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@xxxxxxxxxxxxx>
---
drivers/s390/crypto/ap_bus.h | 1 +
drivers/s390/crypto/vfio_ap_drv.c | 30 +++-
drivers/s390/crypto/vfio_ap_ops.c | 293 +++++++++++++++++++++++++++++++++-
drivers/s390/crypto/vfio_ap_private.h | 11 ++
4 files changed, 328 insertions(+), 7 deletions(-)
diff --git a/drivers/s390/crypto/ap_bus.h b/drivers/s390/crypto/ap_bus.h
index 15a98a6..60e70f3 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_drv.c b/drivers/s390/crypto/vfio_ap_drv.c
index e9824c3..ecaa4ab 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@xxxxxxxxxxxxx>
+ * Pierre Morel <pmorel@xxxxxxxxxxxxx>
*/
#include <linux/module.h>
@@ -40,14 +41,41 @@ static struct ap_device_id ap_queue_ids[] = {
MODULE_DEVICE_TABLE(vfio_ap, ap_queue_ids);
+/**
+ * vfio_ap_queue_dev_probe:
+ *
+ * Allocate a vfio_ap_queue structure and associate it
+ * with the device as driver_data.
+ */
static int vfio_ap_queue_dev_probe(struct ap_device *apdev)
{
+ struct vfio_ap_queue *q;
+
+ q = kzalloc(sizeof(*q), GFP_KERNEL);
+ if (!q)
+ return -ENOMEM;
+ dev_set_drvdata(&apdev->device, q);
+ q->apqn = to_ap_queue(&apdev->device)->qid;
+ q->a_isc = VFIO_AP_ISC_INVALID;
+ q->p_isc = VFIO_AP_ISC_INVALID;
return 0;
}
+/**
+ * vfio_ap_queue_dev_remove:
+ *
+ * Takes the matrix lock to avoid actions on this device while removing
+ * Free the associated vfio_ap_queue structure
+ */
static void vfio_ap_queue_dev_remove(struct ap_device *apdev)
{
- /* Nothing to do yet */
+ struct vfio_ap_queue *q;
+
+ mutex_lock(&matrix_dev->lock);
+ q = dev_get_drvdata(&apdev->device);
+ kfree(q);
+ dev_set_drvdata(&apdev->device, NULL);
+ mutex_unlock(&matrix_dev->lock);
}
static void vfio_ap_matrix_dev_release(struct device *dev)
diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
index e8e87bf..c22b996 100644
--- a/drivers/s390/crypto/vfio_ap_ops.c
+++ b/drivers/s390/crypto/vfio_ap_ops.c
@@ -24,6 +24,252 @@
#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, 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
+ */
+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_free_irq_data:
+ * @q: The vfio_ap_queue
+ *
+ * Unpin the guest NIB
+ * Unregister the ISC from the GIB alert
+ * Clear the vfio_ap_queue intern fields
+ *
+ * Important notice:
+ * Before calling this function, interrupt must have been
+ * unregistered by use of ap_zapq/ap_reset or ap_aqic.
+ */
+static void vfio_ap_free_irq_data(struct vfio_ap_queue *q)
+{
+ if (!q)
+ return;
+
+ if (q->a_isc != VFIO_AP_ISC_INVALID && q->matrix_mdev)
+ kvm_s390_gisc_unregister(q->matrix_mdev->kvm, q->a_isc);
+ if (q->a_pfn && q->matrix_mdev)
+ vfio_unpin_pages(mdev_dev(q->matrix_mdev->mdev), &q->a_pfn, 1);
+
+ q->a_pfn = 0;
+ q->p_pfn = 0;
+ q->a_isc = VFIO_AP_ISC_INVALID;
+ q->p_isc = VFIO_AP_ISC_INVALID;
+ q->matrix_mdev = NULL;
+}
+
+/**
+ * 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;
+ int checks = 10;
+
+ status = ap_aqic(q->apqn, aqic_gisa, NULL);
+ if (!status.response_code) {
+ while (status.irq_enabled && checks--) {
+ msleep(20);
+ status = ap_tapq(q->apqn, NULL);
+ }
+ if (checks >= 0)
+ vfio_ap_free_irq_data(q);
+ else
+ WARN_ONCE("%s: failed disabling IRQ", __func__);
+ }
+
+ 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 h_nib, h_pfn;
+ int ret;
+
+ q->a_pfn = q->a_nib >> PAGE_SHIFT;
+ ret = vfio_pin_pages(mdev_dev(q->matrix_mdev->mdev), &q->a_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;
+ }
+
+ kvm = q->matrix_mdev->kvm;
+ gisa = kvm->arch.gisa_int.origin;
+
+ h_nib = (h_pfn << PAGE_SHIFT) | (q->a_nib & ~PAGE_MASK);
+ aqic_gisa.gisc = q->a_isc;
+ aqic_gisa.isc = kvm_s390_gisc_register(kvm, q->a_isc);
+ aqic_gisa.ir = 1;
+ aqic_gisa.gisa = gisa->next_alert >> 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 */
+ if (q->p_pfn)
+ vfio_unpin_pages(mdev_dev(q->matrix_mdev->mdev),
+ &q->p_pfn, 1);
+ if (q->p_isc != VFIO_AP_ISC_INVALID)
+ kvm_s390_gisc_unregister(kvm, q->p_isc);
+ q->p_pfn = q->a_pfn;
+ q->p_isc = q->a_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), &q->a_pfn, 1);
+ kvm_s390_gisc_unregister(kvm, q->a_isc);
+ break;
+ default: /* Fall Through */
+ pr_warn("%s: apqn %04x: response: %02x\n", __func__, q->apqn,
+ status.response_code);
+ vfio_ap_free_irq_data(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) {
+ q->a_isc = status & 0x07;
+ q->a_nib = vcpu->run->s.regs.gprs[2];
+ qstatus = vfio_ap_setirq(q);
+ if (qstatus.response_code) {
+ q->a_nib = 0;
+ q->a_isc = VFIO_AP_ISC_INVALID;
+ }
+ } else
+ qstatus = vfio_ap_clrirq(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 +291,11 @@ 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 +311,7 @@ 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);
@@ -754,6 +1004,8 @@ 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;
@@ -819,15 +1071,37 @@ 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)
+void vfio_ap_free_irq_data_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_free_irq_data(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);
+ vfio_ap_free_irq_data_apqn(apqn);
return 0;
case AP_RESPONSE_RESET_IN_PROGRESS:
case AP_RESPONSE_BUSY:
@@ -904,15 +1178,20 @@ 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);
}
@@ -941,6 +1220,7 @@ 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);
@@ -952,6 +1232,7 @@ static ssize_t vfio_ap_mdev_ioctl(struct mdev_device *mdev,
ret = -EOPNOTSUPP;
break;
}
+ mutex_unlock(&matrix_dev->lock);
return ret;
}
diff --git a/drivers/s390/crypto/vfio_ap_private.h b/drivers/s390/crypto/vfio_ap_private.h
index 18dcc4d..7cc02ff 100644
--- a/drivers/s390/crypto/vfio_ap_private.h
+++ b/drivers/s390/crypto/vfio_ap_private.h
@@ -4,6 +4,7 @@
*
* Author(s): Tony Krowiak <akrowiak@xxxxxxxxxxxxx>
* Halil Pasic <pasic@xxxxxxxxxxxxx>
+ * Pierre Morel <pmorel@xxxxxxxxxxxxx>
*
* Copyright IBM Corp. 2018
*/
@@ -90,4 +91,14 @@ struct ap_matrix_mdev {
extern int vfio_ap_mdev_register(void);
extern void vfio_ap_mdev_unregister(void);
+struct vfio_ap_queue {
+ struct ap_matrix_mdev *matrix_mdev;
+ unsigned long a_nib;
+ unsigned long a_pfn;
+ unsigned long p_pfn;
+ int apqn;
+#define VFIO_AP_ISC_INVALID 0xff
+ unsigned char a_isc;
+ unsigned char p_isc;
+};
#endif /* _VFIO_AP_PRIVATE_H_ */
--
2.7.4
