From a8f2e5c8fffbaf7fbd4f0efc8efbeebade78008f Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Wed, 6 Apr 2016 12:16:27 +0200 Subject: virtio-scsi: use aio handler for data plane In addition to handling IO in vcpu thread and in io thread, dataplane introduces yet another mode: handling it by AioContext. This reuses the same handler as previous modes, which triggers races as these were not designed to be reentrant. Use a separate handler just for aio, and disable regular handlers when dataplane is active. Reviewed-by: Cornelia Huck Signed-off-by: Paolo Bonzini Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- hw/scsi/virtio-scsi-dataplane.c | 43 ++++++++++++++++++++++++--- hw/scsi/virtio-scsi.c | 65 ++++++++++++++++++++++++++++------------- include/hw/virtio/virtio-scsi.h | 6 ++-- 3 files changed, 86 insertions(+), 28 deletions(-) diff --git a/hw/scsi/virtio-scsi-dataplane.c b/hw/scsi/virtio-scsi-dataplane.c index b44ac5dfa0..39ad086db7 100644 --- a/hw/scsi/virtio-scsi-dataplane.c +++ b/hw/scsi/virtio-scsi-dataplane.c @@ -38,7 +38,35 @@ void virtio_scsi_set_iothread(VirtIOSCSI *s, IOThread *iothread) } } -static int virtio_scsi_vring_init(VirtIOSCSI *s, VirtQueue *vq, int n) +static void virtio_scsi_data_plane_handle_cmd(VirtIODevice *vdev, + VirtQueue *vq) +{ + VirtIOSCSI *s = (VirtIOSCSI *)vdev; + + assert(s->ctx && s->dataplane_started); + virtio_scsi_handle_cmd_vq(s, vq); +} + +static void virtio_scsi_data_plane_handle_ctrl(VirtIODevice *vdev, + VirtQueue *vq) +{ + VirtIOSCSI *s = VIRTIO_SCSI(vdev); + + assert(s->ctx && s->dataplane_started); + virtio_scsi_handle_ctrl_vq(s, vq); +} + +static void virtio_scsi_data_plane_handle_event(VirtIODevice *vdev, + VirtQueue *vq) +{ + VirtIOSCSI *s = VIRTIO_SCSI(vdev); + + assert(s->ctx && s->dataplane_started); + virtio_scsi_handle_event_vq(s, vq); +} + +static int virtio_scsi_vring_init(VirtIOSCSI *s, VirtQueue *vq, int n, + void (*fn)(VirtIODevice *vdev, VirtQueue *vq)) { BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(s))); VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); @@ -54,6 +82,7 @@ static int virtio_scsi_vring_init(VirtIOSCSI *s, VirtQueue *vq, int n) } virtio_queue_aio_set_host_notifier_handler(vq, s->ctx, true, true); + virtio_set_queue_aio(vq, fn); return 0; } @@ -71,9 +100,12 @@ static void virtio_scsi_clear_aio(VirtIOSCSI *s) int i; virtio_queue_aio_set_host_notifier_handler(vs->ctrl_vq, s->ctx, false, false); + virtio_set_queue_aio(vs->ctrl_vq, NULL); virtio_queue_aio_set_host_notifier_handler(vs->event_vq, s->ctx, false, false); + virtio_set_queue_aio(vs->event_vq, NULL); for (i = 0; i < vs->conf.num_queues; i++) { virtio_queue_aio_set_host_notifier_handler(vs->cmd_vqs[i], s->ctx, false, false); + virtio_set_queue_aio(vs->cmd_vqs[i], NULL); } } @@ -104,16 +136,19 @@ void virtio_scsi_dataplane_start(VirtIOSCSI *s) } aio_context_acquire(s->ctx); - rc = virtio_scsi_vring_init(s, vs->ctrl_vq, 0); + rc = virtio_scsi_vring_init(s, vs->ctrl_vq, 0, + virtio_scsi_data_plane_handle_ctrl); if (rc) { goto fail_vrings; } - rc = virtio_scsi_vring_init(s, vs->event_vq, 1); + rc = virtio_scsi_vring_init(s, vs->event_vq, 1, + virtio_scsi_data_plane_handle_event); if (rc) { goto fail_vrings; } for (i = 0; i < vs->conf.num_queues; i++) { - rc = virtio_scsi_vring_init(s, vs->cmd_vqs[i], i + 2); + rc = virtio_scsi_vring_init(s, vs->cmd_vqs[i], i + 2, + virtio_scsi_data_plane_handle_cmd); if (rc) { goto fail_vrings; } diff --git a/hw/scsi/virtio-scsi.c b/hw/scsi/virtio-scsi.c index 38f1e2c2eb..30415c6a92 100644 --- a/hw/scsi/virtio-scsi.c +++ b/hw/scsi/virtio-scsi.c @@ -374,7 +374,7 @@ fail: return ret; } -void virtio_scsi_handle_ctrl_req(VirtIOSCSI *s, VirtIOSCSIReq *req) +static void virtio_scsi_handle_ctrl_req(VirtIOSCSI *s, VirtIOSCSIReq *req) { VirtIODevice *vdev = (VirtIODevice *)s; uint32_t type; @@ -412,20 +412,28 @@ void virtio_scsi_handle_ctrl_req(VirtIOSCSI *s, VirtIOSCSIReq *req) } } -static void virtio_scsi_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq) +void virtio_scsi_handle_ctrl_vq(VirtIOSCSI *s, VirtQueue *vq) { - VirtIOSCSI *s = (VirtIOSCSI *)vdev; VirtIOSCSIReq *req; - if (s->ctx && !s->dataplane_started) { - virtio_scsi_dataplane_start(s); - return; - } while ((req = virtio_scsi_pop_req(s, vq))) { virtio_scsi_handle_ctrl_req(s, req); } } +static void virtio_scsi_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq) +{ + VirtIOSCSI *s = (VirtIOSCSI *)vdev; + + if (s->ctx) { + virtio_scsi_dataplane_start(s); + if (!s->dataplane_fenced) { + return; + } + } + virtio_scsi_handle_ctrl_vq(s, vq); +} + static void virtio_scsi_complete_cmd_req(VirtIOSCSIReq *req) { /* Sense data is not in req->resp and is copied separately @@ -508,7 +516,7 @@ static void virtio_scsi_fail_cmd_req(VirtIOSCSIReq *req) virtio_scsi_complete_cmd_req(req); } -bool virtio_scsi_handle_cmd_req_prepare(VirtIOSCSI *s, VirtIOSCSIReq *req) +static bool virtio_scsi_handle_cmd_req_prepare(VirtIOSCSI *s, VirtIOSCSIReq *req) { VirtIOSCSICommon *vs = &s->parent_obj; SCSIDevice *d; @@ -550,7 +558,7 @@ bool virtio_scsi_handle_cmd_req_prepare(VirtIOSCSI *s, VirtIOSCSIReq *req) return true; } -void virtio_scsi_handle_cmd_req_submit(VirtIOSCSI *s, VirtIOSCSIReq *req) +static void virtio_scsi_handle_cmd_req_submit(VirtIOSCSI *s, VirtIOSCSIReq *req) { SCSIRequest *sreq = req->sreq; if (scsi_req_enqueue(sreq)) { @@ -560,17 +568,11 @@ void virtio_scsi_handle_cmd_req_submit(VirtIOSCSI *s, VirtIOSCSIReq *req) scsi_req_unref(sreq); } -static void virtio_scsi_handle_cmd(VirtIODevice *vdev, VirtQueue *vq) +void virtio_scsi_handle_cmd_vq(VirtIOSCSI *s, VirtQueue *vq) { - /* use non-QOM casts in the data path */ - VirtIOSCSI *s = (VirtIOSCSI *)vdev; VirtIOSCSIReq *req, *next; QTAILQ_HEAD(, VirtIOSCSIReq) reqs = QTAILQ_HEAD_INITIALIZER(reqs); - if (s->ctx && !s->dataplane_started) { - virtio_scsi_dataplane_start(s); - return; - } while ((req = virtio_scsi_pop_req(s, vq))) { if (virtio_scsi_handle_cmd_req_prepare(s, req)) { QTAILQ_INSERT_TAIL(&reqs, req, next); @@ -582,6 +584,20 @@ static void virtio_scsi_handle_cmd(VirtIODevice *vdev, VirtQueue *vq) } } +static void virtio_scsi_handle_cmd(VirtIODevice *vdev, VirtQueue *vq) +{ + /* use non-QOM casts in the data path */ + VirtIOSCSI *s = (VirtIOSCSI *)vdev; + + if (s->ctx) { + virtio_scsi_dataplane_start(s); + if (!s->dataplane_fenced) { + return; + } + } + virtio_scsi_handle_cmd_vq(s, vq); +} + static void virtio_scsi_get_config(VirtIODevice *vdev, uint8_t *config) { @@ -725,17 +741,24 @@ out: } } +void virtio_scsi_handle_event_vq(VirtIOSCSI *s, VirtQueue *vq) +{ + if (s->events_dropped) { + virtio_scsi_push_event(s, NULL, VIRTIO_SCSI_T_NO_EVENT, 0); + } +} + static void virtio_scsi_handle_event(VirtIODevice *vdev, VirtQueue *vq) { VirtIOSCSI *s = VIRTIO_SCSI(vdev); - if (s->ctx && !s->dataplane_started) { + if (s->ctx) { virtio_scsi_dataplane_start(s); - return; - } - if (s->events_dropped) { - virtio_scsi_push_event(s, NULL, VIRTIO_SCSI_T_NO_EVENT, 0); + if (!s->dataplane_fenced) { + return; + } } + virtio_scsi_handle_event_vq(s, vq); } static void virtio_scsi_change(SCSIBus *bus, SCSIDevice *dev, SCSISense sense) diff --git a/include/hw/virtio/virtio-scsi.h b/include/hw/virtio/virtio-scsi.h index eef4e954f5..ba2f5ce07c 100644 --- a/include/hw/virtio/virtio-scsi.h +++ b/include/hw/virtio/virtio-scsi.h @@ -139,9 +139,9 @@ void virtio_scsi_common_realize(DeviceState *dev, Error **errp, HandleOutput cmd); void virtio_scsi_common_unrealize(DeviceState *dev, Error **errp); -void virtio_scsi_handle_ctrl_req(VirtIOSCSI *s, VirtIOSCSIReq *req); -bool virtio_scsi_handle_cmd_req_prepare(VirtIOSCSI *s, VirtIOSCSIReq *req); -void virtio_scsi_handle_cmd_req_submit(VirtIOSCSI *s, VirtIOSCSIReq *req); +void virtio_scsi_handle_event_vq(VirtIOSCSI *s, VirtQueue *vq); +void virtio_scsi_handle_cmd_vq(VirtIOSCSI *s, VirtQueue *vq); +void virtio_scsi_handle_ctrl_vq(VirtIOSCSI *s, VirtQueue *vq); void virtio_scsi_init_req(VirtIOSCSI *s, VirtQueue *vq, VirtIOSCSIReq *req); void virtio_scsi_free_req(VirtIOSCSIReq *req); void virtio_scsi_push_event(VirtIOSCSI *s, SCSIDevice *dev, -- cgit v1.2.1