diff options
Diffstat (limited to 'usr/src/cmd/bhyve/virtio.c')
| -rw-r--r-- | usr/src/cmd/bhyve/virtio.c | 68 |
1 files changed, 54 insertions, 14 deletions
diff --git a/usr/src/cmd/bhyve/virtio.c b/usr/src/cmd/bhyve/virtio.c index c3b11dc439..47a3ed29ba 100644 --- a/usr/src/cmd/bhyve/virtio.c +++ b/usr/src/cmd/bhyve/virtio.c @@ -1,6 +1,9 @@ /*- + * SPDX-License-Identifier: BSD-2-Clause-FreeBSD + * * Copyright (c) 2013 Chris Torek <torek @ torek net> * All rights reserved. + * Copyright (c) 2019 Joyent, Inc. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions @@ -25,11 +28,13 @@ */ #include <sys/cdefs.h> -__FBSDID("$FreeBSD: head/usr.sbin/bhyve/virtio.c 270326 2014-08-22 13:01:22Z tychon $"); +__FBSDID("$FreeBSD$"); #include <sys/param.h> #include <sys/uio.h> +#include <machine/atomic.h> + #include <stdio.h> #include <stdint.h> #include <pthread.h> @@ -49,7 +54,7 @@ __FBSDID("$FreeBSD: head/usr.sbin/bhyve/virtio.c 270326 2014-08-22 13:01:22Z tyc * front of virtio-based device softc" constraint, let's use * this to convert. */ -#define DEV_SOFTC(vs) ((void *)(vs)) +#define DEV_SOFTC(vs) ((void *)(vs)) /* * Link a virtio_softc to its constants, the device softc, and @@ -97,6 +102,7 @@ vi_reset_dev(struct virtio_softc *vs) for (vq = vs->vs_queues, i = 0; i < nvq; vq++, i++) { vq->vq_flags = 0; vq->vq_last_avail = 0; + vq->vq_save_used = 0; vq->vq_pfn = 0; vq->vq_msix_idx = VIRTIO_MSI_NO_VECTOR; } @@ -147,8 +153,13 @@ vi_intr_init(struct virtio_softc *vs, int barnum, int use_msix) return (1); } else vs->vs_flags &= ~VIRTIO_USE_MSIX; + /* Only 1 MSI vector for bhyve */ pci_emul_add_msicap(vs->vs_pi, 1); + + /* Legacy interrupts are mandatory for virtio devices */ + pci_lintr_request(vs->vs_pi); + return (0); } @@ -188,6 +199,7 @@ vi_vq_init(struct virtio_softc *vs, uint32_t pfn) /* Mark queue as allocated, and start at 0 when we use it. */ vq->vq_flags = VQ_ALLOC; vq->vq_last_avail = 0; + vq->vq_save_used = 0; } /* @@ -247,12 +259,12 @@ _vq_record(int i, volatile struct virtio_desc *vd, struct vmctx *ctx, * that vq_has_descs() does one). */ int -vq_getchain(struct vqueue_info *vq, +vq_getchain(struct vqueue_info *vq, uint16_t *pidx, struct iovec *iov, int n_iov, uint16_t *flags) { int i; u_int ndesc, n_indir; - u_int idx, head, next; + u_int idx, next; volatile struct virtio_desc *vdir, *vindir, *vp; struct vmctx *ctx; struct virtio_softc *vs; @@ -295,8 +307,8 @@ vq_getchain(struct vqueue_info *vq, * index, but we just abort if the count gets excessive. */ ctx = vs->vs_pi->pi_vmctx; - head = vq->vq_avail->va_ring[idx & (vq->vq_qsize - 1)]; - next = head; + *pidx = next = vq->vq_avail->va_ring[idx & (vq->vq_qsize - 1)]; + vq->vq_last_avail++; for (i = 0; i < VQ_MAX_DESCRIPTORS; next = vdir->vd_next) { if (next >= vq->vq_qsize) { fprintf(stderr, @@ -309,7 +321,7 @@ vq_getchain(struct vqueue_info *vq, if ((vdir->vd_flags & VRING_DESC_F_INDIRECT) == 0) { _vq_record(i, vdir, ctx, iov, n_iov, flags); i++; - } else if ((vs->vs_negotiated_caps & + } else if ((vs->vs_vc->vc_hv_caps & VIRTIO_RING_F_INDIRECT_DESC) == 0) { fprintf(stderr, "%s: descriptor has forbidden INDIRECT flag, " @@ -370,16 +382,29 @@ loopy: } /* - * Return the currently-first request chain to the guest, setting - * its I/O length to the provided value. + * Return the currently-first request chain back to the available queue. * * (This chain is the one you handled when you called vq_getchain() * and used its positive return value.) */ void -vq_relchain(struct vqueue_info *vq, uint32_t iolen) +vq_retchain(struct vqueue_info *vq) { - uint16_t head, uidx, mask; + + vq->vq_last_avail--; +} + +/* + * Return specified request chain to the guest, setting its I/O length + * to the provided value. + * + * (This chain is the one you handled when you called vq_getchain() + * and used its positive return value.) + */ +void +vq_relchain(struct vqueue_info *vq, uint16_t idx, uint32_t iolen) +{ + uint16_t uidx, mask; volatile struct vring_used *vuh; volatile struct virtio_used *vue; @@ -395,12 +420,17 @@ vq_relchain(struct vqueue_info *vq, uint32_t iolen) */ mask = vq->vq_qsize - 1; vuh = vq->vq_used; - head = vq->vq_avail->va_ring[vq->vq_last_avail++ & mask]; uidx = vuh->vu_idx; vue = &vuh->vu_ring[uidx++ & mask]; - vue->vu_idx = head; /* ie, vue->id = head */ + vue->vu_idx = idx; vue->vu_tlen = iolen; + + /* + * Ensure the used descriptor is visible before updating the index. + * This is necessary on ISAs with memory ordering less strict than x86. + */ + atomic_thread_fence_rel(); vuh->vu_idx = uidx; } @@ -436,8 +466,15 @@ vq_endchains(struct vqueue_info *vq, int used_all_avail) * entire avail was processed, we need to interrupt always. */ vs = vq->vq_vs; - new_idx = vq->vq_used->vu_idx; old_idx = vq->vq_save_used; + vq->vq_save_used = new_idx = vq->vq_used->vu_idx; + + /* + * Use full memory barrier between vu_idx store from preceding + * vq_relchain() call and the loads from VQ_USED_EVENT_IDX() or + * va_flags below. + */ + atomic_thread_fence_seq_cst(); if (used_all_avail && (vs->vs_negotiated_caps & VIRTIO_F_NOTIFY_ON_EMPTY)) intr = 1; @@ -698,6 +735,9 @@ bad: switch (offset) { case VTCFG_R_GUESTCAP: vs->vs_negotiated_caps = value & vc->vc_hv_caps; + if (vc->vc_apply_features) + (*vc->vc_apply_features)(DEV_SOFTC(vs), + vs->vs_negotiated_caps); break; case VTCFG_R_PFN: if (vs->vs_curq >= vc->vc_nvq) |