From: Stefan Hajnoczi <stefanha@redhat.com>
The dataplane code used to be significantly different from the
non-dataplane code and therefore had a separate source file.
Over time the difference has gotten smaller because the I/O code paths
were unified. Nowadays the distinction between the VirtIOBlock and
VirtIOBlockDataPlane structs is more of an inconvenience that hinders
code simplification.
Move hw/block/dataplane/virtio-blk.c into hw/block/virtio-blk.c, merging
VirtIOBlockDataPlane's fields into VirtIOBlock.
hw/block/virtio-blk.c used VirtIOBlock->dataplane to check if
virtio_blk_data_plane_create() was successful. This is not necessary
because ->dataplane_started and ->dataplane_disabled can be used
instead. This patch makes those changes in order to drop
VirtIOBlock->dataplane.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20240119135748.270944-2-stefanha@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
hw/block/dataplane/trace.h | 1 -
hw/block/dataplane/virtio-blk.h | 34 ---
include/hw/virtio/virtio-blk.h | 12 +-
hw/block/dataplane/virtio-blk.c | 404 --------------------------------
hw/block/virtio-blk.c | 362 ++++++++++++++++++++++++++--
hw/block/dataplane/meson.build | 1 -
hw/block/dataplane/trace-events | 5 -
meson.build | 1 -
8 files changed, 357 insertions(+), 463 deletions(-)
delete mode 100644 hw/block/dataplane/trace.h
delete mode 100644 hw/block/dataplane/virtio-blk.h
delete mode 100644 hw/block/dataplane/virtio-blk.c
delete mode 100644 hw/block/dataplane/trace-events
diff --git a/hw/block/dataplane/trace.h b/hw/block/dataplane/trace.h
deleted file mode 100644
index 240cc59834..0000000000
--- a/hw/block/dataplane/trace.h
+++ /dev/null
@@ -1 +0,0 @@
-#include "trace/trace-hw_block_dataplane.h"
diff --git a/hw/block/dataplane/virtio-blk.h b/hw/block/dataplane/virtio-blk.h
deleted file mode 100644
index 1a806fe447..0000000000
--- a/hw/block/dataplane/virtio-blk.h
+++ /dev/null
@@ -1,34 +0,0 @@
-/*
- * Dedicated thread for virtio-blk I/O processing
- *
- * Copyright 2012 IBM, Corp.
- * Copyright 2012 Red Hat, Inc. and/or its affiliates
- *
- * Authors:
- * Stefan Hajnoczi <stefanha@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.
- *
- */
-
-#ifndef HW_DATAPLANE_VIRTIO_BLK_H
-#define HW_DATAPLANE_VIRTIO_BLK_H
-
-#include "hw/virtio/virtio.h"
-
-typedef struct VirtIOBlockDataPlane VirtIOBlockDataPlane;
-
-bool virtio_blk_data_plane_create(VirtIODevice *vdev, VirtIOBlkConf *conf,
- VirtIOBlockDataPlane **dataplane,
- Error **errp);
-void virtio_blk_data_plane_destroy(VirtIOBlockDataPlane *s);
-void virtio_blk_data_plane_notify(VirtIOBlockDataPlane *s, VirtQueue *vq);
-
-int virtio_blk_data_plane_start(VirtIODevice *vdev);
-void virtio_blk_data_plane_stop(VirtIODevice *vdev);
-
-void virtio_blk_data_plane_detach(VirtIOBlockDataPlane *s);
-void virtio_blk_data_plane_attach(VirtIOBlockDataPlane *s);
-
-#endif /* HW_DATAPLANE_VIRTIO_BLK_H */
diff --git a/include/hw/virtio/virtio-blk.h b/include/hw/virtio/virtio-blk.h
index 5e4091e4da..fecffdc303 100644
--- a/include/hw/virtio/virtio-blk.h
+++ b/include/hw/virtio/virtio-blk.h
@@ -50,8 +50,6 @@ struct VirtIOBlkConf
bool x_enable_wce_if_config_wce;
};
-struct VirtIOBlockDataPlane;
-
struct VirtIOBlockReq;
struct VirtIOBlock {
VirtIODevice parent_obj;
@@ -64,7 +62,15 @@ struct VirtIOBlock {
VMChangeStateEntry *change;
bool dataplane_disabled;
bool dataplane_started;
- struct VirtIOBlockDataPlane *dataplane;
+ bool dataplane_starting;
+ bool dataplane_stopping;
+
+ /*
+ * The AioContext for each virtqueue. The BlockDriverState will use the
+ * first element as its AioContext.
+ */
+ AioContext **vq_aio_context;
+
uint64_t host_features;
size_t config_size;
BlockRAMRegistrar blk_ram_registrar;
diff --git a/hw/block/dataplane/virtio-blk.c b/hw/block/dataplane/virtio-blk.c
deleted file mode 100644
index ba22732497..0000000000
--- a/hw/block/dataplane/virtio-blk.c
+++ /dev/null
@@ -1,404 +0,0 @@
-/*
- * Dedicated thread for virtio-blk I/O processing
- *
- * Copyright 2012 IBM, Corp.
- * Copyright 2012 Red Hat, Inc. and/or its affiliates
- *
- * Authors:
- * Stefan Hajnoczi <stefanha@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 "qemu/osdep.h"
-#include "qapi/error.h"
-#include "trace.h"
-#include "qemu/iov.h"
-#include "qemu/main-loop.h"
-#include "qemu/thread.h"
-#include "qemu/error-report.h"
-#include "hw/virtio/virtio-blk.h"
-#include "virtio-blk.h"
-#include "block/aio.h"
-#include "hw/virtio/virtio-bus.h"
-#include "qom/object_interfaces.h"
-
-struct VirtIOBlockDataPlane {
- bool starting;
- bool stopping;
-
- VirtIOBlkConf *conf;
- VirtIODevice *vdev;
-
- /*
- * The AioContext for each virtqueue. The BlockDriverState will use the
- * first element as its AioContext.
- */
- AioContext **vq_aio_context;
-};
-
-/* Raise an interrupt to signal guest, if necessary */
-void virtio_blk_data_plane_notify(VirtIOBlockDataPlane *s, VirtQueue *vq)
-{
- virtio_notify_irqfd(s->vdev, vq);
-}
-
-/* Generate vq:AioContext mappings from a validated iothread-vq-mapping list */
-static void
-apply_vq_mapping(IOThreadVirtQueueMappingList *iothread_vq_mapping_list,
- AioContext **vq_aio_context, uint16_t num_queues)
-{
- IOThreadVirtQueueMappingList *node;
- size_t num_iothreads = 0;
- size_t cur_iothread = 0;
-
- for (node = iothread_vq_mapping_list; node; node = node->next) {
- num_iothreads++;
- }
-
- for (node = iothread_vq_mapping_list; node; node = node->next) {
- IOThread *iothread = iothread_by_id(node->value->iothread);
- AioContext *ctx = iothread_get_aio_context(iothread);
-
- /* Released in virtio_blk_data_plane_destroy() */
- object_ref(OBJECT(iothread));
-
- if (node->value->vqs) {
- uint16List *vq;
-
- /* Explicit vq:IOThread assignment */
- for (vq = node->value->vqs; vq; vq = vq->next) {
- vq_aio_context[vq->value] = ctx;
- }
- } else {
- /* Round-robin vq:IOThread assignment */
- for (unsigned i = cur_iothread; i < num_queues;
- i += num_iothreads) {
- vq_aio_context[i] = ctx;
- }
- }
-
- cur_iothread++;
- }
-}
-
-/* Context: BQL held */
-bool virtio_blk_data_plane_create(VirtIODevice *vdev, VirtIOBlkConf *conf,
- VirtIOBlockDataPlane **dataplane,
- Error **errp)
-{
- VirtIOBlockDataPlane *s;
- BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
- VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
-
- *dataplane = NULL;
-
- if (conf->iothread || conf->iothread_vq_mapping_list) {
- if (!k->set_guest_notifiers || !k->ioeventfd_assign) {
- error_setg(errp,
- "device is incompatible with iothread "
- "(transport does not support notifiers)");
- return false;
- }
- if (!virtio_device_ioeventfd_enabled(vdev)) {
- error_setg(errp, "ioeventfd is required for iothread");
- return false;
- }
-
- /* If dataplane is (re-)enabled while the guest is running there could
- * be block jobs that can conflict.
- */
- if (blk_op_is_blocked(conf->conf.blk, BLOCK_OP_TYPE_DATAPLANE, errp)) {
- error_prepend(errp, "cannot start virtio-blk dataplane: ");
- return false;
- }
- }
- /* Don't try if transport does not support notifiers. */
- if (!virtio_device_ioeventfd_enabled(vdev)) {
- return false;
- }
-
- s = g_new0(VirtIOBlockDataPlane, 1);
- s->vdev = vdev;
- s->conf = conf;
- s->vq_aio_context = g_new(AioContext *, conf->num_queues);
-
- if (conf->iothread_vq_mapping_list) {
- apply_vq_mapping(conf->iothread_vq_mapping_list, s->vq_aio_context,
- conf->num_queues);
- } else if (conf->iothread) {
- AioContext *ctx = iothread_get_aio_context(conf->iothread);
- for (unsigned i = 0; i < conf->num_queues; i++) {
- s->vq_aio_context[i] = ctx;
- }
-
- /* Released in virtio_blk_data_plane_destroy() */
- object_ref(OBJECT(conf->iothread));
- } else {
- AioContext *ctx = qemu_get_aio_context();
- for (unsigned i = 0; i < conf->num_queues; i++) {
- s->vq_aio_context[i] = ctx;
- }
- }
-
- *dataplane = s;
-
- return true;
-}
-
-/* Context: BQL held */
-void virtio_blk_data_plane_destroy(VirtIOBlockDataPlane *s)
-{
- VirtIOBlock *vblk;
- VirtIOBlkConf *conf;
-
- if (!s) {
- return;
- }
-
- vblk = VIRTIO_BLK(s->vdev);
- assert(!vblk->dataplane_started);
- conf = s->conf;
-
- if (conf->iothread_vq_mapping_list) {
- IOThreadVirtQueueMappingList *node;
-
- for (node = conf->iothread_vq_mapping_list; node; node = node->next) {
- IOThread *iothread = iothread_by_id(node->value->iothread);
- object_unref(OBJECT(iothread));
- }
- }
-
- if (conf->iothread) {
- object_unref(OBJECT(conf->iothread));
- }
-
- g_free(s->vq_aio_context);
- g_free(s);
-}
-
-/* Context: BQL held */
-int virtio_blk_data_plane_start(VirtIODevice *vdev)
-{
- VirtIOBlock *vblk = VIRTIO_BLK(vdev);
- VirtIOBlockDataPlane *s = vblk->dataplane;
- BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vblk)));
- VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
- unsigned i;
- unsigned nvqs = s->conf->num_queues;
- Error *local_err = NULL;
- int r;
-
- if (vblk->dataplane_started || s->starting) {
- return 0;
- }
-
- s->starting = true;
-
- /* Set up guest notifier (irq) */
- r = k->set_guest_notifiers(qbus->parent, nvqs, true);
- if (r != 0) {
- error_report("virtio-blk failed to set guest notifier (%d), "
- "ensure -accel kvm is set.", r);
- goto fail_guest_notifiers;
- }
-
- /*
- * Batch all the host notifiers in a single transaction to avoid
- * quadratic time complexity in address_space_update_ioeventfds().
- */
- memory_region_transaction_begin();
-
- /* Set up virtqueue notify */
- for (i = 0; i < nvqs; i++) {
- r = virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), i, true);
- if (r != 0) {
- int j = i;
-
- fprintf(stderr, "virtio-blk failed to set host notifier (%d)\n", r);
- while (i--) {
- virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), i, false);
- }
-
- /*
- * The transaction expects the ioeventfds to be open when it
- * commits. Do it now, before the cleanup loop.
- */
- memory_region_transaction_commit();
-
- while (j--) {
- virtio_bus_cleanup_host_notifier(VIRTIO_BUS(qbus), j);
- }
- goto fail_host_notifiers;
- }
- }
-
- memory_region_transaction_commit();
-
- trace_virtio_blk_data_plane_start(s);
-
- r = blk_set_aio_context(s->conf->conf.blk, s->vq_aio_context[0],
- &local_err);
- if (r < 0) {
- error_report_err(local_err);
- goto fail_aio_context;
- }
-
- /*
- * These fields must be visible to the IOThread when it processes the
- * virtqueue, otherwise it will think dataplane has not started yet.
- *
- * Make sure ->dataplane_started is false when blk_set_aio_context() is
- * called above so that draining does not cause the host notifier to be
- * detached/attached prematurely.
- */
- s->starting = false;
- vblk->dataplane_started = true;
- smp_wmb(); /* paired with aio_notify_accept() on the read side */
-
- /* Get this show started by hooking up our callbacks */
- if (!blk_in_drain(s->conf->conf.blk)) {
- for (i = 0; i < nvqs; i++) {
- VirtQueue *vq = virtio_get_queue(s->vdev, i);
- AioContext *ctx = s->vq_aio_context[i];
-
- /* Kick right away to begin processing requests already in vring */
- event_notifier_set(virtio_queue_get_host_notifier(vq));
-
- virtio_queue_aio_attach_host_notifier(vq, ctx);
- }
- }
- return 0;
-
- fail_aio_context:
- memory_region_transaction_begin();
-
- for (i = 0; i < nvqs; i++) {
- virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), i, false);
- }
-
- memory_region_transaction_commit();
-
- for (i = 0; i < nvqs; i++) {
- virtio_bus_cleanup_host_notifier(VIRTIO_BUS(qbus), i);
- }
- fail_host_notifiers:
- k->set_guest_notifiers(qbus->parent, nvqs, false);
- fail_guest_notifiers:
- vblk->dataplane_disabled = true;
- s->starting = false;
- return -ENOSYS;
-}
-
-/* Stop notifications for new requests from guest.
- *
- * Context: BH in IOThread
- */
-static void virtio_blk_data_plane_stop_vq_bh(void *opaque)
-{
- VirtQueue *vq = opaque;
- EventNotifier *host_notifier = virtio_queue_get_host_notifier(vq);
-
- virtio_queue_aio_detach_host_notifier(vq, qemu_get_current_aio_context());
-
- /*
- * Test and clear notifier after disabling event, in case poll callback
- * didn't have time to run.
- */
- virtio_queue_host_notifier_read(host_notifier);
-}
-
-/* Context: BQL held */
-void virtio_blk_data_plane_stop(VirtIODevice *vdev)
-{
- VirtIOBlock *vblk = VIRTIO_BLK(vdev);
- VirtIOBlockDataPlane *s = vblk->dataplane;
- BusState *qbus = qdev_get_parent_bus(DEVICE(vblk));
- VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
- unsigned i;
- unsigned nvqs = s->conf->num_queues;
-
- if (!vblk->dataplane_started || s->stopping) {
- return;
- }
-
- /* Better luck next time. */
- if (vblk->dataplane_disabled) {
- vblk->dataplane_disabled = false;
- vblk->dataplane_started = false;
- return;
- }
- s->stopping = true;
- trace_virtio_blk_data_plane_stop(s);
-
- if (!blk_in_drain(s->conf->conf.blk)) {
- for (i = 0; i < nvqs; i++) {
- VirtQueue *vq = virtio_get_queue(s->vdev, i);
- AioContext *ctx = s->vq_aio_context[i];
-
- aio_wait_bh_oneshot(ctx, virtio_blk_data_plane_stop_vq_bh, vq);
- }
- }
-
- /*
- * Batch all the host notifiers in a single transaction to avoid
- * quadratic time complexity in address_space_update_ioeventfds().
- */
- memory_region_transaction_begin();
-
- for (i = 0; i < nvqs; i++) {
- virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), i, false);
- }
-
- /*
- * The transaction expects the ioeventfds to be open when it
- * commits. Do it now, before the cleanup loop.
- */
- memory_region_transaction_commit();
-
- for (i = 0; i < nvqs; i++) {
- virtio_bus_cleanup_host_notifier(VIRTIO_BUS(qbus), i);
- }
-
- /*
- * Set ->dataplane_started to false before draining so that host notifiers
- * are not detached/attached anymore.
- */
- vblk->dataplane_started = false;
-
- /* Wait for virtio_blk_dma_restart_bh() and in flight I/O to complete */
- blk_drain(s->conf->conf.blk);
-
- /*
- * Try to switch bs back to the QEMU main loop. If other users keep the
- * BlockBackend in the iothread, that's ok
- */
- blk_set_aio_context(s->conf->conf.blk, qemu_get_aio_context(), NULL);
-
- /* Clean up guest notifier (irq) */
- k->set_guest_notifiers(qbus->parent, nvqs, false);
-
- s->stopping = false;
-}
-
-void virtio_blk_data_plane_detach(VirtIOBlockDataPlane *s)
-{
- VirtIODevice *vdev = VIRTIO_DEVICE(s->vdev);
-
- for (uint16_t i = 0; i < s->conf->num_queues; i++) {
- VirtQueue *vq = virtio_get_queue(vdev, i);
- virtio_queue_aio_detach_host_notifier(vq, s->vq_aio_context[i]);
- }
-}
-
-void virtio_blk_data_plane_attach(VirtIOBlockDataPlane *s)
-{
- VirtIODevice *vdev = VIRTIO_DEVICE(s->vdev);
-
- for (uint16_t i = 0; i < s->conf->num_queues; i++) {
- VirtQueue *vq = virtio_get_queue(vdev, i);
- virtio_queue_aio_attach_host_notifier(vq, s->vq_aio_context[i]);
- }
-}
diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c
index b7a344ca97..510cb4248d 100644
--- a/hw/block/virtio-blk.c
+++ b/hw/block/virtio-blk.c
@@ -27,7 +27,6 @@
#include "sysemu/sysemu.h"
#include "sysemu/runstate.h"
#include "hw/virtio/virtio-blk.h"
-#include "dataplane/virtio-blk.h"
#include "scsi/constants.h"
#ifdef __linux__
# include <scsi/sg.h>
@@ -66,7 +65,7 @@ static void virtio_blk_req_complete(VirtIOBlockReq *req, unsigned char status)
iov_discard_undo(&req->outhdr_undo);
virtqueue_push(req->vq, &req->elem, req->in_len);
if (s->dataplane_started && !s->dataplane_disabled) {
- virtio_blk_data_plane_notify(s->dataplane, req->vq);
+ virtio_notify_irqfd(vdev, req->vq);
} else {
virtio_notify(vdev, req->vq);
}
@@ -1142,7 +1141,7 @@ static void virtio_blk_handle_output(VirtIODevice *vdev, VirtQueue *vq)
{
VirtIOBlock *s = (VirtIOBlock *)vdev;
- if (s->dataplane && !s->dataplane_started) {
+ if (!s->dataplane_disabled && !s->dataplane_started) {
/* Some guests kick before setting VIRTIO_CONFIG_S_DRIVER_OK so start
* dataplane here instead of waiting for .set_status().
*/
@@ -1546,16 +1545,34 @@ static void virtio_blk_resize(void *opaque)
aio_bh_schedule_oneshot(qemu_get_aio_context(), virtio_resize_cb, vdev);
}
+static void virtio_blk_data_plane_detach(VirtIOBlock *s)
+{
+ VirtIODevice *vdev = VIRTIO_DEVICE(s);
+
+ for (uint16_t i = 0; i < s->conf.num_queues; i++) {
+ VirtQueue *vq = virtio_get_queue(vdev, i);
+ virtio_queue_aio_detach_host_notifier(vq, s->vq_aio_context[i]);
+ }
+}
+
+static void virtio_blk_data_plane_attach(VirtIOBlock *s)
+{
+ VirtIODevice *vdev = VIRTIO_DEVICE(s);
+
+ for (uint16_t i = 0; i < s->conf.num_queues; i++) {
+ VirtQueue *vq = virtio_get_queue(vdev, i);
+ virtio_queue_aio_attach_host_notifier(vq, s->vq_aio_context[i]);
+ }
+}
+
/* Suspend virtqueue ioeventfd processing during drain */
static void virtio_blk_drained_begin(void *opaque)
{
VirtIOBlock *s = opaque;
- if (!s->dataplane || !s->dataplane_started) {
- return;
+ if (s->dataplane_started) {
+ virtio_blk_data_plane_detach(s);
}
-
- virtio_blk_data_plane_detach(s->dataplane);
}
/* Resume virtqueue ioeventfd processing after drain */
@@ -1563,11 +1580,9 @@ static void virtio_blk_drained_end(void *opaque)
{
VirtIOBlock *s = opaque;
- if (!s->dataplane || !s->dataplane_started) {
- return;
+ if (s->dataplane_started) {
+ virtio_blk_data_plane_attach(s);
}
-
- virtio_blk_data_plane_attach(s->dataplane);
}
static const BlockDevOps virtio_block_ops = {
@@ -1576,6 +1591,326 @@ static const BlockDevOps virtio_block_ops = {
.drained_end = virtio_blk_drained_end,
};
+/* Generate vq:AioContext mappings from a validated iothread-vq-mapping list */
+static void
+apply_vq_mapping(IOThreadVirtQueueMappingList *iothread_vq_mapping_list,
+ AioContext **vq_aio_context, uint16_t num_queues)
+{
+ IOThreadVirtQueueMappingList *node;
+ size_t num_iothreads = 0;
+ size_t cur_iothread = 0;
+
+ for (node = iothread_vq_mapping_list; node; node = node->next) {
+ num_iothreads++;
+ }
+
+ for (node = iothread_vq_mapping_list; node; node = node->next) {
+ IOThread *iothread = iothread_by_id(node->value->iothread);
+ AioContext *ctx = iothread_get_aio_context(iothread);
+
+ /* Released in virtio_blk_data_plane_destroy() */
+ object_ref(OBJECT(iothread));
+
+ if (node->value->vqs) {
+ uint16List *vq;
+
+ /* Explicit vq:IOThread assignment */
+ for (vq = node->value->vqs; vq; vq = vq->next) {
+ vq_aio_context[vq->value] = ctx;
+ }
+ } else {
+ /* Round-robin vq:IOThread assignment */
+ for (unsigned i = cur_iothread; i < num_queues;
+ i += num_iothreads) {
+ vq_aio_context[i] = ctx;
+ }
+ }
+
+ cur_iothread++;
+ }
+}
+
+/* Context: BQL held */
+static bool virtio_blk_data_plane_create(VirtIOBlock *s, Error **errp)
+{
+ VirtIODevice *vdev = VIRTIO_DEVICE(s);
+ VirtIOBlkConf *conf = &s->conf;
+ BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
+ VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
+
+ if (conf->iothread || conf->iothread_vq_mapping_list) {
+ if (!k->set_guest_notifiers || !k->ioeventfd_assign) {
+ error_setg(errp,
+ "device is incompatible with iothread "
+ "(transport does not support notifiers)");
+ return false;
+ }
+ if (!virtio_device_ioeventfd_enabled(vdev)) {
+ error_setg(errp, "ioeventfd is required for iothread");
+ return false;
+ }
+
+ /*
+ * If dataplane is (re-)enabled while the guest is running there could
+ * be block jobs that can conflict.
+ */
+ if (blk_op_is_blocked(conf->conf.blk, BLOCK_OP_TYPE_DATAPLANE, errp)) {
+ error_prepend(errp, "cannot start virtio-blk dataplane: ");
+ return false;
+ }
+ }
+ /* Don't try if transport does not support notifiers. */
+ if (!virtio_device_ioeventfd_enabled(vdev)) {
+ s->dataplane_disabled = true;
+ return false;
+ }
+
+ s->vq_aio_context = g_new(AioContext *, conf->num_queues);
+
+ if (conf->iothread_vq_mapping_list) {
+ apply_vq_mapping(conf->iothread_vq_mapping_list, s->vq_aio_context,
+ conf->num_queues);
+ } else if (conf->iothread) {
+ AioContext *ctx = iothread_get_aio_context(conf->iothread);
+ for (unsigned i = 0; i < conf->num_queues; i++) {
+ s->vq_aio_context[i] = ctx;
+ }
+
+ /* Released in virtio_blk_data_plane_destroy() */
+ object_ref(OBJECT(conf->iothread));
+ } else {
+ AioContext *ctx = qemu_get_aio_context();
+ for (unsigned i = 0; i < conf->num_queues; i++) {
+ s->vq_aio_context[i] = ctx;
+ }
+ }
+
+ return true;
+}
+
+/* Context: BQL held */
+static void virtio_blk_data_plane_destroy(VirtIOBlock *s)
+{
+ VirtIOBlkConf *conf = &s->conf;
+
+ assert(!s->dataplane_started);
+
+ if (conf->iothread_vq_mapping_list) {
+ IOThreadVirtQueueMappingList *node;
+
+ for (node = conf->iothread_vq_mapping_list; node; node = node->next) {
+ IOThread *iothread = iothread_by_id(node->value->iothread);
+ object_unref(OBJECT(iothread));
+ }
+ }
+
+ if (conf->iothread) {
+ object_unref(OBJECT(conf->iothread));
+ }
+
+ g_free(s->vq_aio_context);
+ s->vq_aio_context = NULL;
+}
+
+/* Context: BQL held */
+static int virtio_blk_data_plane_start(VirtIODevice *vdev)
+{
+ VirtIOBlock *s = VIRTIO_BLK(vdev);
+ BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(s)));
+ VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
+ unsigned i;
+ unsigned nvqs = s->conf.num_queues;
+ Error *local_err = NULL;
+ int r;
+
+ if (s->dataplane_started || s->dataplane_starting) {
+ return 0;
+ }
+
+ s->dataplane_starting = true;
+
+ /* Set up guest notifier (irq) */
+ r = k->set_guest_notifiers(qbus->parent, nvqs, true);
+ if (r != 0) {
+ error_report("virtio-blk failed to set guest notifier (%d), "
+ "ensure -accel kvm is set.", r);
+ goto fail_guest_notifiers;
+ }
+
+ /*
+ * Batch all the host notifiers in a single transaction to avoid
+ * quadratic time complexity in address_space_update_ioeventfds().
+ */
+ memory_region_transaction_begin();
+
+ /* Set up virtqueue notify */
+ for (i = 0; i < nvqs; i++) {
+ r = virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), i, true);
+ if (r != 0) {
+ int j = i;
+
+ fprintf(stderr, "virtio-blk failed to set host notifier (%d)\n", r);
+ while (i--) {
+ virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), i, false);
+ }
+
+ /*
+ * The transaction expects the ioeventfds to be open when it
+ * commits. Do it now, before the cleanup loop.
+ */
+ memory_region_transaction_commit();
+
+ while (j--) {
+ virtio_bus_cleanup_host_notifier(VIRTIO_BUS(qbus), j);
+ }
+ goto fail_host_notifiers;
+ }
+ }
+
+ memory_region_transaction_commit();
+
+ r = blk_set_aio_context(s->conf.conf.blk, s->vq_aio_context[0],
+ &local_err);
+ if (r < 0) {
+ error_report_err(local_err);
+ goto fail_aio_context;
+ }
+
+ /*
+ * These fields must be visible to the IOThread when it processes the
+ * virtqueue, otherwise it will think dataplane has not started yet.
+ *
+ * Make sure ->dataplane_started is false when blk_set_aio_context() is
+ * called above so that draining does not cause the host notifier to be
+ * detached/attached prematurely.
+ */
+ s->dataplane_starting = false;
+ s->dataplane_started = true;
+ smp_wmb(); /* paired with aio_notify_accept() on the read side */
+
+ /* Get this show started by hooking up our callbacks */
+ if (!blk_in_drain(s->conf.conf.blk)) {
+ for (i = 0; i < nvqs; i++) {
+ VirtQueue *vq = virtio_get_queue(vdev, i);
+ AioContext *ctx = s->vq_aio_context[i];
+
+ /* Kick right away to begin processing requests already in vring */
+ event_notifier_set(virtio_queue_get_host_notifier(vq));
+
+ virtio_queue_aio_attach_host_notifier(vq, ctx);
+ }
+ }
+ return 0;
+
+ fail_aio_context:
+ memory_region_transaction_begin();
+
+ for (i = 0; i < nvqs; i++) {
+ virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), i, false);
+ }
+
+ memory_region_transaction_commit();
+
+ for (i = 0; i < nvqs; i++) {
+ virtio_bus_cleanup_host_notifier(VIRTIO_BUS(qbus), i);
+ }
+ fail_host_notifiers:
+ k->set_guest_notifiers(qbus->parent, nvqs, false);
+ fail_guest_notifiers:
+ s->dataplane_disabled = true;
+ s->dataplane_starting = false;
+ return -ENOSYS;
+}
+
+/* Stop notifications for new requests from guest.
+ *
+ * Context: BH in IOThread
+ */
+static void virtio_blk_data_plane_stop_vq_bh(void *opaque)
+{
+ VirtQueue *vq = opaque;
+ EventNotifier *host_notifier = virtio_queue_get_host_notifier(vq);
+
+ virtio_queue_aio_detach_host_notifier(vq, qemu_get_current_aio_context());
+
+ /*
+ * Test and clear notifier after disabling event, in case poll callback
+ * didn't have time to run.
+ */
+ virtio_queue_host_notifier_read(host_notifier);
+}
+
+/* Context: BQL held */
+static void virtio_blk_data_plane_stop(VirtIODevice *vdev)
+{
+ VirtIOBlock *s = VIRTIO_BLK(vdev);
+ BusState *qbus = qdev_get_parent_bus(DEVICE(s));
+ VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
+ unsigned i;
+ unsigned nvqs = s->conf.num_queues;
+
+ if (!s->dataplane_started || s->dataplane_stopping) {
+ return;
+ }
+
+ /* Better luck next time. */
+ if (s->dataplane_disabled) {
+ s->dataplane_disabled = false;
+ s->dataplane_started = false;
+ return;
+ }
+ s->dataplane_stopping = true;
+
+ if (!blk_in_drain(s->conf.conf.blk)) {
+ for (i = 0; i < nvqs; i++) {
+ VirtQueue *vq = virtio_get_queue(vdev, i);
+ AioContext *ctx = s->vq_aio_context[i];
+
+ aio_wait_bh_oneshot(ctx, virtio_blk_data_plane_stop_vq_bh, vq);
+ }
+ }
+
+ /*
+ * Batch all the host notifiers in a single transaction to avoid
+ * quadratic time complexity in address_space_update_ioeventfds().
+ */
+ memory_region_transaction_begin();
+
+ for (i = 0; i < nvqs; i++) {
+ virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), i, false);
+ }
+
+ /*
+ * The transaction expects the ioeventfds to be open when it
+ * commits. Do it now, before the cleanup loop.
+ */
+ memory_region_transaction_commit();
+
+ for (i = 0; i < nvqs; i++) {
+ virtio_bus_cleanup_host_notifier(VIRTIO_BUS(qbus), i);
+ }
+
+ /*
+ * Set ->dataplane_started to false before draining so that host notifiers
+ * are not detached/attached anymore.
+ */
+ s->dataplane_started = false;
+
+ /* Wait for virtio_blk_dma_restart_bh() and in flight I/O to complete */
+ blk_drain(s->conf.conf.blk);
+
+ /*
+ * Try to switch bs back to the QEMU main loop. If other users keep the
+ * BlockBackend in the iothread, that's ok
+ */
+ blk_set_aio_context(s->conf.conf.blk, qemu_get_aio_context(), NULL);
+
+ /* Clean up guest notifier (irq) */
+ k->set_guest_notifiers(qbus->parent, nvqs, false);
+
+ s->dataplane_stopping = false;
+}
+
static void virtio_blk_device_realize(DeviceState *dev, Error **errp)
{
VirtIODevice *vdev = VIRTIO_DEVICE(dev);
@@ -1680,7 +2015,7 @@ static void virtio_blk_device_realize(DeviceState *dev, Error **errp)
virtio_add_queue(vdev, conf->queue_size, virtio_blk_handle_output);
}
qemu_coroutine_inc_pool_size(conf->num_queues * conf->queue_size / 2);
- virtio_blk_data_plane_create(vdev, conf, &s->dataplane, &err);
+ virtio_blk_data_plane_create(s, &err);
if (err != NULL) {
error_propagate(errp, err);
for (i = 0; i < conf->num_queues; i++) {
@@ -1717,8 +2052,7 @@ static void virtio_blk_device_unrealize(DeviceState *dev)
blk_drain(s->blk);
del_boot_device_lchs(dev, "/disk@0,0");
- virtio_blk_data_plane_destroy(s->dataplane);
- s->dataplane = NULL;
+ virtio_blk_data_plane_destroy(s);
for (i = 0; i < conf->num_queues; i++) {
virtio_del_queue(vdev, i);
}
diff --git a/hw/block/dataplane/meson.build b/hw/block/dataplane/meson.build
index 025b3b061b..11a5eba2f4 100644
--- a/hw/block/dataplane/meson.build
+++ b/hw/block/dataplane/meson.build
@@ -1,2 +1 @@
-system_ss.add(when: 'CONFIG_VIRTIO_BLK', if_true: files('virtio-blk.c'))
specific_ss.add(when: 'CONFIG_XEN_BUS', if_true: files('xen-block.c'))
diff --git a/hw/block/dataplane/trace-events b/hw/block/dataplane/trace-events
deleted file mode 100644
index 38fc3e7507..0000000000
--- a/hw/block/dataplane/trace-events
+++ /dev/null
@@ -1,5 +0,0 @@
-# See docs/devel/tracing.rst for syntax documentation.
-
-# virtio-blk.c
-virtio_blk_data_plane_start(void *s) "dataplane %p"
-virtio_blk_data_plane_stop(void *s) "dataplane %p"
diff --git a/meson.build b/meson.build
index d0329966f1..5ffa8c9716 100644
--- a/meson.build
+++ b/meson.build
@@ -3286,7 +3286,6 @@ if have_system
'hw/arm',
'hw/audio',
'hw/block',
- 'hw/block/dataplane',
'hw/char',
'hw/display',
'hw/dma',
--
2.43.0© 2016 - 2024 Red Hat, Inc.