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From: patrick.fu@intel.com
To: dev@dpdk.org, maxime.coquelin@redhat.com, chenbo.xia@intel.com
Cc: Patrick Fu <patrick.fu@intel.com>
Subject: [dpdk-dev] [PATCH v4] vhost: fix async copy fail on multi-page buffers
Date: Tue, 28 Jul 2020 11:28:51 +0800
Message-ID: <20200728032851.3704083-1-patrick.fu@intel.com> (raw)
In-Reply-To: <20200720025242.3066787-1-patrick.fu@intel.com>

From: Patrick Fu <patrick.fu@intel.com>

Async copy fails when single ring buffer vector is splited on multiple
physical pages. This happens because current hpa address translation
function doesn't handle multi-page buffers. A new gpa to hpa address
conversion function, which returns the hpa on the first hitting host
pages, is implemented in this patch. Async data path recursively calls
this new function to construct a multi-segments async copy descriptor
for ring buffers crossing physical page boundaries.

Fixes: cd6760da1076 ("vhost: introduce async enqueue for split ring")

Signed-off-by: Patrick Fu <patrick.fu@intel.com>
---
v2:
 - change commit message and title
 - v1 patch used CPU to copy multi-page buffers; v2 patch split the
copy into multiple async copy segments whenever possible

v3:
 - added fixline

v4:
 - fix miss translation of the gpa which is the same length with host
   page size

 lib/librte_vhost/vhost.h      | 50 +++++++++++++++++++++++++++++++++++
 lib/librte_vhost/virtio_net.c | 40 +++++++++++++++++-----------
 2 files changed, 75 insertions(+), 15 deletions(-)

diff --git a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h
index 0f7212f88..05c202a57 100644
--- a/lib/librte_vhost/vhost.h
+++ b/lib/librte_vhost/vhost.h
@@ -616,6 +616,56 @@ gpa_to_hpa(struct virtio_net *dev, uint64_t gpa, uint64_t size)
 	return 0;
 }
 
+static __rte_always_inline rte_iova_t
+gpa_to_first_hpa(struct virtio_net *dev, uint64_t gpa,
+	uint64_t gpa_size, uint64_t *hpa_size)
+{
+	uint32_t i;
+	struct guest_page *page;
+	struct guest_page key;
+
+	*hpa_size = gpa_size;
+	if (dev->nr_guest_pages >= VHOST_BINARY_SEARCH_THRESH) {
+		key.guest_phys_addr = gpa & ~(dev->guest_pages[0].size - 1);
+		page = bsearch(&key, dev->guest_pages, dev->nr_guest_pages,
+			       sizeof(struct guest_page), guest_page_addrcmp);
+		if (page) {
+			if (gpa + gpa_size <=
+					page->guest_phys_addr + page->size) {
+				return gpa - page->guest_phys_addr +
+					page->host_phys_addr;
+			} else if (gpa < page->guest_phys_addr +
+						page->size) {
+				*hpa_size = page->guest_phys_addr +
+					page->size - gpa;
+				return gpa - page->guest_phys_addr +
+					page->host_phys_addr;
+			}
+		}
+	} else {
+		for (i = 0; i < dev->nr_guest_pages; i++) {
+			page = &dev->guest_pages[i];
+
+			if (gpa >= page->guest_phys_addr) {
+				if (gpa + gpa_size <=
+					page->guest_phys_addr + page->size) {
+					return gpa - page->guest_phys_addr +
+						page->host_phys_addr;
+				} else if (gpa < page->guest_phys_addr +
+							page->size) {
+					*hpa_size = page->guest_phys_addr +
+						page->size - gpa;
+					return gpa - page->guest_phys_addr +
+						page->host_phys_addr;
+				}
+			}
+		}
+	}
+
+	*hpa_size = 0;
+	return 0;
+}
+
 static __rte_always_inline uint64_t
 hva_to_gpa(struct virtio_net *dev, uint64_t vva, uint64_t len)
 {
diff --git a/lib/librte_vhost/virtio_net.c b/lib/librte_vhost/virtio_net.c
index 95a0bc19f..124a33a10 100644
--- a/lib/librte_vhost/virtio_net.c
+++ b/lib/librte_vhost/virtio_net.c
@@ -980,6 +980,7 @@ async_mbuf_to_desc(struct virtio_net *dev, struct vhost_virtqueue *vq,
 	struct batch_copy_elem *batch_copy = vq->batch_copy_elems;
 	struct virtio_net_hdr_mrg_rxbuf tmp_hdr, *hdr = NULL;
 	int error = 0;
+	uint64_t mapped_len;
 
 	uint32_t tlen = 0;
 	int tvec_idx = 0;
@@ -1072,24 +1073,31 @@ async_mbuf_to_desc(struct virtio_net *dev, struct vhost_virtqueue *vq,
 
 		cpy_len = RTE_MIN(buf_avail, mbuf_avail);
 
-		if (unlikely(cpy_len >= cpy_threshold)) {
-			hpa = (void *)(uintptr_t)gpa_to_hpa(dev,
-					buf_iova + buf_offset, cpy_len);
+		while (unlikely(cpy_len && cpy_len >= cpy_threshold)) {
+			hpa = (void *)(uintptr_t)gpa_to_first_hpa(dev,
+					buf_iova + buf_offset,
+					cpy_len, &mapped_len);
 
-			if (unlikely(!hpa)) {
-				error = -1;
-				goto out;
-			}
+			if (unlikely(!hpa || mapped_len < cpy_threshold))
+				break;
 
 			async_fill_vec(src_iovec + tvec_idx,
 				(void *)(uintptr_t)rte_pktmbuf_iova_offset(m,
-						mbuf_offset), cpy_len);
+				mbuf_offset), (size_t)mapped_len);
 
-			async_fill_vec(dst_iovec + tvec_idx, hpa, cpy_len);
+			async_fill_vec(dst_iovec + tvec_idx,
+					hpa, (size_t)mapped_len);
 
-			tlen += cpy_len;
+			tlen += (uint32_t)mapped_len;
+			cpy_len -= (uint32_t)mapped_len;
+			mbuf_avail  -= (uint32_t)mapped_len;
+			mbuf_offset += (uint32_t)mapped_len;
+			buf_avail  -= (uint32_t)mapped_len;
+			buf_offset += (uint32_t)mapped_len;
 			tvec_idx++;
-		} else {
+		}
+
+		if (likely(cpy_len)) {
 			if (unlikely(vq->batch_copy_nb_elems >= vq->size)) {
 				rte_memcpy(
 				(void *)((uintptr_t)(buf_addr + buf_offset)),
@@ -1112,10 +1120,12 @@ async_mbuf_to_desc(struct virtio_net *dev, struct vhost_virtqueue *vq,
 			}
 		}
 
-		mbuf_avail  -= cpy_len;
-		mbuf_offset += cpy_len;
-		buf_avail  -= cpy_len;
-		buf_offset += cpy_len;
+		if (cpy_len) {
+			mbuf_avail  -= cpy_len;
+			mbuf_offset += cpy_len;
+			buf_avail  -= cpy_len;
+			buf_offset += cpy_len;
+		}
 	}
 
 out:
-- 
2.18.4


  parent reply	other threads:[~2020-07-28  3:31 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-20  2:52 [dpdk-dev] [PATCH v1] vhost: support cross page buf in async data path patrick.fu
2020-07-20 16:39 ` Maxime Coquelin
2020-07-21  2:57   ` Fu, Patrick
2020-07-21  8:35     ` Maxime Coquelin
2020-07-21  9:01       ` Fu, Patrick
2020-07-24 13:49 ` [dpdk-dev] [PATCH v2] vhost: fix async copy fail on multi-page buffers patrick.fu
2020-07-27  6:33 ` [dpdk-dev] [PATCH v3] " patrick.fu
2020-07-27 13:14   ` Xia, Chenbo
2020-07-28  3:09     ` Fu, Patrick
2020-07-28  3:28 ` patrick.fu [this message]
2020-07-28 13:55   ` [dpdk-dev] [PATCH v4] " Maxime Coquelin
2020-07-29  1:40     ` Fu, Patrick
2020-07-29  2:05       ` Fu, Patrick
2020-07-29  2:04 ` [dpdk-dev] [PATCH v5] " Patrick Fu
2020-07-29 14:24   ` Maxime Coquelin
2020-07-29 14:55   ` Maxime Coquelin

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