diff options
Diffstat (limited to 'drivers/vhost/vringh.c')
| -rw-r--r-- | drivers/vhost/vringh.c | 191 |
1 files changed, 150 insertions, 41 deletions
diff --git a/drivers/vhost/vringh.c b/drivers/vhost/vringh.c index a1e27da54481..955d938eb663 100644 --- a/drivers/vhost/vringh.c +++ b/drivers/vhost/vringh.c @@ -636,9 +636,9 @@ static inline int xfer_to_user(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. - * @desc: the userpace descriptor pointer. - * @avail: the userpace avail pointer. - * @used: the userpace used pointer. + * @desc: the userspace descriptor pointer. + * @avail: the userspace avail pointer. + * @used: the userspace used pointer. * * Returns an error if num is invalid: you should check pointers * yourself! @@ -911,9 +911,9 @@ static inline int kern_xfer(const struct vringh *vrh, void *dst, * @features: the feature bits for this ring. * @num: the number of elements. * @weak_barriers: true if we only need memory barriers, not I/O. - * @desc: the userpace descriptor pointer. - * @avail: the userpace avail pointer. - * @used: the userpace used pointer. + * @desc: the userspace descriptor pointer. + * @avail: the userspace avail pointer. + * @used: the userspace used pointer. * * Returns an error if num is invalid. */ @@ -1094,10 +1094,17 @@ 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; +}; + 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 +1114,11 @@ static int iotlb_translate(const struct vringh *vrh, spin_lock(vrh->iotlb_lock); while (len > s) { - u64 size, pa, pfn; + uintptr_t io_addr; + size_t io_len; + u64 size; - if (unlikely(ret >= iov_size)) { + if (unlikely(ret >= ivec->count)) { ret = -ENOBUFS; break; } @@ -1124,10 +1133,22 @@ 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)); + io_len = min(len - s, size); + io_addr = map->addr - map->start + addr; + + if (vrh->use_va) { + struct iovec *iovec = ivec->iov.iovec; + + iovec[ret].iov_len = io_len; + iovec[ret].iov_base = (void __user *)io_addr; + } else { + u64 pfn = io_addr >> PAGE_SHIFT; + struct bio_vec *bvec = ivec->iov.bvec; + + bvec_set_page(&bvec[ret], pfn_to_page(pfn), io_len, + io_addr & (PAGE_SIZE - 1)); + } + s += size; addr += size; ++ret; @@ -1141,26 +1162,41 @@ static int iotlb_translate(const struct vringh *vrh, return ret; } +#define IOTLB_IOV_STRIDE 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_STRIDE]; + struct bio_vec bvec[IOTLB_IOV_STRIDE]; + } iov; u64 total_translated = 0; + ivec.iov.iovec = iov.iovec; + ivec.count = IOTLB_IOV_STRIDE; + while (total_translated < len) { - struct bio_vec iov[16]; struct iov_iter iter; u64 translated; int ret; ret = iotlb_translate(vrh, (u64)(uintptr_t)src, len - total_translated, &translated, - iov, ARRAY_SIZE(iov), VHOST_MAP_RO); + &ivec, VHOST_MAP_RO); if (ret == -ENOBUFS) - ret = ARRAY_SIZE(iov); + ret = IOTLB_IOV_STRIDE; else if (ret < 0) return ret; - iov_iter_bvec(&iter, ITER_SOURCE, iov, ret, translated); + if (vrh->use_va) { + iov_iter_init(&iter, ITER_SOURCE, ivec.iov.iovec, ret, + translated); + } else { + iov_iter_bvec(&iter, ITER_SOURCE, ivec.iov.bvec, ret, + translated); + } ret = copy_from_iter(dst, translated, &iter); if (ret < 0) @@ -1177,23 +1213,36 @@ static inline int copy_from_iotlb(const struct vringh *vrh, void *dst, static inline int copy_to_iotlb(const struct vringh *vrh, void *dst, void *src, size_t len) { + struct iotlb_vec ivec; + union { + struct iovec iovec[IOTLB_IOV_STRIDE]; + struct bio_vec bvec[IOTLB_IOV_STRIDE]; + } iov; u64 total_translated = 0; + ivec.iov.iovec = iov.iovec; + ivec.count = IOTLB_IOV_STRIDE; + while (total_translated < len) { - struct bio_vec iov[16]; struct iov_iter iter; u64 translated; int ret; ret = iotlb_translate(vrh, (u64)(uintptr_t)dst, len - total_translated, &translated, - iov, ARRAY_SIZE(iov), VHOST_MAP_WO); + &ivec, VHOST_MAP_WO); if (ret == -ENOBUFS) - ret = ARRAY_SIZE(iov); + ret = IOTLB_IOV_STRIDE; else if (ret < 0) return ret; - iov_iter_bvec(&iter, ITER_DEST, iov, ret, translated); + if (vrh->use_va) { + iov_iter_init(&iter, ITER_DEST, ivec.iov.iovec, ret, + translated); + } else { + iov_iter_bvec(&iter, ITER_DEST, ivec.iov.bvec, ret, + translated); + } ret = copy_to_iter(src, translated, &iter); if (ret < 0) @@ -1210,20 +1259,36 @@ static inline int copy_to_iotlb(const struct vringh *vrh, void *dst, static inline int getu16_iotlb(const struct vringh *vrh, u16 *val, const __virtio16 *p) { - struct bio_vec iov; - void *kaddr, *from; + struct iotlb_vec ivec; + union { + struct iovec iovec[1]; + struct bio_vec bvec[1]; + } iov; + __virtio16 tmp; int ret; + ivec.iov.iovec = iov.iovec; + ivec.count = 1; + /* Atomic read is needed for getu16 */ - ret = iotlb_translate(vrh, (u64)(uintptr_t)p, sizeof(*p), NULL, - &iov, 1, VHOST_MAP_RO); + ret = iotlb_translate(vrh, (u64)(uintptr_t)p, sizeof(*p), + NULL, &ivec, VHOST_MAP_RO); if (ret < 0) return ret; - kaddr = kmap_atomic(iov.bv_page); - from = kaddr + iov.bv_offset; - *val = vringh16_to_cpu(vrh, READ_ONCE(*(__virtio16 *)from)); - kunmap_atomic(kaddr); + if (vrh->use_va) { + ret = __get_user(tmp, (__virtio16 __user *)ivec.iov.iovec[0].iov_base); + if (ret) + return ret; + } else { + void *kaddr = kmap_local_page(ivec.iov.bvec[0].bv_page); + void *from = kaddr + ivec.iov.bvec[0].bv_offset; + + tmp = READ_ONCE(*(__virtio16 *)from); + kunmap_local(kaddr); + } + + *val = vringh16_to_cpu(vrh, tmp); return 0; } @@ -1231,20 +1296,36 @@ static inline int getu16_iotlb(const struct vringh *vrh, static inline int putu16_iotlb(const struct vringh *vrh, __virtio16 *p, u16 val) { - struct bio_vec iov; - void *kaddr, *to; + struct iotlb_vec ivec; + union { + struct iovec iovec; + struct bio_vec bvec; + } iov; + __virtio16 tmp; int ret; + ivec.iov.iovec = &iov.iovec; + ivec.count = 1; + /* Atomic write is needed for putu16 */ - ret = iotlb_translate(vrh, (u64)(uintptr_t)p, sizeof(*p), NULL, - &iov, 1, VHOST_MAP_WO); + ret = iotlb_translate(vrh, (u64)(uintptr_t)p, sizeof(*p), + NULL, &ivec, VHOST_MAP_RO); if (ret < 0) return ret; - kaddr = kmap_atomic(iov.bv_page); - to = kaddr + iov.bv_offset; - WRITE_ONCE(*(__virtio16 *)to, cpu_to_vringh16(vrh, val)); - kunmap_atomic(kaddr); + tmp = cpu_to_vringh16(vrh, val); + + if (vrh->use_va) { + ret = __put_user(tmp, (__virtio16 __user *)ivec.iov.iovec[0].iov_base); + if (ret) + return ret; + } else { + void *kaddr = kmap_local_page(ivec.iov.bvec[0].bv_page); + void *to = kaddr + ivec.iov.bvec[0].bv_offset; + + WRITE_ONCE(*(__virtio16 *)to, tmp); + kunmap_local(kaddr); + } return 0; } @@ -1306,9 +1387,9 @@ 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. - * @desc: the userpace descriptor pointer. - * @avail: the userpace avail pointer. - * @used: the userpace used pointer. + * @desc: the userspace descriptor pointer. + * @avail: the userspace avail pointer. + * @used: the userspace used pointer. * * Returns an error if num is invalid. */ @@ -1318,12 +1399,40 @@ int vringh_init_iotlb(struct vringh *vrh, u64 features, struct vring_avail *avail, struct vring_used *used) { + vrh->use_va = false; + return vringh_init_kern(vrh, features, num, weak_barriers, desc, avail, used); } EXPORT_SYMBOL(vringh_init_iotlb); /** + * vringh_init_iotlb_va - initialize a vringh for a ring with IOTLB containing + * user VA. + * @vrh: the vringh to initialize. + * @features: the feature bits for this ring. + * @num: the number of elements. + * @weak_barriers: true if we only need memory barriers, not I/O. + * @desc: the userspace descriptor pointer. + * @avail: the userspace avail pointer. + * @used: the userspace used pointer. + * + * Returns an error if num is invalid. + */ +int vringh_init_iotlb_va(struct vringh *vrh, u64 features, + unsigned int num, bool weak_barriers, + struct vring_desc *desc, + struct vring_avail *avail, + struct vring_used *used) +{ + vrh->use_va = true; + + return vringh_init_kern(vrh, features, num, weak_barriers, + desc, avail, used); +} +EXPORT_SYMBOL(vringh_init_iotlb_va); + +/** * vringh_set_iotlb - initialize a vringh for a ring with IOTLB. * @vrh: the vring * @iotlb: iotlb associated with this vring |