From e24a47c5b73e04f94030e2daa356c7582aebfca2 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Sun, 14 Feb 2016 18:17:10 +0100 Subject: virtio-scsi: do not use vring in dataplane Signed-off-by: Paolo Bonzini Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin Acked-by: Stefan Hajnoczi --- hw/scsi/virtio-scsi-dataplane.c | 196 +++++----------------------------------- hw/scsi/virtio-scsi.c | 52 ++--------- include/hw/virtio/virtio-scsi.h | 21 +---- 3 files changed, 35 insertions(+), 234 deletions(-) diff --git a/hw/scsi/virtio-scsi-dataplane.c b/hw/scsi/virtio-scsi-dataplane.c index 8340326..367e476 100644 --- a/hw/scsi/virtio-scsi-dataplane.c +++ b/hw/scsi/virtio-scsi-dataplane.c @@ -39,14 +39,10 @@ void virtio_scsi_set_iothread(VirtIOSCSI *s, IOThread *iothread) } } -static VirtIOSCSIVring *virtio_scsi_vring_init(VirtIOSCSI *s, - VirtQueue *vq, - EventNotifierHandler *handler, - int n) +static int virtio_scsi_vring_init(VirtIOSCSI *s, VirtQueue *vq, int n) { BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(s))); VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); - VirtIOSCSIVring *r; int rc; /* Set up virtqueue notify */ @@ -55,105 +51,17 @@ static VirtIOSCSIVring *virtio_scsi_vring_init(VirtIOSCSI *s, fprintf(stderr, "virtio-scsi: Failed to set host notifier (%d)\n", rc); s->dataplane_fenced = true; - return NULL; + return rc; } - r = g_new(VirtIOSCSIVring, 1); - r->host_notifier = *virtio_queue_get_host_notifier(vq); - r->guest_notifier = *virtio_queue_get_guest_notifier(vq); - aio_set_event_notifier(s->ctx, &r->host_notifier, true, handler); - - r->parent = s; - - if (!vring_setup(&r->vring, VIRTIO_DEVICE(s), n)) { - fprintf(stderr, "virtio-scsi: VRing setup failed\n"); - goto fail_vring; - } - return r; - -fail_vring: - aio_set_event_notifier(s->ctx, &r->host_notifier, true, NULL); - k->set_host_notifier(qbus->parent, n, false); - g_free(r); - return NULL; -} - -VirtIOSCSIReq *virtio_scsi_pop_req_vring(VirtIOSCSI *s, - VirtIOSCSIVring *vring) -{ - VirtIOSCSICommon *vs = (VirtIOSCSICommon *)s; - VirtIOSCSIReq *req; - - req = vring_pop((VirtIODevice *)s, &vring->vring, - sizeof(VirtIOSCSIReq) + vs->cdb_size); - if (!req) { - return NULL; - } - virtio_scsi_init_req(s, NULL, req); - req->vring = vring; - return req; -} - -void virtio_scsi_vring_push_notify(VirtIOSCSIReq *req) -{ - VirtIODevice *vdev = VIRTIO_DEVICE(req->vring->parent); - - vring_push(vdev, &req->vring->vring, &req->elem, - req->qsgl.size + req->resp_iov.size); - - if (vring_should_notify(vdev, &req->vring->vring)) { - event_notifier_set(&req->vring->guest_notifier); - } + virtio_queue_aio_set_host_notifier_handler(vq, s->ctx, true, true); + return 0; } -static void virtio_scsi_iothread_handle_ctrl(EventNotifier *notifier) +void virtio_scsi_dataplane_notify(VirtIODevice *vdev, VirtIOSCSIReq *req) { - VirtIOSCSIVring *vring = container_of(notifier, - VirtIOSCSIVring, host_notifier); - VirtIOSCSI *s = VIRTIO_SCSI(vring->parent); - VirtIOSCSIReq *req; - - event_notifier_test_and_clear(notifier); - while ((req = virtio_scsi_pop_req_vring(s, vring))) { - virtio_scsi_handle_ctrl_req(s, req); - } -} - -static void virtio_scsi_iothread_handle_event(EventNotifier *notifier) -{ - VirtIOSCSIVring *vring = container_of(notifier, - VirtIOSCSIVring, host_notifier); - VirtIOSCSI *s = vring->parent; - VirtIODevice *vdev = VIRTIO_DEVICE(s); - - event_notifier_test_and_clear(notifier); - - if (!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) { - return; - } - - if (s->events_dropped) { - virtio_scsi_push_event(s, NULL, VIRTIO_SCSI_T_NO_EVENT, 0); - } -} - -static void virtio_scsi_iothread_handle_cmd(EventNotifier *notifier) -{ - VirtIOSCSIVring *vring = container_of(notifier, - VirtIOSCSIVring, host_notifier); - VirtIOSCSI *s = (VirtIOSCSI *)vring->parent; - VirtIOSCSIReq *req, *next; - QTAILQ_HEAD(, VirtIOSCSIReq) reqs = QTAILQ_HEAD_INITIALIZER(reqs); - - event_notifier_test_and_clear(notifier); - while ((req = virtio_scsi_pop_req_vring(s, vring))) { - if (virtio_scsi_handle_cmd_req_prepare(s, req)) { - QTAILQ_INSERT_TAIL(&reqs, req, next); - } - } - - QTAILQ_FOREACH_SAFE(req, &reqs, next, next) { - virtio_scsi_handle_cmd_req_submit(s, req); + if (virtio_should_notify(vdev, req->vq)) { + event_notifier_set(virtio_queue_get_guest_notifier(req->vq)); } } @@ -163,46 +71,10 @@ static void virtio_scsi_clear_aio(VirtIOSCSI *s) VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s); int i; - if (s->ctrl_vring) { - aio_set_event_notifier(s->ctx, &s->ctrl_vring->host_notifier, - true, NULL); - } - if (s->event_vring) { - aio_set_event_notifier(s->ctx, &s->event_vring->host_notifier, - true, NULL); - } - if (s->cmd_vrings) { - for (i = 0; i < vs->conf.num_queues && s->cmd_vrings[i]; i++) { - aio_set_event_notifier(s->ctx, &s->cmd_vrings[i]->host_notifier, - true, NULL); - } - } -} - -static void virtio_scsi_vring_teardown(VirtIOSCSI *s) -{ - VirtIODevice *vdev = VIRTIO_DEVICE(s); - VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s); - int i; - - if (s->ctrl_vring) { - vring_teardown(&s->ctrl_vring->vring, vdev, 0); - g_free(s->ctrl_vring); - s->ctrl_vring = NULL; - } - if (s->event_vring) { - vring_teardown(&s->event_vring->vring, vdev, 1); - g_free(s->event_vring); - s->event_vring = NULL; - } - if (s->cmd_vrings) { - for (i = 0; i < vs->conf.num_queues && s->cmd_vrings[i]; i++) { - vring_teardown(&s->cmd_vrings[i]->vring, vdev, 2 + i); - g_free(s->cmd_vrings[i]); - s->cmd_vrings[i] = NULL; - } - free(s->cmd_vrings); - s->cmd_vrings = NULL; + virtio_queue_aio_set_host_notifier_handler(vs->ctrl_vq, s->ctx, false, false); + virtio_queue_aio_set_host_notifier_handler(vs->event_vq, s->ctx, false, false); + for (i = 0; i < vs->conf.num_queues; i++) { + virtio_queue_aio_set_host_notifier_handler(vs->cmd_vqs[i], s->ctx, false, false); } } @@ -229,30 +101,21 @@ void virtio_scsi_dataplane_start(VirtIOSCSI *s) if (rc != 0) { fprintf(stderr, "virtio-scsi: Failed to set guest notifiers (%d), " "ensure -enable-kvm is set\n", rc); - s->dataplane_fenced = true; goto fail_guest_notifiers; } aio_context_acquire(s->ctx); - s->ctrl_vring = virtio_scsi_vring_init(s, vs->ctrl_vq, - virtio_scsi_iothread_handle_ctrl, - 0); - if (!s->ctrl_vring) { + rc = virtio_scsi_vring_init(s, vs->ctrl_vq, 0); + if (rc) { goto fail_vrings; } - s->event_vring = virtio_scsi_vring_init(s, vs->event_vq, - virtio_scsi_iothread_handle_event, - 1); - if (!s->event_vring) { + rc = virtio_scsi_vring_init(s, vs->event_vq, 1); + if (rc) { goto fail_vrings; } - s->cmd_vrings = g_new(VirtIOSCSIVring *, vs->conf.num_queues); for (i = 0; i < vs->conf.num_queues; i++) { - s->cmd_vrings[i] = - virtio_scsi_vring_init(s, vs->cmd_vqs[i], - virtio_scsi_iothread_handle_cmd, - i + 2); - if (!s->cmd_vrings[i]) { + rc = virtio_scsi_vring_init(s, vs->cmd_vqs[i], i + 2); + if (rc) { goto fail_vrings; } } @@ -265,13 +128,14 @@ void virtio_scsi_dataplane_start(VirtIOSCSI *s) fail_vrings: virtio_scsi_clear_aio(s); aio_context_release(s->ctx); - virtio_scsi_vring_teardown(s); for (i = 0; i < vs->conf.num_queues + 2; i++) { k->set_host_notifier(qbus->parent, i, false); } k->set_guest_notifiers(qbus->parent, vs->conf.num_queues + 2, false); fail_guest_notifiers: + s->dataplane_fenced = true; s->dataplane_starting = false; + s->dataplane_started = true; } /* Context: QEMU global mutex held */ @@ -282,12 +146,14 @@ void virtio_scsi_dataplane_stop(VirtIOSCSI *s) VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s); int i; + if (!s->dataplane_started || s->dataplane_stopping) { + return; + } + /* Better luck next time. */ if (s->dataplane_fenced) { s->dataplane_fenced = false; - return; - } - if (!s->dataplane_started || s->dataplane_stopping) { + s->dataplane_started = false; return; } s->dataplane_stopping = true; @@ -295,24 +161,12 @@ void virtio_scsi_dataplane_stop(VirtIOSCSI *s) aio_context_acquire(s->ctx); - aio_set_event_notifier(s->ctx, &s->ctrl_vring->host_notifier, - true, NULL); - aio_set_event_notifier(s->ctx, &s->event_vring->host_notifier, - true, NULL); - for (i = 0; i < vs->conf.num_queues; i++) { - aio_set_event_notifier(s->ctx, &s->cmd_vrings[i]->host_notifier, - true, NULL); - } + virtio_scsi_clear_aio(s); blk_drain_all(); /* ensure there are no in-flight requests */ aio_context_release(s->ctx); - /* Sync vring state back to virtqueue so that non-dataplane request - * processing can continue when we disable the host notifier below. - */ - virtio_scsi_vring_teardown(s); - for (i = 0; i < vs->conf.num_queues + 2; i++) { k->set_host_notifier(qbus->parent, i, false); } diff --git a/hw/scsi/virtio-scsi.c b/hw/scsi/virtio-scsi.c index 5b29bac..0c30d2e 100644 --- a/hw/scsi/virtio-scsi.c +++ b/hw/scsi/virtio-scsi.c @@ -23,7 +23,6 @@ #include #include #include "hw/virtio/virtio-access.h" -#include "migration/migration.h" static inline int virtio_scsi_get_lun(uint8_t *lun) { @@ -43,7 +42,8 @@ static inline SCSIDevice *virtio_scsi_device_find(VirtIOSCSI *s, uint8_t *lun) void virtio_scsi_init_req(VirtIOSCSI *s, VirtQueue *vq, VirtIOSCSIReq *req) { - const size_t zero_skip = offsetof(VirtIOSCSIReq, vring); + const size_t zero_skip = + offsetof(VirtIOSCSIReq, resp_iov) + sizeof(req->resp_iov); req->vq = vq; req->dev = s; @@ -66,11 +66,10 @@ static void virtio_scsi_complete_req(VirtIOSCSIReq *req) VirtIODevice *vdev = VIRTIO_DEVICE(s); qemu_iovec_from_buf(&req->resp_iov, 0, &req->resp, req->resp_size); - if (req->vring) { - assert(req->vq == NULL); - virtio_scsi_vring_push_notify(req); + virtqueue_push(vq, &req->elem, req->qsgl.size + req->resp_iov.size); + if (s->dataplane_started) { + virtio_scsi_dataplane_notify(vdev, req); } else { - virtqueue_push(vq, &req->elem, req->qsgl.size + req->resp_iov.size); virtio_notify(vdev, vq); } @@ -417,7 +416,7 @@ static void virtio_scsi_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq) VirtIOSCSI *s = (VirtIOSCSI *)vdev; VirtIOSCSIReq *req; - if (s->ctx && !s->dataplane_disabled) { + if (s->ctx && !s->dataplane_started) { virtio_scsi_dataplane_start(s); return; } @@ -567,7 +566,7 @@ static void virtio_scsi_handle_cmd(VirtIODevice *vdev, VirtQueue *vq) VirtIOSCSIReq *req, *next; QTAILQ_HEAD(, VirtIOSCSIReq) reqs = QTAILQ_HEAD_INITIALIZER(reqs); - if (s->ctx && !s->dataplane_disabled) { + if (s->ctx && !s->dataplane_started) { virtio_scsi_dataplane_start(s); return; } @@ -687,11 +686,7 @@ void virtio_scsi_push_event(VirtIOSCSI *s, SCSIDevice *dev, aio_context_acquire(s->ctx); } - if (s->dataplane_started) { - req = virtio_scsi_pop_req_vring(s, s->event_vring); - } else { - req = virtio_scsi_pop_req(s, vs->event_vq); - } + req = virtio_scsi_pop_req(s, vs->event_vq); if (!req) { s->events_dropped = true; goto out; @@ -733,7 +728,7 @@ static void virtio_scsi_handle_event(VirtIODevice *vdev, VirtQueue *vq) { VirtIOSCSI *s = VIRTIO_SCSI(vdev); - if (s->ctx && !s->dataplane_disabled) { + if (s->ctx && !s->dataplane_started) { virtio_scsi_dataplane_start(s); return; } @@ -901,31 +896,6 @@ void virtio_scsi_common_realize(DeviceState *dev, Error **errp, } } -/* Disable dataplane thread during live migration since it does not - * update the dirty memory bitmap yet. - */ -static void virtio_scsi_migration_state_changed(Notifier *notifier, void *data) -{ - VirtIOSCSI *s = container_of(notifier, VirtIOSCSI, - migration_state_notifier); - MigrationState *mig = data; - - if (migration_in_setup(mig)) { - if (!s->dataplane_started) { - return; - } - virtio_scsi_dataplane_stop(s); - s->dataplane_disabled = true; - } else if (migration_has_finished(mig) || - migration_has_failed(mig)) { - if (s->dataplane_started) { - return; - } - blk_drain_all(); /* complete in-flight non-dataplane requests */ - s->dataplane_disabled = false; - } -} - static void virtio_scsi_device_realize(DeviceState *dev, Error **errp) { VirtIODevice *vdev = VIRTIO_DEVICE(dev); @@ -956,8 +926,6 @@ static void virtio_scsi_device_realize(DeviceState *dev, Error **errp) register_savevm(dev, "virtio-scsi", virtio_scsi_id++, 1, virtio_scsi_save, virtio_scsi_load, s); - s->migration_state_notifier.notify = virtio_scsi_migration_state_changed; - add_migration_state_change_notifier(&s->migration_state_notifier); error_setg(&s->blocker, "block device is in use by data plane"); @@ -991,8 +959,6 @@ static void virtio_scsi_device_unrealize(DeviceState *dev, Error **errp) error_free(s->blocker); unregister_savevm(dev, "virtio-scsi", s); - remove_migration_state_change_notifier(&s->migration_state_notifier); - virtio_scsi_common_unrealize(dev, errp); } diff --git a/include/hw/virtio/virtio-scsi.h b/include/hw/virtio/virtio-scsi.h index a8029aa..209eaa4 100644 --- a/include/hw/virtio/virtio-scsi.h +++ b/include/hw/virtio/virtio-scsi.h @@ -22,7 +22,6 @@ #include "hw/pci/pci.h" #include "hw/scsi/scsi.h" #include "sysemu/iothread.h" -#include "hw/virtio/dataplane/vring.h" #define TYPE_VIRTIO_SCSI_COMMON "virtio-scsi-common" #define VIRTIO_SCSI_COMMON(obj) \ @@ -58,13 +57,6 @@ struct VirtIOSCSIConf { struct VirtIOSCSI; -typedef struct { - struct VirtIOSCSI *parent; - Vring vring; - EventNotifier host_notifier; - EventNotifier guest_notifier; -} VirtIOSCSIVring; - typedef struct VirtIOSCSICommon { VirtIODevice parent_obj; VirtIOSCSIConf conf; @@ -96,18 +88,12 @@ typedef struct VirtIOSCSI { QTAILQ_HEAD(, VirtIOSCSIBlkChangeNotifier) insert_notifiers; QTAILQ_HEAD(, VirtIOSCSIBlkChangeNotifier) remove_notifiers; - /* Vring is used instead of vq in dataplane code, because of the underlying - * memory layer thread safety */ - VirtIOSCSIVring *ctrl_vring; - VirtIOSCSIVring *event_vring; - VirtIOSCSIVring **cmd_vrings; bool dataplane_started; bool dataplane_starting; bool dataplane_stopping; bool dataplane_disabled; bool dataplane_fenced; Error *blocker; - Notifier migration_state_notifier; uint32_t host_features; } VirtIOSCSI; @@ -123,9 +109,6 @@ typedef struct VirtIOSCSIReq { QEMUSGList qsgl; QEMUIOVector resp_iov; - /* Set by dataplane code. */ - VirtIOSCSIVring *vring; - union { /* Used for two-stage request submission */ QTAILQ_ENTRY(VirtIOSCSIReq) next; @@ -168,8 +151,6 @@ void virtio_scsi_push_event(VirtIOSCSI *s, SCSIDevice *dev, void virtio_scsi_set_iothread(VirtIOSCSI *s, IOThread *iothread); void virtio_scsi_dataplane_start(VirtIOSCSI *s); void virtio_scsi_dataplane_stop(VirtIOSCSI *s); -void virtio_scsi_vring_push_notify(VirtIOSCSIReq *req); -VirtIOSCSIReq *virtio_scsi_pop_req_vring(VirtIOSCSI *s, - VirtIOSCSIVring *vring); +void virtio_scsi_dataplane_notify(VirtIODevice *vdev, VirtIOSCSIReq *req); #endif /* _QEMU_VIRTIO_SCSI_H */ -- cgit v1.1