The branch main has been updated by andrew: URL: https://cgit.FreeBSD.org/src/commit/?id=dc00f118405e8638ceb13b288e14164a8a9ba669
commit dc00f118405e8638ceb13b288e14164a8a9ba669 Author: Andrew Turner <[email protected]> AuthorDate: 2026-05-05 09:17:51 +0000 Commit: Andrew Turner <[email protected]> CommitDate: 2026-05-05 09:18:14 +0000 Revert "virtio_net: Use bus_dma for rxq/txq buffers" This reverts commit c16c95192f01237a876eb7bc336e3bbda9310171. Revert until we can fix reported issues --- sys/dev/virtio/network/if_vtnet.c | 275 +++-------------------------------- sys/dev/virtio/network/if_vtnetvar.h | 10 -- 2 files changed, 17 insertions(+), 268 deletions(-) diff --git a/sys/dev/virtio/network/if_vtnet.c b/sys/dev/virtio/network/if_vtnet.c index e88602a44664..ef01833b9e03 100644 --- a/sys/dev/virtio/network/if_vtnet.c +++ b/sys/dev/virtio/network/if_vtnet.c @@ -96,17 +96,6 @@ #define VTNET_ETHER_ALIGN ETHER_ALIGN #endif -/* - * Worst case offset to ensure header doesn't share any cache lines with - * payload. - */ -#define VTNET_RX_BUFFER_HEADER_OFFSET 128 - -struct vtnet_rx_buffer_header { - bus_addr_t addr; - bus_dmamap_t dmap; -}; - static int vtnet_modevent(module_t, int, void *); static int vtnet_probe(device_t); @@ -395,17 +384,6 @@ MODULE_DEPEND(vtnet, netmap, 1, 1, 1); VIRTIO_SIMPLE_PNPINFO(vtnet, VIRTIO_ID_NETWORK, "VirtIO Networking Adapter"); -static struct vtnet_rx_buffer_header * -vtnet_mbuf_to_rx_buffer_header(struct vtnet_softc *sc, struct mbuf *m) -{ - if (VTNET_ETHER_ALIGN != 0 && sc->vtnet_hdr_size % 4 == 0) - return (struct vtnet_rx_buffer_header *)((uintptr_t)m->m_data - - VTNET_RX_BUFFER_HEADER_OFFSET - VTNET_ETHER_ALIGN); - else - return (struct vtnet_rx_buffer_header *)((uintptr_t)m->m_data - - VTNET_RX_BUFFER_HEADER_OFFSET); -} - static int vtnet_modevent(module_t mod __unused, int type, void *unused __unused) { @@ -479,60 +457,6 @@ vtnet_attach(device_t dev) goto fail; } - mtx_init(&sc->vtnet_rx_mtx, device_get_nameunit(dev), - "VirtIO Net RX lock", MTX_DEF); - - error = bus_dma_tag_create( - bus_get_dma_tag(dev), /* parent */ - sizeof(uint16_t), /* alignment */ - 0, /* boundary */ - BUS_SPACE_MAXADDR, /* lowaddr */ - BUS_SPACE_MAXADDR, /* highaddr */ - NULL, NULL, /* filter, filterarg */ - MJUM9BYTES, /* max request size */ - 1, /* max # segments */ - MJUM9BYTES, /* maxsegsize - worst case */ - BUS_DMA_COHERENT, /* flags */ - busdma_lock_mutex, /* lockfunc */ - &sc->vtnet_rx_mtx, /* lockarg */ - &sc->vtnet_rx_dmat); - if (error) { - device_printf(dev, "cannot create bus_dma_tag\n"); - goto fail; - } - - mtx_init(&sc->vtnet_tx_mtx, device_get_nameunit(dev), - "VirtIO Net TX lock", MTX_DEF); - - error = bus_dma_tag_create( - bus_get_dma_tag(dev), /* parent */ - sizeof(uint16_t), /* alignment */ - 0, /* boundary */ - BUS_SPACE_MAXADDR, /* lowaddr */ - BUS_SPACE_MAXADDR, /* highaddr */ - NULL, NULL, /* filter, filterarg */ - sc->vtnet_tx_nsegs * MJUM9BYTES, /* max request size */ - sc->vtnet_tx_nsegs, /* max # segments */ - MJUM9BYTES, /* maxsegsize */ - BUS_DMA_COHERENT, /* flags */ - busdma_lock_mutex, /* lockfunc */ - &sc->vtnet_tx_mtx, /* lockarg */ - &sc->vtnet_tx_dmat); - if (error) { - device_printf(dev, "cannot create bus_dma_tag\n"); - goto fail; - } - -#ifdef __powerpc__ - /* - * Virtio uses physical addresses rather than bus addresses, so we - * need to ask busdma to skip the iommu physical->bus mapping. At - * present, this is only a thing on the powerpc architectures. - */ - bus_dma_tag_set_iommu(sc->vtnet_rx_dmat, NULL, NULL); - bus_dma_tag_set_iommu(sc->vtnet_tx_dmat, NULL, NULL); -#endif - error = vtnet_alloc_rx_filters(sc); if (error) { device_printf(dev, "cannot allocate Rx filters\n"); @@ -1621,11 +1545,6 @@ static struct mbuf * vtnet_rx_alloc_buf(struct vtnet_softc *sc, int nbufs, struct mbuf **m_tailp) { struct mbuf *m_head, *m_tail, *m; - struct vtnet_rx_buffer_header *vthdr; - bus_dma_segment_t segs[1]; - bus_dmamap_t dmap; - int nsegs; - int err; int i, size; m_head = NULL; @@ -1643,43 +1562,13 @@ vtnet_rx_alloc_buf(struct vtnet_softc *sc, int nbufs, struct mbuf **m_tailp) } m->m_len = size; - vthdr = (struct vtnet_rx_buffer_header *)m->m_data; - - /* Reserve space for header */ - m_adj(m, VTNET_RX_BUFFER_HEADER_OFFSET); - /* * Need to offset the mbuf if the header we're going to add * will misalign. */ - if (VTNET_ETHER_ALIGN != 0 && sc->vtnet_hdr_size % 4 == 0) + if (VTNET_ETHER_ALIGN != 0 && sc->vtnet_hdr_size % 4 == 0) { m_adj(m, VTNET_ETHER_ALIGN); - - err = bus_dmamap_create(sc->vtnet_rx_dmat, 0, &dmap); - if (err) { - printf("Failed to create dmamap, err :%d\n", - err); - m_freem(m); - return (NULL); } - - nsegs = 0; - err = bus_dmamap_load_mbuf_sg(sc->vtnet_rx_dmat, dmap, m, segs, - &nsegs, BUS_DMA_NOWAIT); - if (err != 0) { - printf("Failed to map mbuf into DMA visible memory, err: %d\n", - err); - m_freem(m); - bus_dmamap_destroy(sc->vtnet_rx_dmat, dmap); - return (NULL); - } - KASSERT(nsegs == 1, - ("%s: unexpected number of DMA segments for rx buffer: %d", - __func__, nsegs)); - - vthdr->addr = segs[0].ds_addr; - vthdr->dmap = dmap; - if (m_head != NULL) { m_tail->m_next = m; m_tail = m; @@ -1705,7 +1594,7 @@ vtnet_rxq_replace_lro_nomrg_buf(struct vtnet_rxq *rxq, struct mbuf *m0, int len, clustersz, nreplace, error; sc = rxq->vtnrx_sc; - clustersz = sc->vtnet_rx_clustersz - VTNET_RX_BUFFER_HEADER_OFFSET; + clustersz = sc->vtnet_rx_clustersz; /* * Need to offset the mbuf if the header we're going to add will * misalign, account for that here. @@ -1820,12 +1709,9 @@ vtnet_rxq_replace_buf(struct vtnet_rxq *rxq, struct mbuf *m, int len) static int vtnet_rxq_enqueue_buf(struct vtnet_rxq *rxq, struct mbuf *m) { - struct vtnet_rx_buffer_header *hdr; struct vtnet_softc *sc; struct sglist *sg; int header_inlined, error; - bus_addr_t paddr; - struct mbuf *mp; sc = rxq->vtnrx_sc; sg = rxq->vtnrx_sg; @@ -1838,38 +1724,28 @@ vtnet_rxq_enqueue_buf(struct vtnet_rxq *rxq, struct mbuf *m) header_inlined = vtnet_modern(sc) || (sc->vtnet_flags & VTNET_FLAG_MRG_RXBUFS) != 0; /* TODO: ANY_LAYOUT */ - hdr = vtnet_mbuf_to_rx_buffer_header(sc, m); - paddr = hdr->addr; - /* * Note: The mbuf has been already adjusted when we allocate it if we * have to do strict alignment. */ - if (header_inlined) { - error = sglist_append_phys(sg, paddr, m->m_len); - } else { + if (header_inlined) + error = sglist_append_mbuf(sg, m); + else { + struct vtnet_rx_header *rxhdr = + mtod(m, struct vtnet_rx_header *); MPASS(sc->vtnet_hdr_size == sizeof(struct virtio_net_hdr)); /* Append the header and remaining mbuf data. */ - error = sglist_append_phys(sg, paddr, sc->vtnet_hdr_size); + error = sglist_append(sg, &rxhdr->vrh_hdr, sc->vtnet_hdr_size); if (error) return (error); - error = sglist_append_phys(sg, - paddr + sizeof(struct vtnet_rx_header), + error = sglist_append(sg, &rxhdr[1], m->m_len - sizeof(struct vtnet_rx_header)); if (error) return (error); - mp = m->m_next; - while (mp) { - hdr = vtnet_mbuf_to_rx_buffer_header(sc, mp); - paddr = hdr->addr; - error = sglist_append_phys(sg, paddr, mp->m_len); - if (error) - return (error); - - mp = mp->m_next; - } + if (m->m_next != NULL) + error = sglist_append_mbuf(sg, m->m_next); } if (error) @@ -2055,7 +1931,6 @@ vtnet_rxq_merged_eof(struct vtnet_rxq *rxq, struct mbuf *m_head, int nbufs) m_tail = m_head; while (--nbufs > 0) { - struct vtnet_rx_buffer_header *vthdr; struct mbuf *m; uint32_t len; @@ -2065,10 +1940,6 @@ vtnet_rxq_merged_eof(struct vtnet_rxq *rxq, struct mbuf *m_head, int nbufs) goto fail; } - vthdr = vtnet_mbuf_to_rx_buffer_header(sc, m); - bus_dmamap_sync(sc->vtnet_rx_dmat, vthdr->dmap, - BUS_DMASYNC_POSTREAD); - if (vtnet_rxq_new_buf(rxq) != 0) { rxq->vtnrx_stats.vrxs_iqdrops++; vtnet_rxq_discard_buf(rxq, m); @@ -2189,7 +2060,6 @@ static int vtnet_rxq_eof(struct vtnet_rxq *rxq) { struct virtio_net_hdr lhdr, *hdr; - struct vtnet_rx_buffer_header *vthdr; struct vtnet_softc *sc; if_t ifp; struct virtqueue *vq; @@ -2205,31 +2075,14 @@ vtnet_rxq_eof(struct vtnet_rxq *rxq) CURVNET_SET(if_getvnet(ifp)); while (count-- > 0) { - struct mbuf *m, *mp; + struct mbuf *m; uint32_t len, nbufs, adjsz; - uint32_t synced; m = virtqueue_dequeue(vq, &len); if (m == NULL) break; deq++; - mp = m; - - /* - * Sync all mbufs in this packet. There will only be a single - * mbuf unless LRO is in use. - */ - synced = 0; - while (mp && synced < len) { - vthdr = vtnet_mbuf_to_rx_buffer_header(sc, mp); - bus_dmamap_sync(sc->vtnet_rx_dmat, vthdr->dmap, - BUS_DMASYNC_POSTREAD); - - synced += mp->m_len; - mp = mp->m_next; - } - if (len < sc->vtnet_hdr_size + ETHER_HDR_LEN) { rxq->vtnrx_stats.vrxs_ierrors++; vtnet_rxq_discard_buf(rxq, m); @@ -2489,14 +2342,6 @@ vtnet_txq_free_mbufs(struct vtnet_txq *txq) while ((txhdr = virtqueue_drain(vq, &last)) != NULL) { if (kring == NULL) { - bus_dmamap_unload(txq->vtntx_sc->vtnet_tx_dmat, - txhdr->dmap); - bus_dmamap_destroy(txq->vtntx_sc->vtnet_tx_dmat, - txhdr->dmap); - bus_dmamap_unload(txq->vtntx_sc->vtnet_tx_dmat, - txhdr->hdr_dmap); - bus_dmamap_destroy(txq->vtntx_sc->vtnet_tx_dmat, - txhdr->hdr_dmap); m_freem(txhdr->vth_mbuf); uma_zfree(vtnet_tx_header_zone, txhdr); } @@ -2666,36 +2511,15 @@ drop: return (NULL); } -static void -vtnet_txq_enqueue_callback(void *arg, bus_dma_segment_t *segs, - int nsegs, int error) -{ - vm_paddr_t *hdr_paddr; - - if (error != 0) - return; - - KASSERT(nsegs == 1, ("%s: %d segments returned!", __func__, nsegs)); - - hdr_paddr = (vm_paddr_t *)arg; - *hdr_paddr = segs[0].ds_addr; -} - static int vtnet_txq_enqueue_buf(struct vtnet_txq *txq, struct mbuf **m_head, struct vtnet_tx_header *txhdr) { - bus_dma_segment_t segs[VTNET_TX_SEGS_MAX]; - int nsegs; struct vtnet_softc *sc; struct virtqueue *vq; struct sglist *sg; struct mbuf *m; int error; - vm_paddr_t hdr_paddr; - bus_dmamap_t hdr_dmap; - bus_dmamap_t dmap; - int i; sc = txq->vtntx_sc; vq = txq->vtntx_vq; @@ -2703,55 +2527,15 @@ vtnet_txq_enqueue_buf(struct vtnet_txq *txq, struct mbuf **m_head, m = *m_head; sglist_reset(sg); - - error = bus_dmamap_create(sc->vtnet_tx_dmat, 0, &hdr_dmap); - if (error) - goto fail; - - error = bus_dmamap_load(sc->vtnet_tx_dmat, hdr_dmap, &txhdr->vth_uhdr, - sc->vtnet_hdr_size, vtnet_txq_enqueue_callback, &hdr_paddr, - BUS_DMA_NOWAIT); - if (error) - goto fail_hdr_dmamap_destroy; - - error = sglist_append_phys(sg, hdr_paddr, sc->vtnet_hdr_size); + error = sglist_append(sg, &txhdr->vth_uhdr, sc->vtnet_hdr_size); if (error != 0 || sg->sg_nseg != 1) { KASSERT(0, ("%s: cannot add header to sglist error %d nseg %d", __func__, error, sg->sg_nseg)); - goto fail_hdr_dmamap_unload; + goto fail; } - bus_dmamap_sync(sc->vtnet_tx_dmat, hdr_dmap, BUS_DMASYNC_PREWRITE); - - error = bus_dmamap_create(sc->vtnet_tx_dmat, 0, &dmap); - if (error) - goto fail_hdr_dmamap_unload; - - nsegs = 0; - error = bus_dmamap_load_mbuf_sg(sc->vtnet_tx_dmat, dmap, m, segs, - &nsegs, BUS_DMA_NOWAIT); - if (error != 0) - goto fail_dmamap_destroy; - KASSERT(nsegs <= sc->vtnet_tx_nsegs, - ("%s: unexpected number of DMA segments for tx buffer: %d (max %d)", - __func__, nsegs, sc->vtnet_tx_nsegs)); - - bus_dmamap_sync(sc->vtnet_tx_dmat, dmap, BUS_DMASYNC_PREWRITE); - - for (i = 0; i < nsegs && !error; i++) - error = sglist_append_phys(sg, segs[i].ds_addr, segs[i].ds_len); - + error = sglist_append_mbuf(sg, m); if (error) { - sglist_reset(sg); - bus_dmamap_unload(sc->vtnet_tx_dmat, dmap); - - error = sglist_append_phys(sg, hdr_paddr, sc->vtnet_hdr_size); - if (error != 0 || sg->sg_nseg != 1) { - KASSERT(0, ("%s: cannot add header to sglist error %d nseg %d", - __func__, error, sg->sg_nseg)); - goto fail_dmamap_destroy; - } - m = m_defrag(m, M_NOWAIT); if (m == NULL) { sc->vtnet_stats.tx_defrag_failed++; @@ -2761,41 +2545,16 @@ vtnet_txq_enqueue_buf(struct vtnet_txq *txq, struct mbuf **m_head, *m_head = m; sc->vtnet_stats.tx_defragged++; - nsegs = 0; - error = bus_dmamap_load_mbuf_sg(sc->vtnet_tx_dmat, dmap, m, - segs, &nsegs, BUS_DMA_NOWAIT); - if (error != 0) - goto fail_dmamap_destroy; - KASSERT(nsegs <= sc->vtnet_tx_nsegs, - ("%s: unexpected number of DMA segments for tx buffer: %d (max %d)", - __func__, nsegs, sc->vtnet_tx_nsegs)); - - bus_dmamap_sync(sc->vtnet_tx_dmat, dmap, BUS_DMASYNC_PREWRITE); - - for (i = 0; i < nsegs && !error; i++) - error = sglist_append_phys(sg, segs[i].ds_addr, - segs[i].ds_len); - + error = sglist_append_mbuf(sg, m); if (error) - goto fail_dmamap_unload; + goto fail; } txhdr->vth_mbuf = m; - txhdr->dmap = dmap; - txhdr->hdr_dmap = hdr_dmap; - error = virtqueue_enqueue(vq, txhdr, sg, sg->sg_nseg, 0); return (error); -fail_dmamap_unload: - bus_dmamap_unload(sc->vtnet_tx_dmat, dmap); -fail_dmamap_destroy: - bus_dmamap_destroy(sc->vtnet_tx_dmat, dmap); -fail_hdr_dmamap_unload: - bus_dmamap_unload(sc->vtnet_tx_dmat, hdr_dmap); -fail_hdr_dmamap_destroy: - bus_dmamap_destroy(sc->vtnet_tx_dmat, hdr_dmap); fail: m_freem(*m_head); *m_head = NULL; diff --git a/sys/dev/virtio/network/if_vtnetvar.h b/sys/dev/virtio/network/if_vtnetvar.h index 6cafe827d733..eb5e6784b07f 100644 --- a/sys/dev/virtio/network/if_vtnetvar.h +++ b/sys/dev/virtio/network/if_vtnetvar.h @@ -190,12 +190,6 @@ struct vtnet_softc { struct mtx vtnet_mtx; char vtnet_mtx_name[16]; uint8_t vtnet_hwaddr[ETHER_ADDR_LEN]; - - bus_dma_tag_t vtnet_rx_dmat; - struct mtx vtnet_rx_mtx; - - bus_dma_tag_t vtnet_tx_dmat; - struct mtx vtnet_tx_mtx; }; /* vtnet flag descriptions for use with printf(9) %b identifier. */ #define VTNET_FLAGS_BITS \ @@ -279,10 +273,6 @@ struct vtnet_tx_header { } vth_uhdr; struct mbuf *vth_mbuf; - - bus_dmamap_t dmap; - - bus_dmamap_t hdr_dmap; }; /*
