Date: Mon, 11 Jan 2021 21:42:25 GMT From: Vincenzo Maffione <vmaffione@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: 3005e10ddbfb - main - netmap: vtnet: fix RX initialization after netmap_reset() Message-ID: <202101112142.10BLgP1e002745@gitrepo.freebsd.org>
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The branch main has been updated by vmaffione: URL: https://cgit.FreeBSD.org/src/commit/?id=3005e10ddbfbec3ecf46a080607bb0d85986eee5 commit 3005e10ddbfbec3ecf46a080607bb0d85986eee5 Author: Vincenzo Maffione <vmaffione@FreeBSD.org> AuthorDate: 2021-01-11 21:38:32 +0000 Commit: Vincenzo Maffione <vmaffione@FreeBSD.org> CommitDate: 2021-01-11 21:38:32 +0000 netmap: vtnet: fix RX initialization after netmap_reset() At device reset, we must not publish those netmap receive buffers that are owned by userspace (nm_kr_rxspace). MFC after: 1 week --- sys/dev/netmap/if_vtnet_netmap.h | 19 ++++++++++++------- 1 file changed, 12 insertions(+), 7 deletions(-) diff --git a/sys/dev/netmap/if_vtnet_netmap.h b/sys/dev/netmap/if_vtnet_netmap.h index f787bf573a28..cd652938bca5 100644 --- a/sys/dev/netmap/if_vtnet_netmap.h +++ b/sys/dev/netmap/if_vtnet_netmap.h @@ -213,20 +213,25 @@ vtnet_netmap_rxq_populate(struct vtnet_rxq *rxq) struct netmap_kring *kring; struct netmap_slot *slot; int error; + int num; slot = netmap_reset(na, NR_RX, rxq->vtnrx_id, 0); if (slot == NULL) return -1; kring = na->rx_rings[rxq->vtnrx_id]; - /* Expose all the RX netmap buffers we can. In case of no indirect + /* + * Expose all the RX netmap buffers we can. In case of no indirect * buffers, the number of netmap slots in the RX ring matches the * maximum number of 2-elements sglist that the RX virtqueue can - * accommodate. We need to start from kring->nr_hwcur, which is 0 - * on netmap register and may be different from 0 if a virtio - * re-init happens while the device is in use by netmap. */ - rxq->vtnrx_nm_refill = kring->nr_hwcur; - error = vtnet_netmap_kring_refill(kring, na->num_rx_desc - 1); + * accommodate. We need to start from kring->nr_hwtail, which is 0 + * on the first netmap register and may be different from 0 if a + * virtio re-init (caused by a netma register or i.e., ifconfig) + * happens while the device is in use by netmap. + */ + rxq->vtnrx_nm_refill = kring->nr_hwtail; + num = na->num_rx_desc - 1 - nm_kr_rxspace(kring); + error = vtnet_netmap_kring_refill(kring, num); virtqueue_notify(rxq->vtnrx_vq); return error; @@ -256,7 +261,7 @@ vtnet_netmap_rxsync(struct netmap_kring *kring, int flags) * First part: import newly received packets. * Only accept our own buffers (matching the token). We should only get * matching buffers. The hwtail should never overrun hwcur, because - * we publish only N-1 receive buffers (and non N). + * we publish only N-1 receive buffers (and not N). * In any case we must not leave this routine with the interrupts * disabled, pending packets in the VQ and hwtail == (hwcur - 1), * otherwise the pending packets could stall.
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