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

pc, pci, virtio: fixes for rc3

A bunch of fixes all over the place.

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

# gpg: Signature made Fri 01 Dec 2017 17:06:33 GMT
# gpg:                using RSA key 0x281F0DB8D28D5469
# gpg: Good signature from "Michael S. Tsirkin <mst@kernel.org>"
# gpg:                 aka "Michael S. Tsirkin <mst@redhat.com>"
# 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:
  pc: fix crash on attempted cpu unplug
  virtio: check VirtQueue Vring object is set
  vhost: fix error check in vhost_verify_ring_mappings()
  dump-guest-memory.py: fix No symbol "vmcoreinfo_find"
  vhost: restore avail index from vring used index on disconnection
  virtio: Add queue interface to restore avail index from vring used index
  i386/msi: Correct mask of destination ID in MSI address

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

3 files changed, 33 insertions, 6 deletions

diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index c3afe5b7f1..186545d2a4 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -1842,6 +1842,11 @@ static void pc_cpu_unplug_request_cb(HotplugHandler *hotplug_dev,
     X86CPU *cpu = X86_CPU(dev);
     PCMachineState *pcms = PC_MACHINE(hotplug_dev);
 
+    if (!pcms->acpi_dev) {
+        error_setg(&local_err, "CPU hot unplug not supported without ACPI");
+        goto out;
+    }
+
     pc_find_cpu_slot(MACHINE(pcms), cpu->apic_id, &idx);
     assert(idx != -1);
     if (idx == 0) {
diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index ddc42f0f93..e4290ce93d 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -493,21 +493,21 @@ static int vhost_verify_ring_mappings(struct vhost_dev *dev,
         j = 0;
         r = vhost_verify_ring_part_mapping(dev, vq->desc, vq->desc_phys,
                                            vq->desc_size, start_addr, size);
-        if (!r) {
+        if (r) {
             break;
         }
 
         j++;
         r = vhost_verify_ring_part_mapping(dev, vq->avail, vq->avail_phys,
                                            vq->avail_size, start_addr, size);
-        if (!r) {
+        if (r) {
             break;
         }
 
         j++;
         r = vhost_verify_ring_part_mapping(dev, vq->used, vq->used_phys,
                                            vq->used_size, start_addr, size);
-        if (!r) {
+        if (r) {
             break;
         }
     }
@@ -1138,6 +1138,10 @@ static void vhost_virtqueue_stop(struct vhost_dev *dev,
     r = dev->vhost_ops->vhost_get_vring_base(dev, &state);
     if (r < 0) {
         VHOST_OPS_DEBUG("vhost VQ %d ring restore failed: %d", idx, r);
+        /* Connection to the backend is broken, so let's sync internal
+         * last avail idx to the device used idx.
+         */
+        virtio_queue_restore_last_avail_idx(vdev, idx);
     } else {
         virtio_queue_set_last_avail_idx(vdev, idx, state.num);
     }
diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index ea532dc35f..ad564b0132 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -182,7 +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;
     }
@@ -1414,6 +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);
 }
@@ -1426,6 +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;
@@ -1494,8 +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)
@@ -2310,6 +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();