[PATCH V2 4/6] vhost_vdpa: implement IRQ offloading in vhost_vdpa
From: Zhu Lingshan <hidden>
Date: 2020-07-16 11:28:02
Also in:
kvm, virtualization
Subsystem:
the rest, virtio host (vhost) · Maintainers:
Linus Torvalds, "Michael S. Tsirkin", Jason Wang
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. Signed-off-by: Zhu Lingshan <redacted> Suggested-by: Jason Wang <jasowang@redhat.com> --- drivers/vhost/Kconfig | 1 + drivers/vhost/vdpa.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 49 insertions(+)
diff --git a/drivers/vhost/Kconfig b/drivers/vhost/Kconfig
index d3688c6..587fbae 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 2fcc422..b9078d4 100644
--- a/drivers/vhost/vdpa.c
+++ b/drivers/vhost/vdpa.c@@ -115,6 +115,43 @@ static irqreturn_t vhost_vdpa_config_cb(void *private) return IRQ_HANDLED; } +static void vhost_vdpa_setup_vq_irq(struct vdpa_device *dev, int qid, int irq) +{ + struct vhost_vdpa *v = vdpa_get_drvdata(dev); + struct vhost_virtqueue *vq = &v->vqs[qid]; + int ret; + + spin_lock(&vq->call_ctx.ctx_lock); + if (!vq->call_ctx.ctx) { + 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 vdpa_device *dev, int qid) +{ + struct vhost_vdpa *v = vdpa_get_drvdata(dev); + 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); + 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;
@@ -332,6 +369,7 @@ 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 +428,14 @@ static long vhost_vdpa_vring_ioctl(struct vhost_vdpa *v, unsigned int cmd, cb.private = NULL; } ops->set_vq_cb(vdpa, idx, &cb); + /* + * 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) + vhost_vdpa_update_vq_irq(vq); break; case VHOST_SET_VRING_NUM:
@@ -951,6 +997,8 @@ static void vhost_vdpa_remove(struct vdpa_device *vdpa) }, .probe = vhost_vdpa_probe, .remove = vhost_vdpa_remove, + .setup_vq_irq = vhost_vdpa_setup_vq_irq, + .unsetup_vq_irq = vhost_vdpa_unsetup_vq_irq, }; static int __init vhost_vdpa_init(void)
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1.8.3.1