Messages in this thread Patch in this message | | | Subject | Re: [PATCH v3 7/9] s390: ap: implement PAPQ AQIC interception in kernel | From | Tony Krowiak <> | Date | Fri, 15 Feb 2019 18:11:20 -0500 |
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On 2/14/19 8:51 AM, Pierre Morel wrote: > We register the AP PQAP instruction hook during the open > of the mediated device. And unregister it on release. > > In the AP PQAP instruction hook, if we receive a demand to > enable IRQs, > - we retrieve the vfio_ap_queue based on the APQN we receive > in REG1, > - we retrieve the page of the guest address, (NIB), from > register REG2 > - we the mediated device to use the VFIO pinning infratrsucture > to pin the page of the guest address, > - we retrieve the pointer to KVM to register the guest ISC > and retrieve the host ISC > - finaly we activate GISA > > If we receive a demand to disable IRQs, > - we deactivate GISA > - unregister from the GIB > - unping the NIB > > Signed-off-by: Pierre Morel <pmorel@linux.ibm.com> > --- > drivers/s390/crypto/ap_bus.h | 1 + > drivers/s390/crypto/vfio_ap_ops.c | 191 +++++++++++++++++++++++++++++++++- > drivers/s390/crypto/vfio_ap_private.h | 2 + > 3 files changed, 191 insertions(+), 3 deletions(-) > > diff --git a/drivers/s390/crypto/ap_bus.h b/drivers/s390/crypto/ap_bus.h > index bfc66e4..323f2aa 100644 > --- a/drivers/s390/crypto/ap_bus.h > +++ b/drivers/s390/crypto/ap_bus.h > @@ -43,6 +43,7 @@ static inline int ap_test_bit(unsigned int *ptr, unsigned int nr) > #define AP_RESPONSE_BUSY 0x05 > #define AP_RESPONSE_INVALID_ADDRESS 0x06 > #define AP_RESPONSE_OTHERWISE_CHANGED 0x07 > +#define AP_RESPONSE_INVALID_GISA 0x08 > #define AP_RESPONSE_Q_FULL 0x10 > #define AP_RESPONSE_NO_PENDING_REPLY 0x10 > #define AP_RESPONSE_INDEX_TOO_BIG 0x11 > diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c > index 6eddc2c..5664cf3 100644 > --- a/drivers/s390/crypto/vfio_ap_ops.c > +++ b/drivers/s390/crypto/vfio_ap_ops.c > @@ -77,6 +77,28 @@ static void vfio_ap_put_queue(struct vfio_ap_queue *q) > q->dev = NULL; > } > > +/** > + * vfio_ap_free_irq: > + * @q: The vfio_ap_queue > + * > + * Unpin the guest NIB > + * 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) > +{ > + unsigned long pfn = q->nib >> PAGE_SHIFT; > + > + if (!q) > + return; > + if (q->nib) > + vfio_unpin_pages(mdev_dev(q->matrix->mdev), &pfn, 1); > + if (q->isc) > + kvm_s390_gisc_unregister(q->matrix->kvm, q->isc); > + q->nib = 0; > + q->isc = 0; > +} > + > static void vfio_ap_matrix_init(struct ap_config_info *info, > struct ap_matrix *matrix) > { > @@ -98,6 +120,7 @@ static int vfio_ap_mdev_create(struct kobject *kobj, struct mdev_device *mdev) > return -ENOMEM; > } > > + matrix_mdev->mdev = mdev; > vfio_ap_matrix_init(&matrix_dev->info, &matrix_mdev->matrix); > mdev_set_drvdata(mdev, matrix_mdev); > mutex_lock(&matrix_dev->lock); > @@ -781,6 +804,156 @@ static const struct attribute_group *vfio_ap_mdev_attr_groups[] = { > }; > > /** > + * vfio_ap_clrirq: Disable Interruption for a APQN > + * > + * @dev: the device associated with the ap_queue > + * @q: the vfio_ap_queue holding AQIC parameters > + * > + * Issue the host side PQAP/AQIC > + * On success: unpin the NIB saved in *q and unregister from GIB > + * interface > + * > + * Return the ap_queue_status returned by the ap_aqic() > + */ > +static struct ap_queue_status vfio_ap_clrirq(struct vfio_ap_queue *q) > +{ > + struct ap_qirq_ctrl aqic_gisa = {}; > + struct ap_queue_status status; > + > + status = ap_aqic(q->apqn, aqic_gisa, NULL); > + if (!status.response_code) > + vfio_ap_free_irq(q); > + > + return status; > +} > + > +/** > + * vfio_ap_setirq: Enable Interruption for a APQN > + * > + * @dev: the device associated with the ap_queue > + * @q: the vfio_ap_queue holding AQIC parameters > + * > + * Pin the NIB saved in *q > + * Register the guest ISC to GIB interface and retrieve the > + * host ISC to issue the host side PQAP/AQIC > + * > + * Response.status may be set to following Response Code in case of error: > + * - AP_RESPONSE_INVALID_ADDRESS: vfio_pin_pages failed > + * - AP_RESPONSE_OTHERWISE_CHANGED: Hypervizor GISA internal error > + * > + * Otherwise return the ap_queue_status returned by the ap_aqic() > + */ > +static struct ap_queue_status vfio_ap_setirq(struct vfio_ap_queue *q) > +{ > + struct ap_qirq_ctrl aqic_gisa = {}; > + struct ap_queue_status status = {}; > + struct kvm_s390_gisa *gisa; > + struct kvm *kvm; > + unsigned long g_pfn, h_nib, h_pfn; > + int ret; > + > + kvm = q->matrix->kvm; > + gisa = kvm->arch.gisa_int.origin; > + > + g_pfn = q->nib >> PAGE_SHIFT; > + ret = vfio_pin_pages(mdev_dev(q->matrix->mdev), &g_pfn, 1, > + IOMMU_READ | IOMMU_WRITE, &h_pfn); > + switch (ret) { > + case 1: > + break; > + case -EINVAL: > + case -E2BIG: > + status.response_code = AP_RESPONSE_INVALID_ADDRESS; > + /* Fallthrough */ > + default: > + return status; > + } > + > + h_nib = (h_pfn << PAGE_SHIFT) | (q->nib & ~PAGE_MASK); > + aqic_gisa.gisc = q->isc; > + aqic_gisa.isc = kvm_s390_gisc_register(kvm, q->isc); > + aqic_gisa.ir = 1; > + aqic_gisa.gisa = gisa->next_alert >> 4; > + > + status = ap_aqic(q->apqn, aqic_gisa, (void *)h_nib); > + if (status.response_code == AP_RESPONSE_INVALID_GISA) { > + status.response_code = AP_RESPONSE_OTHERWISE_CHANGED; > + pr_warn("vfio_ap: apqn %02x.%04x: AP_RESPONSE_INVALID_GISA\n", > + (q->apqn >> 8) & 0xff, q->apqn & 0xff); > + } > + > + if (status.response_code) > + vfio_ap_free_irq(q); > + > + return status; > +} > + > +/** > + * handle_pqap: PQAP instruction callback > + * > + * @vcpu: The vcpu on which we received the PQAP instruction > + * > + * Get the general register contents to initialize internal variables. > + * REG[0]: APQN > + * REG[1]: IR and ISC > + * REG[2]: NIB > + * > + * Response.status may be set to following Response Code: > + * - AP_RESPONSE_Q_NOT_AVAIL: if the queue is not available > + * - AP_RESPONSE_DECONFIGURED: if the queue is not configured > + * - AP_RESPONSE_NORMAL (0) : in case of successs > + * Check vfio_ap_setirq() and vfio_ap_clrirq() for other possible RC. > + * > + * Return 0 if we could handle the request inside KVM. > + * otherwise, returns -EOPNOTSUPP to let QEMU handle the fault. > + */
This function be nothing more than a switch statement for the function code sent with the PQAP instruction. Each case should be a call to a appropriate PQAP function handler. This will make it much easier to add additional handlers for the 6 other PQAP functions if necessary at some time down the road.
> +static int handle_pqap(struct kvm_vcpu *vcpu) > +{ int ret. uint8_t fc;
fc = vcpu->run->s.regs.gprs[0] >> 24; switch(fc) { case 0x03: ret = handle_pqap_aqic(vcpu); default: ret = -EOPNOTSUPP; }
return ret; }
static int handle_pqap_aqic(struct kvm_vcpu *vcpu) { > + uint64_t status; > + uint16_t apqn; struct device *qdev; > + struct vfio_ap_queue *q; > + struct ap_queue_status qstatus = {}; > + struct ap_matrix_mdev *matrix_mdev; > + > + /* If we do not use the AIV facility just go to userland */ > + if (!(vcpu->arch.sie_block->eca & ECA_AIV)) > + return -EOPNOTSUPP; > + > + apqn = vcpu->run->s.regs.gprs[0] & 0xffff; > + q = vfio_ap_get_queue(apqn);
Replace with: qdev = vfio_ap_get_queue_dev(apqn);
> + if (!q) {
Replace with: if (!qdev)
> + qstatus.response_code = AP_RESPONSE_Q_NOT_AVAIL; > + goto out; > + } > + > + /* Check if the queue is associated with a guest matrix */
Add this: q = dev_get_drvdata(qdev);
> + matrix_mdev = q->matrix; > + if (!matrix_mdev || !matrix_mdev->kvm) { > + qstatus.response_code = AP_RESPONSE_DECONFIGURED
> + goto out; > + } > + > + status = vcpu->run->s.regs.gprs[1]; > + > + /* If IR bit(16) is set we enable the interrupt */ > + if ((status >> (63 - 16)) & 0x01) { > + q->isc = status & 0x07; > + q->nib = vcpu->run->s.regs.gprs[2]; > + qstatus = vfio_ap_setirq(q); > + if (qstatus.response_code) { > + q->nib = 0; > + q->isc = 0; > + } > + } else > + qstatus = vfio_ap_clrirq(q); > + > +out: > + memcpy(&vcpu->run->s.regs.gprs[1], &qstatus, sizeof(qstatus)); > + vfio_ap_put_queue(q);
Replace with: put_device(qdev);
Can we just do a put_device(qdev) right after we get it since we only need it to get the drvdata, or do we need to wait until the other work is done?
> + return 0; > +} > + > + /* > * vfio_ap_mdev_iommu_notifier: IOMMU notifier callback > * > * @nb: The notifier block > @@ -802,7 +975,9 @@ static int vfio_ap_mdev_iommu_notifier(struct notifier_block *nb, > struct vfio_iommu_type1_dma_unmap *unmap = data; > unsigned long g_pfn = unmap->iova >> PAGE_SHIFT; > > - vfio_unpin_pages(mdev_dev(matrix_mdev->mdev), &g_pfn, 1); > + if (matrix_mdev->mdev) > + vfio_unpin_pages(mdev_dev(matrix_mdev->mdev), > + &g_pfn, 1); > return NOTIFY_OK; > } > > @@ -877,11 +1052,15 @@ static int vfio_ap_mdev_reset_queue(unsigned int apid, unsigned int apqi, > unsigned int retry) > { > struct ap_queue_status status; > + struct vfio_ap_queue *q; > + > + q = vfio_ap_get_queue(AP_MKQID(apid, apqi)); > > do { > status = ap_zapq(AP_MKQID(apid, apqi)); > switch (status.response_code) { > case AP_RESPONSE_NORMAL: > + vfio_ap_free_irq(q); > return 0; > case AP_RESPONSE_RESET_IN_PROGRESS: > case AP_RESPONSE_BUSY: > @@ -999,6 +1178,11 @@ static int vfio_ap_mdev_open(struct mdev_device *mdev) > if (ret) > goto err_group; > > + if (!matrix_mdev->kvm) { > + ret = -ENODEV; > + goto err_iommu; > + } > + > matrix_mdev->iommu_notifier.notifier_call = vfio_ap_mdev_iommu_notifier; > events = VFIO_IOMMU_NOTIFY_DMA_UNMAP; > > @@ -1011,6 +1195,7 @@ static int vfio_ap_mdev_open(struct mdev_device *mdev) > if (ret) > goto err_associate; > > + matrix_mdev->kvm->arch.crypto.pqap_hook = handle_pqap; > return 0; > > err_associate: > @@ -1031,12 +1216,12 @@ static void vfio_ap_mdev_release(struct mdev_device *mdev) > if (matrix_mdev->kvm) > kvm_arch_crypto_clear_masks(matrix_mdev->kvm); > > - vfio_ap_mdev_reset_queues(mdev); > + matrix_mdev->kvm->arch.crypto.pqap_hook = NULL; > + vfio_ap_dissociate_queues(matrix_mdev); > vfio_unregister_notifier(mdev_dev(mdev), VFIO_GROUP_NOTIFY, > &matrix_mdev->group_notifier); > vfio_unregister_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY, > &matrix_mdev->iommu_notifier); > - vfio_ap_dissociate_queues(matrix_mdev); > matrix_mdev->kvm = NULL; > module_put(THIS_MODULE); > } > diff --git a/drivers/s390/crypto/vfio_ap_private.h b/drivers/s390/crypto/vfio_ap_private.h > index 2781720..16c99e9 100644 > --- a/drivers/s390/crypto/vfio_ap_private.h > +++ b/drivers/s390/crypto/vfio_ap_private.h > @@ -92,5 +92,7 @@ struct vfio_ap_queue { > struct device *dev; > int apqn; > struct ap_matrix_mdev *matrix; > + unsigned long nib; > + unsigned char isc;
> }; > #endif /* _VFIO_AP_PRIVATE_H_ */ >
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