From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E9AD5C47083 for ; Fri, 4 Jun 2021 05:55:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D505761415 for ; Fri, 4 Jun 2021 05:55:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230226AbhFDF45 (ORCPT ); Fri, 4 Jun 2021 01:56:57 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:34239 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230212AbhFDF44 (ORCPT ); Fri, 4 Jun 2021 01:56:56 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1622786110; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=PAsMdBaHH54UtnD5ZOdRbSiDTadfouyxNC4i/WeqrP4=; b=VKDNjgyrFPzlSSwJu9Y1gNLAzTWsifWMi93KEWKjsiuU2LbToxcr2XOLcFaqzDDarH1snt nUtLrAjq86RPaOBGVp/et3lSg6qO1ze60uQtst4vpnfZLZ6ultDW+HAOU4i1IMgykzGSOc 89icnOR/QgRTprLwHKSL8R9WkAf4Q9c= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-574-P459AZLbO0-BDbnOOSvnJA-1; Fri, 04 Jun 2021 01:55:08 -0400 X-MC-Unique: P459AZLbO0-BDbnOOSvnJA-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 3901F8030CF; Fri, 4 Jun 2021 05:55:07 +0000 (UTC) Received: from localhost.localdomain (ovpn-12-212.pek2.redhat.com [10.72.12.212]) by smtp.corp.redhat.com (Postfix) with ESMTP id 94E6318ED6; Fri, 4 Jun 2021 05:54:58 +0000 (UTC) From: Jason Wang To: mst@redhat.com Cc: virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org, xieyongji@bytedance.com, stefanha@redhat.com, file@sect.tu-berlin.de, ashish.kalra@amd.com, konrad.wilk@oracle.com, kvm@vger.kernel.org, hch@infradead.org, ak@linux.intel.com, luto@kernel.org, Jason Wang Subject: [PATCH 7/7] virtio-ring: store DMA metadata in desc_extra for split virtqueue Date: Fri, 4 Jun 2021 13:53:50 +0800 Message-Id: <20210604055350.58753-8-jasowang@redhat.com> In-Reply-To: <20210604055350.58753-1-jasowang@redhat.com> References: <20210604055350.58753-1-jasowang@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org For split virtqueue, we used to depend on the address, length and flags stored in the descriptor ring for DMA unmapping. This is unsafe for the case since the device can manipulate the behavior of virtio driver, IOMMU drivers and swiotlb. For safety, maintain the DMA address, DMA length, descriptor flags and next filed of the non indirect descriptors in vring_desc_state_extra when DMA API is used for virtio as we did for packed virtqueue and use those metadata for performing DMA operations. Indirect descriptors should be safe since they are using streaming mappings. With this the descriptor ring is write only form the view of the driver. This slight increase the footprint of the drive but it's not noticed through pktgen (64B) test and netperf test in the case of virtio-net. Signed-off-by: Jason Wang --- drivers/virtio/virtio_ring.c | 112 +++++++++++++++++++++++++++-------- 1 file changed, 87 insertions(+), 25 deletions(-) diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index 9800f1c9ce4c..5f0076eeb39c 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -130,6 +130,7 @@ struct vring_virtqueue { /* Per-descriptor state. */ struct vring_desc_state_split *desc_state; + struct vring_desc_extra *desc_extra; /* DMA address and size information */ dma_addr_t queue_dma_addr; @@ -364,8 +365,8 @@ static int vring_mapping_error(const struct vring_virtqueue *vq, * Split ring specific functions - *_split(). */ -static void vring_unmap_one_split(const struct vring_virtqueue *vq, - struct vring_desc *desc) +static void vring_unmap_one_split_indirect(const struct vring_virtqueue *vq, + struct vring_desc *desc) { u16 flags; @@ -389,6 +390,35 @@ static void vring_unmap_one_split(const struct vring_virtqueue *vq, } } +static unsigned int vring_unmap_one_split(const struct vring_virtqueue *vq, + unsigned int i) +{ + struct vring_desc_extra *extra = vq->split.desc_extra; + u16 flags; + + if (!vq->use_dma_api) + goto out; + + flags = extra[i].flags; + + if (flags & VRING_DESC_F_INDIRECT) { + dma_unmap_single(vring_dma_dev(vq), + extra[i].addr, + extra[i].len, + (flags & VRING_DESC_F_WRITE) ? + DMA_FROM_DEVICE : DMA_TO_DEVICE); + } else { + dma_unmap_page(vring_dma_dev(vq), + extra[i].addr, + extra[i].len, + (flags & VRING_DESC_F_WRITE) ? + DMA_FROM_DEVICE : DMA_TO_DEVICE); + } + +out: + return extra[i].next; +} + static struct vring_desc *alloc_indirect_split(struct virtqueue *_vq, unsigned int total_sg, gfp_t gfp) @@ -417,13 +447,28 @@ static inline unsigned int virtqueue_add_desc_split(struct virtqueue *vq, unsigned int i, dma_addr_t addr, unsigned int len, - u16 flags) + u16 flags, + bool indirect) { + struct vring_virtqueue *vring = to_vvq(vq); + struct vring_desc_extra *extra = vring->split.desc_extra; + u16 next; + desc[i].flags = cpu_to_virtio16(vq->vdev, flags); desc[i].addr = cpu_to_virtio64(vq->vdev, addr); desc[i].len = cpu_to_virtio32(vq->vdev, len); - return virtio16_to_cpu(vq->vdev, desc[i].next); + if (!indirect) { + next = extra[i].next; + desc[i].next = cpu_to_virtio16(vq->vdev, next); + + extra[i].addr = addr; + extra[i].len = len; + extra[i].flags = flags; + } else + next = virtio16_to_cpu(vq->vdev, desc[i].next); + + return next; } static inline int virtqueue_add_split(struct virtqueue *_vq, @@ -499,8 +544,12 @@ static inline int virtqueue_add_split(struct virtqueue *_vq, goto unmap_release; prev = i; + /* Note that we trust indirect descriptor + * table since it use stream DMA mapping. + */ i = virtqueue_add_desc_split(_vq, desc, i, addr, sg->length, - VRING_DESC_F_NEXT); + VRING_DESC_F_NEXT, + indirect); } } for (; n < (out_sgs + in_sgs); n++) { @@ -510,14 +559,21 @@ static inline int virtqueue_add_split(struct virtqueue *_vq, goto unmap_release; prev = i; + /* Note that we trust indirect descriptor + * table since it use stream DMA mapping. + */ i = virtqueue_add_desc_split(_vq, desc, i, addr, sg->length, VRING_DESC_F_NEXT | - VRING_DESC_F_WRITE); + VRING_DESC_F_WRITE, + indirect); } } /* Last one doesn't continue. */ desc[prev].flags &= cpu_to_virtio16(_vq->vdev, ~VRING_DESC_F_NEXT); + if (!indirect && vq->use_dma_api) + vq->split.desc_extra[prev & (vq->split.vring.num - 1)].flags = + ~VRING_DESC_F_NEXT; if (indirect) { /* Now that the indirect table is filled in, map it. */ @@ -530,7 +586,8 @@ static inline int virtqueue_add_split(struct virtqueue *_vq, virtqueue_add_desc_split(_vq, vq->split.vring.desc, head, addr, total_sg * sizeof(struct vring_desc), - VRING_DESC_F_INDIRECT); + VRING_DESC_F_INDIRECT, + false); } /* We're using some buffers from the free list. */ @@ -538,8 +595,7 @@ static inline int virtqueue_add_split(struct virtqueue *_vq, /* Update free pointer */ if (indirect) - vq->free_head = virtio16_to_cpu(_vq->vdev, - vq->split.vring.desc[head].next); + vq->free_head = vq->split.desc_extra[head].next; else vq->free_head = i; @@ -584,8 +640,11 @@ static inline int virtqueue_add_split(struct virtqueue *_vq, for (n = 0; n < total_sg; n++) { if (i == err_idx) break; - vring_unmap_one_split(vq, &desc[i]); - i = virtio16_to_cpu(_vq->vdev, desc[i].next); + if (indirect) { + vring_unmap_one_split_indirect(vq, &desc[i]); + i = virtio16_to_cpu(_vq->vdev, desc[i].next); + } else + i = vring_unmap_one_split(vq, i); } if (indirect) @@ -639,14 +698,13 @@ static void detach_buf_split(struct vring_virtqueue *vq, unsigned int head, i = head; while (vq->split.vring.desc[i].flags & nextflag) { - vring_unmap_one_split(vq, &vq->split.vring.desc[i]); - i = virtio16_to_cpu(vq->vq.vdev, vq->split.vring.desc[i].next); + vring_unmap_one_split(vq, i); + i = vq->split.desc_extra[i].next; vq->vq.num_free++; } - vring_unmap_one_split(vq, &vq->split.vring.desc[i]); - vq->split.vring.desc[i].next = cpu_to_virtio16(vq->vq.vdev, - vq->free_head); + vring_unmap_one_split(vq, i); + vq->split.desc_extra[i].next = vq->free_head; vq->free_head = head; /* Plus final descriptor */ @@ -661,15 +719,14 @@ static void detach_buf_split(struct vring_virtqueue *vq, unsigned int head, if (!indir_desc) return; - len = virtio32_to_cpu(vq->vq.vdev, - vq->split.vring.desc[head].len); + len = vq->split.desc_extra[head].len; - BUG_ON(!(vq->split.vring.desc[head].flags & - cpu_to_virtio16(vq->vq.vdev, VRING_DESC_F_INDIRECT))); + BUG_ON(!(vq->split.desc_extra[head].flags & + VRING_DESC_F_INDIRECT)); BUG_ON(len == 0 || len % sizeof(struct vring_desc)); for (j = 0; j < len / sizeof(struct vring_desc); j++) - vring_unmap_one_split(vq, &indir_desc[j]); + vring_unmap_one_split_indirect(vq, &indir_desc[j]); kfree(indir_desc); vq->split.desc_state[head].indir_desc = NULL; @@ -2085,7 +2142,6 @@ struct virtqueue *__vring_new_virtqueue(unsigned int index, void (*callback)(struct virtqueue *), const char *name) { - unsigned int i; struct vring_virtqueue *vq; if (virtio_has_feature(vdev, VIRTIO_F_RING_PACKED)) @@ -2140,16 +2196,20 @@ struct virtqueue *__vring_new_virtqueue(unsigned int index, if (!vq->split.desc_state) goto err_state; + vq->split.desc_extra = vring_alloc_desc_extra(vq, vring.num); + if (!vq->split.desc_extra) + goto err_extra; + /* Put everything in free lists. */ vq->free_head = 0; - for (i = 0; i < vring.num-1; i++) - vq->split.vring.desc[i].next = cpu_to_virtio16(vdev, i + 1); memset(vq->split.desc_state, 0, vring.num * sizeof(struct vring_desc_state_split)); list_add_tail(&vq->vq.list, &vdev->vqs); return &vq->vq; +err_extra: + kfree(vq->split.desc_state); err_state: kfree(vq); return NULL; @@ -2233,8 +2293,10 @@ void vring_del_virtqueue(struct virtqueue *_vq) vq->split.queue_dma_addr); } } - if (!vq->packed_ring) + if (!vq->packed_ring) { kfree(vq->split.desc_state); + kfree(vq->split.desc_extra); + } list_del(&_vq->list); kfree(vq); } -- 2.25.1