vhost: do not verify ring mappings when IOMMU is enabled

[qemu.git] / hw / virtio / virtio.c

diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index 03592c542a55892331abd9c0e02513e03deca153..006d3d1148fef758f1115470995d9f9e9237c4ab 100644 (file)
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -21,7 +21,6 @@
 #include "hw/virtio/virtio.h"
 #include "qemu/atomic.h"
 #include "hw/virtio/virtio-bus.h"
-#include "migration/migration.h"
 #include "hw/virtio/virtio-access.h"
 #include "sysemu/dma.h"
 
@@ -183,7 +182,7 @@ void virtio_queue_update_rings(VirtIODevice *vdev, int n)
 {
     VRing *vring = &vdev->vq[n].vring;
 
-    if (!vring->desc) {
+    if (!vring->num || !vring->desc || !vring->align) {
         /* not yet setup -> nothing to do */
         return;
     }
@@ -816,6 +815,7 @@ static void *virtqueue_alloc_element(size_t sz, unsigned out_num, unsigned in_nu
 
     assert(sz >= sizeof(VirtQueueElement));
     elem = g_malloc(out_sg_end);
+    trace_virtqueue_alloc_element(elem, sz, in_num, out_num);
     elem->out_num = out_num;
     elem->in_num = in_num;
     elem->in_addr = (void *)elem + in_addr_ofs;
@@ -834,7 +834,7 @@ void *virtqueue_pop(VirtQueue *vq, size_t sz)
     int64_t len;
     VirtIODevice *vdev = vq->vdev;
     VirtQueueElement *elem = NULL;
-    unsigned out_num, in_num;
+    unsigned out_num, in_num, elem_entries;
     hwaddr addr[VIRTQUEUE_MAX_SIZE];
     struct iovec iov[VIRTQUEUE_MAX_SIZE];
     VRingDesc desc;
@@ -852,7 +852,7 @@ void *virtqueue_pop(VirtQueue *vq, size_t sz)
     smp_rmb();
 
     /* When we start there are none of either input nor output. */
-    out_num = in_num = 0;
+    out_num = in_num = elem_entries = 0;
 
     max = vq->vring.num;
 
@@ -922,7 +922,7 @@ void *virtqueue_pop(VirtQueue *vq, size_t sz)
         }
 
         /* If we've got too many, that implies a descriptor loop. */
-        if ((in_num + out_num) > max) {
+        if (++elem_entries > max) {
             virtio_error(vdev, "Looped descriptor");
             goto err_undo_map;
         }
@@ -1025,11 +1025,9 @@ void *qemu_get_virtqueue_element(VirtIODevice *vdev, QEMUFile *f, size_t sz)
 
     /* TODO: teach all callers that this can fail, and return failure instead
      * of asserting here.
-     * When we do, we might be able to re-enable NDEBUG below.
+     * This is just one thing (there are probably more) that must be
+     * fixed before we can allow NDEBUG compilation.
      */
-#ifdef NDEBUG
-#error building with NDEBUG is not supported
-#endif
     assert(ARRAY_SIZE(data.in_addr) >= data.in_num);
     assert(ARRAY_SIZE(data.out_addr) >= data.out_num);
 
@@ -1416,6 +1414,9 @@ void virtio_config_modern_writel(VirtIODevice *vdev,
 
 void virtio_queue_set_addr(VirtIODevice *vdev, int n, hwaddr addr)
 {
+    if (!vdev->vq[n].vring.num) {
+        return;
+    }
     vdev->vq[n].vring.desc = addr;
     virtio_queue_update_rings(vdev, n);
 }
@@ -1428,6 +1429,9 @@ hwaddr virtio_queue_get_addr(VirtIODevice *vdev, int n)
 void virtio_queue_set_rings(VirtIODevice *vdev, int n, hwaddr desc,
                             hwaddr avail, hwaddr used)
 {
+    if (!vdev->vq[n].vring.num) {
+        return;
+    }
     vdev->vq[n].vring.desc = desc;
     vdev->vq[n].vring.avail = avail;
     vdev->vq[n].vring.used = used;
@@ -1496,8 +1500,10 @@ void virtio_queue_set_align(VirtIODevice *vdev, int n, int align)
      */
     assert(k->has_variable_vring_alignment);
 
-    vdev->vq[n].vring.align = align;
-    virtio_queue_update_rings(vdev, n);
+    if (align) {
+        vdev->vq[n].vring.align = align;
+        virtio_queue_update_rings(vdev, n);
+    }
 }
 
 static bool virtio_queue_notify_aio_vq(VirtQueue *vq)
@@ -1899,7 +1905,7 @@ static const VMStateDescription vmstate_virtio = {
     }
 };
 
-void virtio_save(VirtIODevice *vdev, QEMUFile *f)
+int virtio_save(VirtIODevice *vdev, QEMUFile *f)
 {
     BusState *qbus = qdev_get_parent_bus(DEVICE(vdev));
     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
@@ -1949,20 +1955,21 @@ void virtio_save(VirtIODevice *vdev, QEMUFile *f)
     }
 
     if (vdc->vmsd) {
-        vmstate_save_state(f, vdc->vmsd, vdev, NULL);
+        int ret = vmstate_save_state(f, vdc->vmsd, vdev, NULL);
+        if (ret) {
+            return ret;
+        }
     }
 
     /* Subsections */
-    vmstate_save_state(f, &vmstate_virtio, vdev, NULL);
+    return vmstate_save_state(f, &vmstate_virtio, vdev, NULL);
 }
 
 /* A wrapper for use as a VMState .put function */
 static int virtio_device_put(QEMUFile *f, void *opaque, size_t size,
                               VMStateField *field, QJSON *vmdesc)
 {
-    virtio_save(VIRTIO_DEVICE(opaque), f);
-
-    return 0;
+    return virtio_save(VIRTIO_DEVICE(opaque), f);
 }
 
 /* A wrapper for use as a VMState .get function */
@@ -2311,6 +2318,16 @@ void virtio_queue_set_last_avail_idx(VirtIODevice *vdev, int n, uint16_t idx)
     vdev->vq[n].shadow_avail_idx = idx;
 }
 
+void virtio_queue_restore_last_avail_idx(VirtIODevice *vdev, int n)
+{
+    rcu_read_lock();
+    if (vdev->vq[n].vring.desc) {
+        vdev->vq[n].last_avail_idx = vring_used_idx(&vdev->vq[n]);
+        vdev->vq[n].shadow_avail_idx = vdev->vq[n].last_avail_idx;
+    }
+    rcu_read_unlock();
+}
+
 void virtio_queue_update_used_idx(VirtIODevice *vdev, int n)
 {
     rcu_read_lock();
@@ -2451,12 +2468,12 @@ void GCC_FMT_ATTR(2, 3) virtio_error(VirtIODevice *vdev, const char *fmt, ...)
     error_vreport(fmt, ap);
     va_end(ap);
 
-    vdev->broken = true;
-
     if (virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) {
-        virtio_set_status(vdev, vdev->status | VIRTIO_CONFIG_S_NEEDS_RESET);
+        vdev->status = vdev->status | VIRTIO_CONFIG_S_NEEDS_RESET;
         virtio_notify_config(vdev);
     }
+
+    vdev->broken = true;
 }
 
 static void virtio_memory_listener_commit(MemoryListener *listener)
@@ -2492,6 +2509,7 @@ static void virtio_device_realize(DeviceState *dev, Error **errp)
     virtio_bus_device_plugged(vdev, &err);
     if (err != NULL) {
         error_propagate(errp, err);
+        vdc->unrealize(dev, NULL);
         return;
     }
 
@@ -2554,8 +2572,9 @@ static Property virtio_properties[] = {
 static int virtio_device_start_ioeventfd_impl(VirtIODevice *vdev)
 {
     VirtioBusState *qbus = VIRTIO_BUS(qdev_get_parent_bus(DEVICE(vdev)));
-    int n, r, err;
+    int i, n, r, err;
 
+    memory_region_transaction_begin();
     for (n = 0; n < VIRTIO_QUEUE_MAX; n++) {
         VirtQueue *vq = &vdev->vq[n];
         if (!virtio_queue_get_num(vdev, n)) {
@@ -2578,9 +2597,11 @@ static int virtio_device_start_ioeventfd_impl(VirtIODevice *vdev)
         }
         event_notifier_set(&vq->host_notifier);
     }
+    memory_region_transaction_commit();
     return 0;
 
 assign_error:
+    i = n; /* save n for a second iteration after transaction is committed. */
     while (--n >= 0) {
         VirtQueue *vq = &vdev->vq[n];
         if (!virtio_queue_get_num(vdev, n)) {
@@ -2591,6 +2612,14 @@ assign_error:
         r = virtio_bus_set_host_notifier(qbus, n, false);
         assert(r >= 0);
     }
+    memory_region_transaction_commit();
+
+    while (--i >= 0) {
+        if (!virtio_queue_get_num(vdev, i)) {
+            continue;
+        }
+        virtio_bus_cleanup_host_notifier(qbus, i);
+    }
     return err;
 }
 
@@ -2607,6 +2636,7 @@ static void virtio_device_stop_ioeventfd_impl(VirtIODevice *vdev)
     VirtioBusState *qbus = VIRTIO_BUS(qdev_get_parent_bus(DEVICE(vdev)));
     int n, r;
 
+    memory_region_transaction_begin();
     for (n = 0; n < VIRTIO_QUEUE_MAX; n++) {
         VirtQueue *vq = &vdev->vq[n];
 
@@ -2617,6 +2647,14 @@ static void virtio_device_stop_ioeventfd_impl(VirtIODevice *vdev)
         r = virtio_bus_set_host_notifier(qbus, n, false);
         assert(r >= 0);
     }
+    memory_region_transaction_commit();
+
+    for (n = 0; n < VIRTIO_QUEUE_MAX; n++) {
+        if (!virtio_queue_get_num(vdev, n)) {
+            continue;
+        }
+        virtio_bus_cleanup_host_notifier(qbus, n);
+    }
 }
 
 void virtio_device_stop_ioeventfd(VirtIODevice *vdev)