* [PATCH v6 2/2] vfio/cdx: add interrupt support
2024-04-23 11:10 [PATCH v6 1/2] genirq/msi: add wrapper msi allocation API and export msi functions Nipun Gupta
@ 2024-04-23 11:10 ` Nipun Gupta
2024-04-23 21:09 ` [PATCH v6 1/2] genirq/msi: add wrapper msi allocation API and export msi functions Alex Williamson
1 sibling, 0 replies; 5+ messages in thread
From: Nipun Gupta @ 2024-04-23 11:10 UTC (permalink / raw)
To: alex.williamson, tglx, gregkh, linux-kernel, kvm
Cc: maz, git, harpreet.anand, pieter.jansen-van-vuuren,
nikhil.agarwal, michal.simek, abhijit.gangurde, srivatsa,
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>
---
Changes v5->v6:
- add support for DATA_BOOL
- rename irq_count to msi_count
- fix sending irq_index as 0 in vfio_cdx_set_msi_trigger()
- fix return value in vfio_cdx_ioctl_get_irq_info() when
msi are not supported on a CDX device
- reorder data fields in vfio_cdx_region to avoid holes
Changes v4->v5:
- Rebased on 6.9-rc1
Changes v3->v4:
- Added VFIO_IRQ_INFO_NORESIZE flag
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 | 217 +++++++++++++++++++++++++++++++++++++
drivers/vfio/cdx/main.c | 63 ++++++++++-
drivers/vfio/cdx/private.h | 18 +++
4 files changed, 298 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..986fa2a45fa4
--- /dev/null
+++ b/drivers/vfio/cdx/intr.c
@@ -0,0 +1,217 @@
+// 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->msi_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->msi_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->msi_count || start + count > vdev->msi_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->msi_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->msi_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);
+ } else if (flags & VFIO_IRQ_SET_DATA_BOOL) {
+ u8 *bools = data;
+
+ if (bools[i - start])
+ 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, 0, 0, 0, VFIO_IRQ_SET_DATA_NONE, NULL);
+}
diff --git a/drivers/vfio/cdx/main.c b/drivers/vfio/cdx/main.c
index 9cff8d75789e..67465fad5b4b 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 +153,62 @@ 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;
+
+ if (!cdx_dev->num_msi)
+ return -EINVAL;
+
+ info.flags = VFIO_IRQ_INFO_EVENTFD | VFIO_IRQ_INFO_NORESIZE;
+ 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 +221,10 @@ 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..dc56729b3114 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;
@@ -23,8 +31,18 @@ struct vfio_cdx_region {
struct vfio_cdx_device {
struct vfio_device vdev;
struct vfio_cdx_region *regions;
+ struct vfio_cdx_irq *cdx_irqs;
u32 flags;
#define BME_SUPPORT BIT(0)
+ u32 msi_count;
+ u8 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
^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [PATCH v6 1/2] genirq/msi: add wrapper msi allocation API and export msi functions
2024-04-23 11:10 [PATCH v6 1/2] genirq/msi: add wrapper msi allocation API and export msi functions Nipun Gupta
2024-04-23 11:10 ` [PATCH v6 2/2] vfio/cdx: add interrupt support Nipun Gupta
@ 2024-04-23 21:09 ` Alex Williamson
2024-04-24 17:21 ` Thomas Gleixner
2024-04-29 18:55 ` Alex Williamson
1 sibling, 2 replies; 5+ messages in thread
From: Alex Williamson @ 2024-04-23 21:09 UTC (permalink / raw)
To: Nipun Gupta
Cc: tglx, gregkh, linux-kernel, kvm, maz, git, harpreet.anand,
pieter.jansen-van-vuuren, nikhil.agarwal, michal.simek,
abhijit.gangurde, srivatsa
On Tue, 23 Apr 2024 16:40:20 +0530
Nipun Gupta <nipun.gupta@amd.com> wrote:
> SI functions for allocation and free can be directly used by
We lost the ^M in this version.
> 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 interrupts rather than range for simpler driver usage.
>
> Signed-off-by: Nipun Gupta <nipun.gupta@amd.com>
> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
> ---
>
> No change in v5->v6
>
> Changes in v4->v5:
> - updated commit description as per the comments.
I see in https://lore.kernel.org/all/87edbyfj0d.ffs@tglx/ that Thomas
also suggested a new subject:
genirq/msi: Add MSI allocation helper and export MSI functions
I'll address both of these on commit if there are no objections or
further comments. Patch 2/ looks ok to me now as well. Thanks,
Alex
> - Rebased on 6.9-rc1
>
> Changes in v3->v4:
> - No change
>
> 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 84859a9aa091..dc27cf3903d5 100644
> --- a/include/linux/msi.h
> +++ b/include/linux/msi.h
> @@ -674,6 +674,12 @@ int platform_device_msi_init_and_alloc_irqs(struct device *dev, unsigned int nve
> void platform_device_msi_free_irqs_all(struct device *dev);
>
> 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 f90952ebc494..2024f89baea4 100644
> --- a/kernel/irq/msi.c
> +++ b/kernel/irq/msi.c
> @@ -1434,6 +1434,7 @@ 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
> @@ -1680,6 +1681,7 @@ 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
^ permalink raw reply [flat|nested] 5+ messages in thread