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vhost_vdpa: implement IRQ offloading in vhost_vdpa

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This patch introduce a set of functions for setup/unsetup
and update irq offloading respectively by register/unregister
and re-register the irq_bypass_producer.

With these functions, this commit can setup/unsetup
irq offloading through setting DRIVER_OK/!DRIVER_OK, and
update irq offloading through SET_VRING_CALL.

Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
Suggested-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20200731065533.4144-5-lingshan.zhu@intel.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Zhu Lingshan 2020-07-31 14:55:31 +08:00 committed by Michael S. Tsirkin
parent 7164675ab5
commit 2cf1ba9a4d
2 changed files with 63 additions and 1 deletions
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1
drivers/vhost/Kconfig
View File

@ -65,6 +65,7 @@ config VHOST_VDPA
tristate "Vhost driver for vDPA-based backend"
depends on EVENTFD
select VHOST
select IRQ_BYPASS_MANAGER
depends on VDPA
help
This kernel module can be loaded in host kernel to accelerate

63
drivers/vhost/vdpa.c
View File

@ -82,6 +82,39 @@ static irqreturn_t vhost_vdpa_config_cb(void *private)
return IRQ_HANDLED;
}
static void vhost_vdpa_setup_vq_irq(struct vhost_vdpa *v, u16 qid)
{
struct vhost_virtqueue *vq = &v->vqs[qid];
const struct vdpa_config_ops *ops = v->vdpa->config;
struct vdpa_device *vdpa = v->vdpa;
int ret, irq;
if (!ops->get_vq_irq)
return;
irq = ops->get_vq_irq(vdpa, qid);
spin_lock(&vq->call_ctx.ctx_lock);
irq_bypass_unregister_producer(&vq->call_ctx.producer);
if (!vq->call_ctx.ctx || irq < 0) {
spin_unlock(&vq->call_ctx.ctx_lock);
return;
}
vq->call_ctx.producer.token = vq->call_ctx.ctx;
vq->call_ctx.producer.irq = irq;
ret = irq_bypass_register_producer(&vq->call_ctx.producer);
spin_unlock(&vq->call_ctx.ctx_lock);
}
static void vhost_vdpa_unsetup_vq_irq(struct vhost_vdpa *v, u16 qid)
{
struct vhost_virtqueue *vq = &v->vqs[qid];
spin_lock(&vq->call_ctx.ctx_lock);
irq_bypass_unregister_producer(&vq->call_ctx.producer);
spin_unlock(&vq->call_ctx.ctx_lock);
}
static void vhost_vdpa_reset(struct vhost_vdpa *v)
{
struct vdpa_device *vdpa = v->vdpa;
@ -121,11 +154,15 @@ static long vhost_vdpa_set_status(struct vhost_vdpa *v, u8 __user *statusp)
{
struct vdpa_device *vdpa = v->vdpa;
const struct vdpa_config_ops *ops = vdpa->config;
u8 status;
u8 status, status_old;
int nvqs = v->nvqs;
u16 i;
if (copy_from_user(&status, statusp, sizeof(status)))
return -EFAULT;
status_old = ops->get_status(vdpa);
/*
* Userspace shouldn't remove status bits unless reset the
* status to 0.
@ -135,6 +172,15 @@ static long vhost_vdpa_set_status(struct vhost_vdpa *v, u8 __user *statusp)
ops->set_status(vdpa, status);
/* vq irq is not expected to be changed once DRIVER_OK is set */
if ((status & VIRTIO_CONFIG_S_DRIVER_OK) && !(status_old & VIRTIO_CONFIG_S_DRIVER_OK))
for (i = 0; i < nvqs; i++)
vhost_vdpa_setup_vq_irq(v, i);
if ((status_old & VIRTIO_CONFIG_S_DRIVER_OK) && !(status & VIRTIO_CONFIG_S_DRIVER_OK))
for (i = 0; i < nvqs; i++)
vhost_vdpa_unsetup_vq_irq(v, i);
return 0;
}
@ -293,6 +339,7 @@ static long vhost_vdpa_set_config_call(struct vhost_vdpa *v, u32 __user *argp)
return 0;
}
static long vhost_vdpa_vring_ioctl(struct vhost_vdpa *v, unsigned int cmd,
void __user *argp)
{
@ -351,6 +398,7 @@ static long vhost_vdpa_vring_ioctl(struct vhost_vdpa *v, unsigned int cmd,
cb.private = NULL;
}
ops->set_vq_cb(vdpa, idx, &cb);
vhost_vdpa_setup_vq_irq(v, idx);
break;
case VHOST_SET_VRING_NUM:
@ -726,6 +774,18 @@ err:
return r;
}
static void vhost_vdpa_clean_irq(struct vhost_vdpa *v)
{
struct vhost_virtqueue *vq;
int i;
for (i = 0; i < v->nvqs; i++) {
vq = &v->vqs[i];
if (vq->call_ctx.producer.irq)
irq_bypass_unregister_producer(&vq->call_ctx.producer);
}
}
static int vhost_vdpa_release(struct inode *inode, struct file *filep)
{
struct vhost_vdpa *v = filep->private_data;
@ -738,6 +798,7 @@ static int vhost_vdpa_release(struct inode *inode, struct file *filep)
vhost_vdpa_iotlb_free(v);
vhost_vdpa_free_domain(v);
vhost_vdpa_config_put(v);
vhost_vdpa_clean_irq(v);
vhost_dev_cleanup(&v->vdev);
kfree(v->vdev.vqs);
mutex_unlock(&d->mutex);