| Message ID | 20220406034346.74409-12-xuanzhuo@linux.alibaba.com |
|---|---|
| State | Handled Elsewhere |
| Headers | show |
| Series | virtio pci support VIRTIO_F_RING_RESET (refactor vring) | expand |
在 2022/4/6 上午11:43, Xuan Zhuo 写道: > virtio ring split supports resize. > > Only after the new vring is successfully allocated based on the new num, > we will release the old vring. In any case, an error is returned, > indicating that the vring still points to the old vring. > > In the case of an error, the caller must > re-initialize(virtqueue_reinit_split()) the virtqueue to ensure that the > vring can be used. > > In addition, vring_align, may_reduce_num are necessary for reallocating > vring, so they are retained for creating vq. > > Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> > --- > drivers/virtio/virtio_ring.c | 47 ++++++++++++++++++++++++++++++++++++ > 1 file changed, 47 insertions(+) > > diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c > index 3dc6ace2ba7a..33864134a744 100644 > --- a/drivers/virtio/virtio_ring.c > +++ b/drivers/virtio/virtio_ring.c > @@ -139,6 +139,12 @@ struct vring_virtqueue { > /* DMA address and size information */ > dma_addr_t queue_dma_addr; > size_t queue_size_in_bytes; > + > + /* The parameters for creating vrings are reserved for > + * creating new vring. > + */ > + u32 vring_align; > + bool may_reduce_num; > } split; > > /* Available for packed ring */ > @@ -199,6 +205,7 @@ struct vring_virtqueue { > }; > > static struct vring_desc_extra *vring_alloc_desc_extra(unsigned int num); > +static void vring_free(struct virtqueue *_vq); > > /* > * Helpers. > @@ -1088,6 +1095,8 @@ static struct virtqueue *vring_create_virtqueue_split( > return NULL; > } > > + to_vvq(vq)->split.vring_align = vring_align; > + to_vvq(vq)->split.may_reduce_num = may_reduce_num; It looks to me the above should belong to patch 6. > to_vvq(vq)->split.queue_dma_addr = dma_addr; > to_vvq(vq)->split.queue_size_in_bytes = queue_size_in_bytes; > to_vvq(vq)->we_own_ring = true; > @@ -1095,6 +1104,44 @@ static struct virtqueue *vring_create_virtqueue_split( > return vq; > } > > +static int virtqueue_resize_split(struct virtqueue *_vq, u32 num) > +{ > + struct vring_virtqueue *vq = to_vvq(_vq); > + struct virtio_device *vdev = _vq->vdev; > + struct vring_desc_state_split *state; > + struct vring_desc_extra *extra; > + size_t queue_size_in_bytes; > + dma_addr_t dma_addr; > + struct vring vring; > + int err = -ENOMEM; > + void *queue; > + > + queue = vring_alloc_queue_split(vdev, &dma_addr, &num, > + vq->split.vring_align, > + vq->weak_barriers, > + vq->split.may_reduce_num); > + if (!queue) > + return -ENOMEM; > + > + queue_size_in_bytes = vring_size(num, vq->split.vring_align); > + > + err = vring_alloc_state_extra_split(num, &state, &extra); > + if (err) { > + vring_free_queue(vdev, queue_size_in_bytes, queue, dma_addr); > + return -ENOMEM; > + } > + > + vring_free(&vq->vq); > + > + vring_init(&vring, num, queue, vq->split.vring_align); > + vring_virtqueue_attach_split(vq, vring, state, extra); > + vq->split.queue_dma_addr = dma_addr; > + vq->split.queue_size_in_bytes = queue_size_in_bytes; I wonder if it's better to move the above assignments to vring_virtqueue_attach_split(). Other looks good. Thanks > + > + vring_virtqueue_init_split(vq, vdev, true); > + return 0; > +} > + > > /* > * Packed ring specific functions - *_packed().
On Tue, 12 Apr 2022 13:53:44 +0800, Jason Wang <jasowang@redhat.com> wrote: > > 在 2022/4/6 上午11:43, Xuan Zhuo 写道: > > virtio ring split supports resize. > > > > Only after the new vring is successfully allocated based on the new num, > > we will release the old vring. In any case, an error is returned, > > indicating that the vring still points to the old vring. > > > > In the case of an error, the caller must > > re-initialize(virtqueue_reinit_split()) the virtqueue to ensure that the > > vring can be used. > > > > In addition, vring_align, may_reduce_num are necessary for reallocating > > vring, so they are retained for creating vq. > > > > Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> > > --- > > drivers/virtio/virtio_ring.c | 47 ++++++++++++++++++++++++++++++++++++ > > 1 file changed, 47 insertions(+) > > > > diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c > > index 3dc6ace2ba7a..33864134a744 100644 > > --- a/drivers/virtio/virtio_ring.c > > +++ b/drivers/virtio/virtio_ring.c > > @@ -139,6 +139,12 @@ struct vring_virtqueue { > > /* DMA address and size information */ > > dma_addr_t queue_dma_addr; > > size_t queue_size_in_bytes; > > + > > + /* The parameters for creating vrings are reserved for > > + * creating new vring. > > + */ > > + u32 vring_align; > > + bool may_reduce_num; > > } split; > > > > /* Available for packed ring */ > > @@ -199,6 +205,7 @@ struct vring_virtqueue { > > }; > > > > static struct vring_desc_extra *vring_alloc_desc_extra(unsigned int num); > > +static void vring_free(struct virtqueue *_vq); > > > > /* > > * Helpers. > > @@ -1088,6 +1095,8 @@ static struct virtqueue *vring_create_virtqueue_split( > > return NULL; > > } > > > > + to_vvq(vq)->split.vring_align = vring_align; > > + to_vvq(vq)->split.may_reduce_num = may_reduce_num; > > > It looks to me the above should belong to patch 6. patch 6 just extracts a function, no logical modification. to_vvq(vq)->split.may_reduce_num is newly added, so I don't think it should be merged into patch 6. > > > > to_vvq(vq)->split.queue_dma_addr = dma_addr; > > to_vvq(vq)->split.queue_size_in_bytes = queue_size_in_bytes; > > to_vvq(vq)->we_own_ring = true; > > @@ -1095,6 +1104,44 @@ static struct virtqueue *vring_create_virtqueue_split( > > return vq; > > } > > > > +static int virtqueue_resize_split(struct virtqueue *_vq, u32 num) > > +{ > > + struct vring_virtqueue *vq = to_vvq(_vq); > > + struct virtio_device *vdev = _vq->vdev; > > + struct vring_desc_state_split *state; > > + struct vring_desc_extra *extra; > > + size_t queue_size_in_bytes; > > + dma_addr_t dma_addr; > > + struct vring vring; > > + int err = -ENOMEM; > > + void *queue; > > + > > + queue = vring_alloc_queue_split(vdev, &dma_addr, &num, > > + vq->split.vring_align, > > + vq->weak_barriers, > > + vq->split.may_reduce_num); > > + if (!queue) > > + return -ENOMEM; > > + > > + queue_size_in_bytes = vring_size(num, vq->split.vring_align); > > + > > + err = vring_alloc_state_extra_split(num, &state, &extra); > > + if (err) { > > + vring_free_queue(vdev, queue_size_in_bytes, queue, dma_addr); > > + return -ENOMEM; > > + } > > + > > + vring_free(&vq->vq); > > + > > + vring_init(&vring, num, queue, vq->split.vring_align); > > + vring_virtqueue_attach_split(vq, vring, state, extra); > > + vq->split.queue_dma_addr = dma_addr; > > + vq->split.queue_size_in_bytes = queue_size_in_bytes; > > > I wonder if it's better to move the above assignments to > vring_virtqueue_attach_split(). I also think so, the reason for not doing this is that there is no dma_addr and queue_size_in_bytes when vring_virtqueue_attach_split is called in __vring_new_virtqueue. As discussed in patch 12, we can pass the struct struct vring_virtqueue_split to vring_virtqueue_attach_split(). This is much more convenient. Thanks. > > Other looks good. > > Thanks > > > > + > > + vring_virtqueue_init_split(vq, vdev, true); > > + return 0; > > +} > > + > > > > /* > > * Packed ring specific functions - *_packed(). >
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index 3dc6ace2ba7a..33864134a744 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -139,6 +139,12 @@ struct vring_virtqueue { /* DMA address and size information */ dma_addr_t queue_dma_addr; size_t queue_size_in_bytes; + + /* The parameters for creating vrings are reserved for + * creating new vring. + */ + u32 vring_align; + bool may_reduce_num; } split; /* Available for packed ring */ @@ -199,6 +205,7 @@ struct vring_virtqueue { }; static struct vring_desc_extra *vring_alloc_desc_extra(unsigned int num); +static void vring_free(struct virtqueue *_vq); /* * Helpers. @@ -1088,6 +1095,8 @@ static struct virtqueue *vring_create_virtqueue_split( return NULL; } + to_vvq(vq)->split.vring_align = vring_align; + to_vvq(vq)->split.may_reduce_num = may_reduce_num; to_vvq(vq)->split.queue_dma_addr = dma_addr; to_vvq(vq)->split.queue_size_in_bytes = queue_size_in_bytes; to_vvq(vq)->we_own_ring = true; @@ -1095,6 +1104,44 @@ static struct virtqueue *vring_create_virtqueue_split( return vq; } +static int virtqueue_resize_split(struct virtqueue *_vq, u32 num) +{ + struct vring_virtqueue *vq = to_vvq(_vq); + struct virtio_device *vdev = _vq->vdev; + struct vring_desc_state_split *state; + struct vring_desc_extra *extra; + size_t queue_size_in_bytes; + dma_addr_t dma_addr; + struct vring vring; + int err = -ENOMEM; + void *queue; + + queue = vring_alloc_queue_split(vdev, &dma_addr, &num, + vq->split.vring_align, + vq->weak_barriers, + vq->split.may_reduce_num); + if (!queue) + return -ENOMEM; + + queue_size_in_bytes = vring_size(num, vq->split.vring_align); + + err = vring_alloc_state_extra_split(num, &state, &extra); + if (err) { + vring_free_queue(vdev, queue_size_in_bytes, queue, dma_addr); + return -ENOMEM; + } + + vring_free(&vq->vq); + + vring_init(&vring, num, queue, vq->split.vring_align); + vring_virtqueue_attach_split(vq, vring, state, extra); + vq->split.queue_dma_addr = dma_addr; + vq->split.queue_size_in_bytes = queue_size_in_bytes; + + vring_virtqueue_init_split(vq, vdev, true); + return 0; +} + /* * Packed ring specific functions - *_packed().
virtio ring split supports resize. Only after the new vring is successfully allocated based on the new num, we will release the old vring. In any case, an error is returned, indicating that the vring still points to the old vring. In the case of an error, the caller must re-initialize(virtqueue_reinit_split()) the virtqueue to ensure that the vring can be used. In addition, vring_align, may_reduce_num are necessary for reallocating vring, so they are retained for creating vq. Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> --- drivers/virtio/virtio_ring.c | 47 ++++++++++++++++++++++++++++++++++++ 1 file changed, 47 insertions(+)