[Qemu-devel] [PATCHv4 3/4] block/iscsi: set max_transfer_length

[Peter Lieven]

the limit of 0xffffff for 16 byte CDBs is intentional to
avoid overflows on 32-bit architectures.

Signed-off-by: Peter Lieven <address@hidden>
Reviewed-by: Ronnie Sahlberg <address@hidden>
---
 block/iscsi.c |   12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/block/iscsi.c b/block/iscsi.c
index 3a01de0..c873d13 100644
--- a/block/iscsi.c
+++ b/block/iscsi.c
@@ -1449,10 +1449,18 @@ static void iscsi_close(BlockDriverState *bs)
 
 static void iscsi_refresh_limits(BlockDriverState *bs, Error **errp)
 {
-    IscsiLun *iscsilun = bs->opaque;
-
     /* We don't actually refresh here, but just return data queried in
      * iscsi_open(): iscsi targets don't change their limits. */
+
+    IscsiLun *iscsilun = bs->opaque;
+    uint32_t max_xfer_len = iscsilun->use_16_for_rw ? 0xffffff : 0xffff;
+
+    if (iscsilun->bl.max_xfer_len) {
+        max_xfer_len = MIN(max_xfer_len, iscsilun->bl.max_xfer_len);
+    }
+
+    bs->bl.max_transfer_length = sector_lun2qemu(max_xfer_len, iscsilun);
+
     if (iscsilun->lbp.lbpu) {
         if (iscsilun->bl.max_unmap < 0xffffffff) {
             bs->bl.max_discard = sector_lun2qemu(iscsilun->bl.max_unmap,
-- 
1.7.9.5