Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost

[sfrench/cifs-2.6.git] / drivers / vhost / vhost.c

diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index b45519ca66a7e9a0d0ff5fe9ead216db6297fded..9ad45e1d27f0f0d80eb904098de60c77f376de33 100644 (file)
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -1290,6 +1290,11 @@ static bool vq_access_ok(struct vhost_virtqueue *vq, unsigned int num,
                         vring_used_t __user *used)
 
 {
+       /* If an IOTLB device is present, the vring addresses are
+        * GIOVAs. Access validation occurs at prefetch time. */
+       if (vq->iotlb)
+               return true;
+
        return access_ok(desc, vhost_get_desc_size(vq, num)) &&
               access_ok(avail, vhost_get_avail_size(vq, num)) &&
               access_ok(used, vhost_get_used_size(vq, num));
@@ -1365,6 +1370,20 @@ bool vhost_log_access_ok(struct vhost_dev *dev)
 }
 EXPORT_SYMBOL_GPL(vhost_log_access_ok);
 
+static bool vq_log_used_access_ok(struct vhost_virtqueue *vq,
+                                 void __user *log_base,
+                                 bool log_used,
+                                 u64 log_addr)
+{
+       /* If an IOTLB device is present, log_addr is a GIOVA that
+        * will never be logged by log_used(). */
+       if (vq->iotlb)
+               return true;
+
+       return !log_used || log_access_ok(log_base, log_addr,
+                                         vhost_get_used_size(vq, vq->num));
+}
+
 /* Verify access for write logging. */
 /* Caller should have vq mutex and device mutex */
 static bool vq_log_access_ok(struct vhost_virtqueue *vq,
@@ -1372,8 +1391,7 @@ static bool vq_log_access_ok(struct vhost_virtqueue *vq,
 {
        return vq_memory_access_ok(log_base, vq->umem,
                                   vhost_has_feature(vq, VHOST_F_LOG_ALL)) &&
-               (!vq->log_used || log_access_ok(log_base, vq->log_addr,
-                                 vhost_get_used_size(vq, vq->num)));
+               vq_log_used_access_ok(vq, log_base, vq->log_used, vq->log_addr);
 }
 
 /* Can we start vq? */
@@ -1383,10 +1401,6 @@ bool vhost_vq_access_ok(struct vhost_virtqueue *vq)
        if (!vq_log_access_ok(vq, vq->log_base))
                return false;
 
-       /* Access validation occurs at prefetch time with IOTLB */
-       if (vq->iotlb)
-               return true;
-
        return vq_access_ok(vq, vq->num, vq->desc, vq->avail, vq->used);
 }
 EXPORT_SYMBOL_GPL(vhost_vq_access_ok);
@@ -1516,10 +1530,9 @@ static long vhost_vring_set_addr(struct vhost_dev *d,
                        return -EINVAL;
 
                /* Also validate log access for used ring if enabled. */
-               if ((a.flags & (0x1 << VHOST_VRING_F_LOG)) &&
-                       !log_access_ok(vq->log_base, a.log_guest_addr,
-                               sizeof *vq->used +
-                               vq->num * sizeof *vq->used->ring))
+               if (!vq_log_used_access_ok(vq, vq->log_base,
+                               a.flags & (0x1 << VHOST_VRING_F_LOG),
+                               a.log_guest_addr))
                        return -EINVAL;
        }