On 2020/7/31 ??2:55, Zhu Lingshan wrote:> This commit introduces struct vhost_vring_call which replaced
> raw struct eventfd_ctx *call_ctx in struct vhost_virtqueue.
> Besides eventfd_ctx, it contains a spin lock and an
> irq_bypass_producer in its structure.
>
> Signed-off-by: Zhu Lingshan <lingshan.zhu at intel.com>
> Suggested-by: Jason Wang <jasowang at redhat.com>
> ---
> drivers/vhost/vdpa.c | 4 ++--
> drivers/vhost/vhost.c | 22 ++++++++++++++++------
> drivers/vhost/vhost.h | 9 ++++++++-
> 3 files changed, 26 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
> index a54b60d6623f..df3cf386b0cd 100644
> --- a/drivers/vhost/vdpa.c
> +++ b/drivers/vhost/vdpa.c
> @@ -96,7 +96,7 @@ static void handle_vq_kick(struct vhost_work *work)
> static irqreturn_t vhost_vdpa_virtqueue_cb(void *private)
> {
> struct vhost_virtqueue *vq = private;
> - struct eventfd_ctx *call_ctx = vq->call_ctx;
> + struct eventfd_ctx *call_ctx = vq->call_ctx.ctx;
>
> if (call_ctx)
> eventfd_signal(call_ctx, 1);
> @@ -382,7 +382,7 @@ static long vhost_vdpa_vring_ioctl(struct vhost_vdpa
*v, unsigned int cmd,
> break;
>
> case VHOST_SET_VRING_CALL:
> - if (vq->call_ctx) {
> + if (vq->call_ctx.ctx) {
> cb.callback = vhost_vdpa_virtqueue_cb;
> cb.private = vq;
> } else {
> diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
> index d7b8df3edffc..9f1a845a9302 100644
> --- a/drivers/vhost/vhost.c
> +++ b/drivers/vhost/vhost.c
> @@ -298,6 +298,13 @@ static void vhost_vq_meta_reset(struct vhost_dev *d)
> __vhost_vq_meta_reset(d->vqs[i]);
> }
>
> +static void vhost_vring_call_reset(struct vhost_vring_call *call_ctx)
> +{
> + call_ctx->ctx = NULL;
> + memset(&call_ctx->producer, 0x0, sizeof(struct
irq_bypass_producer));
> + spin_lock_init(&call_ctx->ctx_lock);
> +}
> +
> static void vhost_vq_reset(struct vhost_dev *dev,
> struct vhost_virtqueue *vq)
> {
> @@ -319,13 +326,13 @@ static void vhost_vq_reset(struct vhost_dev *dev,
> vq->log_base = NULL;
> vq->error_ctx = NULL;
> vq->kick = NULL;
> - vq->call_ctx = NULL;
> vq->log_ctx = NULL;
> vhost_reset_is_le(vq);
> vhost_disable_cross_endian(vq);
> vq->busyloop_timeout = 0;
> vq->umem = NULL;
> vq->iotlb = NULL;
> + vhost_vring_call_reset(&vq->call_ctx);
> __vhost_vq_meta_reset(vq);
> }
>
> @@ -685,8 +692,8 @@ void vhost_dev_cleanup(struct vhost_dev *dev)
> eventfd_ctx_put(dev->vqs[i]->error_ctx);
> if (dev->vqs[i]->kick)
> fput(dev->vqs[i]->kick);
> - if (dev->vqs[i]->call_ctx)
> - eventfd_ctx_put(dev->vqs[i]->call_ctx);
> + if (dev->vqs[i]->call_ctx.ctx)
> + eventfd_ctx_put(dev->vqs[i]->call_ctx.ctx);
> vhost_vq_reset(dev, dev->vqs[i]);
> }
> vhost_dev_free_iovecs(dev);
> @@ -1629,7 +1636,10 @@ long vhost_vring_ioctl(struct vhost_dev *d, unsigned
int ioctl, void __user *arg
> r = PTR_ERR(ctx);
> break;
> }
> - swap(ctx, vq->call_ctx);
> +
> + spin_lock(&vq->call_ctx.ctx_lock);
> + swap(ctx, vq->call_ctx.ctx);
> + spin_unlock(&vq->call_ctx.ctx_lock);
> break;
> case VHOST_SET_VRING_ERR:
> if (copy_from_user(&f, argp, sizeof f)) {
> @@ -2440,8 +2450,8 @@ static bool vhost_notify(struct vhost_dev *dev,
struct vhost_virtqueue *vq)
> void vhost_signal(struct vhost_dev *dev, struct vhost_virtqueue *vq)
> {
> /* Signal the Guest tell them we used something up. */
> - if (vq->call_ctx && vhost_notify(dev, vq))
> - eventfd_signal(vq->call_ctx, 1);
> + if (vq->call_ctx.ctx && vhost_notify(dev, vq))
> + eventfd_signal(vq->call_ctx.ctx, 1);
> }
> EXPORT_SYMBOL_GPL(vhost_signal);
>
> diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
> index c8e96a095d3b..38eb1aa3b68d 100644
> --- a/drivers/vhost/vhost.h
> +++ b/drivers/vhost/vhost.h
> @@ -13,6 +13,7 @@
> #include <linux/virtio_ring.h>
> #include <linux/atomic.h>
> #include <linux/vhost_iotlb.h>
> +#include <linux/irqbypass.h>
>
> struct vhost_work;
> typedef void (*vhost_work_fn_t)(struct vhost_work *work);
> @@ -60,6 +61,12 @@ enum vhost_uaddr_type {
> VHOST_NUM_ADDRS = 3,
> };
>
> +struct vhost_vring_call {
> + struct eventfd_ctx *ctx;
> + struct irq_bypass_producer producer;
> + spinlock_t ctx_lock;
It's not clear to me why we need ctx_lock here.
Thanks
> +};
> +
> /* The virtqueue structure describes a queue attached to a device. */
> struct vhost_virtqueue {
> struct vhost_dev *dev;
> @@ -72,7 +79,7 @@ struct vhost_virtqueue {
> vring_used_t __user *used;
> const struct vhost_iotlb_map *meta_iotlb[VHOST_NUM_ADDRS];
> struct file *kick;
> - struct eventfd_ctx *call_ctx;
> + struct vhost_vring_call call_ctx;
> struct eventfd_ctx *error_ctx;
> struct eventfd_ctx *log_ctx;
>
