remove maps list from DMA controller (#674)

->maps existed so that if a consumer does vfu_map_sg() and then we are asked to
enable dirty page tracking, we won't mark those pages as dirty, and will hence
potentially lose data.

Now that we require quiesce and the use of either vfu_unmap_sg() or
vfu_sg_mark_dirty(), there's no need to have this list any more.

Signed-off-by: John Levon <john.levon@nutanix.com>
Reviewed-by: Thanos Makatos <thanos.makatos@nutanix.com>

1 files changed, 0 insertions, 21 deletions

diff --git a/lib/dma.c b/lib/dma.c
index 2719639..daa1b58 100644
--- a/lib/dma.c
+++ b/lib/dma.c
@@ -99,7 +99,6 @@ dma_controller_create(vfu_ctx_t *vfu_ctx, size_t max_regions, size_t max_size)
     dma->nregions = 0;
     memset(dma->regions, 0, max_regions * sizeof(dma->regions[0]));
     dma->dirty_pgsize = 0;
-    LIST_INIT(&dma->maps);
 
     return dma;
 }
@@ -468,22 +467,6 @@ out:
     return cnt;
 }
 
-static void
-dma_mark_dirty_sgs(dma_controller_t *dma)
-{
-    struct dma_sg *sg;
-
-    if (dma->dirty_pgsize == 0) {
-        return;
-    }
-
-    LIST_FOREACH(sg, &dma->maps, entry) {
-        if (sg->writeable) {
-            _dma_mark_dirty(dma, &dma->regions[sg->region], sg);
-        }
-    }
-}
-
 int
 dma_controller_dirty_page_logging_start(dma_controller_t *dma, size_t pgsize)
 {
@@ -523,8 +506,6 @@ dma_controller_dirty_page_logging_start(dma_controller_t *dma, size_t pgsize)
     }
     dma->dirty_pgsize = pgsize;
 
-    dma_mark_dirty_sgs(dma);
-
     vfu_log(dma->vfu_ctx, LOG_DEBUG, "dirty pages: started logging");
 
     return 0;
@@ -628,8 +609,6 @@ dma_controller_dirty_page_get(dma_controller_t *dma, vfu_dma_addr_t addr,
 #endif
     memset(region->dirty_bitmap, 0, size);
 
-    dma_mark_dirty_sgs(dma);
-
     return 0;
 }