virtio, pc: fixes, features

New virtio iommu.
 Unrealize memory leaks.
 In-band kick/call support.
 Bugfixes, documentation all over the place.
 
 Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
 -----BEGIN PGP SIGNATURE-----
 
 iQFDBAABCAAtFiEEXQn9CHHI+FuUyooNKB8NuNKNVGkFAl5XgekPHG1zdEByZWRo
 YXQuY29tAAoJECgfDbjSjVRpPe0IAJzRlUZMmT0pJ0ppCfydAlnChGyoOmm5BnuV
 1u0qSxDYv3qDmIHa+LVcAwJCc4OmmWzFgWiO2V2+vnjwu/RwsiwzZOzXwecRnlsn
 0OjROmROAyR5j8h6pSzinWyRLcaKSS8tasDMRbRh7wlkEns78970V5GBPnvVQsGt
 WG2BO8cvkoCksry16YnzPQEuQ055q1x19rsw2yeZ+3yVfLtiSoplxo5/7UAIGcaE
 K4zUTQ3ktAbYfKxE96t7rxlmjbFM8H/W0GvKaPqjBDHEoi0SN+uIpyh5rHSeSsp8
 WS4KUMFvr/z5eEsD02bxsA87nC2PDeTWEgOO/QyBUMtgUt6i274=
 =ue55
 -----END PGP SIGNATURE-----

Merge remote-tracking branch 'remotes/mst/tags/for_upstream' into staging

virtio, pc: fixes, features

New virtio iommu.
Unrealize memory leaks.
In-band kick/call support.
Bugfixes, documentation all over the place.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

# gpg: Signature made Thu 27 Feb 2020 08:46:33 GMT
# gpg:                using RSA key 5D09FD0871C8F85B94CA8A0D281F0DB8D28D5469
# gpg:                issuer "mst@redhat.com"
# gpg: Good signature from "Michael S. Tsirkin <mst@kernel.org>" [full]
# gpg:                 aka "Michael S. Tsirkin <mst@redhat.com>" [full]
# Primary key fingerprint: 0270 606B 6F3C DF3D 0B17  0970 C350 3912 AFBE 8E67
#      Subkey fingerprint: 5D09 FD08 71C8 F85B 94CA  8A0D 281F 0DB8 D28D 5469

* remotes/mst/tags/for_upstream: (30 commits)
  Fixed assert in vhost_user_set_mem_table_postcopy
  vhost-user: only set slave channel for first vq
  acpi: cpuhp: document CPHP_GET_CPU_ID_CMD command
  libvhost-user: implement in-band notifications
  docs: vhost-user: add in-band kick/call messages
  libvhost-user: handle NOFD flag in call/kick/err better
  libvhost-user-glib: use g_main_context_get_thread_default()
  libvhost-user-glib: fix VugDev main fd cleanup
  libvhost-user: implement VHOST_USER_PROTOCOL_F_REPLY_ACK
  MAINTAINERS: add virtio-iommu related files
  hw/arm/virt: Add the virtio-iommu device tree mappings
  virtio-iommu-pci: Add virtio iommu pci support
  virtio-iommu: Support migration
  virtio-iommu: Implement fault reporting
  virtio-iommu: Implement translate
  virtio-iommu: Implement map/unmap
  virtio-iommu: Implement attach/detach command
  virtio-iommu: Decode the command payload
  virtio-iommu: Add skeleton
  virtio: gracefully handle invalid region caches
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

hw/virtio/virtio.c

@@ -282,15 +282,19 @@ static void vring_packed_flags_write(VirtIODevice *vdev,
 /* Called within rcu_read_lock().  */
 static VRingMemoryRegionCaches *vring_get_region_caches(struct VirtQueue *vq)
 {
-    VRingMemoryRegionCaches *caches = atomic_rcu_read(&vq->vring.caches);
-    assert(caches != NULL);
-    return caches;
+    return atomic_rcu_read(&vq->vring.caches);
 }
+
 /* Called within rcu_read_lock().  */
 static inline uint16_t vring_avail_flags(VirtQueue *vq)
 {
     VRingMemoryRegionCaches *caches = vring_get_region_caches(vq);
     hwaddr pa = offsetof(VRingAvail, flags);
+
+    if (!caches) {
+        return 0;
+    }
+
     return virtio_lduw_phys_cached(vq->vdev, &caches->avail, pa);
 }
 
@@ -299,6 +303,11 @@ static inline uint16_t vring_avail_idx(VirtQueue *vq)
 {
     VRingMemoryRegionCaches *caches = vring_get_region_caches(vq);
     hwaddr pa = offsetof(VRingAvail, idx);
+
+    if (!caches) {
+        return 0;
+    }
+
     vq->shadow_avail_idx = virtio_lduw_phys_cached(vq->vdev, &caches->avail, pa);
     return vq->shadow_avail_idx;
 }
@@ -308,6 +317,11 @@ static inline uint16_t vring_avail_ring(VirtQueue *vq, int i)
 {
     VRingMemoryRegionCaches *caches = vring_get_region_caches(vq);
     hwaddr pa = offsetof(VRingAvail, ring[i]);
+
+    if (!caches) {
+        return 0;
+    }
+
     return virtio_lduw_phys_cached(vq->vdev, &caches->avail, pa);
 }
 
@@ -323,6 +337,11 @@ static inline void vring_used_write(VirtQueue *vq, VRingUsedElem *uelem,
 {
     VRingMemoryRegionCaches *caches = vring_get_region_caches(vq);
     hwaddr pa = offsetof(VRingUsed, ring[i]);
+
+    if (!caches) {
+        return;
+    }
+
     virtio_tswap32s(vq->vdev, &uelem->id);
     virtio_tswap32s(vq->vdev, &uelem->len);
     address_space_write_cached(&caches->used, pa, uelem, sizeof(VRingUsedElem));
@@ -334,6 +353,11 @@ static uint16_t vring_used_idx(VirtQueue *vq)
 {
     VRingMemoryRegionCaches *caches = vring_get_region_caches(vq);
     hwaddr pa = offsetof(VRingUsed, idx);
+
+    if (!caches) {
+        return 0;
+    }
+
     return virtio_lduw_phys_cached(vq->vdev, &caches->used, pa);
 }
 
@@ -342,8 +366,12 @@ static inline void vring_used_idx_set(VirtQueue *vq, uint16_t val)
 {
     VRingMemoryRegionCaches *caches = vring_get_region_caches(vq);
     hwaddr pa = offsetof(VRingUsed, idx);
-    virtio_stw_phys_cached(vq->vdev, &caches->used, pa, val);
-    address_space_cache_invalidate(&caches->used, pa, sizeof(val));
+
+    if (caches) {
+        virtio_stw_phys_cached(vq->vdev, &caches->used, pa, val);
+        address_space_cache_invalidate(&caches->used, pa, sizeof(val));
+    }
+
     vq->used_idx = val;
 }
 
@@ -353,8 +381,13 @@ static inline void vring_used_flags_set_bit(VirtQueue *vq, int mask)
     VRingMemoryRegionCaches *caches = vring_get_region_caches(vq);
     VirtIODevice *vdev = vq->vdev;
     hwaddr pa = offsetof(VRingUsed, flags);
-    uint16_t flags = virtio_lduw_phys_cached(vq->vdev, &caches->used, pa);
+    uint16_t flags;
 
+    if (!caches) {
+        return;
+    }
+
+    flags = virtio_lduw_phys_cached(vq->vdev, &caches->used, pa);
     virtio_stw_phys_cached(vdev, &caches->used, pa, flags | mask);
     address_space_cache_invalidate(&caches->used, pa, sizeof(flags));
 }
@@ -365,8 +398,13 @@ static inline void vring_used_flags_unset_bit(VirtQueue *vq, int mask)
     VRingMemoryRegionCaches *caches = vring_get_region_caches(vq);
     VirtIODevice *vdev = vq->vdev;
     hwaddr pa = offsetof(VRingUsed, flags);
-    uint16_t flags = virtio_lduw_phys_cached(vq->vdev, &caches->used, pa);
+    uint16_t flags;
 
+    if (!caches) {
+        return;
+    }
+
+    flags = virtio_lduw_phys_cached(vq->vdev, &caches->used, pa);
     virtio_stw_phys_cached(vdev, &caches->used, pa, flags & ~mask);
     address_space_cache_invalidate(&caches->used, pa, sizeof(flags));
 }
@@ -381,6 +419,10 @@ static inline void vring_set_avail_event(VirtQueue *vq, uint16_t val)
     }
 
     caches = vring_get_region_caches(vq);
+    if (!caches) {
+        return;
+    }
+
     pa = offsetof(VRingUsed, ring[vq->vring.num]);
     virtio_stw_phys_cached(vq->vdev, &caches->used, pa, val);
     address_space_cache_invalidate(&caches->used, pa, sizeof(val));
@@ -410,7 +452,11 @@ static void virtio_queue_packed_set_notification(VirtQueue *vq, int enable)
     VRingMemoryRegionCaches *caches;
 
     RCU_READ_LOCK_GUARD();
-    caches  = vring_get_region_caches(vq);
+    caches = vring_get_region_caches(vq);
+    if (!caches) {
+        return;
+    }
+
     vring_packed_event_read(vq->vdev, &caches->used, &e);
 
     if (!enable) {
@@ -597,6 +643,10 @@ static int virtio_queue_packed_empty_rcu(VirtQueue *vq)
     }
 
     cache = vring_get_region_caches(vq);
+    if (!cache) {
+        return 1;
+    }
+
     vring_packed_desc_read_flags(vq->vdev, &desc.flags, &cache->desc,
                                  vq->last_avail_idx);
 
@@ -777,6 +827,10 @@ static void virtqueue_packed_fill_desc(VirtQueue *vq,
     }
 
     caches = vring_get_region_caches(vq);
+    if (!caches) {
+        return;
+    }
+
     vring_packed_desc_write(vq->vdev, &desc, &caches->desc, head, strict_order);
 }
 
@@ -949,6 +1003,10 @@ static void virtqueue_split_get_avail_bytes(VirtQueue *vq,
 
     max = vq->vring.num;
     caches = vring_get_region_caches(vq);
+    if (!caches) {
+        goto err;
+    }
+
     while ((rc = virtqueue_num_heads(vq, idx)) > 0) {
         MemoryRegionCache *desc_cache = &caches->desc;
         unsigned int num_bufs;
@@ -1089,6 +1147,9 @@ static void virtqueue_packed_get_avail_bytes(VirtQueue *vq,
 
     max = vq->vring.num;
     caches = vring_get_region_caches(vq);
+    if (!caches) {
+        goto err;
+    }
 
     for (;;) {
         unsigned int num_bufs = total_bufs;
@@ -1194,6 +1255,10 @@ void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int *in_bytes,
     }
 
     caches = vring_get_region_caches(vq);
+    if (!caches) {
+        goto err;
+    }
+
     desc_size = virtio_vdev_has_feature(vq->vdev, VIRTIO_F_RING_PACKED) ?
                                 sizeof(VRingPackedDesc) : sizeof(VRingDesc);
     if (caches->desc.len < vq->vring.num * desc_size) {
@@ -1388,6 +1453,11 @@ static void *virtqueue_split_pop(VirtQueue *vq, size_t sz)
     i = head;
 
     caches = vring_get_region_caches(vq);
+    if (!caches) {
+        virtio_error(vdev, "Region caches not initialized");
+        goto done;
+    }
+
     if (caches->desc.len < max * sizeof(VRingDesc)) {
         virtio_error(vdev, "Cannot map descriptor ring");
         goto done;
@@ -1510,6 +1580,11 @@ static void *virtqueue_packed_pop(VirtQueue *vq, size_t sz)
     i = vq->last_avail_idx;
 
     caches = vring_get_region_caches(vq);
+    if (!caches) {
+        virtio_error(vdev, "Region caches not initialized");
+        goto done;
+    }
+
     if (caches->desc.len < max * sizeof(VRingDesc)) {
         virtio_error(vdev, "Cannot map descriptor ring");
         goto done;
@@ -1629,6 +1704,10 @@ static unsigned int virtqueue_packed_drop_all(VirtQueue *vq)
     VRingPackedDesc desc;
 
     caches = vring_get_region_caches(vq);
+    if (!caches) {
+        return 0;
+    }
+
     desc_cache = &caches->desc;
 
     virtio_queue_set_notification(vq, 0);
@@ -2413,6 +2492,10 @@ static bool virtio_packed_should_notify(VirtIODevice *vdev, VirtQueue *vq)
     VRingMemoryRegionCaches *caches;
 
     caches = vring_get_region_caches(vq);
+    if (!caches) {
+        return false;
+    }
+
     vring_packed_event_read(vdev, &caches->avail, &e);
 
     old = vq->signalled_used;