Merge tag 'driver-core-5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git...
[sfrench/cifs-2.6.git] / drivers / s390 / crypto / vfio_ap_ops.c
index 900b9cf20ca5e9a74b2adc452820cca696ad9928..7e85ba7c6ef0170ffc65dbfd0c5ec92b156ec204 100644 (file)
 #define VFIO_AP_MDEV_TYPE_HWVIRT "passthrough"
 #define VFIO_AP_MDEV_NAME_HWVIRT "VFIO AP Passthrough Device"
 
+static int vfio_ap_mdev_reset_queues(struct mdev_device *mdev);
+
+static int match_apqn(struct device *dev, const void *data)
+{
+       struct vfio_ap_queue *q = dev_get_drvdata(dev);
+
+       return (q->apqn == *(int *)(data)) ? 1 : 0;
+}
+
+/**
+ * vfio_ap_get_queue: Retrieve a queue with a specific APQN from a list
+ * @matrix_mdev: the associated mediated matrix
+ * @apqn: The queue APQN
+ *
+ * Retrieve a queue with a specific APQN from the list of the
+ * devices of the vfio_ap_drv.
+ * Verify that the APID and the APQI are set in the matrix.
+ *
+ * Returns the pointer to the associated vfio_ap_queue
+ */
+static struct vfio_ap_queue *vfio_ap_get_queue(
+                                       struct ap_matrix_mdev *matrix_mdev,
+                                       int apqn)
+{
+       struct vfio_ap_queue *q;
+       struct device *dev;
+
+       if (!test_bit_inv(AP_QID_CARD(apqn), matrix_mdev->matrix.apm))
+               return NULL;
+       if (!test_bit_inv(AP_QID_QUEUE(apqn), matrix_mdev->matrix.aqm))
+               return NULL;
+
+       dev = driver_find_device(&matrix_dev->vfio_ap_drv->driver, NULL,
+                                &apqn, match_apqn);
+       if (!dev)
+               return NULL;
+       q = dev_get_drvdata(dev);
+       q->matrix_mdev = matrix_mdev;
+       put_device(dev);
+
+       return q;
+}
+
+/**
+ * vfio_ap_wait_for_irqclear
+ * @apqn: The AP Queue number
+ *
+ * Checks the IRQ bit for the status of this APQN using ap_tapq.
+ * Returns if the ap_tapq function succeeded and the bit is clear.
+ * Returns if ap_tapq function failed with invalid, deconfigured or
+ * checkstopped AP.
+ * Otherwise retries up to 5 times after waiting 20ms.
+ *
+ */
+static void vfio_ap_wait_for_irqclear(int apqn)
+{
+       struct ap_queue_status status;
+       int retry = 5;
+
+       do {
+               status = ap_tapq(apqn, NULL);
+               switch (status.response_code) {
+               case AP_RESPONSE_NORMAL:
+               case AP_RESPONSE_RESET_IN_PROGRESS:
+                       if (!status.irq_enabled)
+                               return;
+                       /* Fall through */
+               case AP_RESPONSE_BUSY:
+                       msleep(20);
+                       break;
+               case AP_RESPONSE_Q_NOT_AVAIL:
+               case AP_RESPONSE_DECONFIGURED:
+               case AP_RESPONSE_CHECKSTOPPED:
+               default:
+                       WARN_ONCE(1, "%s: tapq rc %02x: %04x\n", __func__,
+                                 status.response_code, apqn);
+                       return;
+               }
+       } while (--retry);
+
+       WARN_ONCE(1, "%s: tapq rc %02x: %04x could not clear IR bit\n",
+                 __func__, status.response_code, apqn);
+}
+
+/**
+ * vfio_ap_free_aqic_resources
+ * @q: The vfio_ap_queue
+ *
+ * Unregisters the ISC in the GIB when the saved ISC not invalid.
+ * Unpin the guest's page holding the NIB when it exist.
+ * Reset the saved_pfn and saved_isc to invalid values.
+ * Clear the pointer to the matrix mediated device.
+ *
+ */
+static void vfio_ap_free_aqic_resources(struct vfio_ap_queue *q)
+{
+       if (q->saved_isc != VFIO_AP_ISC_INVALID && q->matrix_mdev)
+               kvm_s390_gisc_unregister(q->matrix_mdev->kvm, q->saved_isc);
+       if (q->saved_pfn && q->matrix_mdev)
+               vfio_unpin_pages(mdev_dev(q->matrix_mdev->mdev),
+                                &q->saved_pfn, 1);
+       q->saved_pfn = 0;
+       q->saved_isc = VFIO_AP_ISC_INVALID;
+       q->matrix_mdev = NULL;
+}
+
+/**
+ * vfio_ap_irq_disable
+ * @q: The vfio_ap_queue
+ *
+ * Uses ap_aqic to disable the interruption and in case of success, reset
+ * in progress or IRQ disable command already proceeded: calls
+ * vfio_ap_wait_for_irqclear() to check for the IRQ bit to be clear
+ * and calls vfio_ap_free_aqic_resources() to free the resources associated
+ * with the AP interrupt handling.
+ *
+ * In the case the AP is busy, or a reset is in progress,
+ * retries after 20ms, up to 5 times.
+ *
+ * Returns if ap_aqic function failed with invalid, deconfigured or
+ * checkstopped AP.
+ */
+struct ap_queue_status vfio_ap_irq_disable(struct vfio_ap_queue *q)
+{
+       struct ap_qirq_ctrl aqic_gisa = {};
+       struct ap_queue_status status;
+       int retries = 5;
+
+       do {
+               status = ap_aqic(q->apqn, aqic_gisa, NULL);
+               switch (status.response_code) {
+               case AP_RESPONSE_OTHERWISE_CHANGED:
+               case AP_RESPONSE_NORMAL:
+                       vfio_ap_wait_for_irqclear(q->apqn);
+                       goto end_free;
+               case AP_RESPONSE_RESET_IN_PROGRESS:
+               case AP_RESPONSE_BUSY:
+                       msleep(20);
+                       break;
+               case AP_RESPONSE_Q_NOT_AVAIL:
+               case AP_RESPONSE_DECONFIGURED:
+               case AP_RESPONSE_CHECKSTOPPED:
+               case AP_RESPONSE_INVALID_ADDRESS:
+               default:
+                       /* All cases in default means AP not operational */
+                       WARN_ONCE(1, "%s: ap_aqic status %d\n", __func__,
+                                 status.response_code);
+                       goto end_free;
+               }
+       } while (retries--);
+
+       WARN_ONCE(1, "%s: ap_aqic status %d\n", __func__,
+                 status.response_code);
+end_free:
+       vfio_ap_free_aqic_resources(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 AP_RESPONSE_INVALID_ADDRESS in case the
+ * vfio_pin_pages failed.
+ *
+ * Otherwise return the ap_queue_status returned by the ap_aqic(),
+ * all retry handling will be done by the guest.
+ */
+static struct ap_queue_status vfio_ap_irq_enable(struct vfio_ap_queue *q,
+                                                int isc,
+                                                unsigned long nib)
+{
+       struct ap_qirq_ctrl aqic_gisa = {};
+       struct ap_queue_status status = {};
+       struct kvm_s390_gisa *gisa;
+       struct kvm *kvm;
+       unsigned long h_nib, g_pfn, h_pfn;
+       int ret;
+
+       g_pfn = nib >> PAGE_SHIFT;
+       ret = vfio_pin_pages(mdev_dev(q->matrix_mdev->mdev), &g_pfn, 1,
+                            IOMMU_READ | IOMMU_WRITE, &h_pfn);
+       switch (ret) {
+       case 1:
+               break;
+       default:
+               status.response_code = AP_RESPONSE_INVALID_ADDRESS;
+               return status;
+       }
+
+       kvm = q->matrix_mdev->kvm;
+       gisa = kvm->arch.gisa_int.origin;
+
+       h_nib = (h_pfn << PAGE_SHIFT) | (nib & ~PAGE_MASK);
+       aqic_gisa.gisc = isc;
+       aqic_gisa.isc = kvm_s390_gisc_register(kvm, isc);
+       aqic_gisa.ir = 1;
+       aqic_gisa.gisa = (uint64_t)gisa >> 4;
+
+       status = ap_aqic(q->apqn, aqic_gisa, (void *)h_nib);
+       switch (status.response_code) {
+       case AP_RESPONSE_NORMAL:
+               /* See if we did clear older IRQ configuration */
+               vfio_ap_free_aqic_resources(q);
+               q->saved_pfn = g_pfn;
+               q->saved_isc = isc;
+               break;
+       case AP_RESPONSE_OTHERWISE_CHANGED:
+               /* We could not modify IRQ setings: clear new configuration */
+               vfio_unpin_pages(mdev_dev(q->matrix_mdev->mdev), &g_pfn, 1);
+               kvm_s390_gisc_unregister(kvm, isc);
+               break;
+       default:
+               pr_warn("%s: apqn %04x: response: %02x\n", __func__, q->apqn,
+                       status.response_code);
+               vfio_ap_irq_disable(q);
+               break;
+       }
+
+       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.
+ * We take the matrix_dev lock to ensure serialization on queues and
+ * mediated device access.
+ *
+ * Return 0 if we could handle the request inside KVM.
+ * otherwise, returns -EOPNOTSUPP to let QEMU handle the fault.
+ */
+static int handle_pqap(struct kvm_vcpu *vcpu)
+{
+       uint64_t status;
+       uint16_t apqn;
+       struct vfio_ap_queue *q;
+       struct ap_queue_status qstatus = {
+                              .response_code = AP_RESPONSE_Q_NOT_AVAIL, };
+       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;
+       mutex_lock(&matrix_dev->lock);
+
+       if (!vcpu->kvm->arch.crypto.pqap_hook)
+               goto out_unlock;
+       matrix_mdev = container_of(vcpu->kvm->arch.crypto.pqap_hook,
+                                  struct ap_matrix_mdev, pqap_hook);
+
+       q = vfio_ap_get_queue(matrix_mdev, apqn);
+       if (!q)
+               goto out_unlock;
+
+       status = vcpu->run->s.regs.gprs[1];
+
+       /* If IR bit(16) is set we enable the interrupt */
+       if ((status >> (63 - 16)) & 0x01)
+               qstatus = vfio_ap_irq_enable(q, status & 0x07,
+                                            vcpu->run->s.regs.gprs[2]);
+       else
+               qstatus = vfio_ap_irq_disable(q);
+
+out_unlock:
+       memcpy(&vcpu->run->s.regs.gprs[1], &qstatus, sizeof(qstatus));
+       vcpu->run->s.regs.gprs[1] >>= 32;
+       mutex_unlock(&matrix_dev->lock);
+       return 0;
+}
+
 static void vfio_ap_matrix_init(struct ap_config_info *info,
                                struct ap_matrix *matrix)
 {
@@ -45,8 +335,11 @@ 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);
+       matrix_mdev->pqap_hook.hook = handle_pqap;
+       matrix_mdev->pqap_hook.owner = THIS_MODULE;
        mutex_lock(&matrix_dev->lock);
        list_add(&matrix_mdev->node, &matrix_dev->mdev_list);
        mutex_unlock(&matrix_dev->lock);
@@ -62,6 +355,7 @@ static int vfio_ap_mdev_remove(struct mdev_device *mdev)
                return -EBUSY;
 
        mutex_lock(&matrix_dev->lock);
+       vfio_ap_mdev_reset_queues(mdev);
        list_del(&matrix_mdev->node);
        mutex_unlock(&matrix_dev->lock);
 
@@ -754,11 +1048,42 @@ static int vfio_ap_mdev_set_kvm(struct ap_matrix_mdev *matrix_mdev,
        }
 
        matrix_mdev->kvm = kvm;
+       kvm_get_kvm(kvm);
+       kvm->arch.crypto.pqap_hook = &matrix_mdev->pqap_hook;
        mutex_unlock(&matrix_dev->lock);
 
        return 0;
 }
 
+/*
+ * vfio_ap_mdev_iommu_notifier: IOMMU notifier callback
+ *
+ * @nb: The notifier block
+ * @action: Action to be taken
+ * @data: data associated with the request
+ *
+ * For an UNMAP request, unpin the guest IOVA (the NIB guest address we
+ * pinned before). Other requests are ignored.
+ *
+ */
+static int vfio_ap_mdev_iommu_notifier(struct notifier_block *nb,
+                                      unsigned long action, void *data)
+{
+       struct ap_matrix_mdev *matrix_mdev;
+
+       matrix_mdev = container_of(nb, struct ap_matrix_mdev, iommu_notifier);
+
+       if (action == VFIO_IOMMU_NOTIFY_DMA_UNMAP) {
+               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);
+               return NOTIFY_OK;
+       }
+
+       return NOTIFY_DONE;
+}
+
 static int vfio_ap_mdev_group_notifier(struct notifier_block *nb,
                                       unsigned long action, void *data)
 {
@@ -790,15 +1115,36 @@ static int vfio_ap_mdev_group_notifier(struct notifier_block *nb,
        return NOTIFY_OK;
 }
 
-static int vfio_ap_mdev_reset_queue(unsigned int apid, unsigned int apqi,
-                                   unsigned int retry)
+static void vfio_ap_irq_disable_apqn(int apqn)
+{
+       struct device *dev;
+       struct vfio_ap_queue *q;
+
+       dev = driver_find_device(&matrix_dev->vfio_ap_drv->driver, NULL,
+                                &apqn, match_apqn);
+       if (dev) {
+               q = dev_get_drvdata(dev);
+               vfio_ap_irq_disable(q);
+               put_device(dev);
+       }
+}
+
+int vfio_ap_mdev_reset_queue(unsigned int apid, unsigned int apqi,
+                            unsigned int retry)
 {
        struct ap_queue_status status;
+       int retry2 = 2;
+       int apqn = AP_MKQID(apid, apqi);
 
        do {
-               status = ap_zapq(AP_MKQID(apid, apqi));
+               status = ap_zapq(apqn);
                switch (status.response_code) {
                case AP_RESPONSE_NORMAL:
+                       while (!status.queue_empty && retry2--) {
+                               msleep(20);
+                               status = ap_tapq(apqn, NULL);
+                       }
+                       WARN_ON_ONCE(retry <= 0);
                        return 0;
                case AP_RESPONSE_RESET_IN_PROGRESS:
                case AP_RESPONSE_BUSY:
@@ -832,6 +1178,7 @@ static int vfio_ap_mdev_reset_queues(struct mdev_device *mdev)
                         */
                        if (ret)
                                rc = ret;
+                       vfio_ap_irq_disable_apqn(AP_MKQID(apid, apqi));
                }
        }
 
@@ -858,20 +1205,37 @@ static int vfio_ap_mdev_open(struct mdev_device *mdev)
                return ret;
        }
 
-       return 0;
+       matrix_mdev->iommu_notifier.notifier_call = vfio_ap_mdev_iommu_notifier;
+       events = VFIO_IOMMU_NOTIFY_DMA_UNMAP;
+       ret = vfio_register_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY,
+                                    &events, &matrix_mdev->iommu_notifier);
+       if (!ret)
+               return ret;
+
+       vfio_unregister_notifier(mdev_dev(mdev), VFIO_GROUP_NOTIFY,
+                                &matrix_mdev->group_notifier);
+       module_put(THIS_MODULE);
+       return ret;
 }
 
 static void vfio_ap_mdev_release(struct mdev_device *mdev)
 {
        struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);
 
-       if (matrix_mdev->kvm)
+       mutex_lock(&matrix_dev->lock);
+       if (matrix_mdev->kvm) {
                kvm_arch_crypto_clear_masks(matrix_mdev->kvm);
+               matrix_mdev->kvm->arch.crypto.pqap_hook = NULL;
+               vfio_ap_mdev_reset_queues(mdev);
+               kvm_put_kvm(matrix_mdev->kvm);
+               matrix_mdev->kvm = NULL;
+       }
+       mutex_unlock(&matrix_dev->lock);
 
-       vfio_ap_mdev_reset_queues(mdev);
+       vfio_unregister_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY,
+                                &matrix_mdev->iommu_notifier);
        vfio_unregister_notifier(mdev_dev(mdev), VFIO_GROUP_NOTIFY,
                                 &matrix_mdev->group_notifier);
-       matrix_mdev->kvm = NULL;
        module_put(THIS_MODULE);
 }
 
@@ -900,6 +1264,7 @@ static ssize_t vfio_ap_mdev_ioctl(struct mdev_device *mdev,
 {
        int ret;
 
+       mutex_lock(&matrix_dev->lock);
        switch (cmd) {
        case VFIO_DEVICE_GET_INFO:
                ret = vfio_ap_mdev_get_device_info(arg);
@@ -911,6 +1276,7 @@ static ssize_t vfio_ap_mdev_ioctl(struct mdev_device *mdev,
                ret = -EOPNOTSUPP;
                break;
        }
+       mutex_unlock(&matrix_dev->lock);
 
        return ret;
 }