From: Maxime Coquelin Date: Wed, 24 Jan 2018 16:19:29 +0000 (+0100) Subject: vhost: handle virtually non-contiguous buffers in Tx X-Git-Url: http://git.droids-corp.org/?a=commitdiff_plain;h=91b7b40806b6ea9910d6686fddcf7c970771fa72;p=dpdk.git vhost: handle virtually non-contiguous buffers in Tx This patch enables the handling of buffers non-contiguous in process virtual address space in the dequeue path. When virtio-net header doesn't fit in a single chunck, it is copied into a local variablei before being processed. For packet content, the copy length is limited to the chunck size, next chuncks VAs being fetched afterward. This issue has been assigned CVE-2018-1059. Signed-off-by: Maxime Coquelin --- diff --git a/lib/librte_vhost/virtio_net.c b/lib/librte_vhost/virtio_net.c index e43df8cb67..dcbfbd5ef2 100644 --- a/lib/librte_vhost/virtio_net.c +++ b/lib/librte_vhost/virtio_net.c @@ -931,12 +931,13 @@ copy_desc_to_mbuf(struct virtio_net *dev, struct vhost_virtqueue *vq, struct rte_mempool *mbuf_pool) { struct vring_desc *desc; - uint64_t desc_addr; + uint64_t desc_addr, desc_gaddr; uint32_t desc_avail, desc_offset; uint32_t mbuf_avail, mbuf_offset; uint32_t cpy_len; - uint64_t dlen; + uint64_t desc_chunck_len; struct rte_mbuf *cur = m, *prev = m; + struct virtio_net_hdr tmp_hdr; struct virtio_net_hdr *hdr = NULL; /* A counter to avoid desc dead loop chain */ uint32_t nr_desc = 1; @@ -951,19 +952,52 @@ copy_desc_to_mbuf(struct virtio_net *dev, struct vhost_virtqueue *vq, goto out; } - dlen = desc->len; + desc_chunck_len = desc->len; + desc_gaddr = desc->addr; desc_addr = vhost_iova_to_vva(dev, - vq, desc->addr, - &dlen, + vq, desc_gaddr, + &desc_chunck_len, VHOST_ACCESS_RO); - if (unlikely(!desc_addr || dlen != desc->len)) { + if (unlikely(!desc_addr)) { error = -1; goto out; } if (virtio_net_with_host_offload(dev)) { - hdr = (struct virtio_net_hdr *)((uintptr_t)desc_addr); - rte_prefetch0(hdr); + if (unlikely(desc_chunck_len < sizeof(struct virtio_net_hdr))) { + uint64_t len = desc_chunck_len; + uint64_t remain = sizeof(struct virtio_net_hdr); + uint64_t src = desc_addr; + uint64_t dst = (uint64_t)(uintptr_t)&tmp_hdr; + uint64_t guest_addr = desc_gaddr; + + /* + * No luck, the virtio-net header doesn't fit + * in a contiguous virtual area. + */ + while (remain) { + len = remain; + src = vhost_iova_to_vva(dev, vq, + guest_addr, &len, + VHOST_ACCESS_RO); + if (unlikely(!src || !len)) { + error = -1; + goto out; + } + + rte_memcpy((void *)(uintptr_t)dst, + (void *)(uintptr_t)src, len); + + guest_addr += len; + remain -= len; + dst += len; + } + + hdr = &tmp_hdr; + } else { + hdr = (struct virtio_net_hdr *)((uintptr_t)desc_addr); + rte_prefetch0(hdr); + } } /* @@ -979,12 +1013,13 @@ copy_desc_to_mbuf(struct virtio_net *dev, struct vhost_virtqueue *vq, goto out; } - dlen = desc->len; + desc_chunck_len = desc->len; + desc_gaddr = desc->addr; desc_addr = vhost_iova_to_vva(dev, - vq, desc->addr, - &dlen, + vq, desc_gaddr, + &desc_chunck_len, VHOST_ACCESS_RO); - if (unlikely(!desc_addr || dlen != desc->len)) { + if (unlikely(!desc_addr)) { error = -1; goto out; } @@ -994,19 +1029,37 @@ copy_desc_to_mbuf(struct virtio_net *dev, struct vhost_virtqueue *vq, nr_desc += 1; } else { desc_avail = desc->len - dev->vhost_hlen; - desc_offset = dev->vhost_hlen; + + if (unlikely(desc_chunck_len < dev->vhost_hlen)) { + desc_chunck_len = desc_avail; + desc_gaddr += dev->vhost_hlen; + desc_addr = vhost_iova_to_vva(dev, + vq, desc_gaddr, + &desc_chunck_len, + VHOST_ACCESS_RO); + if (unlikely(!desc_addr)) { + error = -1; + goto out; + } + + desc_offset = 0; + } else { + desc_offset = dev->vhost_hlen; + desc_chunck_len -= dev->vhost_hlen; + } } rte_prefetch0((void *)(uintptr_t)(desc_addr + desc_offset)); - PRINT_PACKET(dev, (uintptr_t)(desc_addr + desc_offset), desc_avail, 0); + PRINT_PACKET(dev, (uintptr_t)(desc_addr + desc_offset), + (uint32_t)desc_chunck_len, 0); mbuf_offset = 0; mbuf_avail = m->buf_len - RTE_PKTMBUF_HEADROOM; while (1) { uint64_t hpa; - cpy_len = RTE_MIN(desc_avail, mbuf_avail); + cpy_len = RTE_MIN(desc_chunck_len, mbuf_avail); /* * A desc buf might across two host physical pages that are @@ -1014,7 +1067,7 @@ copy_desc_to_mbuf(struct virtio_net *dev, struct vhost_virtqueue *vq, * will be copied even though zero copy is enabled. */ if (unlikely(dev->dequeue_zero_copy && (hpa = gpa_to_hpa(dev, - desc->addr + desc_offset, cpy_len)))) { + desc_gaddr + desc_offset, cpy_len)))) { cur->data_len = cpy_len; cur->data_off = 0; cur->buf_addr = (void *)(uintptr_t)(desc_addr @@ -1029,7 +1082,8 @@ copy_desc_to_mbuf(struct virtio_net *dev, struct vhost_virtqueue *vq, } else { if (likely(cpy_len > MAX_BATCH_LEN || copy_nb >= vq->size || - (hdr && cur == m))) { + (hdr && cur == m) || + desc->len != desc_chunck_len)) { rte_memcpy(rte_pktmbuf_mtod_offset(cur, void *, mbuf_offset), (void *)((uintptr_t)(desc_addr + @@ -1050,6 +1104,7 @@ copy_desc_to_mbuf(struct virtio_net *dev, struct vhost_virtqueue *vq, mbuf_avail -= cpy_len; mbuf_offset += cpy_len; desc_avail -= cpy_len; + desc_chunck_len -= cpy_len; desc_offset += cpy_len; /* This desc reaches to its end, get the next one */ @@ -1068,11 +1123,13 @@ copy_desc_to_mbuf(struct virtio_net *dev, struct vhost_virtqueue *vq, goto out; } - dlen = desc->len; + desc_chunck_len = desc->len; + desc_gaddr = desc->addr; desc_addr = vhost_iova_to_vva(dev, - vq, desc->addr, - &dlen, VHOST_ACCESS_RO); - if (unlikely(!desc_addr || dlen != desc->len)) { + vq, desc_gaddr, + &desc_chunck_len, + VHOST_ACCESS_RO); + if (unlikely(!desc_addr)) { error = -1; goto out; } @@ -1082,7 +1139,23 @@ copy_desc_to_mbuf(struct virtio_net *dev, struct vhost_virtqueue *vq, desc_offset = 0; desc_avail = desc->len; - PRINT_PACKET(dev, (uintptr_t)desc_addr, desc->len, 0); + PRINT_PACKET(dev, (uintptr_t)desc_addr, + (uint32_t)desc_chunck_len, 0); + } else if (unlikely(desc_chunck_len == 0)) { + desc_chunck_len = desc_avail; + desc_gaddr += desc_offset; + desc_addr = vhost_iova_to_vva(dev, vq, + desc_gaddr, + &desc_chunck_len, + VHOST_ACCESS_RO); + if (unlikely(!desc_addr)) { + error = -1; + goto out; + } + desc_offset = 0; + + PRINT_PACKET(dev, (uintptr_t)desc_addr, + (uint32_t)desc_chunck_len, 0); } /*