AP_DOMAINS) {
>  		unassigned |= vfio_ap_mdev_unassign_guest_apqi(matrix_mdev,
>  							       apqi);
> +
> +		/*
> +		 * If the APQI is not assigned to the matrix mdev's shadow
> +		 * CRYCB, continue with the next APQI
> +		 */
> +		if (!test_bit_inv(apqi, matrix_mdev->shadow_apcb.aqm))
> +			continue;
> +
> +		/* Unassign the APQI from the matrix mdev's shadow CRYCB */
> +		clear_bit_inv(apqi, matrix_mdev->shadow_apcb.aqm);
> +		unassigned = true;
>  	}
>  
>  	return unassigned;
> @@ -1852,3 +1872,87 @@ void vfio_ap_on_cfg_changed(struct ap_config_info *new_config_info,
>  	}
>  	mutex_unlock(&matrix_dev->lock);
>  }
> +
> +bool vfio_ap_mdev_assign_apids(struct ap_matrix_mdev *matrix_mdev,
> +			       unsigned long *apm_assign)
> +{
> +	unsigned long apid;
> +	bool assigned = false;
> +
> +	for_each_set_bit_inv(apid, apm_assign, AP_DEVICES)
> +		if (test_bit_inv(apid, matrix_mdev->matrix.apm))
> +			if (vfio_ap_mdev_assign_guest_apid(matrix_mdev, apid))
> +				assigned = true;
> +
> +	return assigned;
> +}
> +
> +bool vfio_ap_mdev_assign_apqis(struct ap_matrix_mdev *matrix_mdev,
> +			       unsigned long *aqm_assign)
> +{
> +	unsigned long apqi;
> +	bool assigned = false;
> +
> +	for_each_set_bit_inv(apqi, aqm_assign, AP_DOMAINS)
> +		if (test_bit_inv(apqi, matrix_mdev->matrix.aqm))
> +			if (vfio_ap_mdev_assign_guest_apqi(matrix_mdev, apqi))
> +				assigned = true;
> +
> +	return assigned;
> +}
> +
> +void vfio_ap_on_scan_complete(struct ap_config_info *new_config_info,
> +			      struct ap_config_info *old_config_info)
> +{
> +	struct ap_matrix_mdev *matrix_mdev;
> +	DECLARE_BITMAP(apm_assign, AP_DEVICES);
> +	DECLARE_BITMAP(aqm_assign, AP_DOMAINS);
> +	int ap_add, aq_add;
> +	bool assign;
> +	unsigned long *cur_apm, *cur_aqm, *prev_apm, *prev_aqm;
> +
> +	/*
> +	 * If we are not in the middle of a host configuration change scan it is
> +	 * likely that the vfio_ap driver was loaded mid-scan, so let's handle
> +	 * this scenario by calling the vfio_ap_on_cfg_changed function which
> +	 * gets called at the start of an AP bus scan when the host AP
> +	 * configuration has changed.
> +	 */
> +	if (!(matrix_dev->flags & AP_MATRIX_CFG_CHG))
> +		vfio_ap_on_cfg_changed(new_config_info, old_config_info);

Or we could just let the not-optimized variant handle it. Patch 15 has
to take care of single queues anyway, and 13 and 14 are about avoiding
having a bunch of updates to the CRYCB in short succession. But if we
just loaded the module in a middle of a config changing scan, then I
guess having a bunch of populated mdevs attached to guests is not very
likely.

> +
> +	cur_apm = (unsigned long *)matrix_dev->config_info.apm;
> +	cur_aqm = (unsigned long *)matrix_dev->config_info.aqm;
> +
> +	prev_apm = (unsigned long *)matrix_dev->config_info_prev.apm;
> +	prev_aqm = (unsigned long *)matrix_dev->config_info_prev.aqm;
> +
> +	ap_add = bitmap_andnot(apm_assign, cur_apm, prev_apm, AP_DEVICES);
> +	aq_add = bitmap_andnot(aqm_assign, cur_aqm, prev_aqm, AP_DOMAINS);
> +
> +	mutex_lock(&matrix_dev->lock);
> +	list_for_each_entry(matrix_mdev, &matrix_dev->mdev_list, node) {
> +		if (!vfio_ap_mdev_has_crycb(matrix_mdev))
> +			continue;
> +
> +		assign = false;
> +
> +		if (ap_add)
> +			if (bitmap_intersects(matrix_mdev->matrix.apm,
> +					      apm_assign, AP_DEVICES))
> +				assign |= vfio_ap_mdev_assign_apids(matrix_mdev,
> +								    apm_assign);
> +
> +		if (aq_add)
> +			if (bitmap_intersects(matrix_mdev->matrix.aqm,
> +					      aqm_assign, AP_DOMAINS))
> +				assign |= vfio_ap_mdev_assign_apqis(matrix_mdev,
> +								    aqm_assign);
> +
> +		if (assign)
> +			vfio_ap_mdev_commit_shadow_apcb(matrix_mdev);
> +	}
> +
> +	matrix_dev->flags &= ~AP_MATRIX_CFG_CHG;
> +	mutex_unlock(&matrix_dev->lock);
> +}


There may be a simpler and more concise way to accomplish this logic,
but at this point I don't want to think about that. We can do
refactoring any time we want. I'm more worried about the points I
addressed in reference to the previous patches.

Regards,
Halil

> diff --git a/drivers/s390/crypto/vfio_ap_private.h b/drivers/s390/crypto/vfio_ap_private.h
> index fc8629e28ad3..da1754fd4f66 100644
> --- a/drivers/s390/crypto/vfio_ap_private.h
> +++ b/drivers/s390/crypto/vfio_ap_private.h
> @@ -113,5 +113,7 @@ void vfio_ap_mdev_remove_queue(struct ap_queue *queue);
>  bool vfio_ap_mdev_resource_in_use(unsigned long *apm, unsigned long *aqm);
>  void vfio_ap_on_cfg_changed(struct ap_config_info *new_config_info,
>  			    struct ap_config_info *old_config_info);
> +void vfio_ap_on_scan_complete(struct ap_config_info *new_config_info,
> +			      struct ap_config_info *old_config_info);
>  
>  #endif /* _VFIO_AP_PRIVATE_H_ */
diff mbox series

Patch

diff --git a/drivers/s390/crypto/vfio_ap_drv.c b/drivers/s390/crypto/vfio_ap_drv.c
index ea0a7603e886..21bfae928be5 100644
--- a/drivers/s390/crypto/vfio_ap_drv.c
+++ b/drivers/s390/crypto/vfio_ap_drv.c
@@ -180,6 +180,7 @@  static int __init vfio_ap_init(void)
 	vfio_ap_drv.in_use = vfio_ap_mdev_resource_in_use;
 	vfio_ap_drv.ids = ap_queue_ids;
 	vfio_ap_drv.on_config_changed = vfio_ap_on_cfg_changed;
+	vfio_ap_drv.on_scan_complete = vfio_ap_on_scan_complete;
 
 	ret = ap_driver_register(&vfio_ap_drv, THIS_MODULE, VFIO_AP_DRV_NAME);
 	if (ret) {
diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
index e002d556abab..e6480f31a42b 100644
--- a/drivers/s390/crypto/vfio_ap_ops.c
+++ b/drivers/s390/crypto/vfio_ap_ops.c
@@ -616,14 +616,13 @@  static bool vfio_ap_mdev_config_shadow_apcb(struct ap_matrix_mdev *matrix_mdev)
 		 * CRYCB after filtering, then try filtering the APQIs.
 		 */
 		if (napm == 0) {
-			naqm = vfio_ap_mdev_filter_matrix(matrix_mdev,
-							  &shadow_apcb, false);
-
 			/*
 			 * If there are no APQNs that can be assigned to the
 			 * matrix mdev after filtering the APQIs, then no APQNs
 			 * shall be assigned to the guest's CRYCB.
 			 */
+			naqm = vfio_ap_mdev_filter_matrix(matrix_mdev,
+							  &shadow_apcb, false);
 			if (naqm == 0) {
 				bitmap_clear(shadow_apcb.apm, 0, AP_DEVICES);
 				bitmap_clear(shadow_apcb.aqm, 0, AP_DOMAINS);
@@ -1758,6 +1757,16 @@  static bool vfio_ap_mdev_unassign_apids(struct ap_matrix_mdev *matrix_mdev,
 	for_each_set_bit_inv(apid, apm_unassign, AP_DEVICES) {
 		unassigned |= vfio_ap_mdev_unassign_guest_apid(matrix_mdev,
 							       apid);
+		/*
+		 * If the APID is not assigned to the matrix mdev's shadow
+		 * CRYCB, continue with the next APID.
+		 */
+		if (!test_bit_inv(apid, matrix_mdev->shadow_apcb.apm))
+			continue;
+
+		/* Unassign the APID from the matrix mdev's shadow CRYCB */
+		clear_bit_inv(apid, matrix_mdev->shadow_apcb.apm);
+		unassigned = true;
 	}
 
 	return unassigned;
@@ -1791,6 +1800,17 @@  static bool vfio_ap_mdev_unassign_apqis(struct ap_matrix_mdev *matrix_mdev,
 	for_each_set_bit_inv(apqi, aqm_unassign, AP_DOMAINS) {
 		unassigned |= vfio_ap_mdev_unassign_guest_apqi(matrix_mdev,
 							       apqi);
+
+		/*
+		 * If the APQI is not assigned to the matrix mdev's shadow
+		 * CRYCB, continue with the next APQI
+		 */
+		if (!test_bit_inv(apqi, matrix_mdev->shadow_apcb.aqm))
+			continue;
+
+		/* Unassign the APQI from the matrix mdev's shadow CRYCB */
+		clear_bit_inv(apqi, matrix_mdev->shadow_apcb.aqm);
+		unassigned = true;
 	}
 
 	return unassigned;
@@ -1852,3 +1872,87 @@  void vfio_ap_on_cfg_changed(struct ap_config_info *new_config_info,
 	}
 	mutex_unlock(&matrix_dev->lock);
 }
+
+bool vfio_ap_mdev_assign_apids(struct ap_matrix_mdev *matrix_mdev,
+			       unsigned long *apm_assign)
+{
+	unsigned long apid;
+	bool assigned = false;
+
+	for_each_set_bit_inv(apid, apm_assign, AP_DEVICES)
+		if (test_bit_inv(apid, matrix_mdev->matrix.apm))
+			if (vfio_ap_mdev_assign_guest_apid(matrix_mdev, apid))
+				assigned = true;
+
+	return assigned;
+}
+
+bool vfio_ap_mdev_assign_apqis(struct ap_matrix_mdev *matrix_mdev,
+			       unsigned long *aqm_assign)
+{
+	unsigned long apqi;
+	bool assigned = false;
+
+	for_each_set_bit_inv(apqi, aqm_assign, AP_DOMAINS)
+		if (test_bit_inv(apqi, matrix_mdev->matrix.aqm))
+			if (vfio_ap_mdev_assign_guest_apqi(matrix_mdev, apqi))
+				assigned = true;
+
+	return assigned;
+}
+
+void vfio_ap_on_scan_complete(struct ap_config_info *new_config_info,
+			      struct ap_config_info *old_config_info)
+{
+	struct ap_matrix_mdev *matrix_mdev;
+	DECLARE_BITMAP(apm_assign, AP_DEVICES);
+	DECLARE_BITMAP(aqm_assign, AP_DOMAINS);
+	int ap_add, aq_add;
+	bool assign;
+	unsigned long *cur_apm, *cur_aqm, *prev_apm, *prev_aqm;
+
+	/*
+	 * If we are not in the middle of a host configuration change scan it is
+	 * likely that the vfio_ap driver was loaded mid-scan, so let's handle
+	 * this scenario by calling the vfio_ap_on_cfg_changed function which
+	 * gets called at the start of an AP bus scan when the host AP
+	 * configuration has changed.
+	 */
+	if (!(matrix_dev->flags & AP_MATRIX_CFG_CHG))
+		vfio_ap_on_cfg_changed(new_config_info, old_config_info);
+
+	cur_apm = (unsigned long *)matrix_dev->config_info.apm;
+	cur_aqm = (unsigned long *)matrix_dev->config_info.aqm;
+
+	prev_apm = (unsigned long *)matrix_dev->config_info_prev.apm;
+	prev_aqm = (unsigned long *)matrix_dev->config_info_prev.aqm;
+
+	ap_add = bitmap_andnot(apm_assign, cur_apm, prev_apm, AP_DEVICES);
+	aq_add = bitmap_andnot(aqm_assign, cur_aqm, prev_aqm, AP_DOMAINS);
+
+	mutex_lock(&matrix_dev->lock);
+	list_for_each_entry(matrix_mdev, &matrix_dev->mdev_list, node) {
+		if (!vfio_ap_mdev_has_crycb(matrix_mdev))
+			continue;
+
+		assign = false;
+
+		if (ap_add)
+			if (bitmap_intersects(matrix_mdev->matrix.apm,
+					      apm_assign, AP_DEVICES))
+				assign |= vfio_ap_mdev_assign_apids(matrix_mdev,
+								    apm_assign);
+
+		if (aq_add)
+			if (bitmap_intersects(matrix_mdev->matrix.aqm,
+					      aqm_assign, AP_DOMAINS))
+				assign |= vfio_ap_mdev_assign_apqis(matrix_mdev,
+								    aqm_assign);
+
+		if (assign)
+			vfio_ap_mdev_commit_shadow_apcb(matrix_mdev);
+	}
+
+	matrix_dev->flags &= ~AP_MATRIX_CFG_CHG;
+	mutex_unlock(&matrix_dev->lock);
+}
diff --git a/drivers/s390/crypto/vfio_ap_private.h b/drivers/s390/crypto/vfio_ap_private.h
index fc8629e28ad3..da1754fd4f66 100644
--- a/drivers/s390/crypto/vfio_ap_private.h
+++ b/drivers/s390/crypto/vfio_ap_private.h
@@ -113,5 +113,7 @@  void vfio_ap_mdev_remove_queue(struct ap_queue *queue);
 bool vfio_ap_mdev_resource_in_use(unsigned long *apm, unsigned long *aqm);
 void vfio_ap_on_cfg_changed(struct ap_config_info *new_config_info,
 			    struct ap_config_info *old_config_info);
+void vfio_ap_on_scan_complete(struct ap_config_info *new_config_info,
+			      struct ap_config_info *old_config_info);
 
 #endif /* _VFIO_AP_PRIVATE_H_ */