hw/dma: Let dma_buf_read() / dma_buf_write() propagate MemTxResult

Since commit 292e13142d2, dma_buf_rw() returns a MemTxResult type.
Do not discard it, return it to the caller. Pass the previously
returned value (the QEMUSGList residual size, which was rarely used)
as an optional argument.

With this new API, SCSIRequest::residual might now be accessed via
a pointer. Since the size_t type does not have the same size on
32 and 64-bit host architectures, convert it to a uint64_t, which
is big enough to hold the residual size, and the type is constant
on both 32/64-bit hosts.

Update the few dma_buf_read() / dma_buf_write() callers to the new
API.

Reviewed-by: Klaus Jensen <k.jensen@samsung.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Acked-by: Peter Xu <peterx@redhat.com>
Message-Id: <20220117125130.131828-1-f4bug@amsat.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/include/hw/scsi/scsi.h b/include/hw/scsi/scsi.h
index b27d133b11..1ffb367f94 100644
--- a/include/hw/scsi/scsi.h
+++ b/include/hw/scsi/scsi.h
@@ -30,7 +30,7 @@ struct SCSIRequest {
     int16_t           status;
     int16_t           host_status;
     void              *hba_private;
-    size_t            residual;
+    uint64_t          residual;
     SCSICommand       cmd;
     NotifierList      cancel_notifiers;