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Tsirkin" , kvm@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Mar 2, 2023 at 12:35 PM Stefano Garzarella wr= ote: > > 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 > --- > > Notes: > v2: > - replace kmap_atomic() with kmap_local_page() [see previous patch] > - fix cast warnings when build with W=3D1 C=3D1 > > 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 | 247 ++++++++++++++++++++++++------ > 4 files changed, 205 insertions(+), 53 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 vhos= t_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/ml= x5_vnet.c > index 3a0e721aef05..babc8dd171a6 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 *mv= dev) > > if (mvdev->actual_features & BIT_ULL(VIRTIO_NET_F_CTRL_VQ)) > err =3D vringh_init_iotlb(&cvq->vring, mvdev->actual_feat= ures, > - MLX5_CVQ_MAX_ENT, false, > + MLX5_CVQ_MAX_ENT, false, false, > (struct vring_desc *)(uintptr_t)c= vq->desc_addr, > (struct vring_avail *)(uintptr_t)= cvq->driver_addr, > (struct vring_used *)(uintptr_t)c= vq->device_addr); > diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdp= a_sim.c > index 6a0a65814626..481eb156658b 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 =3D &vdpasim->vqs[idx]; > uint16_t last_avail_idx =3D 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, f= alse, > (struct vring_desc *)(uintptr_t)vq->desc_addr, > (struct vring_avail *) > (uintptr_t)vq->driver_addr, > @@ -81,7 +81,7 @@ static void vdpasim_vq_reset(struct vdpasim *vdpasim, > vq->cb =3D NULL; > vq->private =3D NULL; > vringh_init_iotlb(&vq->vring, vdpasim->dev_attr.supported_feature= s, > - VDPASIM_QUEUE_MAX, false, NULL, NULL, NULL); > + VDPASIM_QUEUE_MAX, false, false, NULL, NULL, NU= LL); > > vq->vring.notify =3D NULL; > } > diff --git a/drivers/vhost/vringh.c b/drivers/vhost/vringh.c > index 0ba3ef809e48..61c79cea44ca 100644 > --- a/drivers/vhost/vringh.c > +++ b/drivers/vhost/vringh.c > @@ -1094,15 +1094,99 @@ EXPORT_SYMBOL(vringh_need_notify_kern); > > #if IS_REACHABLE(CONFIG_VHOST_IOTLB) > > -static int iotlb_translate(const struct vringh *vrh, > - u64 addr, u64 len, u64 *translated, > - struct bio_vec iov[], > - int iov_size, u32 perm) > +static int iotlb_translate_va(const struct vringh *vrh, > + u64 addr, u64 len, u64 *translated, > + struct iovec iov[], > + int iov_size, u32 perm) > { > struct vhost_iotlb_map *map; > struct vhost_iotlb *iotlb =3D vrh->iotlb; > + u64 s =3D 0, last =3D addr + len - 1; > int ret =3D 0; > + > + spin_lock(vrh->iotlb_lock); > + > + while (len > s) { > + u64 size; > + > + if (unlikely(ret >=3D iov_size)) { > + ret =3D -ENOBUFS; > + break; > + } > + > + map =3D vhost_iotlb_itree_first(iotlb, addr, last); > + if (!map || map->start > addr) { > + ret =3D -EINVAL; > + break; > + } else if (!(map->perm & perm)) { > + ret =3D -EPERM; > + break; > + } > + > + size =3D map->size - addr + map->start; > + iov[ret].iov_len =3D min(len - s, size); > + iov[ret].iov_base =3D (void __user *)(unsigned long) > + (map->addr + addr - map->start); > + s +=3D size; > + addr +=3D size; > + ++ret; > + } > + > + spin_unlock(vrh->iotlb_lock); > + > + if (translated) > + *translated =3D min(len, s); > + > + return ret; > +} It seems to me iotlb_translate_va and iotlb_translate_pa are very similar, their only difference is that the argument is that iov is iovec instead of bio_vec. And how to fill it, obviously. It would be great to merge both functions, only differing with a conditional on vrh->use_va, or generics, or similar. Or, if following the style of the rest of vringh code, to provide a callback to fill iovec (although I like conditional more). However I cannot think of an easy way to perform that without long macros or type erasure. > + > +static inline int copy_from_va(const struct vringh *vrh, void *dst, void= *src, > + u64 len, u64 *translated) > +{ > + struct iovec iov[16]; > + struct iov_iter iter; > + int ret; > + > + ret =3D iotlb_translate_va(vrh, (u64)(uintptr_t)src, len, transla= ted, iov, > + ARRAY_SIZE(iov), VHOST_MAP_RO); > + if (ret =3D=3D -ENOBUFS) > + ret =3D ARRAY_SIZE(iov); > + else if (ret < 0) > + return ret; > + > + iov_iter_init(&iter, ITER_SOURCE, iov, ret, *translated); > + > + return copy_from_iter(dst, *translated, &iter); Maybe a good baby step for DRY is to return the iov_iter in copy_from/to_va/pa here? But I'm ok with this version too. Acked-by: Eugenio P=C3=A9rez Martin > +} > + > +static inline int copy_to_va(const struct vringh *vrh, void *dst, void *= src, > + u64 len, u64 *translated) > +{ > + struct iovec iov[16]; > + struct iov_iter iter; > + int ret; > + > + ret =3D iotlb_translate_va(vrh, (u64)(uintptr_t)dst, len, transla= ted, iov, > + ARRAY_SIZE(iov), VHOST_MAP_WO); > + if (ret =3D=3D -ENOBUFS) > + ret =3D ARRAY_SIZE(iov); > + else if (ret < 0) > + return ret; > + > + iov_iter_init(&iter, ITER_DEST, iov, ret, *translated); > + > + return copy_to_iter(src, *translated, &iter); > +} > + > +static int iotlb_translate_pa(const struct vringh *vrh, > + u64 addr, u64 len, u64 *translated, > + struct bio_vec iov[], > + int iov_size, u32 perm) > +{ > + struct vhost_iotlb_map *map; > + struct vhost_iotlb *iotlb =3D vrh->iotlb; > u64 s =3D 0, last =3D addr + len - 1; > + int ret =3D 0; > > spin_lock(vrh->iotlb_lock); > > @@ -1141,28 +1225,61 @@ static int iotlb_translate(const struct vringh *v= rh, > return ret; > } > > +static inline int copy_from_pa(const struct vringh *vrh, void *dst, void= *src, > + u64 len, u64 *translated) > +{ > + struct bio_vec iov[16]; > + struct iov_iter iter; > + int ret; > + > + ret =3D iotlb_translate_pa(vrh, (u64)(uintptr_t)src, len, transla= ted, iov, > + ARRAY_SIZE(iov), VHOST_MAP_RO); > + if (ret =3D=3D -ENOBUFS) > + ret =3D ARRAY_SIZE(iov); > + else if (ret < 0) > + return ret; > + > + iov_iter_bvec(&iter, ITER_SOURCE, iov, ret, *translated); > + > + return copy_from_iter(dst, *translated, &iter); > +} > + > +static inline int copy_to_pa(const struct vringh *vrh, void *dst, void *= src, > + u64 len, u64 *translated) > +{ > + struct bio_vec iov[16]; > + struct iov_iter iter; > + int ret; > + > + ret =3D iotlb_translate_pa(vrh, (u64)(uintptr_t)dst, len, transla= ted, iov, > + ARRAY_SIZE(iov), VHOST_MAP_WO); > + if (ret =3D=3D -ENOBUFS) > + ret =3D ARRAY_SIZE(iov); > + else if (ret < 0) > + return ret; > + > + iov_iter_bvec(&iter, ITER_DEST, iov, ret, *translated); > + > + return copy_to_iter(src, *translated, &iter); > +} > + > static inline int copy_from_iotlb(const struct vringh *vrh, void *dst, > void *src, size_t len) > { > u64 total_translated =3D 0; > > while (total_translated < len) { > - struct bio_vec iov[16]; > - struct iov_iter iter; > u64 translated; > int ret; > > - ret =3D iotlb_translate(vrh, (u64)(uintptr_t)src, > - len - total_translated, &translated= , > - iov, ARRAY_SIZE(iov), VHOST_MAP_RO)= ; > - if (ret =3D=3D -ENOBUFS) > - ret =3D ARRAY_SIZE(iov); > - else if (ret < 0) > - return ret; > - > - iov_iter_bvec(&iter, ITER_SOURCE, iov, ret, translated); > + if (vrh->use_va) { > + ret =3D copy_from_va(vrh, dst, src, > + len - total_translated, &trans= lated); > + } else { > + ret =3D copy_from_pa(vrh, dst, src, > + len - total_translated, &trans= lated); > + } > > - ret =3D copy_from_iter(dst, translated, &iter); > if (ret < 0) > return ret; > > @@ -1180,22 +1297,17 @@ static inline int copy_to_iotlb(const struct vrin= gh *vrh, void *dst, > u64 total_translated =3D 0; > > while (total_translated < len) { > - struct bio_vec iov[16]; > - struct iov_iter iter; > u64 translated; > int ret; > > - ret =3D iotlb_translate(vrh, (u64)(uintptr_t)dst, > - len - total_translated, &translated= , > - iov, ARRAY_SIZE(iov), VHOST_MAP_WO)= ; > - if (ret =3D=3D -ENOBUFS) > - ret =3D ARRAY_SIZE(iov); > - else if (ret < 0) > - return ret; > - > - iov_iter_bvec(&iter, ITER_DEST, iov, ret, translated); > + if (vrh->use_va) { > + ret =3D copy_to_va(vrh, dst, src, > + len - total_translated, &transla= ted); > + } else { > + ret =3D copy_to_pa(vrh, dst, src, > + len - total_translated, &transla= ted); > + } > > - ret =3D copy_to_iter(src, translated, &iter); > if (ret < 0) > return ret; > > @@ -1210,20 +1322,37 @@ static inline int copy_to_iotlb(const struct vrin= gh *vrh, void *dst, > static inline int getu16_iotlb(const struct vringh *vrh, > u16 *val, const __virtio16 *p) > { > - struct bio_vec iov; > - void *kaddr, *from; > int ret; > > /* Atomic read is needed for getu16 */ > - ret =3D iotlb_translate(vrh, (u64)(uintptr_t)p, sizeof(*p), NULL, > - &iov, 1, VHOST_MAP_RO); > - if (ret < 0) > - return ret; > + if (vrh->use_va) { > + struct iovec iov; > + __virtio16 tmp; > + > + ret =3D iotlb_translate_va(vrh, (u64)(uintptr_t)p, sizeof= (*p), > + NULL, &iov, 1, VHOST_MAP_RO); > + if (ret < 0) > + return ret; > > - kaddr =3D kmap_local_page(iov.bv_page); > - from =3D kaddr + iov.bv_offset; > - *val =3D vringh16_to_cpu(vrh, READ_ONCE(*(__virtio16 *)from)); > - kunmap_local(kaddr); > + ret =3D __get_user(tmp, (__virtio16 __user *)iov.iov_base= ); > + if (ret) > + return ret; > + > + *val =3D vringh16_to_cpu(vrh, tmp); > + } else { > + struct bio_vec iov; > + void *kaddr, *from; > + > + ret =3D iotlb_translate_pa(vrh, (u64)(uintptr_t)p, sizeof= (*p), > + NULL, &iov, 1, VHOST_MAP_RO); > + if (ret < 0) > + return ret; > + > + kaddr =3D kmap_local_page(iov.bv_page); > + from =3D kaddr + iov.bv_offset; > + *val =3D vringh16_to_cpu(vrh, READ_ONCE(*(__virtio16 *)fr= om)); > + kunmap_local(kaddr); > + } > > return 0; > } > @@ -1231,20 +1360,37 @@ static inline int getu16_iotlb(const struct vring= h *vrh, > static inline int putu16_iotlb(const struct vringh *vrh, > __virtio16 *p, u16 val) > { > - struct bio_vec iov; > - void *kaddr, *to; > int ret; > > /* Atomic write is needed for putu16 */ > - ret =3D iotlb_translate(vrh, (u64)(uintptr_t)p, sizeof(*p), NULL, > - &iov, 1, VHOST_MAP_WO); > - if (ret < 0) > - return ret; > + if (vrh->use_va) { > + struct iovec iov; > + __virtio16 tmp; > > - kaddr =3D kmap_local_page(iov.bv_page); > - to =3D kaddr + iov.bv_offset; > - WRITE_ONCE(*(__virtio16 *)to, cpu_to_vringh16(vrh, val)); > - kunmap_local(kaddr); > + ret =3D iotlb_translate_va(vrh, (u64)(uintptr_t)p, sizeof= (*p), > + NULL, &iov, 1, VHOST_MAP_RO); > + if (ret < 0) > + return ret; > + > + tmp =3D cpu_to_vringh16(vrh, val); > + > + ret =3D __put_user(tmp, (__virtio16 __user *)iov.iov_base= ); > + if (ret) > + return ret; > + } else { > + struct bio_vec iov; > + void *kaddr, *to; > + > + ret =3D iotlb_translate_pa(vrh, (u64)(uintptr_t)p, sizeof= (*p), NULL, > + &iov, 1, VHOST_MAP_WO); > + if (ret < 0) > + return ret; > + > + kaddr =3D kmap_local_page(iov.bv_page); > + to =3D kaddr + iov.bv_offset; > + WRITE_ONCE(*(__virtio16 *)to, cpu_to_vringh16(vrh, val)); > + kunmap_local(kaddr); > + } > > return 0; > } > @@ -1306,6 +1452,7 @@ static inline int putused_iotlb(const struct vringh= *vrh, > * @features: the feature bits for this ring. > * @num: the number of elements. > * @weak_barriers: true if we only need memory barriers, not I/O. > + * @use_va: true if IOTLB contains user VA > * @desc: the userpace descriptor pointer. > * @avail: the userpace avail pointer. > * @used: the userpace used pointer. > @@ -1313,11 +1460,13 @@ static inline int putused_iotlb(const struct vrin= gh *vrh, > * Returns an error if num is invalid. > */ > 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) > { > + vrh->use_va =3D use_va; > + > return vringh_init_kern(vrh, features, num, weak_barriers, > desc, avail, used); > } > -- > 2.39.2 >