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authorRonnie Sahlberg <ronniesahlberg@gmail.com>2012-05-26 14:56:41 +1000
committerPaolo Bonzini <pbonzini@redhat.com>2012-07-02 10:18:41 +0200
commit622695a4585a786fdcd53852c7af87ed0af1af80 (patch)
tree966a2bbdc0d9083ee704961e4ee9212e8c1f3fbe /block
parent983924532f61091fd90d1f2fafa4aa938c414dbb (diff)
downloadqemu-622695a4585a786fdcd53852c7af87ed0af1af80.tar.gz
ISCSI: force use of sg for SMC and SSC devices
If the device we open is a SMC or SSC device, then force the use of sg. We dont have any medium changer or tape emulation so only passthrough via real sg or scsi-generic via iscsi would work anyway. Forcing sg also makes qemu skip trying to read from the device to guess the image format by reading from the device (find_image_format()). SMC devices do not implement READ6/10/12/16 so it is not possible to read from them (SSC have different CDBs). With this patch I can successfully manage a SMC device wiht iscsi in passthrough mode. Signed-off-by: Ronnie Sahlberg <ronniesahlberg@gmail.com> [Added TYPE_TAPE handling - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'block')
-rw-r--r--block/iscsi.c10
1 files changed, 10 insertions, 0 deletions
diff --git a/block/iscsi.c b/block/iscsi.c
index 029739eb61..ac65277048 100644
--- a/block/iscsi.c
+++ b/block/iscsi.c
@@ -1022,6 +1022,16 @@ static int iscsi_open(BlockDriverState *bs, const char *filename, int flags)
if (iscsi_url != NULL) {
iscsi_destroy_url(iscsi_url);
}
+
+ /* Medium changer or tape. We dont have any emulation for this so this must
+ * be sg ioctl compatible. We force it to be sg, otherwise qemu will try
+ * to read from the device to guess the image format.
+ */
+ if (iscsilun->type == TYPE_MEDIUM_CHANGER ||
+ iscsilun->type == TYPE_TAPE) {
+ bs->sg = 1;
+ }
+
return 0;
failed: