kernel/git/stable/linux.git/drivers/s390/crypto, branch linux-5.12.y

s390/vfio-ap: clean up mdev resources when remove callback invoked

2021-07-07T12:22:38+00:00

[ Upstream commit 8c0795d2a0f50e2b131f5b2a8c2795939a94058e ] 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: Tony Krowiak Reviewed-by: Jason Gunthorpe Link: https://lore.kernel.org/r/20210609224634.575156-2-akrowiak@linux.ibm.com Signed-off-by: Vasily Gorbik Signed-off-by: Sasha Levin

s390/ap: Fix hanging ioctl caused by wrong msg counter

2021-06-23T12:44:07+00:00

commit e73a99f3287a740a07d6618e9470f4d6cb217da8 upstream. When a AP queue is switched to soft offline, all pending requests are purged out of the pending requests list and 'received' by the upper layer like zcrypt device drivers. This is also done for requests which are already enqueued into the firmware queue. A request in a firmware queue may eventually produce an response message, but there is no waiting process any more. However, the response was counted with the queue_counter and as this counter was reset to 0 with the offline switch, the pending response caused the queue_counter to get negative. The next request increased this counter to 0 (instead of 1) which caused the ap code to assume there is nothing to receive and so the response for this valid request was never tried to fetch from the firmware queue. This all caused a queue to not work properly after a switch offline/online and in the end processes to hang forever when trying to send a crypto request after an queue offline/online switch cicle. Fixed by a) making sure the counter does not drop below 0 and b) on a successful enqueue of a message has at least a value of 1. Additionally a warning is emitted, when a reply can't get assigned to a waiting process. This may be normal operation (process had timeout or has been killed) but may give a hint that something unexpected happened (like this odd behavior described above). Signed-off-by: Harald Freudenberger Cc: stable@vger.kernel.org Signed-off-by: Vasily Gorbik Signed-off-by: Greg Kroah-Hartman

s390/vfio-ap: fix circular lockdep when setting/clearing crypto masks

2021-05-12T06:39:27+00:00

commit 0cc00c8d40500c4c8fe058dc014bdaf44a82f4f7 upstream. This patch fixes a lockdep splat introduced by commit f21916ec4826 ("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: f21916ec4826 ("s390/vfio-ap: clean up vfio_ap resources when KVM pointer invalidated") Cc: stable@vger.kernel.org Signed-off-by: Tony Krowiak Signed-off-by: Heiko Carstens Signed-off-by: Greg Kroah-Hartman

s390/zcrypt: fix zcard and zqueue hot-unplug memleak

2021-05-12T06:39:27+00:00

commit 70fac8088cfad9f3b379c9082832b4d7532c16c2 upstream. Tests with kvm and a kmemdebug kernel showed, that on hot unplug the zcard and zqueue structs for the unplugged card or queue are not properly freed because of a mismatch with get/put for the embedded kref counter. This fix now adjusts the handling of the kref counters. With init the kref counter starts with 1. This initial value needs to drop to zero with the unregister of the card or queue to trigger the release and free the object. Fixes: 29c2680fd2bf ("s390/ap: fix ap devices reference counting") Reported-by: Marc Hartmayer Signed-off-by: Harald Freudenberger Cc: stable@vger.kernel.org Reviewed-by: Julian Wiedmann Signed-off-by: Heiko Carstens Signed-off-by: Greg Kroah-Hartman

s390/crypto: return -EFAULT if copy_to_user() fails

2021-03-08T09:46:29+00:00

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: e06670c5fe3b ("s390: vfio-ap: implement VFIO_DEVICE_GET_INFO ioctl") Signed-off-by: Wang Qing Reviewed-by: Tony Krowiak Signed-off-by: Heiko Carstens Link: https://lore.kernel.org/r/1614600502-16714-1-git-send-email-wangqing@vivo.com Signed-off-by: Heiko Carstens

Merge tag 's390-5.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

2021-02-21T21:40:06+00:00

Pull s390 updates from Vasily Gorbik: - Convert to using the generic entry infrastructure. - Add vdso time namespace support. - Switch s390 and alpha to 64-bit ino_t. As discussed at https://lore.kernel.org/linux-mm/YCV7QiyoweJwvN+m@osiris/ - Get rid of expensive stck (store clock) usages where possible. Utilize cpu alternatives to patch stckf when supported. - Make tod_clock usage less error prone by converting it to a union and rework code which is using it. - Machine check handler fixes and cleanups. - Drop couple of minor inline asm optimizations to fix clang build. - Default configs changes notably to make libvirt happy. - Various changes to rework and improve qdio code. - Other small various fixes and improvements all over the code. * tag 's390-5.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (68 commits) s390/qdio: remove 'merge_pending' mechanism s390/qdio: improve handling of PENDING buffers for QEBSM devices s390/qdio: rework q->qdio_error indication s390/qdio: inline qdio_kick_handler() s390/time: remove get_tod_clock_ext() s390/crypto: use store_tod_clock_ext() s390/hypfs: use store_tod_clock_ext() s390/debug: use union tod_clock s390/kvm: use union tod_clock s390/vdso: use union tod_clock s390/time: convert tod_clock_base to union s390/time: introduce new store_tod_clock_ext() s390/time: rename store_tod_clock_ext() and use union tod_clock s390/time: introduce union tod_clock s390,alpha: switch to 64-bit ino_t s390: split cleanup_sie s390: use r13 in cleanup_sie as temp register s390: fix kernel asce loading when sie is interrupted s390: add stack for machine check handler s390: use WRITE_ONCE when re-allocating async stack ...

s390/zcrypt: return EIO when msg retry limit reached

2021-02-09T14:57:04+00:00

When a msg is retried because the lower ap layer returns -EAGAIN there is a retry limit (currently 10). When this limit is reached the last return code from the lower layer is returned, causing the userspace to get -1 on the ioctl with errno EAGAIN. This EAGAIN is misleading here. After 10 retry attempts the userspace should receive a clear failure indication like EINVAL or EIO or ENODEV. However, the reason why these retries all fail is unclear. On an invalid message EINVAL would be returned by the lower layer, and if devices go away or are not available an ENODEV is seen. So this patch now reworks the retry loops to return EIO to userspace when the retry limit is reached. Fixes: 91ffc519c199 ("s390/zcrypt: introduce msg tracking in zcrypt functions") Signed-off-by: Harald Freudenberger Signed-off-by: Vasily Gorbik

s390/crypto: improve retry logic in case of master key change

2021-01-27T12:00:48+00:00

A master key change on a CCA card may cause an immediately following request to derive an protected key from a secure key to fail with error condition 8/2290. The recommendation from firmware is to retry with 1 second sleep. So now the low level cca functions return -EAGAIN when this error condition is seen and the paes retry function will evaluate the return value. Seeing EAGAIN and running in process context results in trying to sleep for 1 s now. Signed-off-by: Harald Freudenberger Reviewed-by: Ingo Franzki Signed-off-by: Vasily Gorbik

s390/vfio-ap: No need to disable IRQ after queue reset

2021-01-27T12:00:04+00:00

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: Tony Krowiak [pasic@linux.ibm.com: minor rework before merging] Signed-off-by: Halil Pasic Fixes: ec89b55e3bce ("s390: ap: implement PAPQ AQIC interception in kernel") Cc: Signed-off-by: Vasily Gorbik

s390/vfio-ap: clean up vfio_ap resources when KVM pointer invalidated

2021-01-27T12:00:04+00:00

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: 258287c994de ("s390: vfio-ap: implement mediated device open callback") Signed-off-by: Tony Krowiak Reviewed-by: Halil Pasic Reviewed-by: Cornelia Huck Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20201223012013.5418-1-akrowiak@linux.ibm.com Signed-off-by: Christian Borntraeger Signed-off-by: Vasily Gorbik