[PATCH] IOMMU and ATS not supported by vhost-user filesystem.

[lagarcia]

From: Leonardo Garcia <lagarcia@br.ibm.com>

Currently, as IOMMU and ATS are not supported, if a user mistakenly set
any of them and tries to mount the vhost-user filesystem inside the
guest, whenever the user tries to access the mount point, the system
will hang forever.

Signed-off-by: Leonardo Garcia <lagarcia@br.ibm.com>
---
 hw/virtio/vhost-user-fs-pci.c | 7 +++++++
 hw/virtio/vhost-user-fs.c     | 5 +++++
 2 files changed, 12 insertions(+)

diff --git a/hw/virtio/vhost-user-fs-pci.c b/hw/virtio/vhost-user-fs-pci.c
index 2ed8492b3f..564d1fd108 100644
--- a/hw/virtio/vhost-user-fs-pci.c
+++ b/hw/virtio/vhost-user-fs-pci.c
@@ -11,6 +11,8 @@
  * top-level directory.
  */
 
+#include "qemu/osdep.h"
+#include "qapi/error.h"
 #include "qemu/osdep.h"
 #include "hw/qdev-properties.h"
 #include "hw/virtio/vhost-user-fs.h"
@@ -45,6 +47,11 @@ static void vhost_user_fs_pci_realize(VirtIOPCIProxy 
*vpci_dev, Error **errp)
         vpci_dev->nvectors = dev->vdev.conf.num_request_queues + 2;
     }
 
+    if (vpci_dev->flags & VIRTIO_PCI_FLAG_ATS) {
+        error_setg(errp, "ATS is currently not supported with 
vhost-user-fs-pci");
+        return;
+    }
+
     qdev_realize(vdev, BUS(&vpci_dev->bus), errp);
 }
 
diff --git a/hw/virtio/vhost-user-fs.c b/hw/virtio/vhost-user-fs.c
index ac4fc34b36..914d68b3ee 100644
--- a/hw/virtio/vhost-user-fs.c
+++ b/hw/virtio/vhost-user-fs.c
@@ -203,6 +203,11 @@ static void vuf_device_realize(DeviceState *dev, Error 
**errp)
         return;
     }
 
+    if (virtio_host_has_feature(vdev, VIRTIO_F_IOMMU_PLATFORM)) {
+        error_setg(errp, "IOMMU is currently not supported with 
vhost-user-fs");
+        return;
+    }
+
     if (!vhost_user_init(&fs->vhost_user, &fs->conf.chardev, errp)) {
         return;
     }
-- 
2.29.2