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  1. 19 7月, 2022 4 次提交
    • T
      s390/vfio-ap: introduce shadow APCB · 49b0109f
      由 Tony Krowiak 提交于 
      The APCB is a field within the CRYCB that provides the AP configuration
to a KVM guest. Let's introduce a shadow copy of the KVM guest's APCB and
maintain it for the lifespan of the guest.

The shadow APCB serves the following purposes:

1. The shadow APCB can be maintained even when the mediated device is not
   currently in use by a KVM guest. Since the mediated device's AP
   configuration is filtered to ensure that no AP queues are passed through
   to the KVM guest that are not bound to the vfio_ap device driver or
   available to the host, the mediated device's AP configuration may differ
   from the guest's. Having a shadow of a guest's APCB allows us to provide
   a sysfs interface to view the guest's APCB even if the mediated device
   is not currently passed through to a KVM guest. This can aid in
   problem determination when the guest is unexpectedly missing AP
   resources.

2. If filtering was done in-place for the real APCB, the guest could pick
   up a transient state. Doing the filtering on a shadow and transferring
   the AP configuration to the real APCB after the guest is started or when
   AP resources are assigned to or unassigned from the mediated device, or
   when the host configuration changes, the guest's AP configuration will
   never be in a transient state.
Signed-off-by: NTony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: NHalil Pasic <pasic@linux.ibm.com>
Signed-off-by: NAlexander Gordeev <agordeev@linux.ibm.com>
      49b0109f
    • T
      s390/vfio-ap: manage link between queue struct and matrix mdev · 11cb2419
      由 Tony Krowiak 提交于 
      Let's create links between each queue device bound to the vfio_ap device
driver and the matrix mdev to which the queue's APQN is assigned. The idea
is to facilitate efficient retrieval of the objects representing the queue
devices and matrix mdevs as well as to verify that a queue assigned to
a matrix mdev is bound to the driver.

The links will be created as follows:

 * When the queue device is probed, if its APQN is assigned to a matrix
   mdev, the structures representing the queue device and the matrix mdev
   will be linked.

 * When an adapter or domain is assigned to a matrix mdev, for each new
   APQN assigned that references a queue device bound to the vfio_ap
   device driver, the structures representing the queue device and the
   matrix mdev will be linked.

The links will be removed as follows:

 * When the queue device is removed, if its APQN is assigned to a matrix
   mdev, the link from the structure representing the matrix mdev to the
   structure representing the queue will be removed. Since the storage
   allocated for the vfio_ap_queue will be freed, there is no need to
   remove the link to the matrix_mdev to which the queue's APQN is
   assigned.

 * When an adapter or domain is unassigned from a matrix mdev, for each
   APQN unassigned that references a queue device bound to the vfio_ap
   device driver, the structures representing the queue device and the
   matrix mdev will be unlinked.

 * When an mdev is removed, the link from any queues assigned to the mdev
   to the mdev will be removed.
Signed-off-by: NTony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: NHalil Pasic <pasic@linux.ibm.com>
Signed-off-by: NAlexander Gordeev <agordeev@linux.ibm.com>
      11cb2419
    • T
      s390/vfio-ap: move probe and remove callbacks to vfio_ap_ops.c · 260f3ea1
      由 Tony Krowiak 提交于 
      Let's move the probe and remove callbacks into the vfio_ap_ops.c
file to keep all code related to managing queues in a single file. This
way, all functions related to queue management can be removed from the
vfio_ap_private.h header file defining the public interfaces for the
vfio_ap device driver.
Signed-off-by: NTony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: NHalil Pasic <pasic@linux.ibm.com>
Signed-off-by: NAlexander Gordeev <agordeev@linux.ibm.com>
      260f3ea1
    • T
      s390/vfio-ap: use new AP bus interface to search for queue devices · 034921cd
      由 Tony Krowiak 提交于 
      This patch refactors the vfio_ap device driver to use the AP bus's
ap_get_qdev() function to retrieve the vfio_ap_queue struct containing
information about a queue that is bound to the vfio_ap device driver.
The bus's ap_get_qdev() function retrieves the queue device from a
hashtable keyed by APQN. This is much more efficient than looping over
the list of devices attached to the AP bus by several orders of
magnitude.
Signed-off-by: NTony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: NHalil Pasic <pasic@linux.ibm.com>
Reviewed-by: NJason J. Herne <jjherne@linux.ibm.com>
Signed-off-by: NAlexander Gordeev <agordeev@linux.ibm.com>
      034921cd
  3. 24 5月, 2022 1 次提交
  5. 12 5月, 2022 2 次提交
  7. 21 4月, 2022 1 次提交
  9. 28 3月, 2022 1 次提交
    • T
      s390/vfio-ap: fix kernel doc and signature of group notifier functions · 71078220
      由 Tony Krowiak 提交于 
      The vfio_ap device driver registers a group notifier function to handle
the VFIO_GROUP_NOTIFY_SET_KVM event signalling the KVM pointer has been
set or cleared. There are two helper functions invoked by the handler
function: One called when the KVM pointer has been set, and the other
when the pointer is cleared.

The kernel doc for both of these functions contains a comment introduced
by commit 0cc00c8d (s390/vfio-ap: fix circular lockdep when
setting/clearing crypto masks) that is no longer valid. This patch removes
this comment from the kernel doc of each helper function.

Commit 86956e70 (s390/vfio-ap: replace open coded locks for
VFIO_GROUP_NOTIFY_SET_KVM notification) added a parameter to the signature
of the helper function that handles the event indicating the KVM pointer
has been cleared. The parameter added was the KVM pointer itself.
One of the function's primary purposes is to clear the KVM pointer from the
ap_matrix_mdev instance in which it is stored. Since the callers of this
function derive the KVM pointer passed to the function from the
ap_matrix_mdev object itself, it is completely unnecessary to include this
parameter in the function's signature since it can simply be retrieved from
the ap_matrix_mdev object which is also passed in. This patch removes the
KVM pointer from the function's signature.
Signed-off-by: NTony Krowiak <akrowiak@linux.ibm.com>
Signed-off-by: NVasily Gorbik <gor@linux.ibm.com>
      71078220
  11. 07 2月, 2022 2 次提交
    • T
      s390/vfio-ap: add s390dbf logging to the vfio_ap_irq_enable function · 783f0a3c
      由 Tony Krowiak 提交于 
      This patch adds s390dbf logging to the function that executes the
PQAP(AQIC) instruction on behalf of the guest to which the queue for which
interrupts are being enabled or disabled is attached.

Currently, the vfio_ap_irq_enable function sets status response code 06
(notification indicator byte address (nib) invalid) in the status word
when the vfio_pin_pages function - called to pin the page containing the
nib - returns an error or a different number of pages pinned than
requested.

Setting the response code returned to userspace without also logging a
message in the kernel makes it impossible to determine whether the response
was due to an error detected by the vfio_ap device driver or because the
response code was returned by the firmware in response to the PQAP(AQIC)
instruction.

In addition to logging a warning for the situation above, this patch adds
the following:

* A function to validate the nib address invoked prior to calling the
  vfio_pin_pages function. This allows for logging a message informing
  the reader of the reason the page containing the nib can not be pinned
  if the nib address is not valid. Response code 06 (invalid nib address)
  will be set in the status word returned to the guest from the
  instruction.

* Checks the return value from the kvm_s390_gisc_register and logs a
  message informing the reader of the failure. Status response code 08
  (invalid gisa) will be set in the status word returned to the guest from
  the PQAP(AQIC) instruction.

* Checks the status response code returned from execution of the PQAP(AQIC)
  instruction and if it indicates an error, logs a message informing the
  reader.
Signed-off-by: NTony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: NMatthew Rosato <mjrosato@linux.ibm.com>
Acked-by: NHeiko Carstens <hca@linux.ibm.com>
Signed-off-by: NVasily Gorbik <gor@linux.ibm.com>
      783f0a3c
    • T
      s390/vfio-ap: add s390dbf logging to the handle_pqap function · 68f554b7
      由 Tony Krowiak 提交于 
      This patch adds s390dbf logging to the function that handles interception
of the PQAP(AQIC) instruction. Several items of data are validated before
ultimately calling the functions that execute the PQAP(AQIC) instruction on
behalf of the guest to which the queue for which interrupts are being
enabled or disabled is attached.

Currently, the handle_pqap function sets status response code 01 (queue not
available) in the status word that is normally returned from the
PQAP(AQIC) instruction under the following conditions:

* Set when the function pointer to the handler is not set in the
  kvm_s390_crypto object (i.e., the PQAP hook is not registered).

* Set when the KVM pointer is not set in the ap_matrix_mdev object
  (i.e., the matrix mdev is not passed through to a guest).

* Set when the queue for which interrupts are being enabled or
  disabled is either not bound to the vfio_ap device driver or not assigned
  to the matrix mdev.

Setting the response code returned to userspace without also logging a
message in the kernel makes it impossible to determine whether the response
was due to an error detected by the vfio_ap device driver or because the
response code was returned by the firmware in response to the PQAP(AQIC)
instruction, so this patch logs a message to the s390dbf log for the
vfio_ap device driver for each of the situations described above.
Signed-off-by: NTony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: NMatthew Rosato <mjrosato@linux.ibm.com>
Acked-by: NHeiko Carstens <hca@linux.ibm.com>
Signed-off-by: NVasily Gorbik <gor@linux.ibm.com>
      68f554b7
  13. 26 10月, 2021 1 次提交
  15. 01 10月, 2021 1 次提交
  17. 25 9月, 2021 1 次提交
  19. 26 8月, 2021 1 次提交
  21. 25 8月, 2021 3 次提交
  23. 11 8月, 2021 1 次提交
  25. 21 6月, 2021 1 次提交
  27. 13 4月, 2021 2 次提交
  29. 05 4月, 2021 1 次提交
    • T
      s390/vfio-ap: fix circular lockdep when setting/clearing crypto masks · 0cc00c8d
      由 Tony Krowiak 提交于 
      This patch fixes a lockdep splat introduced by commit f21916ec
("s390/vfio-ap: clean up vfio_ap resources when KVM pointer invalidated").
The lockdep splat only occurs when starting a Secure Execution guest.
Crypto virtualization (vfio_ap) is not yet supported for SE guests;
however, in order to avoid this problem when support becomes available,
this fix is being provided.

The circular locking dependency was introduced when the setting of the
masks in the guest's APCB was executed while holding the matrix_dev->lock.
While the lock is definitely needed to protect the setting/unsetting of the
matrix_mdev->kvm pointer, it is not necessarily critical for setting the
masks; so, the matrix_dev->lock will be released while the masks are being
set or cleared.

Keep in mind, however, that another process that takes the matrix_dev->lock
can get control while the masks in the guest's APCB are being set or
cleared as a result of the driver being notified that the KVM pointer
has been set or unset. This could result in invalid access to the
matrix_mdev->kvm pointer by the intervening process. To avoid this
scenario, two new fields are being added to the ap_matrix_mdev struct:

struct ap_matrix_mdev {
	...
	bool kvm_busy;
	wait_queue_head_t wait_for_kvm;
   ...
};

The functions that handle notification that the KVM pointer value has
been set or cleared will set the kvm_busy flag to true until they are done
processing at which time they will set it to false and wake up the tasks on
the matrix_mdev->wait_for_kvm wait queue. Functions that require
access to matrix_mdev->kvm will sleep on the wait queue until they are
awakened at which time they can safely access the matrix_mdev->kvm
field.

Fixes: f21916ec ("s390/vfio-ap: clean up vfio_ap resources when KVM pointer invalidated")
Cc: stable@vger.kernel.org
Signed-off-by: NTony Krowiak <akrowiak@linux.ibm.com>
Signed-off-by: NHeiko Carstens <hca@linux.ibm.com>
      0cc00c8d
  31. 08 3月, 2021 1 次提交
  33. 27 1月, 2021 2 次提交
  35. 25 3月, 2020 1 次提交
  37. 05 9月, 2019 1 次提交
  39. 12 7月, 2019 1 次提交
  41. 02 7月, 2019 2 次提交
  43. 22 2月, 2019 1 次提交
  45. 08 10月, 2018 1 次提交
  47. 05 10月, 2018 1 次提交
  49. 28 9月, 2018 4 次提交
  51. 27 9月, 2018 2 次提交
    • T
      s390: vfio-ap: sysfs interface to view matrix mdev matrix · 81b2b4b7
      由 Tony Krowiak 提交于 
      Provides a sysfs interface to view the AP matrix configured for the
mediated matrix device.

The relevant sysfs structures are:

/sys/devices/vfio_ap/matrix/
...... [mdev_supported_types]
......... [vfio_ap-passthrough]
............ [devices]
...............[$uuid]
.................. matrix

To view the matrix configured for the mediated matrix device,
print the matrix file:

	cat matrix

Below are examples of the output from the above command:

Example 1: Adapters and domains assigned
	Assignments:
		Adapters 5 and 6
		Domains 4 and 71 (0x47)

	Output
		05.0004
		05.0047
		06.0004
	06.0047

Examples 2: Only adapters assigned
	Assignments:
		Adapters 5 and 6

	Output:
		05.
		06.

Examples 3: Only domains assigned
	Assignments:
		Domains 4 and 71 (0x47)

	Output:
		.0004
		.0047
Signed-off-by: NTony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: NHalil Pasic <pasic@linux.ibm.com>
Reviewed-by: NCornelia Huck <cohuck@redhat.com>
Tested-by: NMichael Mueller <mimu@linux.ibm.com>
Tested-by: NFarhan Ali <alifm@linux.ibm.com>
Tested-by: NPierre Morel <pmorel@linux.ibm.com>
Message-Id: <20180925231641.4954-10-akrowiak@linux.vnet.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
      81b2b4b7
    • T
      s390: vfio-ap: sysfs interfaces to configure control domains · 3b1eab7f
      由 Tony Krowiak 提交于 
      Provides the sysfs interfaces for:

1. Assigning AP control domains to the mediated matrix device

2. Unassigning AP control domains from a mediated matrix device

3. Displaying the control domains assigned to a mediated matrix
   device

The IDs of the AP control domains assigned to the mediated matrix
device are stored in an AP domain mask (ADM). The bits in the ADM,
from most significant to least significant bit, correspond to
AP domain numbers 0 to 255. On some systems, the maximum allowable
domain number may be less than 255 - depending upon the host's
AP configuration - and assignment may be rejected if the input
domain ID exceeds the limit.

When a control domain is assigned, the bit corresponding its domain
ID will be set in the ADM. Likewise, when a domain is unassigned,
the bit corresponding to its domain ID will be cleared in the ADM.

The relevant sysfs structures are:

/sys/devices/vfio_ap/matrix/
...... [mdev_supported_types]
......... [vfio_ap-passthrough]
............ [devices]
...............[$uuid]
.................. assign_control_domain
.................. unassign_control_domain

To assign a control domain to the $uuid mediated matrix device's
ADM, write its domain number to the assign_control_domain file.
To unassign a domain, write its domain number to the
unassign_control_domain file. The domain number is specified
using conventional semantics: If it begins with 0x the number
will be parsed as a hexadecimal (case insensitive) number;
if it begins with 0, it is parsed as an octal number;
otherwise, it will be parsed as a decimal number.

For example, to assign control domain 173 (0xad) to the mediated
matrix device $uuid:

	echo 173 > assign_control_domain

	or

	echo 0255 > assign_control_domain

	or

	echo 0xad > assign_control_domain

To unassign control domain 173 (0xad):

	echo 173 > unassign_control_domain

	or

	echo 0255 > unassign_control_domain

	or

	echo 0xad > unassign_control_domain

The assignment will be rejected if the APQI exceeds the maximum
value for an AP domain:
  * If the AP Extended Addressing (APXA) facility is installed,
    the max value is 255
  * Else the max value is 15
Signed-off-by: NTony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: NHalil Pasic <pasic@linux.ibm.com>
Reviewed-by: NCornelia Huck <cohuck@redhat.com>
Tested-by: NMichael Mueller <mimu@linux.ibm.com>
Tested-by: NFarhan Ali <alifm@linux.ibm.com>
Tested-by: NPierre Morel <pmorel@linux.ibm.com>
Message-Id: <20180925231641.4954-9-akrowiak@linux.vnet.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
      3b1eab7f