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From: Jason Wang <jasowang@redhat.com>
To: Zhu Lingshan <lingshan.zhu@intel.com>,
	alex.williamson@redhat.com, mst@redhat.com, pbonzini@redhat.com,
	sean.j.christopherson@intel.com, wanpengli@tencent.com
Cc: virtualization@lists.linux-foundation.org,
	netdev@vger.kernel.org, kvm@vger.kernel.org, eli@mellanox.com,
	shahafs@mellanox.com, parav@mellanox.com
Subject: Re: [PATCH V5 1/6] vhost: introduce vhost_vring_call
Date: Tue, 4 Aug 2020 16:38:19 +0800
Message-ID: <5e646141-ca8d-77a5-6f41-d30710d91e6d@redhat.com> (raw)
In-Reply-To: <20200731065533.4144-2-lingshan.zhu@intel.com>


On 2020/7/31 下午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@intel.com>
> Suggested-by: Jason Wang <jasowang@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;
>   


  reply index

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-31  6:55 [PATCH V5 0/6] IRQ offloading for vDPA Zhu Lingshan
2020-07-31  6:55 ` [PATCH V5 1/6] vhost: introduce vhost_vring_call Zhu Lingshan
2020-08-04  8:38   ` Jason Wang [this message]
     [not found]     ` <d51dd4e3-7513-c771-104c-b61f9ee70f30@intel.com>
2020-08-04  8:53       ` Jason Wang
2020-08-04  9:21         ` Michael S. Tsirkin
2020-08-05  2:16           ` Jason Wang
     [not found]             ` <bf10cde9-db86-a1ac-e2a8-363735e49afb@intel.com>
2020-08-05  5:53               ` Jason Wang
2020-08-10 13:37             ` Michael S. Tsirkin
2020-08-11  2:53               ` Jason Wang
     [not found]         ` <4605de34-c426-33d4-714b-e03716d0374c@intel.com>
2020-08-05  2:20           ` Jason Wang
2020-07-31  6:55 ` [PATCH V5 2/6] kvm: detect assigned device via irqbypass manager Zhu Lingshan
2020-07-31  6:55 ` [PATCH V5 3/6] vDPA: add get_vq_irq() in vdpa_config_ops Zhu Lingshan
2020-07-31  6:55 ` [PATCH V5 4/6] vhost_vdpa: implement IRQ offloading in vhost_vdpa Zhu Lingshan
2020-08-04  8:51   ` Jason Wang
     [not found]     ` <ae5385dc-6637-c5a3-b00a-02f66bb9a85f@intel.com>
2020-08-04  9:36       ` Michael S. Tsirkin
2020-08-05  2:36       ` Jason Wang
     [not found]         ` <cb01a490-e9e6-42f5-b6c3-caefa2d91b9f@intel.com>
2020-08-05  5:51           ` Jason Wang
2020-08-05  8:06   ` Jason Wang
2020-08-05  8:12     ` Zhu, Lingshan
2020-07-31  6:55 ` [PATCH V5 5/6] ifcvf: implement vdpa_config_ops.get_vq_irq() Zhu Lingshan
2020-07-31  6:55 ` [PATCH V5 6/6] irqbypass: do not start cons/prod when failed connect Zhu Lingshan

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