Finally add ioctl to allow userspace to create additional workers For now only allow to increase the number of workers
https://jira.sw.ru/browse/PSBM-139414 Signed-off-by: Andrey Zhadchenko <andrey.zhadche...@virtuozzo.com> --- v2: - Make code do what docs suggest. Previously ioctl-supplied new number of workers were treated like an amount that should be added. Use new number as a ceiling instead and add workers up to that number. drivers/vhost/vhost.c | 32 +++++++++++++++++++++++++++++++- include/uapi/linux/vhost.h | 9 +++++++++ 2 files changed, 40 insertions(+), 1 deletion(-) diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index 173a14041678..be184adcdbe5 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -657,6 +657,25 @@ static int vhost_add_worker(struct vhost_dev *dev) return err; } +static int vhost_set_workers(struct vhost_dev *dev, int n) +{ + int i, ret; + + if (n > dev->nvqs) + n = dev->nvqs; + + if (n > VHOST_MAX_WORKERS) + n = VHOST_MAX_WORKERS; + + for (i = 0; i < n - dev->nworkers ; i++) { + ret = vhost_add_worker(dev); + if (ret) + break; + } + + return ret; +} + /* Caller should have device mutex */ long vhost_dev_set_owner(struct vhost_dev *dev) { @@ -1810,7 +1829,7 @@ long vhost_dev_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *argp) struct eventfd_ctx *ctx; u64 p; long r; - int i, fd; + int i, fd, n; /* If you are not the owner, you can become one */ if (ioctl == VHOST_SET_OWNER) { @@ -1867,6 +1886,17 @@ long vhost_dev_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *argp) if (ctx) eventfd_ctx_put(ctx); break; + case VHOST_SET_NWORKERS: + r = get_user(n, (int __user *)argp); + if (r < 0) + break; + if (n < d->nworkers) { + r = -EINVAL; + break; + } + + r = vhost_set_workers(d, n); + break; default: r = -ENOIOCTLCMD; break; diff --git a/include/uapi/linux/vhost.h b/include/uapi/linux/vhost.h index 13caf114bcde..d6d87f6315f6 100644 --- a/include/uapi/linux/vhost.h +++ b/include/uapi/linux/vhost.h @@ -71,6 +71,15 @@ #define VHOST_SET_VRING_ENDIAN _IOW(VHOST_VIRTIO, 0x13, struct vhost_vring_state) #define VHOST_GET_VRING_ENDIAN _IOW(VHOST_VIRTIO, 0x14, struct vhost_vring_state) +/* Set number of vhost workers + * Currently nuber of vhost workers can only be increased. + * All workers are freed upon reset. + * If the value is too big it is silently truncated to the maximum number of + * supported vhost workers + * Even if the error is returned it is possible that some workers were created + */ +#define VHOST_SET_NWORKERS _IOW(VHOST_VIRTIO, 0x1F, int) + /* The following ioctls use eventfd file descriptors to signal and poll * for events. */ -- 2.31.1 _______________________________________________ Devel mailing list Devel@openvz.org https://lists.openvz.org/mailman/listinfo/devel
