X-Git-Url: https://repo.jachan.dev/qemu.git/blobdiff_plain/041ccc922ee474693a2869d4e3b59e920c739bc0..947231ad3b479de82d8f5ec185e2d00f3c96edcd:/hw/scsi/virtio-scsi-dataplane.c

diff --git a/hw/scsi/virtio-scsi-dataplane.c b/hw/scsi/virtio-scsi-dataplane.c
index 418d73b1b4..944ea4eb53 100644
--- a/hw/scsi/virtio-scsi-dataplane.c
+++ b/hw/scsi/virtio-scsi-dataplane.c
@@ -11,146 +11,100 @@
  *
  */
 
+#include "qemu/osdep.h"
+#include "qapi/error.h"
 #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/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)
+void virtio_scsi_dataplane_setup(VirtIOSCSI *s, Error **errp)
 {
-    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)));
+    VirtIODevice *vdev = VIRTIO_DEVICE(s);
+    BusState *qbus = qdev_get_parent_bus(DEVICE(vdev));
     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
-    VirtIOSCSIVring *r = g_slice_new(VirtIOSCSIVring);
-    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->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;
+    if (vs->conf.iothread) {
+        if (!k->set_guest_notifiers || !k->ioeventfd_assign) {
+            error_setg(errp,
+                       "device is incompatible with iothread "
+                       "(transport does not support notifiers)");
+            return;
+        }
+        if (!virtio_device_ioeventfd_enabled(vdev)) {
+            error_setg(errp, "ioeventfd is required for iothread");
+            return;
+        }
+        s->ctx = iothread_get_aio_context(vs->conf.iothread);
+    } else {
+        if (!virtio_device_ioeventfd_enabled(vdev)) {
+            return;
+        }
+        s->ctx = qemu_get_aio_context();
     }
-    return req;
 }
 
-void virtio_scsi_vring_push_notify(VirtIOSCSIReq *req)
+static bool virtio_scsi_data_plane_handle_cmd(VirtIODevice *vdev,
+                                              VirtQueue *vq)
 {
-    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);
-    }
+    bool progress;
+    VirtIOSCSI *s = VIRTIO_SCSI(vdev);
+
+    virtio_scsi_acquire(s);
+    assert(s->ctx && s->dataplane_started);
+    progress = virtio_scsi_handle_cmd_vq(s, vq);
+    virtio_scsi_release(s);
+    return progress;
 }
 
-static void virtio_scsi_iothread_handle_ctrl(EventNotifier *notifier)
+static bool virtio_scsi_data_plane_handle_ctrl(VirtIODevice *vdev,
+                                               VirtQueue *vq)
 {
-    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);
-    }
+    bool progress;
+    VirtIOSCSI *s = VIRTIO_SCSI(vdev);
+
+    virtio_scsi_acquire(s);
+    assert(s->ctx && s->dataplane_started);
+    progress = virtio_scsi_handle_ctrl_vq(s, vq);
+    virtio_scsi_release(s);
+    return progress;
 }
 
-static void virtio_scsi_iothread_handle_event(EventNotifier *notifier)
+static bool virtio_scsi_data_plane_handle_event(VirtIODevice *vdev,
+                                                VirtQueue *vq)
 {
-    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);
-    }
+    bool progress;
+    VirtIOSCSI *s = VIRTIO_SCSI(vdev);
+
+    virtio_scsi_acquire(s);
+    assert(s->ctx && s->dataplane_started);
+    progress = virtio_scsi_handle_event_vq(s, vq);
+    virtio_scsi_release(s);
+    return progress;
 }
 
-static void virtio_scsi_iothread_handle_cmd(EventNotifier *notifier)
+static int virtio_scsi_vring_init(VirtIOSCSI *s, VirtQueue *vq, int n,
+                                  VirtIOHandleAIOOutput fn)
 {
-    VirtIOSCSIVring *vring = container_of(notifier,
-                                          VirtIOSCSIVring, host_notifier);
-    VirtIOSCSI *s = (VirtIOSCSI *)vring->parent;
-    VirtIOSCSIReq *req, *next;
-    QTAILQ_HEAD(, VirtIOSCSIReq) reqs = QTAILQ_HEAD_INITIALIZER(reqs);
+    BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(s)));
+    int rc;
 
-    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);
-        }
+    /* Set up virtqueue notify */
+    rc = virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), n, true);
+    if (rc != 0) {
+        fprintf(stderr, "virtio-scsi: Failed to set host notifier (%d)\n",
+                rc);
+        s->dataplane_fenced = true;
+        return rc;
     }
 
-    QTAILQ_FOREACH_SAFE(req, &reqs, next, next) {
-        virtio_scsi_handle_cmd_req_submit(s, req);
-    }
+    virtio_queue_aio_set_host_notifier_handler(vq, s->ctx, fn);
+    return 0;
 }
 
 /* assumes s->ctx held */
@@ -159,89 +113,54 @@ 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);
-    }
-    if (s->event_vring) {
-        vring_teardown(&s->event_vring->vring, vdev, 1);
-    }
-    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);
-        }
-        free(s->cmd_vrings);
-        s->cmd_vrings = NULL;
+    virtio_queue_aio_set_host_notifier_handler(vs->ctrl_vq, s->ctx, NULL);
+    virtio_queue_aio_set_host_notifier_handler(vs->event_vq, s->ctx, NULL);
+    for (i = 0; i < vs->conf.num_queues; i++) {
+        virtio_queue_aio_set_host_notifier_handler(vs->cmd_vqs[i], s->ctx, NULL);
     }
 }
 
 /* Context: QEMU global mutex held */
-void virtio_scsi_dataplane_start(VirtIOSCSI *s)
+int virtio_scsi_dataplane_start(VirtIODevice *vdev)
 {
     int i;
     int rc;
-    BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(s)));
+    BusState *qbus = qdev_get_parent_bus(DEVICE(vdev));
     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
-    VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
+    VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
+    VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 
     if (s->dataplane_started ||
         s->dataplane_starting ||
-        s->dataplane_fenced ||
-        s->ctx != iothread_get_aio_context(vs->conf.iothread)) {
-        return;
+        s->dataplane_fenced) {
+        return 0;
     }
 
     s->dataplane_starting = true;
 
-    assert(!s->blocker);
-    error_setg(&s->blocker, "block device is in use by data plane");
     /* 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) {
+    rc = virtio_scsi_vring_init(s, vs->ctrl_vq, 0,
+                                virtio_scsi_data_plane_handle_ctrl);
+    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,
+                                virtio_scsi_data_plane_handle_event);
+    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,
+                                    virtio_scsi_data_plane_handle_cmd);
+        if (rc) {
             goto fail_vrings;
         }
     }
@@ -249,60 +168,51 @@ void virtio_scsi_dataplane_start(VirtIOSCSI *s)
     s->dataplane_starting = false;
     s->dataplane_started = true;
     aio_context_release(s->ctx);
-    return;
+    return 0;
 
 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);
+        virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), 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;
+    return -ENOSYS;
 }
 
 /* Context: QEMU global mutex held */
-void virtio_scsi_dataplane_stop(VirtIOSCSI *s)
+void virtio_scsi_dataplane_stop(VirtIODevice *vdev)
 {
-    BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(s)));
+    BusState *qbus = qdev_get_parent_bus(DEVICE(vdev));
     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
-    VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
+    VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
+    VirtIOSCSI *s = VIRTIO_SCSI(vdev);
     int i;
 
+    if (!s->dataplane_started || s->dataplane_stopping) {
+        return;
+    }
+
     /* Better luck next time. */
     if (s->dataplane_fenced) {
         s->dataplane_fenced = false;
+        s->dataplane_started = false;
         return;
     }
-    if (!s->dataplane_started || s->dataplane_stopping) {
-        return;
-    }
-    error_free(s->blocker);
-    s->blocker = NULL;
     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 */
-
+    virtio_scsi_clear_aio(s);
     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);
+    blk_drain_all(); /* ensure there are no in-flight requests */
 
     for (i = 0; i < vs->conf.num_queues + 2; i++) {
-        k->set_host_notifier(qbus->parent, i, false);
+        virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), i, false);
     }
 
     /* Clean up guest notifier (irq) */