Most of the callers of vfio_pin_pages() want "struct page *" and the
low-level mm code to pin pages returns a list of "struct page *" too.
So there's no gain in converting "struct page *" to PFN in between.

Replace the output parameter "phys_pfn" list with a "pages" list, to
simplify callers. This also allows us to replace the vfio_iommu_type1
implementation with a more efficient one.

And drop the pfn_valid check in the gvt code, as there is no need to
do such a check at a page-backed struct page pointer.

For now, also update vfio_iommu_type1 to fit this new parameter too.
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NKirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: NJason Gunthorpe <jgg@nvidia.com>
Reviewed-by: NKevin Tian <kevin.tian@intel.com>
Acked-by: NEric Farman <farman@linux.ibm.com>
Tested-by: NTerrence Xu <terrence.xu@intel.com>
Tested-by: NEric Farman <farman@linux.ibm.com>
Signed-off-by: NNicolin Chen <nicolinc@nvidia.com>
Link: https://lore.kernel.org/r/20220723020256.30081-11-nicolinc@nvidia.comSigned-off-by: NAlex Williamson <alex.williamson@redhat.com>

The vfio_ap_ops code maintains both nib address and its PFN, which
is redundant, merely because vfio_pin/unpin_pages API wanted pfn.
Since vfio_pin/unpin_pages() now accept "iova", change "saved_pfn"
to "saved_iova" and remove pfn in the vfio_ap_validate_nib().
Reviewed-by: NJason Gunthorpe <jgg@nvidia.com>
Reviewed-by: NTony Krowiak <akrowiak@linux.ibm.com>
Tested-by: NEric Farman <farman@linux.ibm.com>
Signed-off-by: NNicolin Chen <nicolinc@nvidia.com>
Link: https://lore.kernel.org/r/20220723020256.30081-7-nicolinc@nvidia.comSigned-off-by: NAlex Williamson <alex.williamson@redhat.com>

The vfio_pin/unpin_pages() so far accepted arrays of PFNs of user IOVA.
Among all three callers, there was only one caller possibly passing in
a non-contiguous PFN list, which is now ensured to have contiguous PFN
inputs too.

Pass in the starting address with "iova" alone to simplify things, so
callers no longer need to maintain a PFN list or to pin/unpin one page
at a time. This also allows VFIO to use more efficient implementations
of pin/unpin_pages.

For now, also update vfio_iommu_type1 to fit this new parameter too,
while keeping its input intact (being user_iova) since we don't want
to spend too much effort swapping its parameters and local variables
at that level.
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NKirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: NJason Gunthorpe <jgg@nvidia.com>
Reviewed-by: NKevin Tian <kevin.tian@intel.com>
Reviewed-by: NTony Krowiak <akrowiak@linux.ibm.com>
Acked-by: NEric Farman <farman@linux.ibm.com>
Tested-by: NTerrence Xu <terrence.xu@intel.com>
Tested-by: NEric Farman <farman@linux.ibm.com>
Signed-off-by: NNicolin Chen <nicolinc@nvidia.com>
Link: https://lore.kernel.org/r/20220723020256.30081-6-nicolinc@nvidia.comSigned-off-by: NAlex Williamson <alex.williamson@redhat.com>

The ap_aqic() is called by vfio_ap_irq_enable() where it passes in a
virt value that's casted from a physical address "h_nib". Inside the
ap_aqic(), it does virt_to_phys() again.

Since ap_aqic() needs a physical address, let's just pass in a pa of
ind directly. So change the "ind" to "pa_ind".
Reviewed-by: NHarald Freudenberger <freude@linux.ibm.com>
Reviewed-by: NJason Gunthorpe <jgg@nvidia.com>
Tested-by: NEric Farman <farman@linux.ibm.com>
Signed-off-by: NNicolin Chen <nicolinc@nvidia.com>
Link: https://lore.kernel.org/r/20220723020256.30081-4-nicolinc@nvidia.comSigned-off-by: NAlex Williamson <alex.williamson@redhat.com>

Instead of having drivers register the notifier with explicit code just
have them provide a dma_unmap callback op in their driver ops and rely on
the core code to wire it up.
Suggested-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NKevin Tian <kevin.tian@intel.com>
Reviewed-by: NTony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: NEric Farman <farman@linux.ibm.com>
Reviewed-by: NZhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: NJason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/1-v4-681e038e30fd+78-vfio_unmap_notif_jgg@nvidia.comSigned-off-by: NAlex Williamson <alex.williamson@redhat.com>

Rather than relying on a notifier for associating the KVM with
the group, let's assume that the association has already been
made prior to device_open.  The first time a device is opened
associate the group KVM with the device.

This fixes a user-triggerable oops in GVT.
Reviewed-by: NTony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: NKevin Tian <kevin.tian@intel.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJason Gunthorpe <jgg@nvidia.com>
Signed-off-by: NMatthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: NJason Gunthorpe <jgg@nvidia.com>
Acked-by: NZhi Wang <zhi.a.wang@intel.com>
Link: https://lore.kernel.org/r/20220519183311.582380-2-mjrosato@linux.ibm.comSigned-off-by: NAlex Williamson <alex.williamson@redhat.com>

Every caller has a readily available vfio_device pointer, use that instead
of passing in a generic struct device. The struct vfio_device already
contains the group we need so this avoids complexity, extra refcountings,
and a confusing lifecycle model.
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Acked-by: NEric Farman <farman@linux.ibm.com>
Reviewed-by: NJason J. Herne <jjherne@linux.ibm.com>
Reviewed-by: NTony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: NKevin Tian <kevin.tian@intel.com>
Signed-off-by: NJason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/3-v4-8045e76bf00b+13d-vfio_mdev_no_group_jgg@nvidia.comSigned-off-by: NAlex Williamson <alex.williamson@redhat.com>

All callers have a struct vfio_device trivially available, pass it in
directly and avoid calling the expensive vfio_group_get_from_dev().
Acked-by: NEric Farman <farman@linux.ibm.com>
Reviewed-by: NJason J. Herne <jjherne@linux.ibm.com>
Reviewed-by: NTony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: NKevin Tian <kevin.tian@intel.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/1-v4-8045e76bf00b+13d-vfio_mdev_no_group_jgg@nvidia.comSigned-off-by: NAlex Williamson <alex.williamson@redhat.com>

The last useful member in this struct is the supported_type_groups, move
it to the mdev_driver and delete mdev_parent_ops.

Replace it with mdev_driver as an argument to mdev_register_device()
Signed-off-by: NJason Gunthorpe <jgg@nvidia.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NZhi Wang <zhi.a.wang@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20220411141403.86980-33-hch@lst.deReviewed-by: NKirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: NZhi Wang <zhi.a.wang@intel.com>

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>

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>

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>

Fixes the kernel-doc warnings in the following source files:

* drivers/s390/crypto/vfio_ap_private.h
* drivers/s390/crypto/vfio_ap_drv.c
* drivers/s390/crypto/vfio_ap_ops.c
Signed-off-by: NTony Krowiak <akrowiak@linux.ibm.com>
Signed-off-by: NVasily Gorbik <gor@linux.ibm.com>

Reuse the logic in vfio_noiommu_group_alloc to allocate a fake
single-device iommu group for mediated devices by factoring out a common
function, and replacing the noiommu boolean field in struct vfio_group
with an enum to distinguish the three different kinds of groups.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NKevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/20210924155705.4258-8-hch@lst.deSigned-off-by: NAlex Williamson <alex.williamson@redhat.com>

Without this call an xarray entry is leaked when the vfio_ap device is
unprobed. It was missed when the below patch was rebased across the
dev_set patch. Keep the remove function in the same order as the error
unwind in probe.

Fixes: eb0feefd ("vfio/ap_ops: Convert to use vfio_register_group_dev()")
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Tested-by: NTony Krowiak <akrowiak@linux.ibm.com>
Signed-off-by: NJason Gunthorpe <jgg@nvidia.com>
Reviewed-by: NTony Krowiak <akrowiak@linux.ibm.com>
Link: https://lore.kernel.org/r/0-v3-f9b50340cdbb+e4-ap_uninit_jgg@nvidia.comSigned-off-by: NAlex Williamson <alex.williamson@redhat.com>

This is straightforward conversion, the ap_matrix_mdev is actually serving
as the vfio_device and we can replace all the mdev_get_drvdata()'s with a
simple container_of() or a dev_get_drvdata() for sysfs paths.

Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Cornelia Huck <cohuck@redhat.com>
Cc: kvm@vger.kernel.org
Cc: Christoph Hellwig <hch@lst.de>
Reviewed-by: NTony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/0-v4-0203a4ab0596+f7-vfio_ap_jgg@nvidia.comSigned-off-by: NAlex Williamson <alex.williamson@redhat.com>

The 0day bot reported some kernel-doc warnings in this file so clean up
all of the kernel-doc and use proper kernel-doc formatting.
There are no more kernel-doc errors or warnings reported in this file.
Signed-off-by: NRandy Dunlap <rdunlap@infradead.org>
Reported-by: Nkernel test robot <lkp@intel.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Tony Krowiak <akrowiak@linux.ibm.com>
Cc: Halil Pasic <pasic@linux.ibm.com>
Cc: Jason Herne <jjherne@linux.ibm.com>
Cc: Harald Freudenberger <freude@linux.ibm.com>
Cc: linux-s390@vger.kernel.org
Reviewed-by: NTony Krowiak <akrowiak@linux.ibm.com>
Link: https://lore.kernel.org/r/20210806050149.9614-1-rdunlap@infradead.orgSigned-off-by: NHeiko Carstens <hca@linux.ibm.com>

It was pointed out during an unrelated patch review that locks should not
be open coded - i.e., writing the algorithm of a standard lock in a
function instead of using a lock from the standard library. The setting and
testing of a busy flag and sleeping on a wait_event is the same thing
a lock does. The open coded locks are invisible to lockdep, so potential
locking problems are not detected.

This patch removes the open coded locks used during
VFIO_GROUP_NOTIFY_SET_KVM notification. The busy flag
and wait queue were introduced to resolve a possible circular locking
dependency reported by lockdep when starting a secure execution guest
configured with AP adapters and domains. Reversing the order in which
the kvm->lock mutex and matrix_dev->lock mutex are locked resolves the
issue reported by lockdep, thus enabling the removal of the open coded
locks.
Signed-off-by: NTony Krowiak <akrowiak@linux.ibm.com>
Acked-by: NHalil Pasic <pasic@linux.ibm.com>
Link: https://lore.kernel.org/r/20210823212047.1476436-3-akrowiak@linux.ibm.comSigned-off-by: NAlex Williamson <alex.williamson@redhat.com>

The function pointer to the interception handler for the PQAP instruction
can get changed during the interception process. Let's add a
semaphore to struct kvm_s390_crypto to control read/write access to the
function pointer contained therein.

The semaphore must be locked for write access by the vfio_ap device driver
when notified that the KVM pointer has been set or cleared. It must be
locked for read access by the interception framework when the PQAP
instruction is intercepted.
Signed-off-by: NTony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: NJason Gunthorpe <jgg@nvidia.com>
Reviewed-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Link: https://lore.kernel.org/r/20210823212047.1476436-2-akrowiak@linux.ibm.comSigned-off-by: NAlex Williamson <alex.williamson@redhat.com>

The user can open multiple device FDs if it likes, however these open()
functions call vfio_register_notifier() on some device global
state. Calling vfio_register_notifier() twice in will trigger a WARN_ON
from notifier_chain_register() and the first close will wrongly delete the
notifier and more.

Since these really want the new open/close_device() semantics just change
the functions over.
Reviewed-by: NCornelia Huck <cohuck@redhat.com>
Signed-off-by: NJason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/12-v4-9ea22c5e6afb+1adf-vfio_reflck_jgg@nvidia.comSigned-off-by: NAlex Williamson <alex.williamson@redhat.com>

The mdev remove callback for the vfio_ap device driver bails out with
-EBUSY if the mdev is in use by a KVM guest (i.e., the KVM pointer in the
struct ap_matrix_mdev is not NULL). The intended purpose was
to prevent the mdev from being removed while in use. There are two
problems with this scenario:

1. Returning a non-zero return code from the remove callback does not
   prevent the removal of the mdev.

2. The KVM pointer in the struct ap_matrix_mdev will always be NULL because
   the remove callback will not get invoked until the mdev fd is closed.
   When the mdev fd is closed, the mdev release callback is invoked and
   clears the KVM pointer from the struct ap_matrix_mdev.

Let's go ahead and remove the check for KVM in the remove callback and
allow the cleanup of mdev resources to proceed.
Signed-off-by: NTony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: NJason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20210609224634.575156-2-akrowiak@linux.ibm.comSigned-off-by: NVasily Gorbik <gor@linux.ibm.com>

The driver core standard is to pass in the properly typed object, the
properly typed attribute and the buffer data. It stems from the root
kobject method:

  ssize_t (*show)(struct kobject *kobj, struct kobj_attribute *attr,..)

Each subclass of kobject should provide their own function with the same
signature but more specific types, eg struct device uses:

  ssize_t (*show)(struct device *dev, struct device_attribute *attr,..)

In this case the existing signature is:

  ssize_t (*show)(struct kobject *kobj, struct device *dev,..)

Where kobj is a 'struct mdev_type *' and dev is 'mdev_type->parent->dev'.

Change the mdev_type related sysfs attribute functions to:

  ssize_t (*show)(struct mdev_type *mtype, struct mdev_type_attribute *attr,..)

In order to restore type safety and match the driver core standard

There are no current users of 'attr', but if it is ever needed it would be
hard to add in retroactively, so do it now.
Reviewed-by: NKevin Tian <kevin.tian@intel.com>
Reviewed-by: NCornelia Huck <cohuck@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJason Gunthorpe <jgg@nvidia.com>
Message-Id: <18-v2-d36939638fc6+d54-vfio2_jgg@nvidia.com>
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>

The kobj here is a type-erased version of mdev_type, which is already
stored in the struct mdev_device being passed in. It was only ever used to
compute the type_group_id, which is now extracted directly from the mdev.
Reviewed-by: NKevin Tian <kevin.tian@intel.com>
Reviewed-by: NCornelia Huck <cohuck@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJason Gunthorpe <jgg@nvidia.com>
Message-Id: <17-v2-d36939638fc6+d54-vfio2_jgg@nvidia.com>
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>

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>

The copy_to_user() function returns the number of bytes remaining to be
copied, but we want to return -EFAULT if the copy doesn't complete.

Fixes: e06670c5 ("s390: vfio-ap: implement VFIO_DEVICE_GET_INFO ioctl")
Signed-off-by: NWang Qing <wangqing@vivo.com>
Reviewed-by: NTony Krowiak <akrowiak@linux.ibm.com>
Signed-off-by: NHeiko Carstens <hca@linux.ibm.com>
Link: https://lore.kernel.org/r/1614600502-16714-1-git-send-email-wangqing@vivo.comSigned-off-by: NHeiko Carstens <hca@linux.ibm.com>

The queues assigned to a matrix mediated device are currently reset when:

* The VFIO_DEVICE_RESET ioctl is invoked
* The mdev fd is closed by userspace (QEMU)
* The mdev is removed from sysfs.

Immediately after the reset of a queue, a call is made to disable
interrupts for the queue. This is entirely unnecessary because the reset of
a queue disables interrupts, so this will be removed.

Furthermore, vfio_ap_irq_disable() does an unconditional PQAP/AQIC which
can result in a specification exception (when the corresponding facility
is not available), so this is actually a bugfix.
Signed-off-by: NTony Krowiak <akrowiak@linux.ibm.com>
[pasic@linux.ibm.com: minor rework before merging]
Signed-off-by: NHalil Pasic <pasic@linux.ibm.com>
Fixes: ec89b55e ("s390: ap: implement PAPQ AQIC interception in kernel")
Cc: <stable@vger.kernel.org>
Signed-off-by: NVasily Gorbik <gor@linux.ibm.com>

The vfio_ap device driver registers a group notifier with VFIO when the
file descriptor for a VFIO mediated device for a KVM guest is opened to
receive notification that the KVM pointer is set (VFIO_GROUP_NOTIFY_SET_KVM
event). When the KVM pointer is set, the vfio_ap driver takes the
following actions:
1. Stashes the KVM pointer in the vfio_ap_mdev struct that holds the state
   of the mediated device.
2. Calls the kvm_get_kvm() function to increment its reference counter.
3. Sets the function pointer to the function that handles interception of
   the instruction that enables/disables interrupt processing.
4. Sets the masks in the KVM guest's CRYCB to pass AP resources through to
   the guest.

In order to avoid memory leaks, when the notifier is called to receive
notification that the KVM pointer has been set to NULL, the vfio_ap device
driver should reverse the actions taken when the KVM pointer was set.

Fixes: 258287c9 ("s390: vfio-ap: implement mediated device open callback")
Signed-off-by: NTony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: NHalil Pasic <pasic@linux.ibm.com>
Reviewed-by: NCornelia Huck <cohuck@redhat.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20201223012013.5418-1-akrowiak@linux.ibm.comSigned-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NVasily Gorbik <gor@linux.ibm.com>

Convert the various uses of fallthrough comments to fallthrough;

Done via script
Link: https://lore.kernel.org/lkml/b56602fcf79f849e733e7b521bb0e17895d390fa.1582230379.git.joe.com/Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NVasily Gorbik <gor@linux.ibm.com>

The intention seems to be to warn once when we don't wait enough for the
reset to complete. Let's use the right retry counter to accomplish that
semantic.
Signed-off-by: NHalil Pasic <pasic@linux.ibm.com>
Link: https://lore.kernel.org/r/20190903133618.9122-1-pasic@linux.ibm.comReviewed-by: NCornelia Huck <cohuck@redhat.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NVasily Gorbik <gor@linux.ibm.com>

vfio_ap_free_aqic_resources is called in two places:
- during registration to have a "known state"
- during interrupt disable

We must not clear q->matrix_mdev in the registration phase as this will
mess up the reference counting and can lead to some warning and other
bugs.

Fixes: ec89b55e ("s390: ap: implement PAPQ AQIC interception in kernel")
Reviewed-by: NHalil Pasic <pasic@linux.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NVasily Gorbik <gor@linux.ibm.com>

We register a AP PQAP instruction hook during the open
of the mediated device. And unregister it on release.

During the probe of the AP device, we allocate a vfio_ap_queue
structure to keep track of the information we need for the
PQAP/AQIC instruction interception.

In the AP PQAP instruction hook, if we receive a demand to
enable IRQs,
- we retrieve the vfio_ap_queue based on the APQN we receive
  in REG1,
- we retrieve the page of the guest address, (NIB), from
  register REG2
- we retrieve the mediated device to use the VFIO pinning
  infrastructure to pin the page of the guest address,
- we retrieve the pointer to KVM to register the guest ISC
  and retrieve the host ISC
- finaly we activate GISA

If we receive a demand to disable IRQs,
- we deactivate GISA
- unregister from the GIB
- unpin the NIB

When removing the AP device from the driver the device is
reseted and this process unregisters the GISA from the GIB,
and unpins the NIB address then we free the vfio_ap_queue
structure.
Signed-off-by: NPierre Morel <pmorel@linux.ibm.com>
Acked-by: NTony Krowiak <akrowiak@linux.ibm.com>
Acked-by: NHarald Freudenberger <freude@linux.ibm.com>
Signed-off-by: NHalil Pasic <pasic@linux.ibm.com>
Signed-off-by: NVasily Gorbik <gor@linux.ibm.com>

To be able to use the VFIO interface to facilitate the
mediated device memory pinning/unpinning we need to register
a notifier for IOMMU.

While we will start to pin one guest page for the interrupt indicator
byte, this is still ok with ballooning as this page will never be
used by the guest virtio-balloon driver.
So the pinned page will never be freed. And even a broken guest does
so, that would not impact the host as the original page is still
in control by vfio.
Signed-off-by: NPierre Morel <pmorel@linux.ibm.com>
Reviewed-by: NCornelia Huck <cohuck@redhat.com>
Reviewed-by: NTony Krowiak <akrowiak@linux.ibm.com>
Acked-by: NHarald Freudenberger <freude@linux.ibm.com>
Signed-off-by: NHalil Pasic <pasic@linux.ibm.com>
Signed-off-by: NVasily Gorbik <gor@linux.ibm.com>

Libudev relies on having a subsystem link for non-root devices. To
avoid libudev (and potentially other userspace tools) choking on the
matrix device let us introduce a matrix bus and with it the matrix
bus subsytem. Also make the matrix device reside within the matrix
bus.

Doing this we remove the forced link from the matrix device to the
vfio_ap driver and the device_type we do not need anymore.

Since the associated matrix driver is not the vfio_ap driver any more,
we have to change the search for the devices on the vfio_ap driver in
the function vfio_ap_verify_queue_reserved.
Fixes: 1fde5734 ("s390: vfio-ap: base implementation of VFIO AP device driver")
Cc: stable@vger.kernel.org
Reported-by: NMarc Hartmayer <mhartmay@linux.ibm.com>
Reported-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NPierre Morel <pmorel@linux.ibm.com>
Tested-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: NCornelia Huck <cohuck@redhat.com>
Reviewed-by: NTony Krowiak <akrowiak@linux.ibm.com>
Acked-by: NHalil Pasic <pasic@linux.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

no functional change, just hygiene.
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: NCornelia Huck <cohuck@redhat.com>
Reviewed-by: NDavid Hildenbrand <david@redhat.com>

We replace the vfio_ap_mdev_copy_masks() by the new
kvm_arch_crypto_set_masks() to be able to use the standard
KVM tracing system.
Signed-off-by: NPierre Morel <pmorel@linux.ibm.com>
Message-Id: <1538728270-10340-3-git-send-email-pmorel@linux.ibm.com>
Reviewed-by: NCornelia Huck <cohuck@redhat.com>
Reviewed-by: NDavid Hildenbrand <david@redhat.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

Implements the VFIO_DEVICE_RESET ioctl. This ioctl zeroizes
all of the AP queues assigned to the guest.
Signed-off-by: NTony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: NHalil Pasic <pasic@linux.ibm.com>
Reviewed-by: NPierre Morel <pmorel@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: <20180925231641.4954-15-akrowiak@linux.vnet.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

Let's call PAPQ(ZAPQ) to zeroize a queue for each queue configured
for a mediated matrix device when it is released.

Zeroizing a queue resets the queue, clears all pending
messages for the queue entries and disables adapter interruptions
associated with the queue.
Signed-off-by: NTony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: NHalil Pasic <pasic@linux.ibm.com>
Tested-by: NMichael Mueller <mimu@linux.ibm.com>
Tested-by: NFarhan Ali <alifm@linux.ibm.com>
Reviewed-by: NCornelia Huck <cohuck@redhat.com>
Message-Id: <20180925231641.4954-14-akrowiak@linux.vnet.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

Adds support for the VFIO_DEVICE_GET_INFO ioctl to the VFIO
AP Matrix device driver. This is a minimal implementation,
as vfio-ap does not use I/O regions.
Signed-off-by: NTony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: NPierre Morel <pmorel@linux.ibm.com>
Reviewed-by: NCornelia Huck <cohuck@redhat.com>
Acked-by: NHalil Pasic <pasic@linux.ibm.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: <20180925231641.4954-13-akrowiak@linux.vnet.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

Implements the open callback on the mediated matrix device.
The function registers a group notifier to receive notification
of the VFIO_GROUP_NOTIFY_SET_KVM event. When notified,
the vfio_ap device driver will get access to the guest's
kvm structure. The open callback must ensure that only one
mediated device shall be opened per guest.
Signed-off-by: NTony Krowiak <akrowiak@linux.ibm.com>
Acked-by: NHalil Pasic <pasic@linux.ibm.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>
Acked-by: NPierre Morel <pmorel@linux.ibm.com>
Reviewed-by: NCornelia Huck <cohuck@redhat.com>
Message-Id: <20180925231641.4954-12-akrowiak@linux.vnet.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

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>