[PATCH 8/8] hw/dma: Let dma_buf_read() / dma_buf_write() propagate MemTxResult

["Philippe Mathieu-Daudé" <philmd@redhat.com>]

Since the previous commit, dma_buf_rw() returns a MemTxResult
type. Do not discard it, return it to the caller.

Since both dma_buf_read/dma_buf_write functions were previously
returning the QEMUSGList size not consumed, add an extra argument
where the unconsummed size can be stored.

Update the few callers.

Reviewed-by: Klaus Jensen <k.jensen@samsung.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
 include/hw/scsi/scsi.h |  2 +-
 include/sysemu/dma.h   |  6 +++--
 hw/ide/ahci.c          |  8 +++---
 hw/nvme/ctrl.c         |  4 +--
 hw/scsi/megasas.c      | 59 ++++++++++++++++++++++++++++++------------
 hw/scsi/scsi-bus.c     |  6 +++--
 softmmu/dma-helpers.c  | 18 +++++--------
 7 files changed, 63 insertions(+), 40 deletions(-)

diff --git a/include/hw/scsi/scsi.h b/include/hw/scsi/scsi.h
index b27d133b113..1ffb367f94f 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;
 
diff --git a/include/sysemu/dma.h b/include/sysemu/dma.h
index 45a2567848c..77a346d5ed1 100644
--- a/include/sysemu/dma.h
+++ b/include/sysemu/dma.h
@@ -303,8 +303,10 @@ BlockAIOCB *dma_blk_read(BlockBackend *blk,
 BlockAIOCB *dma_blk_write(BlockBackend *blk,
                           QEMUSGList *sg, uint64_t offset, uint32_t align,
                           BlockCompletionFunc *cb, void *opaque);
-uint64_t dma_buf_read(void *ptr, int32_t len, QEMUSGList *sg, MemTxAttrs attrs);
-uint64_t dma_buf_write(void *ptr, int32_t len, QEMUSGList *sg, MemTxAttrs attrs);
+MemTxResult dma_buf_read(void *ptr, dma_size_t len, dma_size_t *residual,
+                         QEMUSGList *sg, MemTxAttrs attrs);
+MemTxResult dma_buf_write(void *ptr, dma_size_t len, dma_size_t *residual,
+                          QEMUSGList *sg, MemTxAttrs attrs);
 
 void dma_acct_start(BlockBackend *blk, BlockAcctCookie *cookie,
                     QEMUSGList *sg, enum BlockAcctType type);
diff --git a/hw/ide/ahci.c b/hw/ide/ahci.c
index 256bbc377ce..564293fd492 100644
--- a/hw/ide/ahci.c
+++ b/hw/ide/ahci.c
@@ -1384,9 +1384,9 @@ static void ahci_pio_transfer(const IDEDMA *dma)
         const MemTxAttrs attrs = MEMTXATTRS_UNSPECIFIED;
 
         if (is_write) {
-            dma_buf_write(s->data_ptr, size, &s->sg, attrs);
+            dma_buf_write(s->data_ptr, size, NULL, &s->sg, attrs);
         } else {
-            dma_buf_read(s->data_ptr, size, &s->sg, attrs);
+            dma_buf_read(s->data_ptr, size, NULL, &s->sg, attrs);
         }
     }
 
@@ -1479,9 +1479,9 @@ static int ahci_dma_rw_buf(const IDEDMA *dma, bool is_write)
     }
 
     if (is_write) {
-        dma_buf_read(p, l, &s->sg, MEMTXATTRS_UNSPECIFIED);
+        dma_buf_read(p, l, NULL, &s->sg, MEMTXATTRS_UNSPECIFIED);
     } else {
-        dma_buf_write(p, l, &s->sg, MEMTXATTRS_UNSPECIFIED);
+        dma_buf_write(p, l, NULL, &s->sg, MEMTXATTRS_UNSPECIFIED);
     }
 
     /* free sglist, update byte count */
diff --git a/hw/nvme/ctrl.c b/hw/nvme/ctrl.c
index 4620e662fc9..72faa94a4a3 100644
--- a/hw/nvme/ctrl.c
+++ b/hw/nvme/ctrl.c
@@ -1150,9 +1150,9 @@ static uint16_t nvme_tx(NvmeCtrl *n, NvmeSg *sg, uint8_t *ptr, uint32_t len,
         dma_size_t residual;
 
         if (dir == NVME_TX_DIRECTION_TO_DEVICE) {
-            residual = dma_buf_write(ptr, len, &sg->qsg, attrs);
+            dma_buf_write(ptr, len, &residual, &sg->qsg, attrs);
         } else {
-            residual = dma_buf_read(ptr, len, &sg->qsg, attrs);
+            dma_buf_read(ptr, len, &residual, &sg->qsg, attrs);
         }
 
         if (unlikely(residual)) {
diff --git a/hw/scsi/megasas.c b/hw/scsi/megasas.c
index 7456a25970a..f2daeeb7005 100644
--- a/hw/scsi/megasas.c
+++ b/hw/scsi/megasas.c
@@ -750,6 +750,7 @@ static int megasas_ctrl_get_info(MegasasState *s, MegasasCmd *cmd)
     size_t dcmd_size = sizeof(info);
     BusChild *kid;
     int num_pd_disks = 0;
+    dma_size_t residual;
 
     memset(&info, 0x0, dcmd_size);
     if (cmd->iov_size < dcmd_size) {
@@ -860,7 +861,9 @@ static int megasas_ctrl_get_info(MegasasState *s, MegasasCmd *cmd)
                                        MFI_INFO_PDMIX_SATA |
                                        MFI_INFO_PDMIX_LD);
 
-    cmd->iov_size -= dma_buf_read(&info, dcmd_size, &cmd->qsg, MEMTXATTRS_UNSPECIFIED);
+    dma_buf_read(&info, dcmd_size, &residual, &cmd->qsg,
+                 MEMTXATTRS_UNSPECIFIED);
+    cmd->iov_size -= residual;
     return MFI_STAT_OK;
 }
 
@@ -868,6 +871,7 @@ static int megasas_mfc_get_defaults(MegasasState *s, MegasasCmd *cmd)
 {
     struct mfi_defaults info;
     size_t dcmd_size = sizeof(struct mfi_defaults);
+    dma_size_t residual;
 
     memset(&info, 0x0, dcmd_size);
     if (cmd->iov_size < dcmd_size) {
@@ -890,7 +894,9 @@ static int megasas_mfc_get_defaults(MegasasState *s, MegasasCmd *cmd)
     info.disable_preboot_cli = 1;
     info.cluster_disable = 1;
 
-    cmd->iov_size -= dma_buf_read(&info, dcmd_size, &cmd->qsg, MEMTXATTRS_UNSPECIFIED);
+    dma_buf_read(&info, dcmd_size, &residual, &cmd->qsg,
+                 MEMTXATTRS_UNSPECIFIED);
+    cmd->iov_size -= residual;
     return MFI_STAT_OK;
 }
 
@@ -898,6 +904,7 @@ static int megasas_dcmd_get_bios_info(MegasasState *s, MegasasCmd *cmd)
 {
     struct mfi_bios_data info;
     size_t dcmd_size = sizeof(info);
+    dma_size_t residual;
 
     memset(&info, 0x0, dcmd_size);
     if (cmd->iov_size < dcmd_size) {
@@ -911,7 +918,9 @@ static int megasas_dcmd_get_bios_info(MegasasState *s, MegasasCmd *cmd)
         info.expose_all_drives = 1;
     }
 
-    cmd->iov_size -= dma_buf_read(&info, dcmd_size, &cmd->qsg, MEMTXATTRS_UNSPECIFIED);
+    dma_buf_read(&info, dcmd_size, &residual, &cmd->qsg,
+                 MEMTXATTRS_UNSPECIFIED);
+    cmd->iov_size -= residual;
     return MFI_STAT_OK;
 }
 
@@ -919,10 +928,13 @@ static int megasas_dcmd_get_fw_time(MegasasState *s, MegasasCmd *cmd)
 {
     uint64_t fw_time;
     size_t dcmd_size = sizeof(fw_time);
+    dma_size_t residual;
 
     fw_time = cpu_to_le64(megasas_fw_time());
 
-    cmd->iov_size -= dma_buf_read(&fw_time, dcmd_size, &cmd->qsg, MEMTXATTRS_UNSPECIFIED);
+    dma_buf_read(&fw_time, dcmd_size, &residual, &cmd->qsg,
+                 MEMTXATTRS_UNSPECIFIED);
+    cmd->iov_size -= residual;
     return MFI_STAT_OK;
 }
 
@@ -942,6 +954,7 @@ static int megasas_event_info(MegasasState *s, MegasasCmd *cmd)
 {
     struct mfi_evt_log_state info;
     size_t dcmd_size = sizeof(info);
+    dma_size_t residual;
 
     memset(&info, 0, dcmd_size);
 
@@ -949,7 +962,9 @@ static int megasas_event_info(MegasasState *s, MegasasCmd *cmd)
     info.shutdown_seq_num = cpu_to_le32(s->shutdown_event);
     info.boot_seq_num = cpu_to_le32(s->boot_event);
 
-    cmd->iov_size -= dma_buf_read(&info, dcmd_size, &cmd->qsg, MEMTXATTRS_UNSPECIFIED);
+    dma_buf_read(&info, dcmd_size, &residual, &cmd->qsg,
+                 MEMTXATTRS_UNSPECIFIED);
+    cmd->iov_size -= residual;
     return MFI_STAT_OK;
 }
 
@@ -979,6 +994,7 @@ static int megasas_dcmd_pd_get_list(MegasasState *s, MegasasCmd *cmd)
     size_t dcmd_size = sizeof(info);
     BusChild *kid;
     uint32_t offset, dcmd_limit, num_pd_disks = 0, max_pd_disks;
+    dma_size_t residual;
 
     memset(&info, 0, dcmd_size);
     offset = 8;
@@ -1018,7 +1034,9 @@ static int megasas_dcmd_pd_get_list(MegasasState *s, MegasasCmd *cmd)
     info.size = cpu_to_le32(offset);
     info.count = cpu_to_le32(num_pd_disks);
 
-    cmd->iov_size -= dma_buf_read(&info, offset, &cmd->qsg, MEMTXATTRS_UNSPECIFIED);
+    dma_buf_read(&info, offset, &residual, &cmd->qsg,
+                 MEMTXATTRS_UNSPECIFIED);
+    cmd->iov_size -= residual;
     return MFI_STAT_OK;
 }
 
@@ -1113,8 +1131,9 @@ static int megasas_pd_get_info_submit(SCSIDevice *sdev, int lun,
     info->connected_port_bitmap = 0x1;
     info->device_speed = 1;
     info->link_speed = 1;
-    residual = dma_buf_read(cmd->iov_buf, dcmd_size, &cmd->qsg,
-                            MEMTXATTRS_UNSPECIFIED);
+    dma_buf_read(cmd->iov_buf, dcmd_size, &residual, &cmd->qsg,
+                 MEMTXATTRS_UNSPECIFIED);
+    cmd->iov_size -= residual;
     g_free(cmd->iov_buf);
     cmd->iov_size = dcmd_size - residual;
     cmd->iov_buf = NULL;
@@ -1187,8 +1206,8 @@ static int megasas_dcmd_ld_get_list(MegasasState *s, MegasasCmd *cmd)
     info.ld_count = cpu_to_le32(num_ld_disks);
     trace_megasas_dcmd_ld_get_list(cmd->index, num_ld_disks, max_ld_disks);
 
-    residual = dma_buf_read(&info, dcmd_size, &cmd->qsg,
-                            MEMTXATTRS_UNSPECIFIED);
+    dma_buf_read(&info, dcmd_size, &residual, &cmd->qsg,
+                 MEMTXATTRS_UNSPECIFIED);
     cmd->iov_size = dcmd_size - residual;
     return MFI_STAT_OK;
 }
@@ -1238,8 +1257,8 @@ static int megasas_dcmd_ld_list_query(MegasasState *s, MegasasCmd *cmd)
     info.size = dcmd_size;
     trace_megasas_dcmd_ld_get_list(cmd->index, num_ld_disks, max_ld_disks);
 
-    residual = dma_buf_read(&info, dcmd_size, &cmd->qsg,
-                            MEMTXATTRS_UNSPECIFIED);
+    dma_buf_read(&info, dcmd_size, &residual, &cmd->qsg,
+                 MEMTXATTRS_UNSPECIFIED);
     cmd->iov_size = dcmd_size - residual;
     return MFI_STAT_OK;
 }
@@ -1290,8 +1309,8 @@ static int megasas_ld_get_info_submit(SCSIDevice *sdev, int lun,
     info->ld_config.span[0].num_blocks = info->size;
     info->ld_config.span[0].array_ref = cpu_to_le16(sdev_id);
 
-    residual = dma_buf_read(cmd->iov_buf, dcmd_size, &cmd->qsg,
-                            MEMTXATTRS_UNSPECIFIED);
+    dma_buf_read(cmd->iov_buf, dcmd_size, &residual, &cmd->qsg,
+                 MEMTXATTRS_UNSPECIFIED);
     g_free(cmd->iov_buf);
     cmd->iov_size = dcmd_size - residual;
     cmd->iov_buf = NULL;
@@ -1336,6 +1355,7 @@ static int megasas_dcmd_cfg_read(MegasasState *s, MegasasCmd *cmd)
     struct mfi_config_data *info;
     int num_pd_disks = 0, array_offset, ld_offset;
     BusChild *kid;
+    dma_size_t residual;
 
     if (cmd->iov_size > 4096) {
         return MFI_STAT_INVALID_PARAMETER;
@@ -1410,7 +1430,9 @@ static int megasas_dcmd_cfg_read(MegasasState *s, MegasasCmd *cmd)
         ld_offset += sizeof(struct mfi_ld_config);
     }
 
-    cmd->iov_size -= dma_buf_read(data, info->size, &cmd->qsg, MEMTXATTRS_UNSPECIFIED);
+    dma_buf_read(data, info->size, &residual, &cmd->qsg,
+                 MEMTXATTRS_UNSPECIFIED);
+    cmd->iov_size -= residual;
     return MFI_STAT_OK;
 }
 
@@ -1418,6 +1440,7 @@ static int megasas_dcmd_get_properties(MegasasState *s, MegasasCmd *cmd)
 {
     struct mfi_ctrl_props info;
     size_t dcmd_size = sizeof(info);
+    dma_size_t residual;
 
     memset(&info, 0x0, dcmd_size);
     if (cmd->iov_size < dcmd_size) {
@@ -1440,7 +1463,9 @@ static int megasas_dcmd_get_properties(MegasasState *s, MegasasCmd *cmd)
     info.ecc_bucket_leak_rate = cpu_to_le16(1440);
     info.expose_encl_devices = 1;
 
-    cmd->iov_size -= dma_buf_read(&info, dcmd_size, &cmd->qsg, MEMTXATTRS_UNSPECIFIED);
+    dma_buf_read(&info, dcmd_size, &residual, &cmd->qsg,
+                 MEMTXATTRS_UNSPECIFIED);
+    cmd->iov_size -= residual;
     return MFI_STAT_OK;
 }
 
@@ -1485,7 +1510,7 @@ static int megasas_dcmd_set_properties(MegasasState *s, MegasasCmd *cmd)
                                             dcmd_size);
         return MFI_STAT_INVALID_PARAMETER;
     }
-    dma_buf_write(&info, dcmd_size, &cmd->qsg, MEMTXATTRS_UNSPECIFIED);
+    dma_buf_write(&info, dcmd_size, NULL, &cmd->qsg, MEMTXATTRS_UNSPECIFIED);
     trace_megasas_dcmd_unsupported(cmd->index, cmd->iov_size);
     return MFI_STAT_OK;
 }
diff --git a/hw/scsi/scsi-bus.c b/hw/scsi/scsi-bus.c
index 3466e680ac7..4057e04ce89 100644
--- a/hw/scsi/scsi-bus.c
+++ b/hw/scsi/scsi-bus.c
@@ -1421,9 +1421,11 @@ void scsi_req_data(SCSIRequest *req, int len)
 
     buf = scsi_req_get_buf(req);
     if (req->cmd.mode == SCSI_XFER_FROM_DEV) {
-        req->residual = dma_buf_read(buf, len, req->sg, MEMTXATTRS_UNSPECIFIED);
+        dma_buf_read(buf, len, &req->residual, req->sg,
+                     MEMTXATTRS_UNSPECIFIED);
     } else {
-        req->residual = dma_buf_write(buf, len, req->sg, MEMTXATTRS_UNSPECIFIED);
+        dma_buf_write(buf, len, &req->residual, req->sg,
+                      MEMTXATTRS_UNSPECIFIED);
     }
     scsi_req_continue(req);
 }
diff --git a/softmmu/dma-helpers.c b/softmmu/dma-helpers.c
index 66ba0b2c361..25120ea2792 100644
--- a/softmmu/dma-helpers.c
+++ b/softmmu/dma-helpers.c
@@ -321,22 +321,16 @@ static MemTxResult dma_buf_rw(void *buf, dma_size_t len, dma_size_t *residual,
     return res;
 }
 
-uint64_t dma_buf_read(void *ptr, int32_t len, QEMUSGList *sg, MemTxAttrs attrs)
+MemTxResult dma_buf_read(void *ptr, dma_size_t len, dma_size_t *residual,
+                         QEMUSGList *sg, MemTxAttrs attrs)
 {
-    uint64_t residual;
-
-    dma_buf_rw(ptr, len, &residual, sg, DMA_DIRECTION_FROM_DEVICE, attrs);
-
-    return residual;
+    return dma_buf_rw(ptr, len, residual, sg, DMA_DIRECTION_FROM_DEVICE, attrs);
 }
 
-uint64_t dma_buf_write(void *ptr, int32_t len, QEMUSGList *sg, MemTxAttrs attrs)
+MemTxResult dma_buf_write(void *ptr, dma_size_t len, dma_size_t *residual,
+                          QEMUSGList *sg, MemTxAttrs attrs)
 {
-    uint64_t residual;
-
-    dma_buf_rw(ptr, len, &residual, sg, DMA_DIRECTION_TO_DEVICE, attrs);
-
-    return residual;
+    return dma_buf_rw(ptr, len, residual, sg, DMA_DIRECTION_TO_DEVICE, attrs);
 }
 
 void dma_acct_start(BlockBackend *blk, BlockAcctCookie *cookie,
-- 
2.33.1