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From: Zhu Lingshan <lingshan.zhu@intel.com>
To: jasowang@redhat.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,
	Zhu Lingshan <lingshan.zhu@intel.com>
Subject: [PATCH V5 4/6] vhost_vdpa: implement IRQ offloading in vhost_vdpa
Date: Fri, 31 Jul 2020 14:55:31 +0800
Message-ID: <20200731065533.4144-5-lingshan.zhu@intel.com> (raw)
In-Reply-To: <20200731065533.4144-1-lingshan.zhu@intel.com>

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>
---
 drivers/vhost/Kconfig |  1 +
 drivers/vhost/vdpa.c  | 79 ++++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 79 insertions(+), 1 deletion(-)

diff --git a/drivers/vhost/Kconfig b/drivers/vhost/Kconfig
index d3688c6afb87..587fbae06182 100644
--- a/drivers/vhost/Kconfig
+++ b/drivers/vhost/Kconfig
@@ -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
diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
index df3cf386b0cd..278ea2f00172 100644
--- a/drivers/vhost/vdpa.c
+++ b/drivers/vhost/vdpa.c
@@ -115,6 +115,55 @@ 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;
+
+	spin_lock(&vq->call_ctx.ctx_lock);
+	irq = ops->get_vq_irq(vdpa, qid);
+	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_update_vq_irq(struct vhost_virtqueue *vq)
+{
+	spin_lock(&vq->call_ctx.ctx_lock);
+	/*
+	 * if it has a non-zero irq, means there is a
+	 * previsouly registered irq_bypass_producer,
+	 * we should update it when ctx (its token)
+	 * changes.
+	 */
+	if (!vq->call_ctx.producer.irq) {
+		spin_unlock(&vq->call_ctx.ctx_lock);
+		return;
+	}
+
+	irq_bypass_unregister_producer(&vq->call_ctx.producer);
+	vq->call_ctx.producer.token = vq->call_ctx.ctx;
+	irq_bypass_register_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;
@@ -155,11 +204,15 @@ 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.
@@ -169,6 +222,15 @@ 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;
 }
 
@@ -332,6 +394,7 @@ 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)
 {
@@ -390,6 +453,7 @@ 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_update_vq_irq(vq);
 		break;
 
 	case VHOST_SET_VRING_NUM:
@@ -765,6 +829,18 @@ static int vhost_vdpa_open(struct inode *inode, struct file *filep)
 	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;
@@ -777,6 +853,7 @@ 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);
-- 
2.18.4


  parent 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
     [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 ` Zhu Lingshan [this message]
2020-08-04  8:51   ` [PATCH V5 4/6] vhost_vdpa: implement IRQ offloading in vhost_vdpa 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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