Messages in this thread | | | Subject | Re: [PATCH v4 6/7] s390: ap: Cleanup on removing the AP device | From | Pierre Morel <> | Date | Mon, 11 Mar 2019 09:31:02 +0100 |
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On 08/03/2019 23:43, Tony Krowiak wrote: > On 2/22/19 10:29 AM, Pierre Morel wrote: >> 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 <pmorel@linux.ibm.com> >> --- >> drivers/s390/crypto/vfio_ap_drv.c | 35 >> +++++++++++++++++++++++++++++++++++ >> drivers/s390/crypto/vfio_ap_ops.c | 3 ++- >> drivers/s390/crypto/vfio_ap_private.h | 3 +++ >> 3 files changed, 40 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/s390/crypto/vfio_ap_drv.c >> b/drivers/s390/crypto/vfio_ap_drv.c >> index eca0ffc..e5d91ff 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 <akrowiak@linux.ibm.com> >> + * Pierre Morel <pmorel@linux.ibm.com> >> */ >> #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" >> @@ -61,6 +64,33 @@ static int vfio_ap_queue_dev_probe(struct ap_device >> *apdev) >> } >> /** >> + * 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_mdev; >> + >> + 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: >> * >> * Free the associated vfio_ap_queue structure >> @@ -70,6 +100,11 @@ 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_mdev_reset_queue(q); > > Since the bit corresponding to the APID is cleared in the > vfio_ap_update_crycb() above, shouldn't all queues on that > card also be reset?
I do not think so. The remove function will be called in a loop for all queues by the bus. No need to clear all queues.
> >> list_del(&q->list); >> kfree(q); >> } >> diff --git a/drivers/s390/crypto/vfio_ap_ops.c >> b/drivers/s390/crypto/vfio_ap_ops.c >> index 0196065..5b9bb33 100644 >> --- a/drivers/s390/crypto/vfio_ap_ops.c >> +++ b/drivers/s390/crypto/vfio_ap_ops.c >> @@ -59,6 +59,7 @@ int vfio_ap_mdev_reset_queue(struct vfio_ap_queue *q) >> if (retry <= 0) >> pr_warn("%s: queue 0x%04x not empty\n", >> __func__, q->apqn); >> + vfio_ap_free_irq(q); > > Shouldn't this be done for the response codes that terminate this loop > such as those caught by the default case?
I do not think so, the error code is returned and the caller may want to reset the queue again. I think that doing the free inside the call to reset is not right. I will investigate in this direction.
Regards, Pierre
-- Pierre Morel Linux/KVM/QEMU in Böblingen - Germany
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