When the device is remove, we must make sure to clear the interruption and reset the AP device.
We also need to clear the CRYCB of the guest. Signed-off-by: Pierre Morel <[email protected]> --- drivers/s390/crypto/vfio_ap_drv.c | 92 +++++++++++++++++++++++++++++++++++ drivers/s390/crypto/vfio_ap_ops.c | 2 +- drivers/s390/crypto/vfio_ap_private.h | 2 + 3 files changed, 95 insertions(+), 1 deletion(-) diff --git a/drivers/s390/crypto/vfio_ap_drv.c b/drivers/s390/crypto/vfio_ap_drv.c index 03153e6..50428be 100644 --- a/drivers/s390/crypto/vfio_ap_drv.c +++ b/drivers/s390/crypto/vfio_ap_drv.c @@ -5,6 +5,7 @@ * Copyright IBM Corp. 2018 * * Author(s): Tony Krowiak <[email protected]> + * Pierre Morel <[email protected]> */ #include <linux/module.h> @@ -12,6 +13,8 @@ #include <linux/slab.h> #include <linux/string.h> #include <asm/facility.h> +#include <linux/bitops.h> +#include <linux/kvm_host.h> #include "vfio_ap_private.h" #define VFIO_AP_ROOT_NAME "vfio_ap" @@ -64,6 +67,88 @@ static int vfio_ap_queue_dev_probe(struct ap_device *apdev) return 0; } +/* + * vfio_ap_drain_queue + * @q: the queue to drain + * + * This function waits until the queue is empty. + */ +static void vfio_ap_drain_queue(struct vfio_ap_queue *q) +{ + struct ap_queue_status status; + int retry = 20; + + status = ap_tapq(q->apqn, NULL); + while (!status.queue_empty && retry--) { + msleep(200); + status = ap_tapq(q->apqn, NULL); + } + if (retry <= 0) { + pr_warn("%s: queue not empty after zapq on apqn 0x%04x\n", + __func__, q->apqn); + } +} + +/* + * vfio_ap_zapq + * @q: The queue to zerro + * + * It is best effort, no return value is done, however on success + * we will drain the queue before getting the queue back to the + * AP bus. + */ +static void vfio_ap_zapq(struct vfio_ap_queue *q) +{ + struct ap_queue_status status; + int retry = 20; + + do { + status = ap_zapq(q->apqn); + switch (status.response_code) { + case AP_RESPONSE_RESET_IN_PROGRESS: + case AP_RESPONSE_BUSY: + msleep(20); + break; + default: + pr_warn("%s: zapq error %02x on apqn 0x%04x\n", + __func__, status.response_code, q->apqn); + return; + case AP_RESPONSE_NORMAL: + vfio_ap_drain_queue(q); + return; + } + } while (retry--); + pr_warn("%s: zapq retry count exceeded code %02x on apqn 0x%04x\n", + __func__, status.response_code, q->apqn); +} + +/** + * vfio_ap_update_crycb + * @q: A pointer to the queue being removed + * + * We clear the APID of the queue, making this queue unusable for the guest. + * After this function we can reset the queue without to fear a race with + * the guest to access the queue again. + * We do not fear race with the host as we still get the device. + */ +static void vfio_ap_update_crycb(struct vfio_ap_queue *q) +{ + struct ap_matrix_mdev *matrix_mdev = q->matrix; + + if (!matrix_mdev) + return; + + clear_bit_inv(AP_QID_CARD(q->apqn), matrix_mdev->matrix.apm); + + if (!matrix_mdev->kvm) + return; + + kvm_arch_crypto_set_masks(matrix_mdev->kvm, + matrix_mdev->matrix.apm, + matrix_mdev->matrix.aqm, + matrix_mdev->matrix.adm); +} + /** * vfio_ap_queue_dev_remove: * @@ -74,6 +159,13 @@ static void vfio_ap_queue_dev_remove(struct ap_device *apdev) struct vfio_ap_queue *q; q = dev_get_drvdata(&apdev->device); + if (!q) + return; + + vfio_ap_update_crycb(q); + vfio_ap_zapq(q); + + vfio_ap_free_irq(q); kfree(q); } diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c index 5664cf3..7ec957c 100644 --- a/drivers/s390/crypto/vfio_ap_ops.c +++ b/drivers/s390/crypto/vfio_ap_ops.c @@ -85,7 +85,7 @@ static void vfio_ap_put_queue(struct vfio_ap_queue *q) * Unregister the ISC from the GIB alert * Clear the vfio_ap_queue intern fields */ -static void vfio_ap_free_irq(struct vfio_ap_queue *q) +void vfio_ap_free_irq(struct vfio_ap_queue *q) { unsigned long pfn = q->nib >> PAGE_SHIFT; diff --git a/drivers/s390/crypto/vfio_ap_private.h b/drivers/s390/crypto/vfio_ap_private.h index 16c99e9..d108c6d 100644 --- a/drivers/s390/crypto/vfio_ap_private.h +++ b/drivers/s390/crypto/vfio_ap_private.h @@ -4,6 +4,7 @@ * * Author(s): Tony Krowiak <[email protected]> * Halil Pasic <[email protected]> + * Pierre Morel <[email protected]> * * Copyright IBM Corp. 2018 */ @@ -95,4 +96,5 @@ struct vfio_ap_queue { unsigned long nib; unsigned char isc; }; +void vfio_ap_free_irq(struct vfio_ap_queue *q); #endif /* _VFIO_AP_PRIVATE_H_ */ -- 2.7.4
