Messages in this thread | | | Subject | Re: [PATCH v2 2/7] s390: vfio-ap: maintain a shadow of the guest's CRYCB | From | Tony Krowiak <> | Date | Tue, 7 May 2019 11:15:27 -0400 |
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On 5/7/19 4:22 AM, Pierre Morel wrote: > On 06/05/2019 21:53, Tony Krowiak wrote: >> On 5/6/19 2:49 AM, Pierre Morel wrote: >>> On 03/05/2019 23:14, Tony Krowiak wrote: >>>> This patch introduces a shadow of the CRYCB being used by a guest. This >>>> will enable to more effectively manage dynamic changes to the AP >>>> resources installed on the host that may be assigned to an mdev device >>>> and being used by a guest. For example: >>>> >>>> * AP adapter cards can be dynamically added to and removed from the AP >>>> configuration via the SE or an SCLP command. >>>> >>>> * AP resources that disappear and reappear due to hardware >>>> malfunctions. >>>> >>>> * AP queues bound to and unbound from the vfio_ap device driver by a >>>> root user. >>>> >>>> Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com> >>>> --- >>>> drivers/s390/crypto/vfio_ap_ops.c | 91 >>>> ++++++++++++++++++++++++++++++++--- >>>> drivers/s390/crypto/vfio_ap_private.h | 2 + >>>> 2 files changed, 87 insertions(+), 6 deletions(-) >>>> >>>> diff --git a/drivers/s390/crypto/vfio_ap_ops.c >>>> b/drivers/s390/crypto/vfio_ap_ops.c >>>> index b88a2a2ba075..44a04b4aa9ae 100644 >>>> --- a/drivers/s390/crypto/vfio_ap_ops.c >>>> +++ b/drivers/s390/crypto/vfio_ap_ops.c >>>> @@ -297,6 +297,45 @@ static void >>>> vfio_ap_mdev_wait_for_qempty(unsigned long apid, unsigned long apqi) >>>> } while (--retry); >>>> } >>>> +/* >>>> + * vfio_ap_mdev_update_crycb >>>> + * >>>> + * @matrix_mdev: the mediated matrix device >>>> + * >>>> + * Updates the AP matrix in the guest's CRYCB from it's shadow masks. >>>> + * >>>> + * Returns zero if the guest's CRYCB is successfully updated; >>>> otherwise, >>>> + * returns -ENODEV if a guest is not running or does not have a CRYCB. >>>> + */ >>>> +static int vfio_ap_mdev_update_crycb(struct ap_matrix_mdev >>>> *matrix_mdev) >>>> +{ >>>> + if (!matrix_mdev->kvm || !matrix_mdev->kvm->arch.crypto.crycbd) >>>> + return -ENODEV; >>>> + >>>> + kvm_arch_crypto_set_masks(matrix_mdev->kvm, >>>> + matrix_mdev->shadow_crycb->apm, >>>> + matrix_mdev->shadow_crycb->aqm, >>>> + matrix_mdev->shadow_crycb->adm); >>>> + >>>> + return 0; >>>> +} >>>> + >>>> +static int match_apqn(struct device *dev, void *data) >>>> +{ >>>> + struct ap_queue *apq = to_ap_queue(dev); >>>> + >>>> + return (apq->qid == *(unsigned long *)(data)) ? 1 : 0; >>>> +} >>>> + >>>> +static struct device *vfio_ap_get_queue_dev(unsigned long apid, >>>> + unsigned long apqi) >>>> +{ >>>> + unsigned long apqn = AP_MKQID(apid, apqi); >>>> + >>>> + return driver_find_device(&matrix_dev->vfio_ap_drv->driver, NULL, >>>> + &apqn, match_apqn); >>>> +} >>>> + >>>> /** >>>> * assign_adapter_store >>>> * >>>> @@ -805,14 +844,9 @@ static int vfio_ap_mdev_group_notifier(struct >>>> notifier_block *nb, >>>> if (ret) >>>> return NOTIFY_DONE; >>>> - /* If there is no CRYCB pointer, then we can't copy the masks */ >>>> - if (!matrix_mdev->kvm->arch.crypto.crycbd) >>>> + if (vfio_ap_mdev_update_crycb(matrix_mdev)) >>>> return NOTIFY_DONE; >>>> - kvm_arch_crypto_set_masks(matrix_mdev->kvm, >>>> matrix_mdev->matrix.apm, >>>> - matrix_mdev->matrix.aqm, >>>> - matrix_mdev->matrix.adm); >>>> - >>>> return NOTIFY_OK; >>>> } >>>> @@ -867,12 +901,55 @@ static int vfio_ap_mdev_reset_queues(struct >>>> mdev_device *mdev) >>>> return rc; >>>> } >>>> +static int vfio_ap_mdev_create_shadow_crycb(struct ap_matrix_mdev >>>> *matrix_mdev) >>>> +{ >>>> + unsigned long apid, apqi, domid; >>>> + struct device *dev; >>>> + >>>> + matrix_mdev->shadow_crycb = >>>> kzalloc(sizeof(*matrix_mdev->shadow_crycb), >>>> + GFP_KERNEL); >>>> + if (!matrix_mdev->shadow_crycb) >>>> + return -ENOMEM; >>>> + >>>> + vfio_ap_matrix_init(&matrix_dev->info, matrix_mdev->shadow_crycb); >>>> + >>>> + /* >>>> + * Examine each APQN assigned to the mdev device. Set the APID >>>> and APQI >>>> + * in the shadow CRYCB if and only if the queue device >>>> identified by >>>> + * the APQN is in the configuration. >>>> + */ >>>> + for_each_set_bit_inv(apid, matrix_mdev->matrix.apm, >>>> + matrix_mdev->matrix.apm_max + 1) { >>>> + for_each_set_bit_inv(apqi, matrix_mdev->matrix.aqm, >>>> + matrix_mdev->matrix.aqm_max + 1) { >>>> + dev = vfio_ap_get_queue_dev(apid, apqi); >>>> + if (dev) { >>>> + set_bit_inv(apid, >>>> + matrix_mdev->shadow_crycb->apm); >>>> + set_bit_inv(apqi, >>>> + matrix_mdev->shadow_crycb->aqm); >>>> + put_device(dev); >>>> + } >>> >>> I think that if we do not find a device here we have a problem. >>> Don't we? >> >> Other than the fact that the guest will not have any AP devices, >> what would be the problem? What would you suggest? >> > > Suppose we have in matrix_mdev->matrix: > 1-2 > 1-3 > 2-2 > 2-3 > > We set the shadow_crycb with: > we find 1-2 we set 1 2 > we find 1-3 we se 1 3 > we find 2-2 we set 2 2 > we do not find 2-3 > > we have set apm(1,2) aqm(2,3) > the guest can access 2-3 but we do not have the device.
Good point. I'll fix this for v4.
> > Pierre >
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