From owner-svn-src-all@freebsd.org Tue Jun 11 15:52:43 2019 Return-Path: Delivered-To: svn-src-all@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 2003215BF46B; Tue, 11 Jun 2019 15:52:43 +0000 (UTC) (envelope-from vmaffione@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) server-signature RSA-PSS (4096 bits) client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id BA5456B889; Tue, 11 Jun 2019 15:52:42 +0000 (UTC) (envelope-from vmaffione@FreeBSD.org) Received: from repo.freebsd.org (repo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 9519B3E46; Tue, 11 Jun 2019 15:52:42 +0000 (UTC) (envelope-from vmaffione@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id x5BFqgMZ062536; Tue, 11 Jun 2019 15:52:42 GMT (envelope-from vmaffione@FreeBSD.org) Received: (from vmaffione@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id x5BFqf3l062530; Tue, 11 Jun 2019 15:52:41 GMT (envelope-from vmaffione@FreeBSD.org) Message-Id: <201906111552.x5BFqf3l062530@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: vmaffione set sender to vmaffione@FreeBSD.org using -f From: Vincenzo Maffione Date: Tue, 11 Jun 2019 15:52:41 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r348929 - head/usr.sbin/bhyve X-SVN-Group: head X-SVN-Commit-Author: vmaffione X-SVN-Commit-Paths: head/usr.sbin/bhyve X-SVN-Commit-Revision: 348929 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: BA5456B889 X-Spamd-Bar: -- Authentication-Results: mx1.freebsd.org X-Spamd-Result: default: False [-2.98 / 15.00]; local_wl_from(0.00)[FreeBSD.org]; NEURAL_HAM_MEDIUM(-1.00)[-0.999,0]; NEURAL_HAM_LONG(-1.00)[-1.000,0]; NEURAL_HAM_SHORT(-0.98)[-0.978,0]; ASN(0.00)[asn:11403, ipnet:2610:1c1:1::/48, country:US] X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 11 Jun 2019 15:52:43 -0000 Author: vmaffione Date: Tue Jun 11 15:52:41 2019 New Revision: 348929 URL: https://svnweb.freebsd.org/changeset/base/348929 Log: bhyve: virtio: introduce vq_kick_enable() and vq_kick_disable() The VirtIO standard supports two schemes for notification suppression: a notification enable bit and a more sophisticated one (event_idx) that also supports delayed notifications. Currently bhyve fully supports only the first scheme. This patch hides the notification suppression internals by means of two inline routines, vq_kick_enable() and vq_kick_disable(), and makes the code more readable. Moreover, further improve readability by replacing the call to mb() with a call to atomic_thread_fence_seq_cst(), which is already used in virtio.c Reviewed by: pmooney_pfmooney.com, bryanv MFC after: 2 weeks Differential Revision: https://reviews.freebsd.org/D20581 Modified: head/usr.sbin/bhyve/pci_virtio_console.c head/usr.sbin/bhyve/pci_virtio_net.c head/usr.sbin/bhyve/pci_virtio_scsi.c head/usr.sbin/bhyve/virtio.c head/usr.sbin/bhyve/virtio.h Modified: head/usr.sbin/bhyve/pci_virtio_console.c ============================================================================== --- head/usr.sbin/bhyve/pci_virtio_console.c Tue Jun 11 15:36:36 2019 (r348928) +++ head/usr.sbin/bhyve/pci_virtio_console.c Tue Jun 11 15:52:41 2019 (r348929) @@ -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); } } Modified: head/usr.sbin/bhyve/pci_virtio_net.c ============================================================================== --- head/usr.sbin/bhyve/pci_virtio_net.c Tue Jun 11 15:36:36 2019 (r348928) +++ head/usr.sbin/bhyve/pci_virtio_net.c Tue Jun 11 15:52:41 2019 (r348929) @@ -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); Modified: head/usr.sbin/bhyve/pci_virtio_scsi.c ============================================================================== --- head/usr.sbin/bhyve/pci_virtio_scsi.c Tue Jun 11 15:36:36 2019 (r348928) +++ head/usr.sbin/bhyve/pci_virtio_scsi.c Tue Jun 11 15:52:41 2019 (r348929) @@ -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 Modified: head/usr.sbin/bhyve/virtio.c ============================================================================== --- head/usr.sbin/bhyve/virtio.c Tue Jun 11 15:36:36 2019 (r348928) +++ head/usr.sbin/bhyve/virtio.c Tue Jun 11 15:52:41 2019 (r348929) @@ -428,7 +428,8 @@ vq_relchain(struct vqueue_info *vq, uint16_t idx, uint /* * 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; Modified: head/usr.sbin/bhyve/virtio.h ============================================================================== --- head/usr.sbin/bhyve/virtio.h Tue Jun 11 15:36:36 2019 (r348928) +++ head/usr.sbin/bhyve/virtio.h Tue Jun 11 15:52:41 2019 (r348929) @@ -31,6 +31,8 @@ #ifndef _VIRTIO_H_ #define _VIRTIO_H_ +#include + /* * These are derived from several virtio specifications. * @@ -445,6 +447,26 @@ vq_interrupt(struct virtio_softc *vs, struct vqueue_in pci_lintr_assert(vs->vs_pi); VS_UNLOCK(vs); } +} + +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;