[PATCH 8/8] 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.

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
 include/sysemu/dma.h  |  6 ++++--
 hw/ide/ahci.c         |  8 ++++----
 hw/nvme/ctrl.c        |  4 ++--
 hw/scsi/megasas.c     | 48 ++++++++++++++++++++++++++++++-------------
 hw/scsi/scsi-bus.c    |  4 ++--
 softmmu/dma-helpers.c | 18 ++++++----------
 6 files changed, 52 insertions(+), 36 deletions(-)

diff --git a/include/sysemu/dma.h b/include/sysemu/dma.h
index cdf379fecad..9f998edbea4 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, int32_t len, uint64_t *residp,
+                         QEMUSGList *sg, MemTxAttrs attrs);
+MemTxResult dma_buf_write(void *ptr, int32_t len, uint64_t *residp,
+                          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 205dfdc6622..0c7d31ceada 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 462f79a1f60..fa410a179a6 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,
         uint64_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 dfd48f1a873..619b66ef0f3 100644
--- a/hw/scsi/megasas.c
+++ b/hw/scsi/megasas.c
@@ -737,6 +737,7 @@ static int megasas_ctrl_get_info(MegasasState *s, MegasasCmd *cmd)
     size_t dcmd_size = sizeof(info);
     BusChild *kid;
     int num_pd_disks = 0;
+    uint64_t resid;
 
     memset(&info, 0x0, dcmd_size);
     if (cmd->iov_size < dcmd_size) {
@@ -847,7 +848,8 @@ 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, &resid, &cmd->qsg, MEMTXATTRS_UNSPECIFIED);
+    cmd->iov_size -= resid;
     return MFI_STAT_OK;
 }
 
@@ -855,6 +857,7 @@ static int megasas_mfc_get_defaults(MegasasState *s, MegasasCmd *cmd)
 {
     struct mfi_defaults info;
     size_t dcmd_size = sizeof(struct mfi_defaults);
+    uint64_t resid;
 
     memset(&info, 0x0, dcmd_size);
     if (cmd->iov_size < dcmd_size) {
@@ -877,7 +880,8 @@ 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, &resid, &cmd->qsg, MEMTXATTRS_UNSPECIFIED);
+    cmd->iov_size -= resid;
     return MFI_STAT_OK;
 }
 
@@ -885,6 +889,7 @@ static int megasas_dcmd_get_bios_info(MegasasState *s, MegasasCmd *cmd)
 {
     struct mfi_bios_data info;
     size_t dcmd_size = sizeof(info);
+    uint64_t resid;
 
     memset(&info, 0x0, dcmd_size);
     if (cmd->iov_size < dcmd_size) {
@@ -898,7 +903,8 @@ 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, &resid, &cmd->qsg, MEMTXATTRS_UNSPECIFIED);
+    cmd->iov_size -= resid;
     return MFI_STAT_OK;
 }
 
@@ -906,10 +912,12 @@ static int megasas_dcmd_get_fw_time(MegasasState *s, MegasasCmd *cmd)
 {
     uint64_t fw_time;
     size_t dcmd_size = sizeof(fw_time);
+    uint64_t resid;
 
     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, &resid, &cmd->qsg, MEMTXATTRS_UNSPECIFIED);
+    cmd->iov_size -= resid;
     return MFI_STAT_OK;
 }
 
@@ -929,6 +937,7 @@ static int megasas_event_info(MegasasState *s, MegasasCmd *cmd)
 {
     struct mfi_evt_log_state info;
     size_t dcmd_size = sizeof(info);
+    uint64_t resid;
 
     memset(&info, 0, dcmd_size);
 
@@ -936,7 +945,8 @@ 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, &resid, &cmd->qsg, MEMTXATTRS_UNSPECIFIED);
+    cmd->iov_size -= resid;
     return MFI_STAT_OK;
 }
 
@@ -966,6 +976,7 @@ 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;
+    uint64_t resid;
 
     memset(&info, 0, dcmd_size);
     offset = 8;
@@ -1005,7 +1016,8 @@ 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, &resid, &cmd->qsg, MEMTXATTRS_UNSPECIFIED);
+    cmd->iov_size -= resid;
     return MFI_STAT_OK;
 }
 
@@ -1099,7 +1111,9 @@ static int megasas_pd_get_info_submit(SCSIDevice *sdev, int lun,
     info->connected_port_bitmap = 0x1;
     info->device_speed = 1;
     info->link_speed = 1;
-    resid = dma_buf_read(cmd->iov_buf, dcmd_size, &cmd->qsg, MEMTXATTRS_UNSPECIFIED);
+    dma_buf_read(cmd->iov_buf, dcmd_size, &resid, &cmd->qsg,
+                 MEMTXATTRS_UNSPECIFIED);
+    cmd->iov_size -= resid;
     g_free(cmd->iov_buf);
     cmd->iov_size = dcmd_size - resid;
     cmd->iov_buf = NULL;
@@ -1171,7 +1185,7 @@ 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);
 
-    resid = dma_buf_read(&info, dcmd_size, &cmd->qsg, MEMTXATTRS_UNSPECIFIED);
+    dma_buf_read(&info, dcmd_size, &resid, &cmd->qsg, MEMTXATTRS_UNSPECIFIED);
     cmd->iov_size = dcmd_size - resid;
     return MFI_STAT_OK;
 }
@@ -1220,7 +1234,7 @@ 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);
 
-    resid = dma_buf_read(&info, dcmd_size, &cmd->qsg, MEMTXATTRS_UNSPECIFIED);
+    dma_buf_read(&info, dcmd_size, &resid, &cmd->qsg, MEMTXATTRS_UNSPECIFIED);
     cmd->iov_size = dcmd_size - resid;
     return MFI_STAT_OK;
 }
@@ -1231,9 +1245,10 @@ static int megasas_ld_get_info_submit(SCSIDevice *sdev, int lun,
     struct mfi_ld_info *info = cmd->iov_buf;
     size_t dcmd_size = sizeof(struct mfi_ld_info);
     uint8_t cdb[6];
-    ssize_t len, resid;
+    ssize_t len;
     uint16_t sdev_id = ((sdev->id & 0xFF) << 8) | (lun & 0xFF);
     uint64_t ld_size;
+    uint64_t resid;
 
     if (!cmd->iov_buf) {
         cmd->iov_buf = g_malloc0(dcmd_size);
@@ -1270,7 +1285,8 @@ 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);
 
-    resid = dma_buf_read(cmd->iov_buf, dcmd_size, &cmd->qsg, MEMTXATTRS_UNSPECIFIED);
+    dma_buf_read(cmd->iov_buf, dcmd_size, &resid, &cmd->qsg,
+                 MEMTXATTRS_UNSPECIFIED);
     g_free(cmd->iov_buf);
     cmd->iov_size = dcmd_size - resid;
     cmd->iov_buf = NULL;
@@ -1315,6 +1331,7 @@ 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;
+    uint64_t resid;
 
     if (cmd->iov_size > 4096) {
         return MFI_STAT_INVALID_PARAMETER;
@@ -1389,7 +1406,8 @@ 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, &resid, &cmd->qsg, MEMTXATTRS_UNSPECIFIED);
+    cmd->iov_size -= resid;
     return MFI_STAT_OK;
 }
 
@@ -1397,6 +1415,7 @@ static int megasas_dcmd_get_properties(MegasasState *s, MegasasCmd *cmd)
 {
     struct mfi_ctrl_props info;
     size_t dcmd_size = sizeof(info);
+    uint64_t resid;
 
     memset(&info, 0x0, dcmd_size);
     if (cmd->iov_size < dcmd_size) {
@@ -1419,7 +1438,8 @@ 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, &resid, &cmd->qsg, MEMTXATTRS_UNSPECIFIED);
+    cmd->iov_size -= resid;
     return MFI_STAT_OK;
 }
 
@@ -1464,7 +1484,7 @@ 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 2b5e9dca311..34cf41796bb 100644
--- a/hw/scsi/scsi-bus.c
+++ b/hw/scsi/scsi-bus.c
@@ -1421,9 +1421,9 @@ void scsi_req_data(SCSIRequest *req, int len)
 
     buf = scsi_req_get_buf(req);
     if (req->cmd.mode == SCSI_XFER_FROM_DEV) {
-        req->resid = dma_buf_read(buf, len, req->sg, MEMTXATTRS_UNSPECIFIED);
+        dma_buf_read(buf, len, &req->resid, req->sg, MEMTXATTRS_UNSPECIFIED);
     } else {
-        req->resid = dma_buf_write(buf, len, req->sg, MEMTXATTRS_UNSPECIFIED);
+        dma_buf_write(buf, len, &req->resid, req->sg, MEMTXATTRS_UNSPECIFIED);
     }
     scsi_req_continue(req);
 }
diff --git a/softmmu/dma-helpers.c b/softmmu/dma-helpers.c
index b0be1564797..498303157e9 100644
--- a/softmmu/dma-helpers.c
+++ b/softmmu/dma-helpers.c
@@ -321,22 +321,16 @@ static MemTxResult dma_buf_rw(void *buf, int32_t len, uint64_t *residp,
     return res;
 }
 
-uint64_t dma_buf_read(void *ptr, int32_t len, QEMUSGList *sg, MemTxAttrs attrs)
+MemTxResult dma_buf_read(void *ptr, int32_t len, uint64_t *residp,
+                         QEMUSGList *sg, MemTxAttrs attrs)
 {
-    uint64_t resid;
-
-    dma_buf_rw(ptr, len, &resid, sg, DMA_DIRECTION_FROM_DEVICE, attrs);
-
-    return resid;
+    return dma_buf_rw(ptr, len, residp, 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, int32_t len, uint64_t *residp,
+                          QEMUSGList *sg, MemTxAttrs attrs)
 {
-    uint64_t resid;
-
-    dma_buf_rw(ptr, len, &resid, sg, DMA_DIRECTION_TO_DEVICE, attrs);
-
-    return resid;
+    return dma_buf_rw(ptr, len, residp, sg, DMA_DIRECTION_TO_DEVICE, attrs);
 }
 
 void dma_acct_start(BlockBackend *blk, BlockAcctCookie *cookie,
-- 
2.33.1