[RFC PATCH v6 14/20] vfio/platform: initial interrupts support

Antonios Motakis
2014-06-05T17:05:43Z

This patch allows to set an eventfd for a patform device's interrupt,
and also to trigger the interrupt eventfd from userspace for testing.

Signed-off-by: Antonios Motakis <a.motakis@virtualopensystems.com>
---
drivers/vfio/platform/vfio_platform.c | 36 ++++++-
drivers/vfio/platform/vfio_platform_irq.c | 130 +++++++++++++++++++++++++-
drivers/vfio/platform/vfio_platform_private.h | 7 ++
3 files changed, 169 insertions(+), 4 deletions(-)

diff --git a/drivers/vfio/platform/vfio_platform.c b/drivers/vfio/platform/vfio_platform.c
index 192291c..f4c06c6 100644
--- a/drivers/vfio/platform/vfio_platform.c
+++ b/drivers/vfio/platform/vfio_platform.c
@@ -177,10 +177,40 @@ static long vfio_platform_ioctl(void *device_data,

return copy_to_user((void __user *)arg, &info, minsz);

- } else if (cmd == VFIO_DEVICE_SET_IRQS)
- return -EINVAL;
+ } else if (cmd == VFIO_DEVICE_SET_IRQS) {
+ struct vfio_irq_set hdr;
+ int ret = 0;
+
+ minsz = offsetofend(struct vfio_irq_set, count);
+
+ if (copy_from_user(&hdr, (void __user *)arg, minsz))
+ return -EFAULT;
+
+ if (hdr.argsz < minsz)
+ return -EINVAL;
+
+ if (hdr.index >= vdev->num_irqs)
+ return -EINVAL;
+
+ if (hdr.start != 0 || hdr.count > 1)
+ return -EINVAL;
+
+ if (hdr.count == 0 &&
+ (!(hdr.flags & VFIO_IRQ_SET_DATA_NONE) ||
+ !(hdr.flags & VFIO_IRQ_SET_ACTION_TRIGGER)))
+ return -EINVAL;
+
+ if (hdr.flags & ~(VFIO_IRQ_SET_DATA_TYPE_MASK |
+ VFIO_IRQ_SET_ACTION_TYPE_MASK))
+ return -EINVAL;
+
+ ret = vfio_platform_set_irqs_ioctl(vdev, hdr.flags, hdr.index,
+ hdr.start, hdr.count,
+ (void *)arg+minsz);
+
+ return ret;

- else if (cmd == VFIO_DEVICE_RESET)
+ } else if (cmd == VFIO_DEVICE_RESET)
return -EINVAL;

return -ENOTTY;
diff --git a/drivers/vfio/platform/vfio_platform_irq.c b/drivers/vfio/platform/vfio_platform_irq.c
index 22c214f..d79f5af 100644
--- a/drivers/vfio/platform/vfio_platform_irq.c
+++ b/drivers/vfio/platform/vfio_platform_irq.c
@@ -31,6 +31,9 @@

#include "vfio_platform_private.h"

+static int vfio_set_trigger(struct vfio_platform_device *vdev,
+ int index, int fd);
+
int vfio_platform_irq_init(struct vfio_platform_device *vdev)
{
int cnt = 0, i;
@@ -43,17 +46,142 @@ int vfio_platform_irq_init(struct vfio_platform_device *vdev)
return -ENOMEM;

for (i = 0; i < cnt; i++) {
- vdev->irq[i].flags = 0;
+ int hwirq = platform_get_irq(vdev->pdev, i);
+
+ if (hwirq < 0)
+ goto err;
+
+ vdev->irq[i].flags = VFIO_IRQ_INFO_EVENTFD;
vdev->irq[i].count = 1;
+ vdev->irq[i].hwirq = hwirq;
}

vdev->num_irqs = cnt;

return 0;
+err:
+ kfree(vdev->irq);
+ return -EINVAL;
}

void vfio_platform_irq_cleanup(struct vfio_platform_device *vdev)
{
+ int i;
+
+ for (i = 0; i < vdev->num_irqs; i++)
+ vfio_set_trigger(vdev, i, -1);
+
vdev->num_irqs = 0;
kfree(vdev->irq);
}
+
+static irqreturn_t vfio_irq_handler(int irq, void *dev_id)
+{
+ struct eventfd_ctx *trigger = dev_id;
+
+ eventfd_signal(trigger, 1);
+
+ return IRQ_HANDLED;
+}
+
+static int vfio_set_trigger(struct vfio_platform_device *vdev,
+ int index, int fd)
+{
+ struct vfio_platform_irq *irq = &vdev->irq[index];
+ struct eventfd_ctx *trigger;
+ int ret;
+
+ if (irq->trigger) {
+ free_irq(irq->hwirq, irq);
+ kfree(irq->name);
+ eventfd_ctx_put(irq->trigger);
+ irq->trigger = NULL;
+ }
+
+ if (fd < 0) /* Disable only */
+ return 0;
+
+ irq->name = kasprintf(GFP_KERNEL, "vfio-irq[%d](%s)",
+ irq->hwirq, vdev->pdev->name);
+ if (!irq->name)
+ return -ENOMEM;
+
+ trigger = eventfd_ctx_fdget(fd);
+ if (IS_ERR(trigger)) {
+ kfree(irq->name);
+ return PTR_ERR(trigger);
+ }
+
+ irq->trigger = trigger;
+
+ ret = request_irq(irq->hwirq, vfio_irq_handler, 0, irq->name, irq);
+ if (ret) {
+ kfree(irq->name);
+ eventfd_ctx_put(trigger);
+ irq->trigger = NULL;
+ return ret;
+ }
+
+ return 0;
+}
+
+static int vfio_platform_set_irq_trigger(struct vfio_platform_device *vdev,
+ unsigned index, unsigned start,
+ unsigned count, uint32_t flags, void *data)
+{
+ struct vfio_platform_irq *irq = &vdev->irq[index];
+ uint8_t arr;
+ int32_t fd;
+
+ switch (flags & VFIO_IRQ_SET_DATA_TYPE_MASK) {
+ case VFIO_IRQ_SET_DATA_NONE:
+ if (count == 0)
+ return vfio_set_trigger(vdev, index, -1);
+
+ vfio_irq_handler(irq->hwirq, irq);
+ return 0;
+
+ case VFIO_IRQ_SET_DATA_BOOL:
+ if (copy_from_user(&arr, data, sizeof(uint8_t)))
+ return -EFAULT;
+
+ if (arr == 0x1) {
+ vfio_irq_handler(irq->hwirq, irq);
+ return 0;
+ }
+
+ return -EINVAL;
+
+ case VFIO_IRQ_SET_DATA_EVENTFD:
+ if (copy_from_user(&fd, data, sizeof(int32_t)))
+ return -EFAULT;
+
+ return vfio_set_trigger(vdev, index, fd);
+ }
+
+ return -EFAULT;
+}
+
+int vfio_platform_set_irqs_ioctl(struct vfio_platform_device *vdev,
+ uint32_t flags, unsigned index, unsigned start,
+ unsigned count, void *data)
+{
+ int (*func)(struct vfio_platform_device *vdev, unsigned index,
+ unsigned start, unsigned count, uint32_t flags,
+ void *data) = NULL;
+
+ switch (flags & VFIO_IRQ_SET_ACTION_TYPE_MASK) {
+ case VFIO_IRQ_SET_ACTION_MASK:
+ case VFIO_IRQ_SET_ACTION_UNMASK:
+ /* XXX not implemented */
+ break;
+ case VFIO_IRQ_SET_ACTION_TRIGGER:
+ func = vfio_platform_set_irq_trigger;
+ break;
+ }
+
+ if (!func)
+ return -ENOTTY;
+
+ return func(vdev, index, start, count, flags, data);
+}
diff --git a/drivers/vfio/platform/vfio_platform_private.h b/drivers/vfio/platform/vfio_platform_private.h
index 632a294..d6200df 100644
--- a/drivers/vfio/platform/vfio_platform_private.h
+++ b/drivers/vfio/platform/vfio_platform_private.h
@@ -25,8 +25,11 @@
((u64)(index) << VFIO_PLATFORM_OFFSET_SHIFT)

struct vfio_platform_irq {
+ struct eventfd_ctx *trigger;
u32 flags;
u32 count;
+ int hwirq;
+ char *name;
};

struct vfio_platform_region {
@@ -48,4 +51,8 @@ extern int vfio_platform_irq_init(struct vfio_platform_device *vdev);

extern void vfio_platform_irq_cleanup(struct vfio_platform_device *vdev);

+extern int vfio_platform_set_irqs_ioctl(struct vfio_platform_device *vdev,
+ uint32_t flags, unsigned index, unsigned start,
+ unsigned count, void *data);
+
#endif /* VFIO_PLATFORM_PRIVATE_H */
--
1.8.3.2