2014-10-27 18:10:16

by Antonios Motakis

Subject: [PATCH v9 13/19] vfio/platform: support for level sensitive interrupts

Level sensitive interrupts are exposed as maskable and automasked
interrupts and are masked and disabled automatically when they fire.

Signed-off-by: Antonios Motakis <[email protected]>
---
drivers/vfio/platform/vfio_platform_irq.c | 102 +++++++++++++++++++++++++-
drivers/vfio/platform/vfio_platform_private.h | 2 +
2 files changed, 100 insertions(+), 4 deletions(-)

diff --git a/drivers/vfio/platform/vfio_platform_irq.c b/drivers/vfio/platform/vfio_platform_irq.c
index 2ac8ed7..563abf6 100644
--- a/drivers/vfio/platform/vfio_platform_irq.c
+++ b/drivers/vfio/platform/vfio_platform_irq.c
@@ -31,18 +31,108 @@

#include "vfio_platform_private.h"

+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_set_irq_mask(struct vfio_platform_device *vdev,
unsigned index, unsigned start,
unsigned count, uint32_t flags, void *data)
{
- return -EINVAL;
+ if (start != 0 || count != 1)
+ return -EINVAL;
+
+ if (!(vdev->irqs[index].flags & VFIO_IRQ_INFO_MASKABLE))
+ return -EINVAL;
+
+ if (flags & VFIO_IRQ_SET_DATA_EVENTFD)
+ return -EINVAL; /* not implemented yet */
+
+ if (flags & VFIO_IRQ_SET_DATA_NONE) {
+ vfio_platform_mask(&vdev->irqs[index]);
+
+ } else if (flags & VFIO_IRQ_SET_DATA_BOOL) {
+ uint8_t mask = *(uint8_t *)data;
+
+ if (mask)
+ vfio_platform_mask(&vdev->irqs[index]);
+ }
+
+ return 0;
+}
+
+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 int vfio_platform_set_irq_unmask(struct vfio_platform_device *vdev,
unsigned index, unsigned start,
unsigned count, uint32_t flags, void *data)
{
- return -EINVAL;
+ if (start != 0 || count != 1)
+ return -EINVAL;
+
+ if (!(vdev->irqs[index].flags & VFIO_IRQ_INFO_MASKABLE))
+ return -EINVAL;
+
+ if (flags & VFIO_IRQ_SET_DATA_EVENTFD)
+ return -EINVAL; /* not implemented yet */
+
+ if (flags & VFIO_IRQ_SET_DATA_NONE) {
+ vfio_platform_unmask(&vdev->irqs[index]);
+
+ } else if (flags & VFIO_IRQ_SET_DATA_BOOL) {
+ uint8_t unmask = *(uint8_t *)data;
+
+ if (unmask)
+ vfio_platform_unmask(&vdev->irqs[index]);
+ }
+
+ return 0;
+}
+
+static irqreturn_t vfio_maskable_irq_handler(int irq, void *dev_id)
+{
+ struct vfio_platform_irq *irq_ctx = dev_id;
+ unsigned long flags;
+ int ret = IRQ_NONE;
+
+ spin_lock_irqsave(&irq_ctx->lock, flags);
+
+ if (!irq_ctx->masked) {
+ ret = IRQ_HANDLED;
+
+ /* automask maskable interrupts */
+ disable_irq_nosync(irq_ctx->hwirq);
+ irq_ctx->masked = true;
+ }
+
+ spin_unlock_irqrestore(&irq_ctx->lock, flags);
+
+ if (ret == IRQ_HANDLED)
+ eventfd_signal(irq_ctx->trigger, 1);
+
+ return ret;
}

static irqreturn_t vfio_irq_handler(int irq, void *dev_id)
@@ -103,7 +193,7 @@ static int vfio_platform_set_irq_trigger(struct vfio_platform_device *vdev,
irq_handler_t handler;

if (vdev->irqs[index].flags & VFIO_IRQ_INFO_MASKABLE)
- return -EINVAL; /* not implemented */
+ handler = vfio_maskable_irq_handler;
else
handler = vfio_irq_handler;

@@ -175,13 +265,17 @@ int vfio_platform_irq_init(struct vfio_platform_device *vdev)
if (hwirq < 0)
goto err;

+ spin_lock_init(&vdev->irqs[i].lock);
+
vdev->irqs[i].flags = VFIO_IRQ_INFO_EVENTFD;

if (irq_get_trigger_type(hwirq) & IRQ_TYPE_LEVEL_MASK)
- vdev->irqs[i].flags |= VFIO_IRQ_INFO_MASKABLE;
+ vdev->irqs[i].flags |= VFIO_IRQ_INFO_MASKABLE
+ | VFIO_IRQ_INFO_AUTOMASKED;

vdev->irqs[i].count = 1;
vdev->irqs[i].hwirq = hwirq;
+ vdev->irqs[i].masked = false;
}

vdev->num_irqs = cnt;
diff --git a/drivers/vfio/platform/vfio_platform_private.h b/drivers/vfio/platform/vfio_platform_private.h
index a3f2411..d25c4cd 100644
--- a/drivers/vfio/platform/vfio_platform_private.h
+++ b/drivers/vfio/platform/vfio_platform_private.h
@@ -30,6 +30,8 @@ struct vfio_platform_irq {
int hwirq;
char *name;
struct eventfd_ctx *trigger;
+ bool masked;
+ spinlock_t lock;
};

struct vfio_platform_region {
--
2.1.1

2014-10-31 19:37:03

by Alex Williamson

Subject: Re: [PATCH v9 13/19] vfio/platform: support for level sensitive interrupts

On Mon, 2014-10-27 at 19:07 +0100, Antonios Motakis wrote:
> Level sensitive interrupts are exposed as maskable and automasked
> interrupts and are masked and disabled automatically when they fire.
>
> Signed-off-by: Antonios Motakis <[email protected]>
> ---
> drivers/vfio/platform/vfio_platform_irq.c | 102 +++++++++++++++++++++++++-
> drivers/vfio/platform/vfio_platform_private.h | 2 +
> 2 files changed, 100 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/vfio/platform/vfio_platform_irq.c b/drivers/vfio/platform/vfio_platform_irq.c
> index 2ac8ed7..563abf6 100644
> --- a/drivers/vfio/platform/vfio_platform_irq.c
> +++ b/drivers/vfio/platform/vfio_platform_irq.c
> @@ -31,18 +31,108 @@
>
> #include "vfio_platform_private.h"
>
> +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_set_irq_mask(struct vfio_platform_device *vdev,
> unsigned index, unsigned start,
> unsigned count, uint32_t flags, void *data)
> {
> - return -EINVAL;
> + if (start != 0 || count != 1)
> + return -EINVAL;
> +
> + if (!(vdev->irqs[index].flags & VFIO_IRQ_INFO_MASKABLE))
> + return -EINVAL;
> +
> + if (flags & VFIO_IRQ_SET_DATA_EVENTFD)
> + return -EINVAL; /* not implemented yet */
> +
> + if (flags & VFIO_IRQ_SET_DATA_NONE) {
> + vfio_platform_mask(&vdev->irqs[index]);
> +
> + } else if (flags & VFIO_IRQ_SET_DATA_BOOL) {
> + uint8_t mask = *(uint8_t *)data;
> +
> + if (mask)
> + vfio_platform_mask(&vdev->irqs[index]);
> + }
> +
> + return 0;
> +}
> +
> +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 int vfio_platform_set_irq_unmask(struct vfio_platform_device *vdev,
> unsigned index, unsigned start,
> unsigned count, uint32_t flags, void *data)
> {
> - return -EINVAL;
> + if (start != 0 || count != 1)
> + return -EINVAL;
> +
> + if (!(vdev->irqs[index].flags & VFIO_IRQ_INFO_MASKABLE))
> + return -EINVAL;
> +
> + if (flags & VFIO_IRQ_SET_DATA_EVENTFD)
> + return -EINVAL; /* not implemented yet */
> +
> + if (flags & VFIO_IRQ_SET_DATA_NONE) {
> + vfio_platform_unmask(&vdev->irqs[index]);
> +
> + } else if (flags & VFIO_IRQ_SET_DATA_BOOL) {
> + uint8_t unmask = *(uint8_t *)data;
> +
> + if (unmask)
> + vfio_platform_unmask(&vdev->irqs[index]);
> + }
> +
> + return 0;
> +}
> +
> +static irqreturn_t vfio_maskable_irq_handler(int irq, void *dev_id)
> +{
> + struct vfio_platform_irq *irq_ctx = dev_id;
> + unsigned long flags;
> + int ret = IRQ_NONE;
> +
> + spin_lock_irqsave(&irq_ctx->lock, flags);
> +
> + if (!irq_ctx->masked) {
> + ret = IRQ_HANDLED;
> +
> + /* automask maskable interrupts */
> + disable_irq_nosync(irq_ctx->hwirq);
> + irq_ctx->masked = true;
> + }
> +
> + spin_unlock_irqrestore(&irq_ctx->lock, flags);
> +
> + if (ret == IRQ_HANDLED)
> + eventfd_signal(irq_ctx->trigger, 1);
> +
> + return ret;

This is not just a maskable irq handler, but specifically a level (aka
automasked) handler. So this should only be used for AUTOMASKED irqs.

> }
>
> static irqreturn_t vfio_irq_handler(int irq, void *dev_id)
> @@ -103,7 +193,7 @@ static int vfio_platform_set_irq_trigger(struct vfio_platform_device *vdev,
> irq_handler_t handler;
>
> if (vdev->irqs[index].flags & VFIO_IRQ_INFO_MASKABLE)
> - return -EINVAL; /* not implemented */
> + handler = vfio_maskable_irq_handler;

As noted in the previous patch, this should be a test for AUTOMASKED,
not just MASKABLE.

> else
> handler = vfio_irq_handler;
>
> @@ -175,13 +265,17 @@ int vfio_platform_irq_init(struct vfio_platform_device *vdev)
> if (hwirq < 0)
> goto err;
>
> + spin_lock_init(&vdev->irqs[i].lock);
> +
> vdev->irqs[i].flags = VFIO_IRQ_INFO_EVENTFD;
>
> if (irq_get_trigger_type(hwirq) & IRQ_TYPE_LEVEL_MASK)
> - vdev->irqs[i].flags |= VFIO_IRQ_INFO_MASKABLE;
> + vdev->irqs[i].flags |= VFIO_IRQ_INFO_MASKABLE
> + | VFIO_IRQ_INFO_AUTOMASKED;
>
> vdev->irqs[i].count = 1;
> vdev->irqs[i].hwirq = hwirq;
> + vdev->irqs[i].masked = false;
> }
>
> vdev->num_irqs = cnt;
> diff --git a/drivers/vfio/platform/vfio_platform_private.h b/drivers/vfio/platform/vfio_platform_private.h
> index a3f2411..d25c4cd 100644
> --- a/drivers/vfio/platform/vfio_platform_private.h
> +++ b/drivers/vfio/platform/vfio_platform_private.h
> @@ -30,6 +30,8 @@ struct vfio_platform_irq {
> int hwirq;
> char *name;
> struct eventfd_ctx *trigger;
> + bool masked;
> + spinlock_t lock;
> };
>
> struct vfio_platform_region {

2014-11-05 10:10:28

by Antonios Motakis

Subject: Re: [PATCH v9 13/19] vfio/platform: support for level sensitive interrupts

On Fri, Oct 31, 2014 at 8:36 PM, Alex Williamson
<[email protected]> wrote:
> On Mon, 2014-10-27 at 19:07 +0100, Antonios Motakis wrote:
>> Level sensitive interrupts are exposed as maskable and automasked
>> interrupts and are masked and disabled automatically when they fire.
>>
>> Signed-off-by: Antonios Motakis <[email protected]>
>> ---
>> drivers/vfio/platform/vfio_platform_irq.c | 102 +++++++++++++++++++++++++-
>> drivers/vfio/platform/vfio_platform_private.h | 2 +
>> 2 files changed, 100 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/vfio/platform/vfio_platform_irq.c b/drivers/vfio/platform/vfio_platform_irq.c
>> index 2ac8ed7..563abf6 100644
>> --- a/drivers/vfio/platform/vfio_platform_irq.c
>> +++ b/drivers/vfio/platform/vfio_platform_irq.c
>> @@ -31,18 +31,108 @@
>>
>> #include "vfio_platform_private.h"
>>
>> +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_set_irq_mask(struct vfio_platform_device *vdev,
>> unsigned index, unsigned start,
>> unsigned count, uint32_t flags, void *data)
>> {
>> - return -EINVAL;
>> + if (start != 0 || count != 1)
>> + return -EINVAL;
>> +
>> + if (!(vdev->irqs[index].flags & VFIO_IRQ_INFO_MASKABLE))
>> + return -EINVAL;
>> +
>> + if (flags & VFIO_IRQ_SET_DATA_EVENTFD)
>> + return -EINVAL; /* not implemented yet */
>> +
>> + if (flags & VFIO_IRQ_SET_DATA_NONE) {
>> + vfio_platform_mask(&vdev->irqs[index]);
>> +
>> + } else if (flags & VFIO_IRQ_SET_DATA_BOOL) {
>> + uint8_t mask = *(uint8_t *)data;
>> +
>> + if (mask)
>> + vfio_platform_mask(&vdev->irqs[index]);
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +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 int vfio_platform_set_irq_unmask(struct vfio_platform_device *vdev,
>> unsigned index, unsigned start,
>> unsigned count, uint32_t flags, void *data)
>> {
>> - return -EINVAL;
>> + if (start != 0 || count != 1)
>> + return -EINVAL;
>> +
>> + if (!(vdev->irqs[index].flags & VFIO_IRQ_INFO_MASKABLE))
>> + return -EINVAL;
>> +
>> + if (flags & VFIO_IRQ_SET_DATA_EVENTFD)
>> + return -EINVAL; /* not implemented yet */
>> +
>> + if (flags & VFIO_IRQ_SET_DATA_NONE) {
>> + vfio_platform_unmask(&vdev->irqs[index]);
>> +
>> + } else if (flags & VFIO_IRQ_SET_DATA_BOOL) {
>> + uint8_t unmask = *(uint8_t *)data;
>> +
>> + if (unmask)
>> + vfio_platform_unmask(&vdev->irqs[index]);
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +static irqreturn_t vfio_maskable_irq_handler(int irq, void *dev_id)
>> +{
>> + struct vfio_platform_irq *irq_ctx = dev_id;
>> + unsigned long flags;
>> + int ret = IRQ_NONE;
>> +
>> + spin_lock_irqsave(&irq_ctx->lock, flags);
>> +
>> + if (!irq_ctx->masked) {
>> + ret = IRQ_HANDLED;
>> +
>> + /* automask maskable interrupts */
>> + disable_irq_nosync(irq_ctx->hwirq);
>> + irq_ctx->masked = true;
>> + }
>> +
>> + spin_unlock_irqrestore(&irq_ctx->lock, flags);
>> +
>> + if (ret == IRQ_HANDLED)
>> + eventfd_signal(irq_ctx->trigger, 1);
>> +
>> + return ret;
>
> This is not just a maskable irq handler, but specifically a level (aka
> automasked) handler. So this should only be used for AUTOMASKED irqs.
>
>> }
>>
>> static irqreturn_t vfio_irq_handler(int irq, void *dev_id)
>> @@ -103,7 +193,7 @@ static int vfio_platform_set_irq_trigger(struct vfio_platform_device *vdev,
>> irq_handler_t handler;
>>
>> if (vdev->irqs[index].flags & VFIO_IRQ_INFO_MASKABLE)
>> - return -EINVAL; /* not implemented */
>> + handler = vfio_maskable_irq_handler;
>
> As noted in the previous patch, this should be a test for AUTOMASKED,
> not just MASKABLE.

Ack.

Thanks for your comments.
Antonios

>
>> else
>> handler = vfio_irq_handler;
>>
>> @@ -175,13 +265,17 @@ int vfio_platform_irq_init(struct vfio_platform_device *vdev)
>> if (hwirq < 0)
>> goto err;
>>
>> + spin_lock_init(&vdev->irqs[i].lock);
>> +
>> vdev->irqs[i].flags = VFIO_IRQ_INFO_EVENTFD;
>>
>> if (irq_get_trigger_type(hwirq) & IRQ_TYPE_LEVEL_MASK)
>> - vdev->irqs[i].flags |= VFIO_IRQ_INFO_MASKABLE;
>> + vdev->irqs[i].flags |= VFIO_IRQ_INFO_MASKABLE
>> + | VFIO_IRQ_INFO_AUTOMASKED;
>>
>> vdev->irqs[i].count = 1;
>> vdev->irqs[i].hwirq = hwirq;
>> + vdev->irqs[i].masked = false;
>> }
>>
>> vdev->num_irqs = cnt;
>> diff --git a/drivers/vfio/platform/vfio_platform_private.h b/drivers/vfio/platform/vfio_platform_private.h
>> index a3f2411..d25c4cd 100644
>> --- a/drivers/vfio/platform/vfio_platform_private.h
>> +++ b/drivers/vfio/platform/vfio_platform_private.h
>> @@ -30,6 +30,8 @@ struct vfio_platform_irq {
>> int hwirq;
>> char *name;
>> struct eventfd_ctx *trigger;
>> + bool masked;
>> + spinlock_t lock;
>> };
>>
>> struct vfio_platform_region {
>
>
>