[PATCH v2 05/11] vduse: Introduce bound workqueue for irq injection

From: Xie Yongji
Date: Mon Dec 05 2022 - 03:44:29 EST


This introduces a bound workqueue to support running
irq callback in a specified cpu.

Signed-off-by: Xie Yongji <xieyongji@xxxxxxxxxxxxx>
---
drivers/vdpa/vdpa_user/vduse_dev.c | 29 ++++++++++++++++++++++-------
1 file changed, 22 insertions(+), 7 deletions(-)

diff --git a/drivers/vdpa/vdpa_user/vduse_dev.c b/drivers/vdpa/vdpa_user/vduse_dev.c
index 37809bfcb7ef..d126f3e32a20 100644
--- a/drivers/vdpa/vdpa_user/vduse_dev.c
+++ b/drivers/vdpa/vdpa_user/vduse_dev.c
@@ -57,6 +57,7 @@ struct vduse_virtqueue {
struct vdpa_callback cb;
struct work_struct inject;
struct work_struct kick;
+ int irq_effective_cpu;
};

struct vduse_dev;
@@ -128,6 +129,7 @@ static struct class *vduse_class;
static struct cdev vduse_ctrl_cdev;
static struct cdev vduse_cdev;
static struct workqueue_struct *vduse_irq_wq;
+static struct workqueue_struct *vduse_irq_bound_wq;

static u32 allowed_device_id[] = {
VIRTIO_ID_BLOCK,
@@ -917,7 +919,8 @@ static void vduse_vq_irq_inject(struct work_struct *work)
}

static int vduse_dev_queue_irq_work(struct vduse_dev *dev,
- struct work_struct *irq_work)
+ struct work_struct *irq_work,
+ int irq_effective_cpu)
{
int ret = -EINVAL;

@@ -926,7 +929,11 @@ static int vduse_dev_queue_irq_work(struct vduse_dev *dev,
goto unlock;

ret = 0;
- queue_work(vduse_irq_wq, irq_work);
+ if (irq_effective_cpu == -1)
+ queue_work(vduse_irq_wq, irq_work);
+ else
+ queue_work_on(irq_effective_cpu,
+ vduse_irq_bound_wq, irq_work);
unlock:
up_read(&dev->rwsem);

@@ -1111,7 +1118,7 @@ static long vduse_dev_ioctl(struct file *file, unsigned int cmd,
break;
}
case VDUSE_DEV_INJECT_CONFIG_IRQ:
- ret = vduse_dev_queue_irq_work(dev, &dev->inject);
+ ret = vduse_dev_queue_irq_work(dev, &dev->inject, -1);
break;
case VDUSE_VQ_SETUP: {
struct vduse_vq_config config;
@@ -1198,7 +1205,8 @@ static long vduse_dev_ioctl(struct file *file, unsigned int cmd,
break;

index = array_index_nospec(index, dev->vq_num);
- ret = vduse_dev_queue_irq_work(dev, &dev->vqs[index]->inject);
+ ret = vduse_dev_queue_irq_work(dev, &dev->vqs[index]->inject,
+ dev->vqs[index]->irq_effective_cpu);
break;
}
case VDUSE_IOTLB_REG_UMEM: {
@@ -1367,6 +1375,7 @@ static int vduse_dev_init_vqs(struct vduse_dev *dev, u32 vq_align, u32 vq_num)
goto err;

dev->vqs[i]->index = i;
+ dev->vqs[i]->irq_effective_cpu = -1;
INIT_WORK(&dev->vqs[i]->inject, vduse_vq_irq_inject);
INIT_WORK(&dev->vqs[i]->kick, vduse_vq_kick_work);
spin_lock_init(&dev->vqs[i]->kick_lock);
@@ -1855,12 +1864,15 @@ static int vduse_init(void)
if (ret)
goto err_cdev;

+ ret = -ENOMEM;
vduse_irq_wq = alloc_workqueue("vduse-irq",
WQ_HIGHPRI | WQ_SYSFS | WQ_UNBOUND, 0);
- if (!vduse_irq_wq) {
- ret = -ENOMEM;
+ if (!vduse_irq_wq)
goto err_wq;
- }
+
+ vduse_irq_bound_wq = alloc_workqueue("vduse-irq-bound", WQ_HIGHPRI, 0);
+ if (!vduse_irq_bound_wq)
+ goto err_bound_wq;

ret = vduse_domain_init();
if (ret)
@@ -1874,6 +1886,8 @@ static int vduse_init(void)
err_mgmtdev:
vduse_domain_exit();
err_domain:
+ destroy_workqueue(vduse_irq_bound_wq);
+err_bound_wq:
destroy_workqueue(vduse_irq_wq);
err_wq:
cdev_del(&vduse_cdev);
@@ -1893,6 +1907,7 @@ static void vduse_exit(void)
{
vduse_mgmtdev_exit();
vduse_domain_exit();
+ destroy_workqueue(vduse_irq_bound_wq);
destroy_workqueue(vduse_irq_wq);
cdev_del(&vduse_cdev);
device_destroy(vduse_class, vduse_major);
--
2.20.1