Commit Graph

1105356 Commits

Author SHA1 Message Date
Alexander Gordeev
2e2493c675 s390/setup: rearrange absolute lowcore initialization
Make the absolute lowcore assignments immediately follow
the boot CPU lowcore same member assignments. This way
readability improves when reading from up to down, with
no out of order mcck stack allocation in-between.

Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-07-28 18:05:23 +02:00
Alexander Gordeev
57ad19bcde s390/boot: cleanup adjust_to_uv_max() function
Uncouple input and output arguments by making the latter
the function return value.

Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-07-28 18:05:23 +02:00
Alexander Gordeev
6f5c672d17 s390/smp: enforce lowcore protection on CPU restart
As result of commit 915fea04f9 ("s390/smp: enable DAT before
CPU restart callback is called") the low-address protection bit
gets mistakenly unset in control register 0 save area of the
absolute zero memory. That area is used when manual PSW restart
happened to hit an offline CPU. In this case the low-address
protection for that CPU will be dropped.

Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Fixes: 915fea04f9 ("s390/smp: enable DAT before CPU restart callback is called")
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-07-28 18:05:23 +02:00
Jason Wang
fc7fab3f91 s390/tape: fix comment typo
Remove duplicated `that' in a comment

Signed-off-by: Jason Wang <wangborong@cdjrlc.com>
Link: https://lore.kernel.org/r/20220715053838.5005-1-wangborong@cdjrlc.com
[agordeev@linux.ibm.com rephrased commit message]
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-07-28 18:05:23 +02:00
Randy Dunlap
57c3ae8e44 s390/hmcdrv: fix Kconfig "its" grammar
Use the possessive "its" instead of the contraction "it's"
where appropriate.

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: linux-s390@vger.kernel.org
Link: https://lore.kernel.org/r/20220715020010.12678-1-rdunlap@infradead.org
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-07-28 18:05:22 +02:00
Alexander Gordeev
2f089a3846 Merge branch 'vmcore-iov_iter' into features
Pull changes that finalize switching of copy_oldmem_page() callback
to iov_iter interface. These changes were pulled in work.iov_iter of
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs.git

Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-07-28 17:53:11 +02:00
Alexander Gordeev
9aa938ddce s390/docs: fix warnings for vfio_ap driver doc
Fix multiple warnings produced by make htmldocs

Fixes: cb269e0aba ("s390/vfio-ap: update docs to include dynamic config support")
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-07-22 13:54:07 +02:00
Alexander Gordeev
d384690c6a s390/docs: fix warnings for vfio_ap driver lock usage doc
Fix multiple warnings produced by make htmldocs

Fixes: e32d3827f3 ("s390/Docs: new doc describing lock usage by the vfio_ap device driver")
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-07-22 13:54:06 +02:00
Alexander Gordeev
ebbc957016 s390/crash: support multi-segment iterators
Make it possible to handle not only single-, but also multi-
segment iterators in copy_oldmem_iter() callback. Change the
semantics of called functions to match the iterator model -
instead of an error code the exact number of bytes copied is
returned.

The swap page used to copy data to user space is adopted for
kernel space too. That does not bring any performance impact.

Suggested-by: Matthew Wilcox <willy@infradead.org>
Fixes: cc02e6e21a ("s390/crash: add missing iterator advance in copy_oldmem_page()")
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Tested-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Link: https://lore.kernel.org/r/5af6da3a0bffe48a90b0b7139ecf6a818b2d18e8.1658206891.git.agordeev@linux.ibm.com
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-07-20 17:21:41 +02:00
Alexander Gordeev
6d2e5a4a13 s390/crash: use static swap buffer for copy_to_user_real()
Currently a temporary page-size buffer is allocated for copying
oldmem to user space. That limits copy_to_user_real() operation
only to stages when virtual memory is available and still makes
it possible to fail while the system is being dumped.

Instead of reallocating single page on each copy_oldmem_page()
iteration use a statically allocated buffer.

This also paves the way for a further memcpy_real() rework where
no swap buffer is needed altogether.

Acked-by: Heiko Carstens <hca@linux.ibm.com>
Tested-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Link: https://lore.kernel.org/r/334ed359680c4d45dd32feb104909f610312ef0f.1658206891.git.agordeev@linux.ibm.com
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-07-20 17:21:41 +02:00
Alexander Gordeev
d6da673781 s390/crash: move copy_to_user_real() to crash_dump.c
Function copy_to_user_real() does not really belong to maccess.c.
It is only used for copying oldmem to user space, so let's move
it to the friends.

Acked-by: Heiko Carstens <hca@linux.ibm.com>
Tested-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Link: https://lore.kernel.org/r/e8de968d40202d87caa09aef12e9c67ec23a1c1a.1658206891.git.agordeev@linux.ibm.com
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-07-20 17:21:41 +02:00
Alexander Gordeev
9ffed254d9 s390/zcore: fix race when reading from hardware system area
Memory buffer used for reading out data from hardware system
area is not protected against concurrent access.

Reported-by: Matthew Wilcox <willy@infradead.org>
Fixes: 411ed32257 ("[S390] zfcpdump support.")
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Tested-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Link: https://lore.kernel.org/r/e68137f0f9a0d2558f37becc20af18e2939934f6.1658206891.git.agordeev@linux.ibm.com
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-07-20 17:21:41 +02:00
Alexander Gordeev
f6749da17a s390/crash: fix incorrect number of bytes to copy to user space
The number of bytes in a chunk is correctly calculated, but instead
the total number of bytes is passed to copy_to_user_real() function.

Reported-by: Matthew Wilcox <willy@infradead.org>
Fixes: df9694c797 ("s390/dump: streamline oldmem copy functions")
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-07-20 17:21:41 +02:00
Alexander Gordeev
86caa4b678 s390/crash: remove redundant panic() on save area allocation failure
Make save_area_alloc() return classic NULL on allocation failure.
The only caller smp_save_dump_cpus() does check the return value
already and panics if NULL is returned.

Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-07-20 17:21:41 +02:00
Alexander Gordeev
7190d84966 s390/mm: remove unused tprot() function
Since commit 461e0da7ddbb ("s390: remove broken hibernate / power
management support") there are no users of tprot() left. Remove
the function itself as well.

Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-07-20 17:17:13 +02:00
Steffen Eiden
5fcd0d8ae2 s390/uvdevice: autoload module based on CPU facility
Make sure the uvdevice driver will be automatically loaded when
facility 158 is available.

Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Link: https://lore.kernel.org/r/20220713125644.16121-4-seiden@linux.ibm.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-07-19 16:18:49 +02:00
Heiko Carstens
e2f39c9f54 s390/cpufeature: allow for facility bits
Allow for facility bits to be used in cpu features.

Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: Steffen Eiden <seiden@linux.ibm.com>
Link: https://lore.kernel.org/r/20220713125644.16121-3-seiden@linux.ibm.com
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-07-19 16:18:49 +02:00
Heiko Carstens
0a5f9b382c s390/cpufeature: rework to allow more than only hwcap bits
Rework cpufeature implementation to allow for various cpu feature
indications, which is not only limited to hwcap bits. This is achieved
by adding a sequential list of cpu feature numbers, where each of them
is mapped to an entry which indicates what this number is about.

Each entry contains a type member, which indicates what feature
name space to look into (e.g. hwcap, or cpu facility). If wanted this
allows also to automatically load modules only in e.g. z/VM
configurations.

Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: Hendrik Brueckner <brueckner@linux.ibm.com>
Link: https://lore.kernel.org/r/20220713125644.16121-2-seiden@linux.ibm.com
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-07-19 16:18:49 +02:00
Tony Krowiak
693714b900 MAINTAINERS: pick up all vfio_ap docs for VFIO AP maintainers
A new document, Documentation/s390/vfio-ap-locking.rst was added. Make sure
the new document is picked up for the VFIO AP maintainers by using a
wildcard: Documentation/s390/vfio-ap*.

Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-07-19 16:18:12 +02:00
Tony Krowiak
e32d3827f3 s390/Docs: new doc describing lock usage by the vfio_ap device driver
Introduces a new document describing the locks used by the vfio_ap device
driver and how to use them so as to avoid lockdep reports and deadlock
situations.

Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Jason J. Herne <jjherne@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-07-19 16:18:12 +02:00
Tony Krowiak
cb269e0aba s390/vfio-ap: update docs to include dynamic config support
Update the documentation in vfio-ap.rst to include information about the
AP dynamic configuration support (e.g., hot plug of adapters, domains
and control domains via the matrix mediated device's sysfs assignment
attributes). This patch also makes a few minor tweaks to make corrections
and clarifications.

Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Jason J. Herne <jjherne@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-07-19 16:18:12 +02:00
Tony Krowiak
eeb386aeb5 s390/vfio-ap: handle config changed and scan complete notification
This patch implements two new AP driver callbacks:

void (*on_config_changed)(struct ap_config_info *new_config_info,
                  struct ap_config_info *old_config_info);

void (*on_scan_complete)(struct ap_config_info *new_config_info,
                 struct ap_config_info *old_config_info);

The on_config_changed callback is invoked at the start of the AP bus scan
function when it determines that the host AP configuration information
has changed since the previous scan.

The vfio_ap device driver registers a callback function for this callback
that performs the following operations:

1. Unplugs the adapters, domains and control domains removed from the
host's AP configuration from the guests to which they are
assigned in a single operation.

2. Stores bitmaps identifying the adapters, domains and control domains
added to the host's AP configuration with the structure representing
the mediated device. When the vfio_ap device driver's probe callback is
subsequently invoked, the probe function will recognize that the
queue is being probed due to a change in the host's AP configuration
and the plugging of the queue into the guest will be bypassed.

The on_scan_complete callback is invoked after the ap bus scan is
completed if the host AP configuration data has changed. The vfio_ap
device driver registers a callback function for this callback that hot
plugs each queue and control domain added to the AP configuration for each
guest using them in a single hot plug operation.

Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Jason J. Herne <jjherne@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-07-19 16:18:12 +02:00
Tony Krowiak
f7f795c54d s390/vfio-ap: sysfs attribute to display the guest's matrix
The matrix of adapters and domains configured in a guest's APCB may
differ from the matrix of adapters and domains assigned to the matrix mdev,
so this patch introduces a sysfs attribute to display the matrix of
adapters and domains that are or will be assigned to the APCB of a guest
that is or will be using the matrix mdev. For a matrix mdev denoted by
$uuid, the guest matrix can be displayed as follows:

   cat /sys/devices/vfio_ap/matrix/$uuid/guest_matrix

Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Jason J. Herne <jjherne@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-07-19 16:18:11 +02:00
Tony Krowiak
3f85d1df26 s390/vfio-ap: implement in-use callback for vfio_ap driver
Let's implement the callback to indicate when an APQN
is in use by the vfio_ap device driver. The callback is
invoked whenever a change to the apmask or aqmask would
result in one or more queue devices being removed from the driver. The
vfio_ap device driver will indicate a resource is in use
if the APQN of any of the queue devices to be removed are assigned to
any of the matrix mdevs under the driver's control.

There is potential for a deadlock condition between the
matrix_dev->guests_lock used to lock the guest during assignment of
adapters and domains and the ap_perms_mutex locked by the AP bus when
changes are made to the sysfs apmask/aqmask attributes.

The AP Perms lock controls access to the objects that store the adapter
numbers (ap_perms) and domain numbers (aq_perms) for the sysfs
/sys/bus/ap/apmask and /sys/bus/ap/aqmask attributes. These attributes
identify which queues are reserved for the zcrypt default device drivers.
Before allowing a bit to be removed from either mask, the AP bus must check
with the vfio_ap device driver to verify that none of the queues are
assigned to any of its mediated devices.

The apmask/aqmask attributes can be written or read at any time from
userspace, so care must be taken to prevent a deadlock with asynchronous
operations that might be taking place in the vfio_ap device driver. For
example, consider the following:

1. A system administrator assigns an adapter to a mediated device under the
   control of the vfio_ap device driver. The driver will need to first take
   the matrix_dev->guests_lock to potentially hot plug the adapter into
   the KVM guest.
2. At the same time, a system administrator sets a bit in the sysfs
   /sys/bus/ap/ap_mask attribute. To complete the operation, the AP bus
   must:
   a. Take the ap_perms_mutex lock to update the object storing the values
      for the /sys/bus/ap/ap_mask attribute.
   b. Call the vfio_ap device driver's in-use callback to verify that the
      queues now being reserved for the default zcrypt drivers are not
      assigned to a mediated device owned by the vfio_ap device driver. To
      do the verification, the in-use callback function takes the
      matrix_dev->guests_lock, but has to wait because it is already held
      by the operation in 1 above.
3. The vfio_ap device driver calls an AP bus function to verify that the
   new queues resulting from the assignment of the adapter in step 1 are
   not reserved for the default zcrypt device driver. This AP bus function
   tries to take the ap_perms_mutex lock but gets stuck waiting for the
   waiting for the lock due to step 2a above.

Consequently, we have the following deadlock situation:

matrix_dev->guests_lock locked (1)
ap_perms_mutex lock locked (2a)
Waiting for matrix_dev->gusts_lock (2b) which is currently held (1)
Waiting for ap_perms_mutex lock (3) which is currently held (2a)

To prevent this deadlock scenario, the function called in step 3 will no
longer take the ap_perms_mutex lock and require the caller to take the
lock. The lock will be the first taken by the adapter/domain assignment
functions in the vfio_ap device driver to maintain the proper locking
order.

Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Jason J. Herne <jjherne@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-07-19 16:18:11 +02:00
Tony Krowiak
70aeefe574 s390/vfio-ap: reset queues after adapter/domain unassignment
When an adapter or domain is unassigned from an mdev attached to a KVM
guest, one or more of the guest's queues may get dynamically removed. Since
the removed queues could get re-assigned to another mdev, they need to be
reset. So, when an adapter or domain is unassigned from the mdev, the
queues that are removed from the guest's AP configuration (APCB) will be
reset.

Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Jason J. Herne <jjherne@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-07-19 16:18:11 +02:00
Tony Krowiak
09d31ff787 s390/vfio-ap: hot plug/unplug of AP devices when probed/removed
When an AP queue device is probed or removed, if the mediated device is
attached to a KVM guest, the mediated device's adapter, domain and
control domain bitmaps must be filtered to update the guest's APCB and if
any changes are detected, the guest's APCB must then be hot plugged into
the guest to reflect those changes to the guest.

Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Jason J. Herne <jjherne@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-07-19 16:18:11 +02:00
Tony Krowiak
51dc562af0 s390/vfio-ap: allow hot plug/unplug of AP devices when assigned/unassigned
Let's hot plug an adapter, domain or control domain into the guest when it
is assigned to a matrix mdev that is attached to a KVM guest. Likewise,
let's hot unplug an adapter, domain or control domain from the guest when
it is unassigned from a matrix_mdev that is attached to a KVM guest.

Whenever an assignment or unassignment of an adapter, domain or control
domain is performed, the APQNs and control domains assigned to the matrix
mdev will be filtered and assigned to the AP control block
(APCB) that supplies the AP configuration to the guest so that no
adapter, domain or control domain that is not in the host's AP
configuration nor any APQN that does not reference a queue device bound
to the vfio_ap device driver is assigned.

After updating the APCB, if the mdev is in use by a KVM guest, it is
hot plugged into the guest to dynamically provide access to the adapters,
domains and control domains provided via the newly refreshed APCB.

Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Jason J. Herne <jjherne@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-07-19 16:18:10 +02:00
Tony Krowiak
2c1ee8983a s390/vfio-ap: prepare for dynamic update of guest's APCB on queue probe/remove
The callback functions for probing and removing a queue device must take
and release the locks required to perform a dynamic update of a guest's
APCB in the proper order.

The proper order for taking the locks is:

        matrix_dev->guests_lock => kvm->lock => matrix_dev->mdevs_lock

The proper order for releasing the locks is:

        matrix_dev->mdevs_lock => kvm->lock => matrix_dev->guests_lock

A new helper function is introduced to be used by the probe callback to
acquire the required locks. Since the probe callback only has
access to a queue device when it is called, the helper function will find
the ap_matrix_mdev object to which the queue device's APQN is assigned and
return it so the KVM guest to which the mdev is attached can be dynamically
updated.

Note that in order to find the ap_matrix_mdev (matrix_mdev) object, it is
necessary to search the matrix_dev->mdev_list. This presents a
locking order dilemma because the matrix_dev->mdevs_lock can't be taken to
protect against changes to the list while searching for the matrix_mdev to
which a queue device's APQN is assigned. This is due to the fact that the
proper locking order requires that the matrix_dev->mdevs_lock be taken
after both the matrix_mdev->kvm->lock and the matrix_dev->mdevs_lock.
Consequently, the matrix_dev->guests_lock will be used to protect against
removal of a matrix_mdev object from the list while a queue device is
being probed. This necessitates changes to the mdev probe/remove
callback functions to take the matrix_dev->guests_lock prior to removing
a matrix_mdev object from the list.

A new macro is also introduced to acquire the locks required to dynamically
update the guest's APCB in the proper order when a queue device is
removed.

Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Jason J. Herne <jjherne@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-07-19 16:18:10 +02:00
Tony Krowiak
8ee13ad993 s390/vfio-ap: prepare for dynamic update of guest's APCB on assign/unassign
The functions backing the matrix mdev's sysfs attribute interfaces to
assign/unassign adapters, domains and control domains must take and
release the locks required to perform a dynamic update of a guest's APCB
in the proper order.

The proper order for taking the locks is:

matrix_dev->guests_lock => kvm->lock => matrix_dev->mdevs_lock

The proper order for releasing the locks is:

matrix_dev->mdevs_lock => kvm->lock => matrix_dev->guests_lock

Two new macros are introduced for this purpose: One to take the locks and
the other to release the locks. These macros will be used by the
assignment/unassignment functions to prepare for dynamic update of
the KVM guest's APCB.

Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-07-19 16:18:10 +02:00
Tony Krowiak
b84eb8e050 s390/vfio-ap: use proper locking order when setting/clearing KVM pointer
The group notifier that handles the VFIO_GROUP_NOTIFY_SET_KVM event must
use the required locks in proper locking order to dynamically update the
guest's APCB. The proper locking order is:

       1. matrix_dev->guests_lock: required to use the KVM pointer to
          update a KVM guest's APCB.

       2. matrix_mdev->kvm->lock: required to update a KVM guest's APCB.

       3. matrix_dev->mdevs_lock: required to store or access the data
          stored in a struct ap_matrix_mdev instance.

Two macros are introduced to acquire and release the locks in the proper
order. These macros are now used by the group notifier functions.

Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Jason J. Herne <jjherne@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-07-19 16:18:10 +02:00
Tony Krowiak
21195eb038 s390/vfio-ap: introduce new mutex to control access to the KVM pointer
The vfio_ap device driver registers for notification when the pointer to
the KVM object for a guest is set. Recall that the KVM lock (kvm->lock)
mutex must be taken outside of the matrix_dev->lock mutex to prevent the
reporting by lockdep of a circular locking dependency (a.k.a., a lockdep
splat):

* see commit 0cc00c8d40 ("Fix circular lockdep when setting/clearing
  crypto masks")

* see commit 86956e7076 ("replace open coded locks for
  VFIO_GROUP_NOTIFY_SET_KVM notification")

With the introduction of support for hot plugging/unplugging AP devices
passed through to a KVM guest, a new guests_lock mutex is introduced to
ensure the proper locking order is maintained:

struct ap_matrix_dev {
        ...
        struct mutex guests_lock;
       ...
}

The matrix_dev->guests_lock controls access to the matrix_mdev instances
that hold the state for AP devices that have been passed through to a
KVM guest. This lock must be held to control access to the KVM pointer
(matrix_mdev->kvm) while the vfio_ap device driver is using it to
plug/unplug AP devices passed through to the KVM guest.

Keep in mind, the proper locking order must be maintained whenever
dynamically updating a KVM guest's APCB to plug/unplug adapters, domains
and control domains:

    1. matrix_dev->guests_lock: required to use the KVM pointer - stored in
       a struct ap_matrix_mdev instance - to update a KVM guest's APCB

    2. matrix_mdev->kvm->lock: required to update a guest's APCB

    3. matrix_dev->mdevs_lock: required to access data stored in a
       struct ap_matrix_mdev instance.

Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Jason J. Herne <jjherne@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-07-19 16:18:10 +02:00
Tony Krowiak
d0786556ca s390/vfio-ap: rename matrix_dev->lock mutex to matrix_dev->mdevs_lock
The matrix_dev->lock mutex is being renamed to matrix_dev->mdevs_lock to
better reflect its purpose, which is to control access to the state of the
mediated devices under the control of the vfio_ap device driver.

Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Jason J. Herne <jjherne@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-07-19 16:18:10 +02:00
Tony Krowiak
e2126a7374 s390/vfio-ap: allow assignment of unavailable AP queues to mdev device
The current implementation does not allow assignment of an AP adapter or
domain to an mdev device if each APQN resulting from the assignment
does not reference an AP queue device that is bound to the vfio_ap device
driver. This patch allows assignment of AP resources to the matrix mdev as
long as the APQNs resulting from the assignment:
   1. Are not reserved by the AP BUS for use by the zcrypt device drivers.
   2. Are not assigned to another matrix mdev.

The rationale behind this is that the AP architecture does not preclude
assignment of APQNs to an AP configuration profile that are not available
to the system.

Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-07-19 16:18:09 +02:00
Tony Krowiak
48cae940c3 s390/vfio-ap: refresh guest's APCB by filtering AP resources assigned to mdev
Refresh the guest's APCB by filtering the APQNs and control domain numbers
assigned to the matrix mdev.

Filtering of APQNs:
-----------------
APQNs that do not reference an AP queue device bound to the vfio_ap device
driver must be filtered from the APQNs assigned to the matrix mdev before
they can be assigned to the guest's APCB. Given that the APQNs are
configured in the guest's APCB as a matrix of APIDs (adapters) and APQIs
(domains), it is not possible to filter an individual APQN. For example,
suppose the matrix of APQNs is structured as follows:

                   APIDs
             3      4      5
        0  (3,0)  (4,0)  (5,0)
APQIs   1  (3,1)  (4,1)  (5,1)
        2  (3,2)  (4,2)  (5,2)

Now suppose APQN (4,1) does not reference a queue device bound to the
vfio_ap device driver. If we filter APID 4, the APQNs (4,0), (4,1) and
(4,2) will be removed. Similarly, if we filter domain 1, APQNs (3,1),
(4,1) and (5,1) will be removed.

To resolve this dilemma, the choice was made to filter the APID - in this
case 4 - from the guest's APCB. The reason for this design decision is
because the APID references an AP adapter which is a real hardware device
that can be physically installed, removed, enabled or disabled; whereas, a
domain is a partition within the adapter. It therefore better reflects
reality to remove the APID from the guest's APCB.

Filtering of control domains:
----------------------------
Any control domains that are not assigned to the host's AP configuration
will be filtered from those assigned to the matrix mdev before assigning
them to the guest's APCB.

Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Jason J. Herne <jjherne@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-07-19 16:18:09 +02:00
Tony Krowiak
49b0109fb3 s390/vfio-ap: introduce shadow APCB
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: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-07-19 16:18:09 +02:00
Tony Krowiak
11cb2419fa s390/vfio-ap: manage link between queue struct and matrix mdev
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: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-07-19 16:18:09 +02:00
Tony Krowiak
260f3ea141 s390/vfio-ap: move probe and remove callbacks to vfio_ap_ops.c
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: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-07-19 16:18:08 +02:00
Tony Krowiak
034921cdea s390/vfio-ap: use new AP bus interface to search for queue devices
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: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
Reviewed-by: Jason J. Herne <jjherne@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-07-19 16:18:08 +02:00
Siddh Raman Pant
5352ebf735 tools/testing/crypto: Use vzalloc instead of vmalloc+memset
This fixes the corresponding coccinelle warning.

Signed-off-by: Siddh Raman Pant <code@siddh.me>
Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Link: https://lore.kernel.org/r/20220627075148.140705-1-code@siddh.me
[agordeev@linux.ibm.com added Link]
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-07-05 14:46:36 +02:00
Alexander Gordeev
af2debd58b s390/crash: make copy_oldmem_page() return number of bytes copied
Callback copy_oldmem_page() returns either error code or zero.
Instead, it should return the error code or number of bytes copied.

Fixes: df9694c797 ("s390/dump: streamline oldmem copy functions")
Reviewed-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Tested-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-06-23 17:23:30 +02:00
Alexander Gordeev
cc02e6e21a s390/crash: add missing iterator advance in copy_oldmem_page()
In case old memory was successfully copied the passed iterator
should be advanced as well. Currently copy_oldmem_page() is
always called with single-segment iterator. Should that ever
change - copy_oldmem_user and copy_oldmem_kernel() functions
would need a rework to deal with multi-segment iterators.

Fixes: 5d8de293c2 ("vmcore: convert copy_oldmem_page() to take an iov_iter")
Reviewed-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Tested-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-06-23 17:23:30 +02:00
Linus Torvalds
a111daf0c5 Linux 5.19-rc3 v5.19-rc3 2022-06-19 15:06:47 -05:00
Linus Torvalds
05c6ca8512 Merge tag 'x86-urgent-2022-06-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Thomas Gleixner:

 - Make RESERVE_BRK() work again with older binutils. The recent
   'simplification' broke that.

 - Make early #VE handling increment RIP when successful.

 - Make the #VE code consistent vs. the RIP adjustments and add
   comments.

 - Handle load_unaligned_zeropad() across page boundaries correctly in
   #VE when the second page is shared.

* tag 'x86-urgent-2022-06-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/tdx: Handle load_unaligned_zeropad() page-cross to a shared page
  x86/tdx: Clarify RIP adjustments in #VE handler
  x86/tdx: Fix early #VE handling
  x86/mm: Fix RESERVE_BRK() for older binutils
2022-06-19 09:58:28 -05:00
Linus Torvalds
5d770f11a1 Merge tag 'objtool-urgent-2022-06-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull build tooling updates from Thomas Gleixner:

 - Remove obsolete CONFIG_X86_SMAP reference from objtool

 - Fix overlapping text section failures in faddr2line for real

 - Remove OBJECT_FILES_NON_STANDARD usage from x86 ftrace and replace it
   with finegrained annotations so objtool can validate that code
   correctly.

* tag 'objtool-urgent-2022-06-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/ftrace: Remove OBJECT_FILES_NON_STANDARD usage
  faddr2line: Fix overlapping text section failures, the sequel
  objtool: Fix obsolete reference to CONFIG_X86_SMAP
2022-06-19 09:54:16 -05:00
Linus Torvalds
727c3991df Merge tag 'sched-urgent-2022-06-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fix from Thomas Gleixner:
 "A single scheduler fix plugging a race between sched_setscheduler()
  and balance_push().

  sched_setscheduler() spliced the balance callbacks accross a lock
  break which makes it possible for an interleaving schedule() to
  observe an empty list"

* tag 'sched-urgent-2022-06-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched: Fix balance_push() vs __sched_setscheduler()
2022-06-19 09:51:00 -05:00
Linus Torvalds
4afb65156a Merge tag 'locking-urgent-2022-06-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull lockdep fix from Thomas Gleixner:
 "A RT fix for lockdep.

  lockdep invokes prandom_u32() to create cookies. This worked until
  prandom_u32() was switched to the real random generator, which takes a
  spinlock for extraction, which does not work on RT when invoked from
  atomic contexts.

  lockdep has no requirement for real random numbers and it turns out
  sched_clock() is good enough to create the cookie. That works
  everywhere and is faster"

* tag 'locking-urgent-2022-06-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/lockdep: Use sched_clock() for random numbers
2022-06-19 09:47:41 -05:00
Linus Torvalds
36da9f5fb6 Merge tag 'irq-urgent-2022-06-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq fixes from Thomas Gleixner:
 "A set of interrupt subsystem updates:

  Core:

   - Ensure runtime power management for chained interrupts

  Drivers:

   - A collection of OF node refcount fixes

   - Unbreak MIPS uniprocessor builds

   - Fix xilinx interrupt controller Kconfig dependencies

   - Add a missing compatible string to the Uniphier driver"

* tag 'irq-urgent-2022-06-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip/loongson-liointc: Use architecture register to get coreid
  irqchip/uniphier-aidet: Add compatible string for NX1 SoC
  dt-bindings: interrupt-controller/uniphier-aidet: Add bindings for NX1 SoC
  irqchip/realtek-rtl: Fix refcount leak in map_interrupts
  irqchip/gic-v3: Fix refcount leak in gic_populate_ppi_partitions
  irqchip/gic-v3: Fix error handling in gic_populate_ppi_partitions
  irqchip/apple-aic: Fix refcount leak in aic_of_ic_init
  irqchip/apple-aic: Fix refcount leak in build_fiq_affinity
  irqchip/gic/realview: Fix refcount leak in realview_gic_of_init
  irqchip/xilinx: Remove microblaze+zynq dependency
  genirq: PM: Use runtime PM for chained interrupts
2022-06-19 09:45:16 -05:00
Linus Torvalds
bc94632ceb Merge tag 'char-misc-5.19-rc3-take2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char/misc driver fixes for real from Greg KH:
 "Let's tag the proper branch this time...

  Here are some small char/misc driver fixes for 5.19-rc3 that resolve
  some reported issues.

  They include:

   - mei driver fixes

   - comedi driver fix

   - rtsx build warning fix

   - fsl-mc-bus driver fix

  All of these have been in linux-next for a while with no reported
  issues"

This is what the merge in commit f0ec9c65a8 _should_ have merged, but
Greg fat-fingered the pull request and I got some small changes from
linux-next instead there. Credit to Nathan Chancellor for eagle-eyes.

Link: https://lore.kernel.org/all/Yqywy+Md2AfGDu8v@dev-arch.thelio-3990X/

* tag 'char-misc-5.19-rc3-take2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  bus: fsl-mc-bus: fix KASAN use-after-free in fsl_mc_bus_remove()
  mei: me: add raptor lake point S DID
  mei: hbm: drop capability response on early shutdown
  mei: me: set internal pg flag to off on hardware reset
  misc: rtsx: Fix clang -Wsometimes-uninitialized in rts5261_init_from_hw()
  comedi: vmk80xx: fix expression for tx buffer size
2022-06-19 09:37:29 -05:00
Linus Torvalds
ee4eb6eeaf Merge tag 'i2c-for-5.19-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux
Pull i2c fixes from Wolfram Sang:
 "MAINTAINERS rectifications and a few minor driver fixes"

* tag 'i2c-for-5.19-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: mediatek: Fix an error handling path in mtk_i2c_probe()
  i2c: designware: Use standard optional ref clock implementation
  MAINTAINERS: core DT include belongs to core
  MAINTAINERS: add include/dt-bindings/i2c to I2C SUBSYSTEM HOST DRIVERS
  i2c: npcm7xx: Add check for platform_driver_register
  MAINTAINERS: Update Synopsys DesignWare I2C to Supported
2022-06-19 09:35:09 -05:00
Linus Torvalds
063232b6c4 Merge tag 'xfs-5.19-fixes-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux
Pull xfs fixes from Darrick Wong:
 "There's not a whole lot this time around (I'm still on vacation) but
  here are some important fixes for new features merged in -rc1:

   - Fix a bug where inode flag changes would accidentally drop nrext64

   - Fix a race condition when toggling LARP mode"

* tag 'xfs-5.19-fixes-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  xfs: preserve DIFLAG2_NREXT64 when setting other inode attributes
  xfs: fix variable state usage
  xfs: fix TOCTOU race involving the new logged xattrs control knob
2022-06-19 09:24:49 -05:00