diff --git a/hw/misc/macio/mac_dbdma.c b/hw/misc/macio/mac_dbdma.c
index 4ca0491fab..f47a736182 100644
--- a/hw/misc/macio/mac_dbdma.c
+++ b/hw/misc/macio/mac_dbdma.c
@@ -275,7 +275,9 @@ static void dbdma_end(DBDMA_io *io)
     conditional_branch(ch);
 
 wait:
-    ch->processing = 0;
+    /* Indicate that we're ready for a new DMA round */
+    ch->io.processing = false;
+
     if ((ch->regs[DBDMA_STATUS] & RUN) &&
         (ch->regs[DBDMA_STATUS] & ACTIVE))
         channel_run(ch);
@@ -301,7 +303,7 @@ static void start_output(DBDMA_channel *ch, int key, uint32_t addr,
     ch->io.is_last = is_last;
     ch->io.dma_end = dbdma_end;
     ch->io.is_dma_out = 1;
-    ch->processing = 1;
+    ch->io.processing = true;
     if (ch->rw) {
         ch->rw(&ch->io);
     }
@@ -327,7 +329,7 @@ static void start_input(DBDMA_channel *ch, int key, uint32_t addr,
     ch->io.is_last = is_last;
     ch->io.dma_end = dbdma_end;
     ch->io.is_dma_out = 0;
-    ch->processing = 1;
+    ch->io.processing = true;
     if (ch->rw) {
         ch->rw(&ch->io);
     }
@@ -525,7 +527,7 @@ static void DBDMA_run(DBDMAState *s)
     for (channel = 0; channel < DBDMA_CHANNELS; channel++) {
         DBDMA_channel *ch = &s->channels[channel];
         uint32_t status = ch->regs[DBDMA_STATUS];
-        if (!ch->processing && (status & RUN) && (status & ACTIVE)) {
+        if (!ch->io.processing && (status & RUN) && (status & ACTIVE)) {
             channel_run(ch);
         }
     }
diff --git a/include/hw/ppc/mac_dbdma.h b/include/hw/ppc/mac_dbdma.h
index eb8e0f0075..4d7318df84 100644
--- a/include/hw/ppc/mac_dbdma.h
+++ b/include/hw/ppc/mac_dbdma.h
@@ -37,6 +37,8 @@ struct DBDMA_io {
     int is_last;
     int is_dma_out;
     DBDMA_end dma_end;
+    /* DMA is in progress, don't start another one */
+    bool processing;
 };
 
 /*
@@ -148,7 +150,6 @@ typedef struct DBDMA_channel {
     DBDMA_rw rw;
     DBDMA_flush flush;
     dbdma_cmd current;
-    int processing;
 } DBDMA_channel;
 
 typedef struct {