Re: [PATCH] vhost_vdpa: remove unnecessary spin_lock in vhost_vring_call
From: Jason Wang <jasowang@redhat.com>
Date: 2020-09-09 09:05:04
Also in:
kvm, virtualization
On 2020/9/9 下午2:52, Zhu Lingshan wrote:
This commit removed unnecessary spin_locks in vhost_vring_call and related operations. Because we manipulate irq offloading contents in vhost_vdpa ioctl code path which is already protected by dev mutex and vq mutex. Signed-off-by: Zhu Lingshan <redacted>
Acked-by: Jason Wang <jasowang@redhat.com>
quoted hunk ↗ jump to hunk
--- drivers/vhost/vdpa.c | 8 +------- drivers/vhost/vhost.c | 3 --- drivers/vhost/vhost.h | 1 - 3 files changed, 1 insertion(+), 11 deletions(-)diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c index 3fab94f88894..bc679d0b7b87 100644 --- a/drivers/vhost/vdpa.c +++ b/drivers/vhost/vdpa.c@@ -97,26 +97,20 @@ static void vhost_vdpa_setup_vq_irq(struct vhost_vdpa *v, u16 qid) 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); + if (!vq->call_ctx.ctx || irq < 0) 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)diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index b45519ca66a7..99f27ce982da 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c@@ -302,7 +302,6 @@ 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,@@ -1637,9 +1636,7 @@ long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *arg break; } - 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)) {diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h index 9032d3c2a9f4..486dcf371e06 100644 --- a/drivers/vhost/vhost.h +++ b/drivers/vhost/vhost.h@@ -64,7 +64,6 @@ enum vhost_uaddr_type { struct vhost_vring_call { struct eventfd_ctx *ctx; struct irq_bypass_producer producer; - spinlock_t ctx_lock; }; /* The virtqueue structure describes a queue attached to a device. */