[PATCH v3 1/2] genirq/msi: add wrapper msi allocation API and export msi functions

[PATCH v3 1/2] genirq/msi: add wrapper msi allocation API and export msi functions

[Nipun Gupta]

MSI functions can be for allocation and free can be directly
used by the device drivers without any wrapper provided by
bus drivers. So export these MSI functions.

Also, add a wrapper API to allocate MSIs providing only the
number of IRQ's rather than range for simpler driver usage.

Signed-off-by: Nipun Gupta <nipun.gupta@amd.com>
---

Changes in v3:
- New in this patch series. VFIO-CDX uses the new wrapper API
  msi_domain_alloc_irqs and exported APIs. (This patch is moved
  from CDX interrupt support to vfio-cdx patch, where these APIs
  are used).

 include/linux/msi.h | 6 ++++++
 kernel/irq/msi.c    | 2 ++
 2 files changed, 8 insertions(+)

diff --git a/include/linux/msi.h b/include/linux/msi.h
index ddace8c34dcf..a9f77cbc8847 100644
--- a/include/linux/msi.h
+++ b/include/linux/msi.h
@@ -658,6 +658,12 @@ void platform_msi_device_domain_free(struct irq_domain *domain, unsigned int vir
 void *platform_msi_get_host_data(struct irq_domain *domain);
 
 bool msi_device_has_isolated_msi(struct device *dev);
+
+static inline int msi_domain_alloc_irqs(struct device *dev, unsigned int domid, int nirqs)
+{
+	return msi_domain_alloc_irqs_range(dev, domid, 0, nirqs - 1);
+}
+
 #else /* CONFIG_GENERIC_MSI_IRQ */
 static inline bool msi_device_has_isolated_msi(struct device *dev)
 {
diff --git a/kernel/irq/msi.c b/kernel/irq/msi.c
index 79b4a58ba9c3..4a324f683858 100644
--- a/kernel/irq/msi.c
+++ b/kernel/irq/msi.c
@@ -1404,6 +1404,7 @@ int msi_domain_alloc_irqs_range(struct device *dev, unsigned int domid,
 	msi_unlock_descs(dev);
 	return ret;
 }
+EXPORT_SYMBOL_GPL(msi_domain_alloc_irqs_range);
 
 /**
  * msi_domain_alloc_irqs_all_locked - Allocate all interrupts from a MSI interrupt domain
@@ -1596,6 +1597,7 @@ void msi_domain_free_irqs_range(struct device *dev, unsigned int domid,
 	msi_domain_free_irqs_range_locked(dev, domid, first, last);
 	msi_unlock_descs(dev);
 }
+EXPORT_SYMBOL_GPL(msi_domain_free_irqs_all);
 
 /**
  * msi_domain_free_irqs_all_locked - Free all interrupts from a MSI interrupt domain
-- 
2.34.1

[PATCH v3 2/2] vfio/cdx: add interrupt support

[Nipun Gupta]

Support the following ioctls for CDX devices:
- VFIO_DEVICE_GET_IRQ_INFO
- VFIO_DEVICE_SET_IRQS

This allows user to set an eventfd for cdx device interrupts and
trigger this interrupt eventfd from userspace.
All CDX device interrupts are MSIs. The MSIs are allocated from the
CDX-MSI domain.

Signed-off-by: Nipun Gupta <nipun.gupta@amd.com>
Reviewed-by: Pieter Jansen van Vuuren <pieter.jansen-van-vuuren@amd.com>
---

This patch depends on CDX MSI support patch:
https://lore.kernel.org/lkml/20240226082816.100872-1-nipun.gupta@amd.com/

Changes v2->v3:
- Use generic MSI alloc/free APIs instead of CDX MSI APIs
- Rebased on Linux 6.8-rc6

Changes v1->v2:
- Rebased on Linux 6.7-rc1

 drivers/vfio/cdx/Makefile  |   2 +-
 drivers/vfio/cdx/intr.c    | 211 +++++++++++++++++++++++++++++++++++++
 drivers/vfio/cdx/main.c    |  60 ++++++++++-
 drivers/vfio/cdx/private.h |  18 ++++
 4 files changed, 289 insertions(+), 2 deletions(-)
 create mode 100644 drivers/vfio/cdx/intr.c

diff --git a/drivers/vfio/cdx/Makefile b/drivers/vfio/cdx/Makefile
index cd4a2e6fe609..df92b320122a 100644
--- a/drivers/vfio/cdx/Makefile
+++ b/drivers/vfio/cdx/Makefile
@@ -5,4 +5,4 @@
 
 obj-$(CONFIG_VFIO_CDX) += vfio-cdx.o
 
-vfio-cdx-objs := main.o
+vfio-cdx-objs := main.o intr.o
diff --git a/drivers/vfio/cdx/intr.c b/drivers/vfio/cdx/intr.c
new file mode 100644
index 000000000000..4637b57d0242
--- /dev/null
+++ b/drivers/vfio/cdx/intr.c
@@ -0,0 +1,211 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2022-2023, Advanced Micro Devices, Inc.
+ */
+
+#include <linux/vfio.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/eventfd.h>
+#include <linux/msi.h>
+#include <linux/interrupt.h>
+
+#include "linux/cdx/cdx_bus.h"
+#include "private.h"
+
+static irqreturn_t vfio_cdx_msihandler(int irq_no, void *arg)
+{
+	struct eventfd_ctx *trigger = arg;
+
+	eventfd_signal(trigger);
+	return IRQ_HANDLED;
+}
+
+static int vfio_cdx_msi_enable(struct vfio_cdx_device *vdev, int nvec)
+{
+	struct cdx_device *cdx_dev = to_cdx_device(vdev->vdev.dev);
+	struct device *dev = vdev->vdev.dev;
+	int msi_idx, ret;
+
+	vdev->cdx_irqs = kcalloc(nvec, sizeof(struct vfio_cdx_irq), GFP_KERNEL);
+	if (!vdev->cdx_irqs)
+		return -ENOMEM;
+
+	ret = cdx_enable_msi(cdx_dev);
+	if (ret) {
+		kfree(vdev->cdx_irqs);
+		return ret;
+	}
+
+	/* Allocate cdx MSIs */
+	ret = msi_domain_alloc_irqs(dev, MSI_DEFAULT_DOMAIN, nvec);
+	if (ret) {
+		cdx_disable_msi(cdx_dev);
+		kfree(vdev->cdx_irqs);
+		return ret;
+	}
+
+	for (msi_idx = 0; msi_idx < nvec; msi_idx++)
+		vdev->cdx_irqs[msi_idx].irq_no = msi_get_virq(dev, msi_idx);
+
+	vdev->irq_count = nvec;
+	vdev->config_msi = 1;
+
+	return 0;
+}
+
+static int vfio_cdx_msi_set_vector_signal(struct vfio_cdx_device *vdev,
+					  int vector, int fd)
+{
+	struct eventfd_ctx *trigger;
+	int irq_no, ret;
+
+	if (vector < 0 || vector >= vdev->irq_count)
+		return -EINVAL;
+
+	irq_no = vdev->cdx_irqs[vector].irq_no;
+
+	if (vdev->cdx_irqs[vector].trigger) {
+		free_irq(irq_no, vdev->cdx_irqs[vector].trigger);
+		kfree(vdev->cdx_irqs[vector].name);
+		eventfd_ctx_put(vdev->cdx_irqs[vector].trigger);
+		vdev->cdx_irqs[vector].trigger = NULL;
+	}
+
+	if (fd < 0)
+		return 0;
+
+	vdev->cdx_irqs[vector].name = kasprintf(GFP_KERNEL, "vfio-msi[%d](%s)",
+						vector, dev_name(vdev->vdev.dev));
+	if (!vdev->cdx_irqs[vector].name)
+		return -ENOMEM;
+
+	trigger = eventfd_ctx_fdget(fd);
+	if (IS_ERR(trigger)) {
+		kfree(vdev->cdx_irqs[vector].name);
+		return PTR_ERR(trigger);
+	}
+
+	ret = request_irq(irq_no, vfio_cdx_msihandler, 0,
+			  vdev->cdx_irqs[vector].name, trigger);
+	if (ret) {
+		kfree(vdev->cdx_irqs[vector].name);
+		eventfd_ctx_put(trigger);
+		return ret;
+	}
+
+	vdev->cdx_irqs[vector].trigger = trigger;
+
+	return 0;
+}
+
+static int vfio_cdx_msi_set_block(struct vfio_cdx_device *vdev,
+				  unsigned int start, unsigned int count,
+				  int32_t *fds)
+{
+	int i, j, ret = 0;
+
+	if (start >= vdev->irq_count || start + count > vdev->irq_count)
+		return -EINVAL;
+
+	for (i = 0, j = start; i < count && !ret; i++, j++) {
+		int fd = fds ? fds[i] : -1;
+
+		ret = vfio_cdx_msi_set_vector_signal(vdev, j, fd);
+	}
+
+	if (ret) {
+		for (--j; j >= (int)start; j--)
+			vfio_cdx_msi_set_vector_signal(vdev, j, -1);
+	}
+
+	return ret;
+}
+
+static void vfio_cdx_msi_disable(struct vfio_cdx_device *vdev)
+{
+	struct cdx_device *cdx_dev = to_cdx_device(vdev->vdev.dev);
+	struct device *dev = vdev->vdev.dev;
+
+	vfio_cdx_msi_set_block(vdev, 0, vdev->irq_count, NULL);
+
+	if (!vdev->config_msi)
+		return;
+
+	msi_domain_free_irqs_all(dev, MSI_DEFAULT_DOMAIN);
+	cdx_disable_msi(cdx_dev);
+	kfree(vdev->cdx_irqs);
+
+	vdev->cdx_irqs = NULL;
+	vdev->irq_count = 0;
+	vdev->config_msi = 0;
+}
+
+static int vfio_cdx_set_msi_trigger(struct vfio_cdx_device *vdev,
+				    unsigned int index, unsigned int start,
+				    unsigned int count, u32 flags,
+				    void *data)
+{
+	struct cdx_device *cdx_dev = to_cdx_device(vdev->vdev.dev);
+	int i;
+
+	if (start + count > cdx_dev->num_msi)
+		return -EINVAL;
+
+	if (!count && (flags & VFIO_IRQ_SET_DATA_NONE)) {
+		vfio_cdx_msi_disable(vdev);
+		return 0;
+	}
+
+	if (flags & VFIO_IRQ_SET_DATA_EVENTFD) {
+		s32 *fds = data;
+		int ret;
+
+		if (vdev->config_msi)
+			return vfio_cdx_msi_set_block(vdev, start, count,
+						  fds);
+		ret = vfio_cdx_msi_enable(vdev, cdx_dev->num_msi);
+		if (ret)
+			return ret;
+
+		ret = vfio_cdx_msi_set_block(vdev, start, count, fds);
+		if (ret)
+			vfio_cdx_msi_disable(vdev);
+
+		return ret;
+	}
+
+	for (i = start; i < start + count; i++) {
+		if (!vdev->cdx_irqs[i].trigger)
+			continue;
+		if (flags & VFIO_IRQ_SET_DATA_NONE)
+			eventfd_signal(vdev->cdx_irqs[i].trigger);
+	}
+
+	return 0;
+}
+
+int vfio_cdx_set_irqs_ioctl(struct vfio_cdx_device *vdev,
+			    u32 flags, unsigned int index,
+			    unsigned int start, unsigned int count,
+			    void *data)
+{
+	if (flags & VFIO_IRQ_SET_ACTION_TRIGGER)
+		return vfio_cdx_set_msi_trigger(vdev, index, start,
+			  count, flags, data);
+	else
+		return -EINVAL;
+}
+
+/* Free All IRQs for the given device */
+void vfio_cdx_irqs_cleanup(struct vfio_cdx_device *vdev)
+{
+	/*
+	 * Device does not support any interrupt or the interrupts
+	 * were not configured
+	 */
+	if (!vdev->cdx_irqs)
+		return;
+
+	vfio_cdx_set_msi_trigger(vdev, 1, 0, 0, VFIO_IRQ_SET_DATA_NONE, NULL);
+}
diff --git a/drivers/vfio/cdx/main.c b/drivers/vfio/cdx/main.c
index 9cff8d75789e..eb1c5879150b 100644
--- a/drivers/vfio/cdx/main.c
+++ b/drivers/vfio/cdx/main.c
@@ -61,6 +61,7 @@ static void vfio_cdx_close_device(struct vfio_device *core_vdev)
 
 	kfree(vdev->regions);
 	cdx_dev_reset(core_vdev->dev);
+	vfio_cdx_irqs_cleanup(vdev);
 }
 
 static int vfio_cdx_bm_ctrl(struct vfio_device *core_vdev, u32 flags,
@@ -123,7 +124,7 @@ static int vfio_cdx_ioctl_get_info(struct vfio_cdx_device *vdev,
 	info.flags |= VFIO_DEVICE_FLAGS_RESET;
 
 	info.num_regions = cdx_dev->res_count;
-	info.num_irqs = 0;
+	info.num_irqs = cdx_dev->num_msi ? 1 : 0;
 
 	return copy_to_user(arg, &info, minsz) ? -EFAULT : 0;
 }
@@ -152,6 +153,59 @@ static int vfio_cdx_ioctl_get_region_info(struct vfio_cdx_device *vdev,
 	return copy_to_user(arg, &info, minsz) ? -EFAULT : 0;
 }
 
+static int vfio_cdx_ioctl_get_irq_info(struct vfio_cdx_device *vdev,
+				       struct vfio_irq_info __user *arg)
+{
+	unsigned long minsz = offsetofend(struct vfio_irq_info, count);
+	struct cdx_device *cdx_dev = to_cdx_device(vdev->vdev.dev);
+	struct vfio_irq_info info;
+
+	if (copy_from_user(&info, arg, minsz))
+		return -EFAULT;
+
+	if (info.argsz < minsz)
+		return -EINVAL;
+
+	if (info.index >= 1)
+		return -EINVAL;
+
+	info.flags = VFIO_IRQ_INFO_EVENTFD;
+	info.count = cdx_dev->num_msi;
+
+	return copy_to_user(arg, &info, minsz) ? -EFAULT : 0;
+}
+
+static int vfio_cdx_ioctl_set_irqs(struct vfio_cdx_device *vdev,
+				   struct vfio_irq_set __user *arg)
+{
+	unsigned long minsz = offsetofend(struct vfio_irq_set, count);
+	struct cdx_device *cdx_dev = to_cdx_device(vdev->vdev.dev);
+	struct vfio_irq_set hdr;
+	size_t data_size = 0;
+	u8 *data = NULL;
+	int ret = 0;
+
+	if (copy_from_user(&hdr, arg, minsz))
+		return -EFAULT;
+
+	ret = vfio_set_irqs_validate_and_prepare(&hdr, cdx_dev->num_msi,
+						 1, &data_size);
+	if (ret)
+		return ret;
+
+	if (data_size) {
+		data = memdup_user(arg->data, data_size);
+		if (IS_ERR(data))
+			return PTR_ERR(data);
+	}
+
+	ret = vfio_cdx_set_irqs_ioctl(vdev, hdr.flags, hdr.index,
+				      hdr.start, hdr.count, data);
+	kfree(data);
+
+	return ret;
+}
+
 static long vfio_cdx_ioctl(struct vfio_device *core_vdev,
 			   unsigned int cmd, unsigned long arg)
 {
@@ -164,6 +218,10 @@ static long vfio_cdx_ioctl(struct vfio_device *core_vdev,
 		return vfio_cdx_ioctl_get_info(vdev, uarg);
 	case VFIO_DEVICE_GET_REGION_INFO:
 		return vfio_cdx_ioctl_get_region_info(vdev, uarg);
+	case VFIO_DEVICE_GET_IRQ_INFO:
+		return vfio_cdx_ioctl_get_irq_info(vdev, uarg);
+	case VFIO_DEVICE_SET_IRQS:
+		return vfio_cdx_ioctl_set_irqs(vdev, uarg);
 	case VFIO_DEVICE_RESET:
 		return cdx_dev_reset(core_vdev->dev);
 	default:
diff --git a/drivers/vfio/cdx/private.h b/drivers/vfio/cdx/private.h
index 8e9d25913728..7a8477ae4652 100644
--- a/drivers/vfio/cdx/private.h
+++ b/drivers/vfio/cdx/private.h
@@ -13,6 +13,14 @@ static inline u64 vfio_cdx_index_to_offset(u32 index)
 	return ((u64)(index) << VFIO_CDX_OFFSET_SHIFT);
 }
 
+struct vfio_cdx_irq {
+	u32			flags;
+	u32			count;
+	int			irq_no;
+	struct eventfd_ctx	*trigger;
+	char			*name;
+};
+
 struct vfio_cdx_region {
 	u32			flags;
 	u32			type;
@@ -25,6 +33,16 @@ struct vfio_cdx_device {
 	struct vfio_cdx_region	*regions;
 	u32			flags;
 #define BME_SUPPORT BIT(0)
+	struct vfio_cdx_irq	*cdx_irqs;
+	u32			irq_count;
+	u32			config_msi;
 };
 
+int vfio_cdx_set_irqs_ioctl(struct vfio_cdx_device *vdev,
+			    u32 flags, unsigned int index,
+			    unsigned int start, unsigned int count,
+			    void *data);
+
+void vfio_cdx_irqs_cleanup(struct vfio_cdx_device *vdev);
+
 #endif /* VFIO_CDX_PRIVATE_H */
-- 
2.34.1

Re: [PATCH v3 2/2] vfio/cdx: add interrupt support

[Alex Williamson]

On Mon, 26 Feb 2024 14:18:13 +0530
Nipun Gupta <nipun.gupta@amd.com> wrote:

> Support the following ioctls for CDX devices:
> - VFIO_DEVICE_GET_IRQ_INFO
> - VFIO_DEVICE_SET_IRQS
> 
> This allows user to set an eventfd for cdx device interrupts and
> trigger this interrupt eventfd from userspace.
> All CDX device interrupts are MSIs. The MSIs are allocated from the
> CDX-MSI domain.
> 
> Signed-off-by: Nipun Gupta <nipun.gupta@amd.com>
> Reviewed-by: Pieter Jansen van Vuuren <pieter.jansen-van-vuuren@amd.com>
> ---
> 
> This patch depends on CDX MSI support patch:
> https://lore.kernel.org/lkml/20240226082816.100872-1-nipun.gupta@amd.com/
> 
> Changes v2->v3:
> - Use generic MSI alloc/free APIs instead of CDX MSI APIs
> - Rebased on Linux 6.8-rc6
> 
> Changes v1->v2:
> - Rebased on Linux 6.7-rc1
> 
>  drivers/vfio/cdx/Makefile  |   2 +-
>  drivers/vfio/cdx/intr.c    | 211 +++++++++++++++++++++++++++++++++++++
>  drivers/vfio/cdx/main.c    |  60 ++++++++++-
>  drivers/vfio/cdx/private.h |  18 ++++
>  4 files changed, 289 insertions(+), 2 deletions(-)
>  create mode 100644 drivers/vfio/cdx/intr.c
> 
> diff --git a/drivers/vfio/cdx/Makefile b/drivers/vfio/cdx/Makefile
> index cd4a2e6fe609..df92b320122a 100644
> --- a/drivers/vfio/cdx/Makefile
> +++ b/drivers/vfio/cdx/Makefile
> @@ -5,4 +5,4 @@
>  
>  obj-$(CONFIG_VFIO_CDX) += vfio-cdx.o
>  
> -vfio-cdx-objs := main.o
> +vfio-cdx-objs := main.o intr.o
> diff --git a/drivers/vfio/cdx/intr.c b/drivers/vfio/cdx/intr.c
> new file mode 100644
> index 000000000000..4637b57d0242
> --- /dev/null
> +++ b/drivers/vfio/cdx/intr.c
> @@ -0,0 +1,211 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2022-2023, Advanced Micro Devices, Inc.
> + */
> +
> +#include <linux/vfio.h>
> +#include <linux/slab.h>
> +#include <linux/types.h>
> +#include <linux/eventfd.h>
> +#include <linux/msi.h>
> +#include <linux/interrupt.h>
> +
> +#include "linux/cdx/cdx_bus.h"
> +#include "private.h"
> +
> +static irqreturn_t vfio_cdx_msihandler(int irq_no, void *arg)
> +{
> +	struct eventfd_ctx *trigger = arg;
> +
> +	eventfd_signal(trigger);
> +	return IRQ_HANDLED;
> +}
> +
> +static int vfio_cdx_msi_enable(struct vfio_cdx_device *vdev, int nvec)
> +{
> +	struct cdx_device *cdx_dev = to_cdx_device(vdev->vdev.dev);
> +	struct device *dev = vdev->vdev.dev;
> +	int msi_idx, ret;
> +
> +	vdev->cdx_irqs = kcalloc(nvec, sizeof(struct vfio_cdx_irq), GFP_KERNEL);
> +	if (!vdev->cdx_irqs)
> +		return -ENOMEM;
> +
> +	ret = cdx_enable_msi(cdx_dev);
> +	if (ret) {
> +		kfree(vdev->cdx_irqs);
> +		return ret;
> +	}
> +
> +	/* Allocate cdx MSIs */
> +	ret = msi_domain_alloc_irqs(dev, MSI_DEFAULT_DOMAIN, nvec);
> +	if (ret) {
> +		cdx_disable_msi(cdx_dev);
> +		kfree(vdev->cdx_irqs);
> +		return ret;
> +	}
> +
> +	for (msi_idx = 0; msi_idx < nvec; msi_idx++)
> +		vdev->cdx_irqs[msi_idx].irq_no = msi_get_virq(dev, msi_idx);
> +
> +	vdev->irq_count = nvec;
> +	vdev->config_msi = 1;
> +
> +	return 0;
> +}
> +
> +static int vfio_cdx_msi_set_vector_signal(struct vfio_cdx_device *vdev,
> +					  int vector, int fd)
> +{
> +	struct eventfd_ctx *trigger;
> +	int irq_no, ret;
> +
> +	if (vector < 0 || vector >= vdev->irq_count)
> +		return -EINVAL;
> +
> +	irq_no = vdev->cdx_irqs[vector].irq_no;
> +
> +	if (vdev->cdx_irqs[vector].trigger) {
> +		free_irq(irq_no, vdev->cdx_irqs[vector].trigger);
> +		kfree(vdev->cdx_irqs[vector].name);
> +		eventfd_ctx_put(vdev->cdx_irqs[vector].trigger);
> +		vdev->cdx_irqs[vector].trigger = NULL;
> +	}
> +
> +	if (fd < 0)
> +		return 0;
> +
> +	vdev->cdx_irqs[vector].name = kasprintf(GFP_KERNEL, "vfio-msi[%d](%s)",
> +						vector, dev_name(vdev->vdev.dev));
> +	if (!vdev->cdx_irqs[vector].name)
> +		return -ENOMEM;
> +
> +	trigger = eventfd_ctx_fdget(fd);
> +	if (IS_ERR(trigger)) {
> +		kfree(vdev->cdx_irqs[vector].name);
> +		return PTR_ERR(trigger);
> +	}
> +
> +	ret = request_irq(irq_no, vfio_cdx_msihandler, 0,
> +			  vdev->cdx_irqs[vector].name, trigger);
> +	if (ret) {
> +		kfree(vdev->cdx_irqs[vector].name);
> +		eventfd_ctx_put(trigger);
> +		return ret;
> +	}
> +
> +	vdev->cdx_irqs[vector].trigger = trigger;
> +
> +	return 0;
> +}
> +
> +static int vfio_cdx_msi_set_block(struct vfio_cdx_device *vdev,
> +				  unsigned int start, unsigned int count,
> +				  int32_t *fds)
> +{
> +	int i, j, ret = 0;
> +
> +	if (start >= vdev->irq_count || start + count > vdev->irq_count)
> +		return -EINVAL;
> +
> +	for (i = 0, j = start; i < count && !ret; i++, j++) {
> +		int fd = fds ? fds[i] : -1;
> +
> +		ret = vfio_cdx_msi_set_vector_signal(vdev, j, fd);
> +	}
> +
> +	if (ret) {
> +		for (--j; j >= (int)start; j--)
> +			vfio_cdx_msi_set_vector_signal(vdev, j, -1);
> +	}
> +
> +	return ret;
> +}
> +
> +static void vfio_cdx_msi_disable(struct vfio_cdx_device *vdev)
> +{
> +	struct cdx_device *cdx_dev = to_cdx_device(vdev->vdev.dev);
> +	struct device *dev = vdev->vdev.dev;
> +
> +	vfio_cdx_msi_set_block(vdev, 0, vdev->irq_count, NULL);
> +
> +	if (!vdev->config_msi)
> +		return;
> +
> +	msi_domain_free_irqs_all(dev, MSI_DEFAULT_DOMAIN);
> +	cdx_disable_msi(cdx_dev);
> +	kfree(vdev->cdx_irqs);
> +
> +	vdev->cdx_irqs = NULL;
> +	vdev->irq_count = 0;
> +	vdev->config_msi = 0;
> +}
> +
> +static int vfio_cdx_set_msi_trigger(struct vfio_cdx_device *vdev,
> +				    unsigned int index, unsigned int start,
> +				    unsigned int count, u32 flags,
> +				    void *data)
> +{
> +	struct cdx_device *cdx_dev = to_cdx_device(vdev->vdev.dev);
> +	int i;
> +
> +	if (start + count > cdx_dev->num_msi)
> +		return -EINVAL;
> +
> +	if (!count && (flags & VFIO_IRQ_SET_DATA_NONE)) {
> +		vfio_cdx_msi_disable(vdev);
> +		return 0;
> +	}
> +
> +	if (flags & VFIO_IRQ_SET_DATA_EVENTFD) {
> +		s32 *fds = data;
> +		int ret;
> +
> +		if (vdev->config_msi)
> +			return vfio_cdx_msi_set_block(vdev, start, count,
> +						  fds);
> +		ret = vfio_cdx_msi_enable(vdev, cdx_dev->num_msi);
> +		if (ret)
> +			return ret;
> +
> +		ret = vfio_cdx_msi_set_block(vdev, start, count, fds);
> +		if (ret)
> +			vfio_cdx_msi_disable(vdev);
> +
> +		return ret;
> +	}
> +
> +	for (i = start; i < start + count; i++) {
> +		if (!vdev->cdx_irqs[i].trigger)
> +			continue;
> +		if (flags & VFIO_IRQ_SET_DATA_NONE)
> +			eventfd_signal(vdev->cdx_irqs[i].trigger);
> +	}
> +
> +	return 0;
> +}
> +
> +int vfio_cdx_set_irqs_ioctl(struct vfio_cdx_device *vdev,
> +			    u32 flags, unsigned int index,
> +			    unsigned int start, unsigned int count,
> +			    void *data)
> +{
> +	if (flags & VFIO_IRQ_SET_ACTION_TRIGGER)
> +		return vfio_cdx_set_msi_trigger(vdev, index, start,
> +			  count, flags, data);
> +	else
> +		return -EINVAL;
> +}
> +
> +/* Free All IRQs for the given device */
> +void vfio_cdx_irqs_cleanup(struct vfio_cdx_device *vdev)
> +{
> +	/*
> +	 * Device does not support any interrupt or the interrupts
> +	 * were not configured
> +	 */
> +	if (!vdev->cdx_irqs)
> +		return;
> +
> +	vfio_cdx_set_msi_trigger(vdev, 1, 0, 0, VFIO_IRQ_SET_DATA_NONE, NULL);
> +}
> diff --git a/drivers/vfio/cdx/main.c b/drivers/vfio/cdx/main.c
> index 9cff8d75789e..eb1c5879150b 100644
> --- a/drivers/vfio/cdx/main.c
> +++ b/drivers/vfio/cdx/main.c
> @@ -61,6 +61,7 @@ static void vfio_cdx_close_device(struct vfio_device *core_vdev)
>  
>  	kfree(vdev->regions);
>  	cdx_dev_reset(core_vdev->dev);
> +	vfio_cdx_irqs_cleanup(vdev);
>  }
>  
>  static int vfio_cdx_bm_ctrl(struct vfio_device *core_vdev, u32 flags,
> @@ -123,7 +124,7 @@ static int vfio_cdx_ioctl_get_info(struct vfio_cdx_device *vdev,
>  	info.flags |= VFIO_DEVICE_FLAGS_RESET;
>  
>  	info.num_regions = cdx_dev->res_count;
> -	info.num_irqs = 0;
> +	info.num_irqs = cdx_dev->num_msi ? 1 : 0;
>  
>  	return copy_to_user(arg, &info, minsz) ? -EFAULT : 0;
>  }
> @@ -152,6 +153,59 @@ static int vfio_cdx_ioctl_get_region_info(struct vfio_cdx_device *vdev,
>  	return copy_to_user(arg, &info, minsz) ? -EFAULT : 0;
>  }
>  
> +static int vfio_cdx_ioctl_get_irq_info(struct vfio_cdx_device *vdev,
> +				       struct vfio_irq_info __user *arg)
> +{
> +	unsigned long minsz = offsetofend(struct vfio_irq_info, count);
> +	struct cdx_device *cdx_dev = to_cdx_device(vdev->vdev.dev);
> +	struct vfio_irq_info info;
> +
> +	if (copy_from_user(&info, arg, minsz))
> +		return -EFAULT;
> +
> +	if (info.argsz < minsz)
> +		return -EINVAL;
> +
> +	if (info.index >= 1)
> +		return -EINVAL;
> +
> +	info.flags = VFIO_IRQ_INFO_EVENTFD;


I think the way you're using this you'd also need the
VFIO_IRQ_INFO_NORESIZE to indicate the MSI range cannot be expanded
from the initial setting.  Thanks,

Alex

> +	info.count = cdx_dev->num_msi;
> +
> +	return copy_to_user(arg, &info, minsz) ? -EFAULT : 0;
> +}
> +
> +static int vfio_cdx_ioctl_set_irqs(struct vfio_cdx_device *vdev,
> +				   struct vfio_irq_set __user *arg)
> +{
> +	unsigned long minsz = offsetofend(struct vfio_irq_set, count);
> +	struct cdx_device *cdx_dev = to_cdx_device(vdev->vdev.dev);
> +	struct vfio_irq_set hdr;
> +	size_t data_size = 0;
> +	u8 *data = NULL;
> +	int ret = 0;
> +
> +	if (copy_from_user(&hdr, arg, minsz))
> +		return -EFAULT;
> +
> +	ret = vfio_set_irqs_validate_and_prepare(&hdr, cdx_dev->num_msi,
> +						 1, &data_size);
> +	if (ret)
> +		return ret;
> +
> +	if (data_size) {
> +		data = memdup_user(arg->data, data_size);
> +		if (IS_ERR(data))
> +			return PTR_ERR(data);
> +	}
> +
> +	ret = vfio_cdx_set_irqs_ioctl(vdev, hdr.flags, hdr.index,
> +				      hdr.start, hdr.count, data);
> +	kfree(data);
> +
> +	return ret;
> +}
> +
>  static long vfio_cdx_ioctl(struct vfio_device *core_vdev,
>  			   unsigned int cmd, unsigned long arg)
>  {
> @@ -164,6 +218,10 @@ static long vfio_cdx_ioctl(struct vfio_device *core_vdev,
>  		return vfio_cdx_ioctl_get_info(vdev, uarg);
>  	case VFIO_DEVICE_GET_REGION_INFO:
>  		return vfio_cdx_ioctl_get_region_info(vdev, uarg);
> +	case VFIO_DEVICE_GET_IRQ_INFO:
> +		return vfio_cdx_ioctl_get_irq_info(vdev, uarg);
> +	case VFIO_DEVICE_SET_IRQS:
> +		return vfio_cdx_ioctl_set_irqs(vdev, uarg);
>  	case VFIO_DEVICE_RESET:
>  		return cdx_dev_reset(core_vdev->dev);
>  	default:
> diff --git a/drivers/vfio/cdx/private.h b/drivers/vfio/cdx/private.h
> index 8e9d25913728..7a8477ae4652 100644
> --- a/drivers/vfio/cdx/private.h
> +++ b/drivers/vfio/cdx/private.h
> @@ -13,6 +13,14 @@ static inline u64 vfio_cdx_index_to_offset(u32 index)
>  	return ((u64)(index) << VFIO_CDX_OFFSET_SHIFT);
>  }
>  
> +struct vfio_cdx_irq {
> +	u32			flags;
> +	u32			count;
> +	int			irq_no;
> +	struct eventfd_ctx	*trigger;
> +	char			*name;
> +};
> +
>  struct vfio_cdx_region {
>  	u32			flags;
>  	u32			type;
> @@ -25,6 +33,16 @@ struct vfio_cdx_device {
>  	struct vfio_cdx_region	*regions;
>  	u32			flags;
>  #define BME_SUPPORT BIT(0)
> +	struct vfio_cdx_irq	*cdx_irqs;
> +	u32			irq_count;
> +	u32			config_msi;
>  };
>  
> +int vfio_cdx_set_irqs_ioctl(struct vfio_cdx_device *vdev,
> +			    u32 flags, unsigned int index,
> +			    unsigned int start, unsigned int count,
> +			    void *data);
> +
> +void vfio_cdx_irqs_cleanup(struct vfio_cdx_device *vdev);
> +
>  #endif /* VFIO_CDX_PRIVATE_H */

Re: [PATCH v3 2/2] vfio/cdx: add interrupt support

[Gupta, Nipun]

On 3/1/2024 11:15 PM, Alex Williamson wrote:
> On Mon, 26 Feb 2024 14:18:13 +0530
> Nipun Gupta <nipun.gupta@amd.com> wrote:
> 
>> Support the following ioctls for CDX devices:
>> - VFIO_DEVICE_GET_IRQ_INFO
>> - VFIO_DEVICE_SET_IRQS
>>
>> This allows user to set an eventfd for cdx device interrupts and
>> trigger this interrupt eventfd from userspace.
>> All CDX device interrupts are MSIs. The MSIs are allocated from the
>> CDX-MSI domain.
>>
>> Signed-off-by: Nipun Gupta <nipun.gupta@amd.com>
>> Reviewed-by: Pieter Jansen van Vuuren <pieter.jansen-van-vuuren@amd.com>
>> ---
>>

<snip>

>> +static int vfio_cdx_ioctl_get_irq_info(struct vfio_cdx_device *vdev,
>> +				       struct vfio_irq_info __user *arg)
>> +{
>> +	unsigned long minsz = offsetofend(struct vfio_irq_info, count);
>> +	struct cdx_device *cdx_dev = to_cdx_device(vdev->vdev.dev);
>> +	struct vfio_irq_info info;
>> +
>> +	if (copy_from_user(&info, arg, minsz))
>> +		return -EFAULT;
>> +
>> +	if (info.argsz < minsz)
>> +		return -EINVAL;
>> +
>> +	if (info.index >= 1)
>> +		return -EINVAL;
>> +
>> +	info.flags = VFIO_IRQ_INFO_EVENTFD;
> 
> 
> I think the way you're using this you'd also need the
> VFIO_IRQ_INFO_NORESIZE to indicate the MSI range cannot be expanded
> from the initial setting.  Thanks,

Yes, agree. Will update the flags in the next spin.

Thanks,
Nipun

> 
> Alex