Re: [RFC PATCH 5/8] vhost: allow userspace to bind vqs to CPUs
flat view
From: Jason Wang <hidden>
Date: 2020-12-04 08:11:15
Also in:
linux-scsi, target-devel
On 2020/12/4 下午3:56, Mike Christie wrote:
quoted hunk
+static long vhost_vring_set_cpu(struct vhost_dev *d, struct vhost_virtqueue *vq, + void __user *argp) +{ + struct vhost_vring_state s; + int ret = 0; + + if (vq->private_data) + return -EBUSY; + + if (copy_from_user(&s, argp, sizeof s)) + return -EFAULT; + + if (s.num == -1) { + vq->cpu = s.num; + return 0; + } + + if (s.num >= nr_cpu_ids) + return -EINVAL; + + if (!d->ops || !d->ops->get_workqueue) + return -EINVAL; + + if (!d->wq) + d->wq = d->ops->get_workqueue(); + if (!d->wq) + return -EINVAL; + + vq->cpu = s.num; + return ret; +}
So one question here. Who is in charge of doing this set_cpu? Note that sched_setaffinity(2) requires CAP_SYS_NICE to work, so I wonder whether or not it's legal for unprivileged Qemu to do this. Thanks _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization