scsi: pass residual amount to command_complete

With the upcoming sglist support, HBAs will not see any transfer_data
call and will not have a way to detect short transfers.  So pass the
residual amount of data upon command completion.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

6 files changed, 15 insertions, 9 deletions

diff --git a/hw/esp.c b/hw/esp.c
index 2dda8e3..8d73e56 100644
--- a/hw/esp.c
+++ b/hw/esp.c
@@ -390,7 +390,8 @@ static void esp_do_dma(ESPState *s)
     esp_dma_done(s);
 }
 
-static void esp_command_complete(SCSIRequest *req, uint32_t status)
+static void esp_command_complete(SCSIRequest *req, uint32_t status,
+                                 size_t resid)
 {
     ESPState *s = DO_UPCAST(ESPState, busdev.qdev, req->bus->qbus.parent);
 
diff --git a/hw/lsi53c895a.c b/hw/lsi53c895a.c
index 0acd1d0..edc09b7 100644
--- a/hw/lsi53c895a.c
+++ b/hw/lsi53c895a.c
@@ -699,7 +699,7 @@ static int lsi_queue_req(LSIState *s, SCSIRequest *req, uint32_t len)
 }
 
  /* Callback to indicate that the SCSI layer has completed a command.  */
-static void lsi_command_complete(SCSIRequest *req, uint32_t status)
+static void lsi_command_complete(SCSIRequest *req, uint32_t status, size_t resid)
 {
     LSIState *s = DO_UPCAST(LSIState, dev.qdev, req->bus->qbus.parent);
     int out;
diff --git a/hw/scsi-bus.c b/hw/scsi-bus.c
index b3e97ce..eb97c87 100644
--- a/hw/scsi-bus.c
+++ b/hw/scsi-bus.c
@@ -533,6 +533,8 @@ SCSIRequest *scsi_req_new(SCSIDevice *d, uint32_t tag, uint32_t lun,
     }
 
     req->cmd = cmd;
+    req->resid = req->cmd.xfer;
+
     switch (buf[0]) {
     case INQUIRY:
         trace_scsi_inquiry(d->id, lun, tag, cmd.buf[1], cmd.buf[2]);
@@ -1275,10 +1277,12 @@ void scsi_req_data(SCSIRequest *req, int len)
 {
     if (req->io_canceled) {
         trace_scsi_req_data_canceled(req->dev->id, req->lun, req->tag, len);
-    } else {
-        trace_scsi_req_data(req->dev->id, req->lun, req->tag, len);
-        req->bus->info->transfer_data(req, len);
+        return;
     }
+    trace_scsi_req_data(req->dev->id, req->lun, req->tag, len);
+    assert(req->cmd.mode != SCSI_XFER_NONE);
+    req->resid -= len;
+    req->bus->info->transfer_data(req, len);
 }
 
 void scsi_req_print(SCSIRequest *req)
@@ -1337,7 +1341,7 @@ void scsi_req_complete(SCSIRequest *req, int status)
 
     scsi_req_ref(req);
     scsi_req_dequeue(req);
-    req->bus->info->complete(req, req->status);
+    req->bus->info->complete(req, req->status, req->resid);
     scsi_req_unref(req);
 }
 
diff --git a/hw/scsi.h b/hw/scsi.h
index dc72b6f..8722ef9 100644
--- a/hw/scsi.h
+++ b/hw/scsi.h
@@ -46,6 +46,7 @@ struct SCSIRequest {
     uint32_t          tag;
     uint32_t          lun;
     uint32_t          status;
+    size_t            resid;
     SCSICommand       cmd;
     BlockDriverAIOCB  *aiocb;
     uint8_t sense[SCSI_SENSE_BUF_SIZE];
@@ -112,7 +113,7 @@ struct SCSIBusInfo {
     int tcq;
     int max_channel, max_target, max_lun;
     void (*transfer_data)(SCSIRequest *req, uint32_t arg);
-    void (*complete)(SCSIRequest *req, uint32_t arg);
+    void (*complete)(SCSIRequest *req, uint32_t arg, size_t resid);
     void (*cancel)(SCSIRequest *req);
 };
 
diff --git a/hw/spapr_vscsi.c b/hw/spapr_vscsi.c
index ffce261..2167017 100644
--- a/hw/spapr_vscsi.c
+++ b/hw/spapr_vscsi.c
@@ -494,7 +494,7 @@ static void vscsi_transfer_data(SCSIRequest *sreq, uint32_t len)
 }
 
 /* Callback to indicate that the SCSI layer has completed a transfer.  */
-static void vscsi_command_complete(SCSIRequest *sreq, uint32_t status)
+static void vscsi_command_complete(SCSIRequest *sreq, uint32_t status, size_t resid)
 {
     VSCSIState *s = DO_UPCAST(VSCSIState, vdev.qdev, sreq->bus->qbus.parent);
     vscsi_req *req = sreq->hba_private;
diff --git a/hw/usb-msd.c b/hw/usb-msd.c
index c933efe..5fbd2d0 100644
--- a/hw/usb-msd.c
+++ b/hw/usb-msd.c
@@ -223,7 +223,7 @@ static void usb_msd_transfer_data(SCSIRequest *req, uint32_t len)
     }
 }
 
-static void usb_msd_command_complete(SCSIRequest *req, uint32_t status)
+static void usb_msd_command_complete(SCSIRequest *req, uint32_t status, size_t resid)
 {
     MSDState *s = DO_UPCAST(MSDState, dev.qdev, req->bus->qbus.parent);
     USBPacket *p = s->packet;