From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:45797) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dmiQz-0007pH-I0 for qemu-devel@nongnu.org; Tue, 29 Aug 2017 11:28:10 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dmiQy-0001eB-Io for qemu-devel@nongnu.org; Tue, 29 Aug 2017 11:28:09 -0400 From: =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= Date: Tue, 29 Aug 2017 17:27:50 +0200 Message-Id: <20170829152751.3174-2-marcandre.lureau@redhat.com> In-Reply-To: <20170829152751.3174-1-marcandre.lureau@redhat.com> References: <20170829152751.3174-1-marcandre.lureau@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Subject: [Qemu-devel] [PATCH v2 1/2] libvhost-user: support resuming vq->last_avail_idx based on used_idx List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: victork@redhat.com, qemu-stable@nongnu.org, mst@redhat.com, =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= This is the same workaround as commit 523b018dde3b765, which was lost with libvhost-user transition in commit e10e798c85c2331. Signed-off-by: Marc-Andr=C3=A9 Lureau --- contrib/libvhost-user/libvhost-user.h | 7 +++++++ contrib/libvhost-user/libvhost-user.c | 13 +++++++++++++ 2 files changed, 20 insertions(+) diff --git a/contrib/libvhost-user/libvhost-user.h b/contrib/libvhost-use= r/libvhost-user.h index 53ef222c0b..4021f1124e 100644 --- a/contrib/libvhost-user/libvhost-user.h +++ b/contrib/libvhost-user/libvhost-user.h @@ -132,6 +132,7 @@ typedef void (*vu_set_features_cb) (VuDev *dev, uint6= 4_t features); typedef int (*vu_process_msg_cb) (VuDev *dev, VhostUserMsg *vmsg, int *do_reply); typedef void (*vu_queue_set_started_cb) (VuDev *dev, int qidx, bool star= ted); +typedef bool (*vu_queue_is_processed_in_order_cb) (VuDev *dev, int qidx)= ; =20 typedef struct VuDevIface { /* called by VHOST_USER_GET_FEATURES to get the features bitmask */ @@ -148,6 +149,12 @@ typedef struct VuDevIface { vu_process_msg_cb process_msg; /* tells when queues can be processed */ vu_queue_set_started_cb queue_set_started; + /* + * If the queue is processed in order, in which case it will be + * resumed to vring.used->idx. This can help to support resuming + * on unmanaged exit/crash. + */ + vu_queue_is_processed_in_order_cb queue_is_processed_in_order; } VuDevIface; =20 typedef void (*vu_queue_handler_cb) (VuDev *dev, int qidx); diff --git a/contrib/libvhost-user/libvhost-user.c b/contrib/libvhost-use= r/libvhost-user.c index 35fa0c5e56..d27d6303db 100644 --- a/contrib/libvhost-user/libvhost-user.c +++ b/contrib/libvhost-user/libvhost-user.c @@ -521,6 +521,19 @@ vu_set_vring_addr_exec(VuDev *dev, VhostUserMsg *vms= g) =20 vq->used_idx =3D vq->vring.used->idx; =20 + if (vq->last_avail_idx !=3D vq->used_idx) { + bool resume =3D dev->iface->queue_is_processed_in_order && + dev->iface->queue_is_processed_in_order(dev, index); + + DPRINT("Last avail index !=3D used index: %u !=3D %u%s\n", + vq->last_avail_idx, vq->used_idx, + resume ? ", resuming" : ""); + + if (resume) { + vq->shadow_avail_idx =3D vq->last_avail_idx =3D vq->used_idx= ; + } + } + return false; } =20 --=20 2.14.1.146.gd35faa819