| Message ID | 1604528804-2878-6-git-send-email-michael.christie@oracle.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | vhost: vhost-scsi bug fixes | expand |
On 2020/11/5 上午6:26, Mike Christie wrote: > 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 > indicated to us that it's going to use a vq. > > Signed-off-by: Mike Christie <michael.christie@oracle.com> > --- > 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; This looks like an optimization. Let's try to defer this into another patch. > + > + 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); > +} If it's possible, I would do a patch to introduce vhost_vq_init() and then add vhost_vq_alloc_iovecs() on top. Thanks > + > 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) {
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) {
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 indicated to us that it's going to use a vq. Signed-off-by: Mike Christie <michael.christie@oracle.com> --- drivers/vhost/vhost.c | 71 +++++++++++++++++++++++++++------------------------ 1 file changed, 38 insertions(+), 33 deletions(-)