On Thu, Mar 23, 2023 at 11:36:28AM +0800, Jason Wang wrote:
On Tue, Mar 21, 2023 at 11:43 PM Stefano Garzarella <sgarzare@xxxxxxxxxx> wrote:vDPA supports the possibility to use user VA in the iotlb messages. So, let's add support for user VA in vringh to use it in the vDPA simulators. Signed-off-by: Stefano Garzarella <sgarzare@xxxxxxxxxx> --- Notes: v3: - refactored avoiding code duplication [Eugenio] v2: - replace kmap_atomic() with kmap_local_page() [see previous patch] - fix cast warnings when build with W=1 C=1 include/linux/vringh.h | 5 +- drivers/vdpa/mlx5/net/mlx5_vnet.c | 2 +- drivers/vdpa/vdpa_sim/vdpa_sim.c | 4 +- drivers/vhost/vringh.c | 153 +++++++++++++++++++++++------- 4 files changed, 127 insertions(+), 37 deletions(-) diff --git a/include/linux/vringh.h b/include/linux/vringh.h index 1991a02c6431..d39b9f2dcba0 100644 --- a/include/linux/vringh.h +++ b/include/linux/vringh.h @@ -32,6 +32,9 @@ struct vringh { /* Can we get away with weak barriers? */ bool weak_barriers; + /* Use user's VA */ + bool use_va; + /* Last available index we saw (ie. where we're up to). */ u16 last_avail_idx; @@ -279,7 +282,7 @@ void vringh_set_iotlb(struct vringh *vrh, struct vhost_iotlb *iotlb, spinlock_t *iotlb_lock); int vringh_init_iotlb(struct vringh *vrh, u64 features, - unsigned int num, bool weak_barriers, + unsigned int num, bool weak_barriers, bool use_va, struct vring_desc *desc, struct vring_avail *avail, struct vring_used *used); diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c index 520646ae7fa0..dfd0e000217b 100644 --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c @@ -2537,7 +2537,7 @@ static int setup_cvq_vring(struct mlx5_vdpa_dev *mvdev) if (mvdev->actual_features & BIT_ULL(VIRTIO_NET_F_CTRL_VQ)) err = vringh_init_iotlb(&cvq->vring, mvdev->actual_features, - MLX5_CVQ_MAX_ENT, false, + MLX5_CVQ_MAX_ENT, false, false,To avoid those changes, would it be better to introduce vringh_init_iotlb_va() so vringh_init_iotlb() can stick to pa.
Okay, I don't have a strong opinion, I'll add vringh_init_iotlb_va().
(struct vring_desc *)(uintptr_t)cvq->desc_addr, (struct vring_avail *)(uintptr_t)cvq->driver_addr, (struct vring_used *)(uintptr_t)cvq->device_addr); diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c index eea23c630f7c..47cdf2a1f5b8 100644 --- a/drivers/vdpa/vdpa_sim/vdpa_sim.c +++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c @@ -60,7 +60,7 @@ static void vdpasim_queue_ready(struct vdpasim *vdpasim, unsigned int idx) struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx]; uint16_t last_avail_idx = vq->vring.last_avail_idx; - vringh_init_iotlb(&vq->vring, vdpasim->features, vq->num, true, + vringh_init_iotlb(&vq->vring, vdpasim->features, vq->num, true, false, (struct vring_desc *)(uintptr_t)vq->desc_addr, (struct vring_avail *) (uintptr_t)vq->driver_addr, @@ -92,7 +92,7 @@ static void vdpasim_vq_reset(struct vdpasim *vdpasim, vq->cb = NULL; vq->private = NULL; vringh_init_iotlb(&vq->vring, vdpasim->dev_attr.supported_features, - VDPASIM_QUEUE_MAX, false, NULL, NULL, NULL); + VDPASIM_QUEUE_MAX, false, false, NULL, NULL, NULL); vq->vring.notify = NULL; } diff --git a/drivers/vhost/vringh.c b/drivers/vhost/vringh.c index 0ba3ef809e48..72c88519329a 100644 --- a/drivers/vhost/vringh.c +++ b/drivers/vhost/vringh.c @@ -1094,10 +1094,18 @@ EXPORT_SYMBOL(vringh_need_notify_kern); #if IS_REACHABLE(CONFIG_VHOST_IOTLB) +struct iotlb_vec { + union { + struct iovec *iovec; + struct bio_vec *bvec; + } iov; + size_t count; + bool is_iovec;I wonder if this is needed (if vringh is passed to every iotlb_vec helper).
Yep, I can use vringh->use_va.
+}; + static int iotlb_translate(const struct vringh *vrh, u64 addr, u64 len, u64 *translated, - struct bio_vec iov[], - int iov_size, u32 perm) + struct iotlb_vec *ivec, u32 perm) { struct vhost_iotlb_map *map; struct vhost_iotlb *iotlb = vrh->iotlb; @@ -1107,9 +1115,9 @@ static int iotlb_translate(const struct vringh *vrh, spin_lock(vrh->iotlb_lock); while (len > s) { - u64 size, pa, pfn; + u64 size; - if (unlikely(ret >= iov_size)) { + if (unlikely(ret >= ivec->count)) { ret = -ENOBUFS; break; } @@ -1124,10 +1132,22 @@ static int iotlb_translate(const struct vringh *vrh, } size = map->size - addr + map->start; - pa = map->addr + addr - map->start; - pfn = pa >> PAGE_SHIFT; - bvec_set_page(&iov[ret], pfn_to_page(pfn), min(len - s, size), - pa & (PAGE_SIZE - 1)); + if (ivec->is_iovec) { + struct iovec *iovec = ivec->iov.iovec; + + iovec[ret].iov_len = min(len - s, size); + iovec[ret].iov_base = (void __user *)(unsigned long) + (map->addr + addr - map->start);map->addr - map->start to avoid overflow?
Right, it was pre-existing, but I'll fix since I'm here (also in the else branch). And since it's duplicate code, I'll declare it outside!
+ } else { + u64 pa = map->addr + addr - map->start; + u64 pfn = pa >> PAGE_SHIFT; + struct bio_vec *bvec = ivec->iov.bvec; + + bvec_set_page(&bvec[ret], pfn_to_page(pfn), + min(len - s, size), + pa & (PAGE_SIZE - 1)); + } + s += size; addr += size; ++ret; @@ -1141,26 +1161,42 @@ static int iotlb_translate(const struct vringh *vrh, return ret; } +#define IOTLB_IOV_SIZE 16 + static inline int copy_from_iotlb(const struct vringh *vrh, void *dst, void *src, size_t len) { + struct iotlb_vec ivec; + union { + struct iovec iovec[IOTLB_IOV_SIZE]; + struct bio_vec bvec[IOTLB_IOV_SIZE]; + } iov; u64 total_translated = 0; + ivec.iov.iovec = iov.iovec;ivc.iov = iov ?
I tried, but they are both anonymous unions, so I cannot assign them. Also, this inner union I need to allocate space in the stack to hold both arrays, while the union in iotlb_vec to carry both pointers. I don't know whether to add a third field (e.g. `void *raw`) to both and assign it.
Others look good.
Thanks, Stefano
