Messages in this thread | | | Subject | Re: [PATCH v2 3/8] s390: vfio-ap: allow assignment of unavailable AP resources to mdev device | From | Pierre Morel <> | Date | Tue, 23 Apr 2019 14:46:42 +0200 |
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On 20/04/2019 23:49, Tony Krowiak wrote: > The AP architecture does not preclude assignment of AP resources that are > not yet in the AP configuration (i.e., not available or not online). > Let's go ahead and implement this facet of the AP architecture for linux > guests. > > Access to AP resources is controlled by bit masks in a guest's SIE > state description (i.e., the control block containing the state of a > guest). When an AP instruction is executed on the guest, the firmware > combines the masks from the guest's SIE state description with the masks > from the host by doing a logical bitwise AND of the masks to create what > are defined as effective masks. The effective masks determine which AP > resources can be accessed by the guest. > > Effective masking allows the assignment of AP resources to a guest even > if the underlying device is not in the AP configuration. If the device > subsequently becomes configured, the guest will automatically have access > to the associated AP resources (e.g., AP queues). > > The current implementation does not allow assignment of AP resources to > an mdev device if the AP queues identified by the assignment are not > bound to the vfio_ap device driver. This patch allows assignment of AP > resources to the mdev device even if the AP queues are not bound to the > vfio_ap device driver, as long as the AP queues are not reserved by the > AP BUS for use by the zcrypt device drivers. If the queues are subsequently > bound to the vfio_ap device driver while a running guest is using the mdev > device, the guest will automatically gain access to the queues. Effective > masking prevents access to queues until such time as they become available. > > Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com> > --- > drivers/s390/crypto/vfio_ap_ops.c | 160 +++++--------------------------------- > 1 file changed, 18 insertions(+), 142 deletions(-) > > diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c > index eae4ee24460a..221491a9ba95 100644 > --- a/drivers/s390/crypto/vfio_ap_ops.c > +++ b/drivers/s390/crypto/vfio_ap_ops.c > @@ -113,122 +113,6 @@ static struct attribute_group *vfio_ap_mdev_type_groups[] = { > NULL, > }; > > -struct vfio_ap_queue_reserved { > - unsigned long *apid; > - unsigned long *apqi; > - bool reserved; > -}; > - > -/** > - * vfio_ap_has_queue > - * > - * @dev: an AP queue device > - * @data: a struct vfio_ap_queue_reserved reference > - * > - * Flags whether the AP queue device (@dev) has a queue ID containing the APQN, > - * apid or apqi specified in @data: > - * > - * - If @data contains both an apid and apqi value, then @data will be flagged > - * as reserved if the APID and APQI fields for the AP queue device matches > - * > - * - If @data contains only an apid value, @data will be flagged as > - * reserved if the APID field in the AP queue device matches > - * > - * - If @data contains only an apqi value, @data will be flagged as > - * reserved if the APQI field in the AP queue device matches > - * > - * Returns 0 to indicate the input to function succeeded. Returns -EINVAL if > - * @data does not contain either an apid or apqi. > - */ > -static int vfio_ap_has_queue(struct device *dev, void *data) > -{ > - struct vfio_ap_queue_reserved *qres = data; > - struct ap_queue *ap_queue = to_ap_queue(dev); > - ap_qid_t qid; > - unsigned long id; > - > - if (qres->apid && qres->apqi) { > - qid = AP_MKQID(*qres->apid, *qres->apqi); > - if (qid == ap_queue->qid) > - qres->reserved = true; > - } else if (qres->apid && !qres->apqi) { > - id = AP_QID_CARD(ap_queue->qid); > - if (id == *qres->apid) > - qres->reserved = true; > - } else if (!qres->apid && qres->apqi) { > - id = AP_QID_QUEUE(ap_queue->qid); > - if (id == *qres->apqi) > - qres->reserved = true; > - } else { > - return -EINVAL; > - } > - > - return 0; > -} > - > -/** > - * vfio_ap_verify_queue_reserved > - * > - * @matrix_dev: a mediated matrix device > - * @apid: an AP adapter ID > - * @apqi: an AP queue index > - * > - * Verifies that the AP queue with @apid/@apqi is reserved by the VFIO AP device > - * driver according to the following rules: > - * > - * - If both @apid and @apqi are not NULL, then there must be an AP queue > - * device bound to the vfio_ap driver with the APQN identified by @apid and > - * @apqi > - * > - * - If only @apid is not NULL, then there must be an AP queue device bound > - * to the vfio_ap driver with an APQN containing @apid > - * > - * - If only @apqi is not NULL, then there must be an AP queue device bound > - * to the vfio_ap driver with an APQN containing @apqi > - * > - * Returns 0 if the AP queue is reserved; otherwise, returns -EADDRNOTAVAIL. > - */ > -static int vfio_ap_verify_queue_reserved(unsigned long *apid, > - unsigned long *apqi) > -{ > - int ret; > - struct vfio_ap_queue_reserved qres; > - > - qres.apid = apid; > - qres.apqi = apqi; > - qres.reserved = false; > - > - ret = driver_for_each_device(&matrix_dev->vfio_ap_drv->driver, NULL, > - &qres, vfio_ap_has_queue); > - if (ret) > - return ret; > - > - if (qres.reserved) > - return 0; > - > - return -EADDRNOTAVAIL; > -} > - > -static int > -vfio_ap_mdev_verify_queues_reserved_for_apid(struct ap_matrix_mdev *matrix_mdev, > - unsigned long apid)
You suppress this function but it is still in use in assign_adapter_store...
> -{ > - int ret; > - unsigned long apqi; > - unsigned long nbits = matrix_mdev->matrix.aqm_max + 1; > - > - if (find_first_bit_inv(matrix_mdev->matrix.aqm, nbits) >= nbits) > - return vfio_ap_verify_queue_reserved(&apid, NULL); > - > - for_each_set_bit_inv(apqi, matrix_mdev->matrix.aqm, nbits) { > - ret = vfio_ap_verify_queue_reserved(&apid, &apqi); > - if (ret) > - return ret; > - } > - > - return 0; > -} > - > /** > * vfio_ap_mdev_verify_no_sharing > * > @@ -359,9 +243,17 @@ static ssize_t assign_adapter_store(struct device *dev, > > set_bit_inv(apid, matrix_mdev->matrix.apm); > > + ret = ap_apqn_in_matrix_owned_by_def_drv(matrix_mdev->matrix.apm, > + matrix_mdev->matrix.aqm); > + > + /* If any APQN is owned by a default driver */ > + ret = (ret == 1) ? -EADDRNOTAVAIL : ret; > + if (ret) > + goto error; > + > ret = vfio_ap_mdev_verify_no_sharing(matrix_mdev); > if (ret) > - goto share_err; > + goto error; > > if (matrix_mdev->shadow_crycb) > set_bit_inv(apid, matrix_mdev->shadow_crycb->apm); > @@ -369,7 +261,7 @@ static ssize_t assign_adapter_store(struct device *dev, > ret = count; > goto done; > > -share_err: > +error: > clear_bit_inv(apid, matrix_mdev->matrix.apm); > done: > mutex_unlock(&matrix_dev->lock); > @@ -426,26 +318,6 @@ static ssize_t unassign_adapter_store(struct device *dev, > } > static DEVICE_ATTR_WO(unassign_adapter); > > -static int > -vfio_ap_mdev_verify_queues_reserved_for_apqi(struct ap_matrix_mdev *matrix_mdev, > - unsigned long apqi) > -{ > - int ret; > - unsigned long apid; > - unsigned long nbits = matrix_mdev->matrix.apm_max + 1; > - > - if (find_first_bit_inv(matrix_mdev->matrix.apm, nbits) >= nbits) > - return vfio_ap_verify_queue_reserved(NULL, &apqi); > - > - for_each_set_bit_inv(apid, matrix_mdev->matrix.apm, nbits) { > - ret = vfio_ap_verify_queue_reserved(&apid, &apqi); > - if (ret) > - return ret; > - } > - > - return 0; > -} > - > /** > * assign_domain_store > * > @@ -500,12 +372,16 @@ static ssize_t assign_domain_store(struct device *dev, > > mutex_lock(&matrix_dev->lock); > > - ret = vfio_ap_mdev_verify_queues_reserved_for_apqi(matrix_mdev, apqi); > - if (ret) > - goto done; > - > set_bit_inv(apqi, matrix_mdev->matrix.aqm); > > + ret = ap_apqn_in_matrix_owned_by_def_drv(matrix_mdev->matrix.apm, > + matrix_mdev->matrix.aqm); > + > + /* If any APQN is owned by a default driver */ > + ret = (ret == 1) ? -EADDRNOTAVAIL : ret; > + if (ret) > + goto error;
forget to add the error label ?
> + > ret = vfio_ap_mdev_verify_no_sharing(matrix_mdev); > if (ret) > goto share_err; >
-- Pierre Morel Linux/KVM/QEMU in Böblingen - Germany
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