diff --git a/block/iscsi.c b/block/iscsi.c
index 5f28c6a2ea..e7c1c2b538 100644
--- a/block/iscsi.c
+++ b/block/iscsi.c
@@ -247,7 +247,9 @@ static bool is_request_lun_aligned(int64_t sector_num, int nb_sectors,
 {
     if ((sector_num * BDRV_SECTOR_SIZE) % iscsilun->block_size ||
         (nb_sectors * BDRV_SECTOR_SIZE) % iscsilun->block_size) {
-            error_report("iSCSI misaligned request: iscsilun->block_size %u, sector_num %ld, nb_sectors %d",
+            error_report("iSCSI misaligned request: "
+                         "iscsilun->block_size %u, sector_num %" PRIi64
+                         ", nb_sectors %d",
                          iscsilun->block_size, sector_num, nb_sectors);
             return 0;
     }
diff --git a/block/vmdk.c b/block/vmdk.c
index 3756333c60..e6c50b1e35 100644
--- a/block/vmdk.c
+++ b/block/vmdk.c
@@ -1200,8 +1200,10 @@ static coroutine_fn int vmdk_co_read(BlockDriverState *bs, int64_t sector_num,
 /**
  * vmdk_write:
  * @zeroed:       buf is ignored (data is zero), use zeroed_grain GTE feature
- * if possible, otherwise return -ENOTSUP.
- * @zero_dry_run: used for zeroed == true only, don't update L2 table, just
+ *                if possible, otherwise return -ENOTSUP.
+ * @zero_dry_run: used for zeroed == true only, don't update L2 table, just try
+ *                with each cluster. By dry run we can find if the zero write
+ *                is possible without modifying image data.
  *
  * Returns: error code with 0 for success.
  */
@@ -1328,6 +1330,8 @@ static int coroutine_fn vmdk_co_write_zeroes(BlockDriverState *bs,
     int ret;
     BDRVVmdkState *s = bs->opaque;
     qemu_co_mutex_lock(&s->lock);
+    /* write zeroes could fail if sectors not aligned to cluster, test it with
+     * dry_run == true before really updating image */
     ret = vmdk_write(bs, sector_num, NULL, nb_sectors, true, true);
     if (!ret) {
         ret = vmdk_write(bs, sector_num, NULL, nb_sectors, true, false);
diff --git a/configure b/configure
index f0761ea862..293f1677e6 100755
--- a/configure
+++ b/configure
@@ -231,7 +231,7 @@ libusb=""
 usb_redir=""
 glx=""
 zlib="yes"
-guest_agent="yes"
+guest_agent=""
 want_tools="yes"
 libiscsi=""
 coroutine=""
@@ -3444,10 +3444,15 @@ if test "$softmmu" = yes ; then
       virtfs=no
     fi
   fi
+fi
+if [ "$guest_agent" != "no" ]; then
   if [ "$linux" = "yes" -o "$bsd" = "yes" -o "$solaris" = "yes" ] ; then
-    if [ "$guest_agent" = "yes" ]; then
       tools="qemu-ga\$(EXESUF) $tools"
-    fi
+      guest_agent=yes
+  elif [ "$guest_agent" != yes ]; then
+      guest_agent=no
+  else
+      error_exit "Guest agent is not supported on this platform"
   fi
 fi
 
diff --git a/memory.c b/memory.c
index ac6f3c6a19..886f838951 100644
--- a/memory.c
+++ b/memory.c
@@ -18,7 +18,6 @@
 #include "exec/ioport.h"
 #include "qemu/bitops.h"
 #include "qom/object.h"
-#include "sysemu/kvm.h"
 #include "trace.h"
 #include <assert.h>