Commit 8fb456bc authored by Jason J. Herne's avatar Jason J. Herne Committed by Alexander Gordeev
Browse files

s390/vfio-ap: Add write support to sysfs attr ap_config 



Allow writing a complete set of masks to ap_config. Doing so will
cause the vfio-ap driver to replace the vfio-ap mediated device's
matrix masks with the given set of masks. If the given state cannot
be set, then no changes are made to the vfio-ap mediated device.

The format of the data written to ap_config is as follows:
{amask},{dmask},{cmask}\n

\n is a newline character.

amask, dmask, and cmask are masks identifying which adapters, domains,
and control domains should be assigned to the mediated device.

The format of a mask is as follows:
0xNN..NN

Where NN..NN is 64 hexadecimal characters representing a 256-bit value.
The leftmost (highest order) bit represents adapter/domain 0.

For an example set of masks that represent your mdev's current
configuration, simply cat ap_config.

This attribute is intended to be used by an mdevctl callout script
supporting the mdev type vfio_ap-passthrough to atomically update a
vfio-ap mediated device's state.

Signed-off-by: default avatar"Jason J. Herne" <jjherne@linux.ibm.com>
Reviewed-by: default avatarTony Krowiak <akrowiak@linux.ibm.com>
Tested-by: default avatarMatthew Rosato <mjrosato@linux.ibm.com>
Link: https://lore.kernel.org/r/20240415152555.13152-5-jjherne@linux.ibm.com


Signed-off-by: default avatarAlexander Gordeev <agordeev@linux.ibm.com>
parent f3e3a400

drivers/s390/crypto/vfio_ap_ops.c

+177 −13
Original line number Diff line number Diff line
@@ -1119,19 +1119,28 @@ static void vfio_ap_mdev_unlink_adapter(struct ap_matrix_mdev *matrix_mdev, 
	}

}



static void vfio_ap_mdev_hot_unplug_adapter(struct ap_matrix_mdev *matrix_mdev,

					    unsigned long apid)

static void vfio_ap_mdev_hot_unplug_adapters(struct ap_matrix_mdev *matrix_mdev,

					     unsigned long *apids)

{

	struct vfio_ap_queue *q, *tmpq;

	struct list_head qlist;

	unsigned long apid;

	bool apcb_update = false;



	INIT_LIST_HEAD(&qlist);



	for_each_set_bit_inv(apid, apids, AP_DEVICES) {

		vfio_ap_mdev_unlink_adapter(matrix_mdev, apid, &qlist);



		if (test_bit_inv(apid, matrix_mdev->shadow_apcb.apm)) {

			clear_bit_inv(apid, matrix_mdev->shadow_apcb.apm);

		vfio_ap_mdev_update_guest_apcb(matrix_mdev);

			apcb_update = true;

		}

	}



	/* Only update apcb if needed to avoid impacting guest */

	if (apcb_update)

		vfio_ap_mdev_update_guest_apcb(matrix_mdev);



	vfio_ap_mdev_reset_qlist(&qlist);
@@ -1141,6 +1150,16 @@ static void vfio_ap_mdev_hot_unplug_adapter(struct ap_matrix_mdev *matrix_mdev, 
	}

}



static void vfio_ap_mdev_hot_unplug_adapter(struct ap_matrix_mdev *matrix_mdev,

					    unsigned long apid)

{

	DECLARE_BITMAP(apids, AP_DEVICES);



	bitmap_zero(apids, AP_DEVICES);

	set_bit_inv(apid, apids);

	vfio_ap_mdev_hot_unplug_adapters(matrix_mdev, apids);

}



/**

 * unassign_adapter_store - parses the APID from @buf and clears the

 * corresponding bit in the mediated matrix device's APM
@@ -1301,19 +1320,28 @@ static void vfio_ap_mdev_unlink_domain(struct ap_matrix_mdev *matrix_mdev, 
	}

}



static void vfio_ap_mdev_hot_unplug_domain(struct ap_matrix_mdev *matrix_mdev,

					   unsigned long apqi)

static void vfio_ap_mdev_hot_unplug_domains(struct ap_matrix_mdev *matrix_mdev,

					    unsigned long *apqis)

{

	struct vfio_ap_queue *q, *tmpq;

	struct list_head qlist;

	unsigned long apqi;

	bool apcb_update = false;



	INIT_LIST_HEAD(&qlist);



	for_each_set_bit_inv(apqi, apqis, AP_DOMAINS) {

		vfio_ap_mdev_unlink_domain(matrix_mdev, apqi, &qlist);



		if (test_bit_inv(apqi, matrix_mdev->shadow_apcb.aqm)) {

			clear_bit_inv(apqi, matrix_mdev->shadow_apcb.aqm);

		vfio_ap_mdev_update_guest_apcb(matrix_mdev);

			apcb_update = true;

		}

	}



	/* Only update apcb if needed to avoid impacting guest */

	if (apcb_update)

		vfio_ap_mdev_update_guest_apcb(matrix_mdev);



	vfio_ap_mdev_reset_qlist(&qlist);
@@ -1323,6 +1351,16 @@ static void vfio_ap_mdev_hot_unplug_domain(struct ap_matrix_mdev *matrix_mdev, 
	}

}



static void vfio_ap_mdev_hot_unplug_domain(struct ap_matrix_mdev *matrix_mdev,

					   unsigned long apqi)

{

	DECLARE_BITMAP(apqis, AP_DOMAINS);



	bitmap_zero(apqis, AP_DEVICES);

	set_bit_inv(apqi, apqis);

	vfio_ap_mdev_hot_unplug_domains(matrix_mdev, apqis);

}



/**

 * unassign_domain_store - parses the APQI from @buf and clears the

 * corresponding bit in the mediated matrix device's AQM
@@ -1590,10 +1628,136 @@ static ssize_t ap_config_show(struct device *dev, struct device_attribute *attr, 
	return idx;

}



/* Number of characters needed for a complete hex mask representing the bits in ..  */

#define AP_DEVICES_STRLEN	(AP_DEVICES / 4 + 3)

#define AP_DOMAINS_STRLEN	(AP_DOMAINS / 4 + 3)

#define AP_CONFIG_STRLEN	(AP_DEVICES_STRLEN + 2 * AP_DOMAINS_STRLEN)



static int parse_bitmap(char **strbufptr, unsigned long *bitmap, int nbits)

{

	char *curmask;



	curmask = strsep(strbufptr, ",\n");

	if (!curmask)

		return -EINVAL;



	bitmap_clear(bitmap, 0, nbits);

	return ap_hex2bitmap(curmask, bitmap, nbits);

}



static int ap_matrix_overflow_check(struct ap_matrix_mdev *matrix_mdev)

{

	unsigned long bit;



	for_each_set_bit_inv(bit, matrix_mdev->matrix.apm, AP_DEVICES) {

		if (bit > matrix_mdev->matrix.apm_max)

			return -ENODEV;

	}



	for_each_set_bit_inv(bit, matrix_mdev->matrix.aqm, AP_DOMAINS) {

		if (bit > matrix_mdev->matrix.aqm_max)

			return -ENODEV;

	}



	for_each_set_bit_inv(bit, matrix_mdev->matrix.adm, AP_DOMAINS) {

		if (bit > matrix_mdev->matrix.adm_max)

			return -ENODEV;

	}



	return 0;

}



static void ap_matrix_copy(struct ap_matrix *dst, struct ap_matrix *src)

{

	/* This check works around false positive gcc -Wstringop-overread */

	if (!src)

		return;



	bitmap_copy(dst->apm, src->apm, AP_DEVICES);

	bitmap_copy(dst->aqm, src->aqm, AP_DOMAINS);

	bitmap_copy(dst->adm, src->adm, AP_DOMAINS);

}



static ssize_t ap_config_store(struct device *dev, struct device_attribute *attr,

			       const char *buf, size_t count)

{

	return count;

	struct ap_matrix_mdev *matrix_mdev = dev_get_drvdata(dev);

	struct ap_matrix m_new, m_old, m_added, m_removed;

	DECLARE_BITMAP(apm_filtered, AP_DEVICES);

	unsigned long newbit;

	char *newbuf, *rest;

	int rc = count;

	bool do_update;



	newbuf = kstrndup(buf, AP_CONFIG_STRLEN, GFP_KERNEL);

	if (!newbuf)

		return -ENOMEM;

	rest = newbuf;



	mutex_lock(&ap_perms_mutex);

	get_update_locks_for_mdev(matrix_mdev);



	/* Save old state */

	ap_matrix_copy(&m_old, &matrix_mdev->matrix);

	if (parse_bitmap(&rest, m_new.apm, AP_DEVICES) ||

	    parse_bitmap(&rest, m_new.aqm, AP_DOMAINS) ||

	    parse_bitmap(&rest, m_new.adm, AP_DOMAINS)) {

		rc = -EINVAL;

		goto out;

	}



	bitmap_andnot(m_removed.apm, m_old.apm, m_new.apm, AP_DEVICES);

	bitmap_andnot(m_removed.aqm, m_old.aqm, m_new.aqm, AP_DOMAINS);

	bitmap_andnot(m_added.apm, m_new.apm, m_old.apm, AP_DEVICES);

	bitmap_andnot(m_added.aqm, m_new.aqm, m_old.aqm, AP_DOMAINS);



	/* Need new bitmaps in matrix_mdev for validation */

	ap_matrix_copy(&matrix_mdev->matrix, &m_new);



	/* Ensure new state is valid, else undo new state */

	rc = vfio_ap_mdev_validate_masks(matrix_mdev);

	if (rc) {

		ap_matrix_copy(&matrix_mdev->matrix, &m_old);

		goto out;

	}

	rc = ap_matrix_overflow_check(matrix_mdev);

	if (rc) {

		ap_matrix_copy(&matrix_mdev->matrix, &m_old);

		goto out;

	}

	rc = count;



	/* Need old bitmaps in matrix_mdev for unplug/unlink */

	ap_matrix_copy(&matrix_mdev->matrix, &m_old);



	/* Unlink removed adapters/domains */

	vfio_ap_mdev_hot_unplug_adapters(matrix_mdev, m_removed.apm);

	vfio_ap_mdev_hot_unplug_domains(matrix_mdev, m_removed.aqm);



	/* Need new bitmaps in matrix_mdev for linking new adapters/domains */

	ap_matrix_copy(&matrix_mdev->matrix, &m_new);



	/* Link newly added adapters */

	for_each_set_bit_inv(newbit, m_added.apm, AP_DEVICES)

		vfio_ap_mdev_link_adapter(matrix_mdev, newbit);



	for_each_set_bit_inv(newbit, m_added.aqm, AP_DOMAINS)

		vfio_ap_mdev_link_domain(matrix_mdev, newbit);



	/* filter resources not bound to vfio-ap */

	do_update = vfio_ap_mdev_filter_matrix(matrix_mdev, apm_filtered);

	do_update |= vfio_ap_mdev_filter_cdoms(matrix_mdev);



	/* Apply changes to shadow apbc if things changed */

	if (do_update) {

		vfio_ap_mdev_update_guest_apcb(matrix_mdev);

		reset_queues_for_apids(matrix_mdev, apm_filtered);

	}

out:

	release_update_locks_for_mdev(matrix_mdev);

	mutex_unlock(&ap_perms_mutex);

	kfree(newbuf);

	return rc;

}

static DEVICE_ATTR_RW(ap_config);

drivers/s390/crypto/vfio_ap_private.h

+3 −3
Original line number Diff line number Diff line
@@ -75,11 +75,11 @@ extern struct ap_matrix_dev *matrix_dev; 
 */

struct ap_matrix {

	unsigned long apm_max;

	DECLARE_BITMAP(apm, 256);

	DECLARE_BITMAP(apm, AP_DEVICES);

	unsigned long aqm_max;

	DECLARE_BITMAP(aqm, 256);

	DECLARE_BITMAP(aqm, AP_DOMAINS);

	unsigned long adm_max;

	DECLARE_BITMAP(adm, 256);

	DECLARE_BITMAP(adm, AP_DOMAINS);

};



/**