2014-06-05 17:06:26

by Antonios Motakis

[permalink] [raw]
Subject: [RFC PATCH v6 20/20] vfio/platform: implement IRQ masking/unmasking via an eventfd

With this patch the VFIO user will be able to set an eventfd that can be
used in order to mask and unmask IRQs of platform devices.

Signed-off-by: Antonios Motakis <[email protected]>
---
drivers/vfio/platform/vfio_platform_irq.c | 86 ++++++++++++++++++++++-----
drivers/vfio/platform/vfio_platform_private.h | 2 +
2 files changed, 72 insertions(+), 16 deletions(-)

diff --git a/drivers/vfio/platform/vfio_platform_irq.c b/drivers/vfio/platform/vfio_platform_irq.c
index 10dfbf0..6768508 100644
--- a/drivers/vfio/platform/vfio_platform_irq.c
+++ b/drivers/vfio/platform/vfio_platform_irq.c
@@ -108,6 +108,52 @@ static irqreturn_t vfio_irq_handler(int irq, void *dev_id)
return ret;
}

+static void vfio_platform_unmask(struct vfio_platform_irq *irq_ctx)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&irq_ctx->lock, flags);
+
+ if (irq_ctx->masked) {
+ enable_irq(irq_ctx->hwirq);
+ irq_ctx->masked = false;
+ }
+
+ spin_unlock_irqrestore(&irq_ctx->lock, flags);
+}
+
+static void vfio_platform_mask(struct vfio_platform_irq *irq_ctx)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&irq_ctx->lock, flags);
+
+ if (!irq_ctx->masked) {
+ disable_irq(irq_ctx->hwirq);
+ irq_ctx->masked = true;
+ }
+
+ spin_unlock_irqrestore(&irq_ctx->lock, flags);
+}
+
+static int vfio_platform_unmask_handler(void *opaque, void *unused)
+{
+ struct vfio_platform_irq *irq_ctx = opaque;
+
+ vfio_platform_unmask(irq_ctx);
+
+ return 0;
+}
+
+static int vfio_platform_mask_handler(void *opaque, void *unused)
+{
+ struct vfio_platform_irq *irq_ctx = opaque;
+
+ vfio_platform_mask(irq_ctx);
+
+ return 0;
+}
+
static int vfio_set_trigger(struct vfio_platform_device *vdev,
int index, int fd)
{
@@ -191,6 +237,7 @@ static int vfio_platform_set_irq_unmask(struct vfio_platform_device *vdev,
unsigned count, uint32_t flags, void *data)
{
uint8_t arr;
+ int32_t fd;

if (start != 0 || count != 1)
return -EINVAL;
@@ -204,19 +251,22 @@ static int vfio_platform_set_irq_unmask(struct vfio_platform_device *vdev,
return -EINVAL;

case VFIO_IRQ_SET_DATA_NONE:
+ vfio_platform_unmask(&vdev->irq[index]);
+ return 0;

- spin_lock_irq(&vdev->irq[index].lock);
-
- if (vdev->irq[index].masked) {
- enable_irq(vdev->irq[index].hwirq);
- vdev->irq[index].masked = false;
- }
+ case VFIO_IRQ_SET_DATA_EVENTFD:
+ if (copy_from_user(&fd, data, sizeof(int32_t)))
+ return -EFAULT;

- spin_unlock_irq(&vdev->irq[index].lock);
+ if (fd >= 0)
+ return virqfd_enable((void *) &vdev->irq[index],
+ vfio_platform_unmask_handler,
+ NULL, NULL,
+ &vdev->irq[index].unmask, fd);

+ virqfd_disable(&vdev->irq[index].unmask);
return 0;

- case VFIO_IRQ_SET_DATA_EVENTFD: /* XXX not implemented yet */
default:
return -ENOTTY;
}
@@ -229,6 +279,7 @@ static int vfio_platform_set_irq_mask(struct vfio_platform_device *vdev,
unsigned count, uint32_t flags, void *data)
{
uint8_t arr;
+ int32_t fd;

if (start != 0 || count != 1)
return -EINVAL;
@@ -242,19 +293,22 @@ static int vfio_platform_set_irq_mask(struct vfio_platform_device *vdev,
return -EINVAL;

case VFIO_IRQ_SET_DATA_NONE:
+ vfio_platform_mask(&vdev->irq[index]);
+ return 0;

- spin_lock_irq(&vdev->irq[index].lock);
-
- if (!vdev->irq[index].masked) {
- disable_irq(vdev->irq[index].hwirq);
- vdev->irq[index].masked = true;
- }
+ case VFIO_IRQ_SET_DATA_EVENTFD:
+ if (copy_from_user(&fd, data, sizeof(int32_t)))
+ return -EFAULT;

- spin_unlock_irq(&vdev->irq[index].lock);
+ if (fd >= 0)
+ return virqfd_enable((void *) &vdev->irq[index],
+ vfio_platform_mask_handler,
+ NULL, NULL,
+ &vdev->irq[index].mask, fd);

+ virqfd_disable(&vdev->irq[index].mask);
return 0;

- case VFIO_IRQ_SET_DATA_EVENTFD: /* XXX not implemented yet */
default:
return -ENOTTY;
}
diff --git a/drivers/vfio/platform/vfio_platform_private.h b/drivers/vfio/platform/vfio_platform_private.h
index 4d887fd..86a9201 100644
--- a/drivers/vfio/platform/vfio_platform_private.h
+++ b/drivers/vfio/platform/vfio_platform_private.h
@@ -32,6 +32,8 @@ struct vfio_platform_irq {
char *name;
bool masked;
spinlock_t lock;
+ struct virqfd *unmask;
+ struct virqfd *mask;
};

struct vfio_platform_region {
--
1.8.3.2