From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Christie Date: Thu, 22 Oct 2020 00:34:51 +0000 Subject: [PATCH 05/17] vhost: move vq iovec allocation to dev init time Message-Id: <1603326903-27052-6-git-send-email-michael.christie@oracle.com> List-Id: References: <1603326903-27052-1-git-send-email-michael.christie@oracle.com> In-Reply-To: <1603326903-27052-1-git-send-email-michael.christie@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: martin.petersen@oracle.com, linux-scsi@vger.kernel.org, target-devel@vger.kernel.org, mst@redhat.com, jasowang@redhat.com, pbonzini@redhat.com, stefanha@redhat.com, virtualization@lists.linux-foundation.org The next patches allow us to create vqs on demand after vhost_dev_init and vhost_dev_set_owner have been called. For vhost-scsi we don't know the number of vqs we really want until the vring/vq setup operations have started up. For other devices we know the number of vqs at vhost_dev_init time, so for those devs we init the vq and allocate the needed iovecs. For vhost-scsi we will do it later when userspace has instructed us to create a vq. Signed-off-by: Mike Christie --- drivers/vhost/vhost.c | 71 +++++++++++++++++++++++++++------------------------ 1 file changed, 38 insertions(+), 33 deletions(-) diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index b35229e..a4a4450 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -383,29 +383,27 @@ static void vhost_vq_free_iovecs(struct vhost_virtqueue *vq) vq->heads = NULL; } -/* Helper to allocate iovec buffers for all vqs. */ -static long vhost_dev_alloc_iovecs(struct vhost_dev *dev) +static int vhost_vq_alloc_iovecs(struct vhost_dev *dev, + struct vhost_virtqueue *vq) { - struct vhost_virtqueue *vq; - int i; + vq->indirect = kmalloc_array(UIO_MAXIOV, sizeof(*vq->indirect), + GFP_KERNEL); + if (!vq->indirect) + return -ENOMEM; + + if (!dev->iov_limit) + return 0; + + vq->log = kmalloc_array(dev->iov_limit, sizeof(*vq->log), GFP_KERNEL); + vq->heads = kmalloc_array(dev->iov_limit, sizeof(*vq->heads), + GFP_KERNEL); + if (!vq->log || !vq->heads) + goto err_nomem; - for (i = 0; i < dev->nvqs; ++i) { - vq = dev->vqs[i]; - vq->indirect = kmalloc_array(UIO_MAXIOV, - sizeof(*vq->indirect), - GFP_KERNEL); - vq->log = kmalloc_array(dev->iov_limit, sizeof(*vq->log), - GFP_KERNEL); - vq->heads = kmalloc_array(dev->iov_limit, sizeof(*vq->heads), - GFP_KERNEL); - if (!vq->indirect || !vq->log || !vq->heads) - goto err_nomem; - } return 0; err_nomem: - for (; i >= 0; --i) - vhost_vq_free_iovecs(dev->vqs[i]); + vhost_vq_free_iovecs(vq); return -ENOMEM; } @@ -458,6 +456,21 @@ static size_t vhost_get_desc_size(struct vhost_virtqueue *vq, return sizeof(*vq->desc) * num; } +static int vhost_vq_init(struct vhost_dev *dev, struct vhost_virtqueue *vq) +{ + vq->log = NULL; + vq->indirect = NULL; + vq->heads = NULL; + vq->dev = dev; + mutex_init(&vq->mutex); + vhost_vq_reset(dev, vq); + + if (vq->handle_kick) + vhost_poll_init(&vq->poll, vq->handle_kick, EPOLLIN, dev); + + return vhost_vq_alloc_iovecs(dev, vq); +} + int vhost_dev_init(struct vhost_dev *dev, struct vhost_virtqueue **vqs, int nvqs, int iov_limit, int weight, int byte_weight, @@ -465,7 +478,6 @@ int vhost_dev_init(struct vhost_dev *dev, int (*msg_handler)(struct vhost_dev *dev, struct vhost_iotlb_msg *msg)) { - struct vhost_virtqueue *vq; int i; dev->vqs = vqs; @@ -489,19 +501,16 @@ int vhost_dev_init(struct vhost_dev *dev, for (i = 0; i < dev->nvqs; ++i) { - vq = dev->vqs[i]; - vq->log = NULL; - vq->indirect = NULL; - vq->heads = NULL; - vq->dev = dev; - mutex_init(&vq->mutex); - vhost_vq_reset(dev, vq); - if (vq->handle_kick) - vhost_poll_init(&vq->poll, vq->handle_kick, - EPOLLIN, dev); + if (vhost_vq_init(dev, dev->vqs[i])) + goto err_vq_init; } return 0; + +err_vq_init: + for (--i; i >= 0; --i) + vhost_vq_free_iovecs(dev->vqs[i]); + return -ENOMEM; } EXPORT_SYMBOL_GPL(vhost_dev_init); @@ -606,10 +615,6 @@ long vhost_dev_set_owner(struct vhost_dev *dev) goto err_cgroup; } - err = vhost_dev_alloc_iovecs(dev); - if (err) - goto err_cgroup; - return 0; err_cgroup: if (dev->worker) { -- 1.8.3.1