| Message ID | 20240312033557.6351-4-xuanzhuo@linux.alibaba.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | virtio: drivers maintain dma info for premapped vq | expand |
| Context | Check | Description |
|---|---|---|
| netdev/tree_selection | success | Guessing tree name failed - patch did not apply |
On Tue, Mar 12, 2024 at 11:36 AM Xuan Zhuo <xuanzhuo@linux.alibaba.com> wrote: > > This commit structure the indirect desc table. > Then we can get the desc num directly when doing unmap. > > And save the dma info to the struct, then the indirect > will not use the dma fields of the desc_extra. The subsequent > commits will make the dma fields are optional. But for > the indirect case, we must record the dma info. > > Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> > --- > drivers/virtio/virtio_ring.c | 66 +++++++++++++++++++++--------------- > 1 file changed, 38 insertions(+), 28 deletions(-) > > diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c > index 0dfbd17e5a87..22a588bba166 100644 > --- a/drivers/virtio/virtio_ring.c > +++ b/drivers/virtio/virtio_ring.c > @@ -72,9 +72,16 @@ struct vring_desc_state_split { > struct vring_desc *indir_desc; /* Indirect descriptor, if any. */ > }; > > +struct vring_packed_desc_indir { > + dma_addr_t addr; /* Descriptor Array DMA addr. */ > + u32 len; /* Descriptor Array length. */ > + u32 num; > + struct vring_packed_desc desc[]; > +}; > + > struct vring_desc_state_packed { > void *data; /* Data for callback. */ > - struct vring_packed_desc *indir_desc; /* Indirect descriptor, if any. */ > + struct vring_packed_desc_indir *indir_desc; /* Indirect descriptor, if any. */ Maybe it's better just to have a vring_desc_extra here. Thanks
On Thu, 21 Mar 2024 12:47:18 +0800, Jason Wang <jasowang@redhat.com> wrote: > On Tue, Mar 12, 2024 at 11:36 AM Xuan Zhuo <xuanzhuo@linux.alibaba.com> wrote: > > > > This commit structure the indirect desc table. > > Then we can get the desc num directly when doing unmap. > > > > And save the dma info to the struct, then the indirect > > will not use the dma fields of the desc_extra. The subsequent > > commits will make the dma fields are optional. But for > > the indirect case, we must record the dma info. > > > > Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> > > --- > > drivers/virtio/virtio_ring.c | 66 +++++++++++++++++++++--------------- > > 1 file changed, 38 insertions(+), 28 deletions(-) > > > > diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c > > index 0dfbd17e5a87..22a588bba166 100644 > > --- a/drivers/virtio/virtio_ring.c > > +++ b/drivers/virtio/virtio_ring.c > > @@ -72,9 +72,16 @@ struct vring_desc_state_split { > > struct vring_desc *indir_desc; /* Indirect descriptor, if any. */ > > }; > > > > +struct vring_packed_desc_indir { > > + dma_addr_t addr; /* Descriptor Array DMA addr. */ > > + u32 len; /* Descriptor Array length. */ > > + u32 num; > > + struct vring_packed_desc desc[]; > > +}; > > + > > struct vring_desc_state_packed { > > void *data; /* Data for callback. */ > > - struct vring_packed_desc *indir_desc; /* Indirect descriptor, if any. */ > > + struct vring_packed_desc_indir *indir_desc; /* Indirect descriptor, if any. */ > > Maybe it's better just to have a vring_desc_extra here. Do you mean replacing vring_packed_desc_indir by vring_desc_extra? I am ok for that. But vring_desc_extra has two extra items: u16 flags; /* Descriptor flags. */ u16 next; /* The next desc state in a list. */ vring_packed_desc_indir has "desc". I think that is more convenient. So, I think vring_packed_desc_indir is appropriate. Or I missed something. Thanks. > > Thanks >
On Thu, Mar 21, 2024 at 4:29 PM Xuan Zhuo <xuanzhuo@linux.alibaba.com> wrote: > > On Thu, 21 Mar 2024 12:47:18 +0800, Jason Wang <jasowang@redhat.com> wrote: > > On Tue, Mar 12, 2024 at 11:36 AM Xuan Zhuo <xuanzhuo@linux.alibaba.com> wrote: > > > > > > This commit structure the indirect desc table. > > > Then we can get the desc num directly when doing unmap. > > > > > > And save the dma info to the struct, then the indirect > > > will not use the dma fields of the desc_extra. The subsequent > > > commits will make the dma fields are optional. But for > > > the indirect case, we must record the dma info. > > > > > > Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> > > > --- > > > drivers/virtio/virtio_ring.c | 66 +++++++++++++++++++++--------------- > > > 1 file changed, 38 insertions(+), 28 deletions(-) > > > > > > diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c > > > index 0dfbd17e5a87..22a588bba166 100644 > > > --- a/drivers/virtio/virtio_ring.c > > > +++ b/drivers/virtio/virtio_ring.c > > > @@ -72,9 +72,16 @@ struct vring_desc_state_split { > > > struct vring_desc *indir_desc; /* Indirect descriptor, if any. */ > > > }; > > > > > > +struct vring_packed_desc_indir { > > > + dma_addr_t addr; /* Descriptor Array DMA addr. */ > > > + u32 len; /* Descriptor Array length. */ > > > + u32 num; > > > + struct vring_packed_desc desc[]; > > > +}; > > > + > > > struct vring_desc_state_packed { > > > void *data; /* Data for callback. */ > > > - struct vring_packed_desc *indir_desc; /* Indirect descriptor, if any. */ > > > + struct vring_packed_desc_indir *indir_desc; /* Indirect descriptor, if any. */ > > > > Maybe it's better just to have a vring_desc_extra here. > > > Do you mean replacing vring_packed_desc_indir by vring_desc_extra? Just add a vring_desc_extra in vring_desc_state_packed. > > I am ok for that. But vring_desc_extra has two extra items: > > u16 flags; /* Descriptor flags. */ > u16 next; /* The next desc state in a list. */ > > vring_packed_desc_indir has "desc". I think that is more convenient. > > So, I think vring_packed_desc_indir is appropriate. It reuses the existing structure so we had the chance to reuse the helper. And it could be used for future chained indirect (if it turns out to be necessary). Thanks > Or I missed something. > > > Thanks. > > > > > > Thanks > > >
On Fri, 22 Mar 2024 13:15:10 +0800, Jason Wang <jasowang@redhat.com> wrote: > On Thu, Mar 21, 2024 at 4:29 PM Xuan Zhuo <xuanzhuo@linux.alibaba.com> wrote: > > > > On Thu, 21 Mar 2024 12:47:18 +0800, Jason Wang <jasowang@redhat.com> wrote: > > > On Tue, Mar 12, 2024 at 11:36 AM Xuan Zhuo <xuanzhuo@linux.alibaba.com> wrote: > > > > > > > > This commit structure the indirect desc table. > > > > Then we can get the desc num directly when doing unmap. > > > > > > > > And save the dma info to the struct, then the indirect > > > > will not use the dma fields of the desc_extra. The subsequent > > > > commits will make the dma fields are optional. But for > > > > the indirect case, we must record the dma info. > > > > > > > > Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> > > > > --- > > > > drivers/virtio/virtio_ring.c | 66 +++++++++++++++++++++--------------- > > > > 1 file changed, 38 insertions(+), 28 deletions(-) > > > > > > > > diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c > > > > index 0dfbd17e5a87..22a588bba166 100644 > > > > --- a/drivers/virtio/virtio_ring.c > > > > +++ b/drivers/virtio/virtio_ring.c > > > > @@ -72,9 +72,16 @@ struct vring_desc_state_split { > > > > struct vring_desc *indir_desc; /* Indirect descriptor, if any. */ > > > > }; > > > > > > > > +struct vring_packed_desc_indir { > > > > + dma_addr_t addr; /* Descriptor Array DMA addr. */ > > > > + u32 len; /* Descriptor Array length. */ > > > > + u32 num; > > > > + struct vring_packed_desc desc[]; > > > > +}; > > > > + > > > > struct vring_desc_state_packed { > > > > void *data; /* Data for callback. */ > > > > - struct vring_packed_desc *indir_desc; /* Indirect descriptor, if any. */ > > > > + struct vring_packed_desc_indir *indir_desc; /* Indirect descriptor, if any. */ > > > > > > Maybe it's better just to have a vring_desc_extra here. > > > > > > Do you mean replacing vring_packed_desc_indir by vring_desc_extra? > > Just add a vring_desc_extra in vring_desc_state_packed. I am surprise to here that. Do you mean this: #1 struct vring_desc_state_packed { void *data; /* Data for callback. */ struct vring_packed_desc *indir_desc; /* Indirect descriptor, if any. */ u16 num; /* Descriptor list length. */ u16 last; /* The last desc state in a list. */ struct vring_desc_extra desc_extra; }; Then desc_extra is included by desc_state. I do not think so. I guess you mean this: #2 struct vring_desc_state_packed { void *data; /* Data for callback. */ struct vring_desc_extra *indir_desc; /* Indirect descriptor, if any. */ u16 num; /* Descriptor list length. */ u16 last; /* The last desc state in a list. */ }; indir_desc pointers to memory: |struct vring_desc_extra | struct vring_packed_desc desc[] | > > > > > I am ok for that. But vring_desc_extra has two extra items: > > > > u16 flags; /* Descriptor flags. */ > > u16 next; /* The next desc state in a list. */ > > > > vring_packed_desc_indir has "desc". I think that is more convenient. > > > > So, I think vring_packed_desc_indir is appropriate. > > It reuses the existing structure so we had the chance to reuse the > helper. Which helper? But, if you mean #2. I am ok. Thanks. > And it could be used for future chained indirect (if it turns > out to be necessary). > > Thanks > > > Or I missed something. > > > > > > Thanks. > > > > > > > > > > Thanks > > > > > > >
On Fri, 22 Mar 2024 13:15:10 +0800, Jason Wang <jasowang@redhat.com> wrote: > On Thu, Mar 21, 2024 at 4:29 PM Xuan Zhuo <xuanzhuo@linux.alibaba.com> wrote: > > > > On Thu, 21 Mar 2024 12:47:18 +0800, Jason Wang <jasowang@redhat.com> wrote: > > > On Tue, Mar 12, 2024 at 11:36 AM Xuan Zhuo <xuanzhuo@linux.alibaba.com> wrote: > > > > > > > > This commit structure the indirect desc table. > > > > Then we can get the desc num directly when doing unmap. > > > > > > > > And save the dma info to the struct, then the indirect > > > > will not use the dma fields of the desc_extra. The subsequent > > > > commits will make the dma fields are optional. But for > > > > the indirect case, we must record the dma info. > > > > > > > > Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> > > > > --- > > > > drivers/virtio/virtio_ring.c | 66 +++++++++++++++++++++--------------- > > > > 1 file changed, 38 insertions(+), 28 deletions(-) > > > > > > > > diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c > > > > index 0dfbd17e5a87..22a588bba166 100644 > > > > --- a/drivers/virtio/virtio_ring.c > > > > +++ b/drivers/virtio/virtio_ring.c > > > > @@ -72,9 +72,16 @@ struct vring_desc_state_split { > > > > struct vring_desc *indir_desc; /* Indirect descriptor, if any. */ > > > > }; > > > > > > > > +struct vring_packed_desc_indir { > > > > + dma_addr_t addr; /* Descriptor Array DMA addr. */ > > > > + u32 len; /* Descriptor Array length. */ > > > > + u32 num; > > > > + struct vring_packed_desc desc[]; > > > > +}; > > > > + > > > > struct vring_desc_state_packed { > > > > void *data; /* Data for callback. */ > > > > - struct vring_packed_desc *indir_desc; /* Indirect descriptor, if any. */ > > > > + struct vring_packed_desc_indir *indir_desc; /* Indirect descriptor, if any. */ > > > > > > Maybe it's better just to have a vring_desc_extra here. > > > > > > Do you mean replacing vring_packed_desc_indir by vring_desc_extra? > > Just add a vring_desc_extra in vring_desc_state_packed. > > > > > I am ok for that. But vring_desc_extra has two extra items: > > > > u16 flags; /* Descriptor flags. */ > > u16 next; /* The next desc state in a list. */ > > > > vring_packed_desc_indir has "desc". I think that is more convenient. > > > > So, I think vring_packed_desc_indir is appropriate. > > It reuses the existing structure so we had the chance to reuse the > helper. Do you mean vring_unmap_extra_packed()? After last commit(virtio_ring: packed: remove double check of the unmap ops): /* caller must check vring_need_unmap_buffer() */ static void vring_unmap_extra_packed(const struct vring_virtqueue *vq, const struct vring_desc_extra *extra) { u16 flags; flags = extra->flags; dma_unmap_page(vring_dma_dev(vq), extra->addr, extra->len, (flags & VRING_DESC_F_WRITE) ? DMA_FROM_DEVICE : DMA_TO_DEVICE); } But we should call dma_unmap_single() for indirect desc. We know, dma_unmap_single() and dma_unmap_page() are same in essence. So if we call dma_unmap_page for the indirect desc, we can reuse this function. But I do not prefer doing this. Thanks. > And it could be used for future chained indirect (if it turns > out to be necessary). > > Thanks > > > Or I missed something. > > > > > > Thanks. > > > > > > > > > > Thanks > > > > > > >
On Fri, Mar 22, 2024 at 3:58 PM Xuan Zhuo <xuanzhuo@linux.alibaba.com> wrote: > > On Fri, 22 Mar 2024 13:15:10 +0800, Jason Wang <jasowang@redhat.com> wrote: > > On Thu, Mar 21, 2024 at 4:29 PM Xuan Zhuo <xuanzhuo@linux.alibaba.com> wrote: > > > > > > On Thu, 21 Mar 2024 12:47:18 +0800, Jason Wang <jasowang@redhat.com> wrote: > > > > On Tue, Mar 12, 2024 at 11:36 AM Xuan Zhuo <xuanzhuo@linux.alibaba.com> wrote: > > > > > > > > > > This commit structure the indirect desc table. > > > > > Then we can get the desc num directly when doing unmap. > > > > > > > > > > And save the dma info to the struct, then the indirect > > > > > will not use the dma fields of the desc_extra. The subsequent > > > > > commits will make the dma fields are optional. But for > > > > > the indirect case, we must record the dma info. > > > > > > > > > > Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> > > > > > --- > > > > > drivers/virtio/virtio_ring.c | 66 +++++++++++++++++++++--------------- > > > > > 1 file changed, 38 insertions(+), 28 deletions(-) > > > > > > > > > > diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c > > > > > index 0dfbd17e5a87..22a588bba166 100644 > > > > > --- a/drivers/virtio/virtio_ring.c > > > > > +++ b/drivers/virtio/virtio_ring.c > > > > > @@ -72,9 +72,16 @@ struct vring_desc_state_split { > > > > > struct vring_desc *indir_desc; /* Indirect descriptor, if any. */ > > > > > }; > > > > > > > > > > +struct vring_packed_desc_indir { > > > > > + dma_addr_t addr; /* Descriptor Array DMA addr. */ > > > > > + u32 len; /* Descriptor Array length. */ > > > > > + u32 num; > > > > > + struct vring_packed_desc desc[]; > > > > > +}; > > > > > + > > > > > struct vring_desc_state_packed { > > > > > void *data; /* Data for callback. */ > > > > > - struct vring_packed_desc *indir_desc; /* Indirect descriptor, if any. */ > > > > > + struct vring_packed_desc_indir *indir_desc; /* Indirect descriptor, if any. */ > > > > > > > > Maybe it's better just to have a vring_desc_extra here. > > > > > > > > > Do you mean replacing vring_packed_desc_indir by vring_desc_extra? > > > > Just add a vring_desc_extra in vring_desc_state_packed. > > > > > > > > I am ok for that. But vring_desc_extra has two extra items: > > > > > > u16 flags; /* Descriptor flags. */ > > > u16 next; /* The next desc state in a list. */ > > > > > > vring_packed_desc_indir has "desc". I think that is more convenient. > > > > > > So, I think vring_packed_desc_indir is appropriate. > > > > It reuses the existing structure so we had the chance to reuse the > > helper. > > Do you mean vring_unmap_extra_packed()? Yes. > > After last commit(virtio_ring: packed: remove double check of the unmap ops): > > /* caller must check vring_need_unmap_buffer() */ > static void vring_unmap_extra_packed(const struct vring_virtqueue *vq, > const struct vring_desc_extra *extra) > { > u16 flags; > > flags = extra->flags; > > dma_unmap_page(vring_dma_dev(vq), > extra->addr, extra->len, > (flags & VRING_DESC_F_WRITE) ? > DMA_FROM_DEVICE : DMA_TO_DEVICE); > } > > But we should call dma_unmap_single() for indirect desc. > > We know, dma_unmap_single() and dma_unmap_page() are same in essence. Yes, it's worth tweaking in the future. > So if we call dma_unmap_page for the indirect desc, we can reuse > this function. But I do not prefer doing this. Ok. Thanks > > Thanks. > > > > And it could be used for future chained indirect (if it turns > > out to be necessary). > > > > Thanks > > > > > Or I missed something. > > > > > > > > > Thanks. > > > > > > > > > > > > > > Thanks > > > > > > > > > > > >
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index 0dfbd17e5a87..22a588bba166 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -72,9 +72,16 @@ struct vring_desc_state_split { struct vring_desc *indir_desc; /* Indirect descriptor, if any. */ }; +struct vring_packed_desc_indir { + dma_addr_t addr; /* Descriptor Array DMA addr. */ + u32 len; /* Descriptor Array length. */ + u32 num; + struct vring_packed_desc desc[]; +}; + struct vring_desc_state_packed { void *data; /* Data for callback. */ - struct vring_packed_desc *indir_desc; /* Indirect descriptor, if any. */ + struct vring_packed_desc_indir *indir_desc; /* Indirect descriptor, if any. */ u16 num; /* Descriptor list length. */ u16 last; /* The last desc state in a list. */ }; @@ -1243,10 +1250,13 @@ static void vring_unmap_desc_packed(const struct vring_virtqueue *vq, DMA_FROM_DEVICE : DMA_TO_DEVICE); } -static struct vring_packed_desc *alloc_indirect_packed(unsigned int total_sg, +static struct vring_packed_desc_indir *alloc_indirect_packed(unsigned int total_sg, gfp_t gfp) { - struct vring_packed_desc *desc; + struct vring_packed_desc_indir *in_desc; + u32 size; + + size = struct_size(in_desc, desc, total_sg); /* * We require lowmem mappings for the descriptors because @@ -1255,9 +1265,10 @@ static struct vring_packed_desc *alloc_indirect_packed(unsigned int total_sg, */ gfp &= ~__GFP_HIGHMEM; - desc = kmalloc_array(total_sg, sizeof(struct vring_packed_desc), gfp); - return desc; + in_desc = kmalloc(size, gfp); + + return in_desc; } static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq, @@ -1268,6 +1279,7 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq, void *data, gfp_t gfp) { + struct vring_packed_desc_indir *in_desc; struct vring_packed_desc *desc; struct scatterlist *sg; unsigned int i, n, err_idx; @@ -1275,10 +1287,12 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq, dma_addr_t addr; head = vq->packed.next_avail_idx; - desc = alloc_indirect_packed(total_sg, gfp); - if (!desc) + in_desc = alloc_indirect_packed(total_sg, gfp); + if (!in_desc) return -ENOMEM; + desc = in_desc->desc; + if (unlikely(vq->vq.num_free < 1)) { pr_debug("Can't add buf len 1 - avail = 0\n"); kfree(desc); @@ -1315,17 +1329,19 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq, goto unmap_release; } + if (vring_need_unmap_buffer(vq)) + in_desc->num = i; + + if (vq->use_dma_api) { + in_desc->addr = addr; + in_desc->len = total_sg * sizeof(struct vring_packed_desc); + } + vq->packed.vring.desc[head].addr = cpu_to_le64(addr); vq->packed.vring.desc[head].len = cpu_to_le32(total_sg * sizeof(struct vring_packed_desc)); vq->packed.vring.desc[head].id = cpu_to_le16(id); - if (vq->use_dma_api) { - vq->packed.desc_extra[id].addr = addr; - vq->packed.desc_extra[id].len = total_sg * - sizeof(struct vring_packed_desc); - } - vq->packed.desc_extra[id].flags = VRING_DESC_F_INDIRECT | vq->packed.avail_used_flags; @@ -1356,7 +1372,7 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq, /* Store token and indirect buffer state. */ vq->packed.desc_state[id].num = 1; vq->packed.desc_state[id].data = data; - vq->packed.desc_state[id].indir_desc = desc; + vq->packed.desc_state[id].indir_desc = in_desc; vq->packed.desc_state[id].last = id; vq->num_added += 1; @@ -1375,7 +1391,7 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq, vring_unmap_desc_packed(vq, &desc[i]); free_desc: - kfree(desc); + kfree(in_desc); END_USE(vq); return -ENOMEM; @@ -1589,7 +1605,6 @@ static void detach_buf_packed(struct vring_virtqueue *vq, unsigned int id, void **ctx) { struct vring_desc_state_packed *state = NULL; - struct vring_packed_desc *desc; unsigned int i, curr; u16 flags; @@ -1616,27 +1631,22 @@ static void detach_buf_packed(struct vring_virtqueue *vq, if (ctx) *ctx = state->indir_desc; } else { - const struct vring_desc_extra *extra; - u32 len; + struct vring_packed_desc_indir *in_desc; + + in_desc = state->indir_desc; if (vq->use_dma_api) { - extra = &vq->packed.desc_extra[id]; dma_unmap_single(vring_dma_dev(vq), - extra->addr, extra->len, + in_desc->addr, in_desc->len, (flags & VRING_DESC_F_WRITE) ? DMA_FROM_DEVICE : DMA_TO_DEVICE); } - /* Free the indirect table, if any, now that it's unmapped. */ - desc = state->indir_desc; - if (vring_need_unmap_buffer(vq)) { - len = vq->packed.desc_extra[id].len; - for (i = 0; i < len / sizeof(struct vring_packed_desc); - i++) - vring_unmap_desc_packed(vq, &desc[i]); + for (i = 0; i < in_desc->num; i++) + vring_unmap_desc_packed(vq, &in_desc->desc[i]); } - kfree(desc); + kfree(in_desc); state->indir_desc = NULL; } }
This commit structure the indirect desc table. Then we can get the desc num directly when doing unmap. And save the dma info to the struct, then the indirect will not use the dma fields of the desc_extra. The subsequent commits will make the dma fields are optional. But for the indirect case, we must record the dma info. Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> --- drivers/virtio/virtio_ring.c | 66 +++++++++++++++++++++--------------- 1 file changed, 38 insertions(+), 28 deletions(-)