diff options
author | 2015-08-28 09:58:54 +0800 | |
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committer | 2015-09-01 12:44:00 +0800 | |
commit | e44e3482bdb4d0ebde2d8b41830ac2cdb07948fb (patch) | |
tree | 66b09f592c55df2878107a468a91d21506104d3f /qemu/hw/scsi/virtio-scsi-dataplane.c | |
parent | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (diff) |
Add qemu 2.4.0
Change-Id: Ic99cbad4b61f8b127b7dc74d04576c0bcbaaf4f5
Signed-off-by: Yang Zhang <yang.z.zhang@intel.com>
Diffstat (limited to 'qemu/hw/scsi/virtio-scsi-dataplane.c')
-rw-r--r-- | qemu/hw/scsi/virtio-scsi-dataplane.c | 316 |
1 files changed, 316 insertions, 0 deletions
diff --git a/qemu/hw/scsi/virtio-scsi-dataplane.c b/qemu/hw/scsi/virtio-scsi-dataplane.c new file mode 100644 index 000000000..5575648a9 --- /dev/null +++ b/qemu/hw/scsi/virtio-scsi-dataplane.c @@ -0,0 +1,316 @@ +/* + * Virtio SCSI dataplane + * + * Copyright Red Hat, Inc. 2014 + * + * Authors: + * Fam Zheng <famz@redhat.com> + * + * This work is licensed under the terms of the GNU GPL, version 2 or later. + * See the COPYING file in the top-level directory. + * + */ + +#include "hw/virtio/virtio-scsi.h" +#include "qemu/error-report.h" +#include "sysemu/block-backend.h" +#include <hw/scsi/scsi.h> +#include <block/scsi.h> +#include <hw/virtio/virtio-bus.h> +#include "hw/virtio/virtio-access.h" +#include "stdio.h" + +/* Context: QEMU global mutex held */ +void virtio_scsi_set_iothread(VirtIOSCSI *s, IOThread *iothread) +{ + BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(s))); + VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); + VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s); + + assert(!s->ctx); + s->ctx = iothread_get_aio_context(vs->conf.iothread); + + /* Don't try if transport does not support notifiers. */ + if (!k->set_guest_notifiers || !k->set_host_notifier) { + fprintf(stderr, "virtio-scsi: Failed to set iothread " + "(transport does not support notifiers)"); + exit(1); + } +} + +static VirtIOSCSIVring *virtio_scsi_vring_init(VirtIOSCSI *s, + VirtQueue *vq, + EventNotifierHandler *handler, + 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 */ + rc = k->set_host_notifier(qbus->parent, n, true); + if (rc != 0) { + fprintf(stderr, "virtio-scsi: Failed to set host notifier (%d)\n", + rc); + s->dataplane_fenced = true; + return NULL; + } + + r = g_slice_new(VirtIOSCSIVring); + 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, 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, NULL); + k->set_host_notifier(qbus->parent, n, false); + g_slice_free(VirtIOSCSIVring, r); + return NULL; +} + +VirtIOSCSIReq *virtio_scsi_pop_req_vring(VirtIOSCSI *s, + VirtIOSCSIVring *vring) +{ + VirtIOSCSIReq *req = virtio_scsi_init_req(s, NULL); + int r; + + req->vring = vring; + r = vring_pop((VirtIODevice *)s, &vring->vring, &req->elem); + if (r < 0) { + virtio_scsi_free_req(req); + req = NULL; + } + 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); + } +} + +static void virtio_scsi_iothread_handle_ctrl(EventNotifier *notifier) +{ + 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); + } +} + +/* assumes s->ctx held */ +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, NULL); + } + if (s->event_vring) { + aio_set_event_notifier(s->ctx, &s->event_vring->host_notifier, 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, 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_slice_free(VirtIOSCSIVring, s->ctrl_vring); + s->ctrl_vring = NULL; + } + if (s->event_vring) { + vring_teardown(&s->event_vring->vring, vdev, 1); + g_slice_free(VirtIOSCSIVring, 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_slice_free(VirtIOSCSIVring, s->cmd_vrings[i]); + s->cmd_vrings[i] = NULL; + } + free(s->cmd_vrings); + s->cmd_vrings = NULL; + } +} + +/* Context: QEMU global mutex held */ +void virtio_scsi_dataplane_start(VirtIOSCSI *s) +{ + int i; + int rc; + BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(s))); + VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); + VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s); + + if (s->dataplane_started || + s->dataplane_starting || + s->dataplane_fenced || + s->ctx != iothread_get_aio_context(vs->conf.iothread)) { + return; + } + + s->dataplane_starting = true; + + /* Set up guest notifier (irq) */ + rc = k->set_guest_notifiers(qbus->parent, vs->conf.num_queues + 2, true); + 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) { + goto fail_vrings; + } + s->event_vring = virtio_scsi_vring_init(s, vs->event_vq, + virtio_scsi_iothread_handle_event, + 1); + if (!s->event_vring) { + 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]) { + goto fail_vrings; + } + } + + s->dataplane_starting = false; + s->dataplane_started = true; + aio_context_release(s->ctx); + return; + +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_starting = false; +} + +/* Context: QEMU global mutex held */ +void virtio_scsi_dataplane_stop(VirtIOSCSI *s) +{ + BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(s))); + VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); + VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s); + int i; + + /* Better luck next time. */ + if (s->dataplane_fenced) { + s->dataplane_fenced = false; + return; + } + if (!s->dataplane_started || s->dataplane_stopping) { + return; + } + s->dataplane_stopping = true; + assert(s->ctx == iothread_get_aio_context(vs->conf.iothread)); + + aio_context_acquire(s->ctx); + + aio_set_event_notifier(s->ctx, &s->ctrl_vring->host_notifier, NULL); + aio_set_event_notifier(s->ctx, &s->event_vring->host_notifier, NULL); + for (i = 0; i < vs->conf.num_queues; i++) { + aio_set_event_notifier(s->ctx, &s->cmd_vrings[i]->host_notifier, NULL); + } + + 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); + } + + /* Clean up guest notifier (irq) */ + k->set_guest_notifiers(qbus->parent, vs->conf.num_queues + 2, false); + s->dataplane_stopping = false; + s->dataplane_started = false; +} |