diff --git a/usr.sbin/bhyve/pci_virtio_console.c b/usr.sbin/bhyve/pci_virtio_console.c index ba509e054e64..556f08b6c331 100644 --- a/usr.sbin/bhyve/pci_virtio_console.c +++ b/usr.sbin/bhyve/pci_virtio_console.c @@ -607,7 +607,7 @@ pci_vtcon_notify_rx(void *vsc, struct vqueue_info *vq) if (!port->vsp_rx_ready) { port->vsp_rx_ready = 1; - vq->vq_used->vu_flags |= VRING_USED_F_NO_NOTIFY; + vq_kick_disable(vq); } } diff --git a/usr.sbin/bhyve/pci_virtio_net.c b/usr.sbin/bhyve/pci_virtio_net.c index b94511e736de..f89819ef04b0 100644 --- a/usr.sbin/bhyve/pci_virtio_net.c +++ b/usr.sbin/bhyve/pci_virtio_net.c @@ -39,7 +39,6 @@ __FBSDID("$FreeBSD$"); #include #include #include -#include #include #ifndef NETMAP_WITH_LIBS #define NETMAP_WITH_LIBS @@ -585,7 +584,7 @@ pci_vtnet_ping_rxq(void *vsc, struct vqueue_info *vq) */ if (sc->vsc_rx_ready == 0) { sc->vsc_rx_ready = 1; - vq->vq_used->vu_flags |= VRING_USED_F_NO_NOTIFY; + vq_kick_disable(vq); } } @@ -631,7 +630,7 @@ pci_vtnet_ping_txq(void *vsc, struct vqueue_info *vq) /* Signal the tx thread for processing */ pthread_mutex_lock(&sc->tx_mtx); - vq->vq_used->vu_flags |= VRING_USED_F_NO_NOTIFY; + vq_kick_disable(vq); if (sc->tx_in_progress == 0) pthread_cond_signal(&sc->tx_cond); pthread_mutex_unlock(&sc->tx_mtx); @@ -660,8 +659,7 @@ pci_vtnet_tx_thread(void *param) for (;;) { /* note - tx mutex is locked here */ while (sc->resetting || !vq_has_descs(vq)) { - vq->vq_used->vu_flags &= ~VRING_USED_F_NO_NOTIFY; - mb(); + vq_kick_enable(vq); if (!sc->resetting && vq_has_descs(vq)) break; @@ -669,7 +667,7 @@ pci_vtnet_tx_thread(void *param) error = pthread_cond_wait(&sc->tx_cond, &sc->tx_mtx); assert(error == 0); } - vq->vq_used->vu_flags |= VRING_USED_F_NO_NOTIFY; + vq_kick_disable(vq); sc->tx_in_progress = 1; pthread_mutex_unlock(&sc->tx_mtx); diff --git a/usr.sbin/bhyve/pci_virtio_scsi.c b/usr.sbin/bhyve/pci_virtio_scsi.c index 38e7d918a096..283dd83b6e08 100644 --- a/usr.sbin/bhyve/pci_virtio_scsi.c +++ b/usr.sbin/bhyve/pci_virtio_scsi.c @@ -581,7 +581,7 @@ static void pci_vtscsi_eventq_notify(void *vsc, struct vqueue_info *vq) { - vq->vq_used->vu_flags |= VRING_USED_F_NO_NOTIFY; + vq_kick_disable(vq); } static void diff --git a/usr.sbin/bhyve/virtio.c b/usr.sbin/bhyve/virtio.c index 47a3ed29bac0..2d78b016c6c3 100644 --- a/usr.sbin/bhyve/virtio.c +++ b/usr.sbin/bhyve/virtio.c @@ -428,7 +428,8 @@ vq_relchain(struct vqueue_info *vq, uint16_t idx, uint32_t iolen) /* * Ensure the used descriptor is visible before updating the index. - * This is necessary on ISAs with memory ordering less strict than x86. + * This is necessary on ISAs with memory ordering less strict than x86 + * (and even on x86 to act as a compiler barrier). */ atomic_thread_fence_rel(); vuh->vu_idx = uidx; diff --git a/usr.sbin/bhyve/virtio.h b/usr.sbin/bhyve/virtio.h index 1f5ef2e18b79..e0623f872453 100644 --- a/usr.sbin/bhyve/virtio.h +++ b/usr.sbin/bhyve/virtio.h @@ -31,6 +31,8 @@ #ifndef _VIRTIO_H_ #define _VIRTIO_H_ +#include + /* * These are derived from several virtio specifications. * @@ -447,6 +449,26 @@ vq_interrupt(struct virtio_softc *vs, struct vqueue_info *vq) } } +static inline void +vq_kick_enable(struct vqueue_info *vq) +{ + + vq->vq_used->vu_flags &= ~VRING_USED_F_NO_NOTIFY; + /* + * Full memory barrier to make sure the store to vu_flags + * happens before the load from va_idx, which results from + * a subsequent call to vq_has_descs(). + */ + atomic_thread_fence_seq_cst(); +} + +static inline void +vq_kick_disable(struct vqueue_info *vq) +{ + + vq->vq_used->vu_flags |= VRING_USED_F_NO_NOTIFY; +} + struct iovec; void vi_softc_linkup(struct virtio_softc *vs, struct virtio_consts *vc, void *dev_softc, struct pci_devinst *pi,