add unit tests for DMA regions without file descriptor

Signed-off-by: Thanos Makatos <thanos.makatos@nutanix.com>

4 files changed, 29 insertions, 17 deletions

diff --git a/lib/common.h b/lib/common.h
index e30bc2e..dbd3c9b 100644
--- a/lib/common.h
+++ b/lib/common.h
@@ -55,6 +55,9 @@
 #define ROUND_DOWN(x, a)    ((x) & ~((a)-1))
 #define ROUND_UP(x,a)       ROUND_DOWN((x)+(a)-1, a)
 
+#define UNIT_TEST_SYMBOL(x) \
+    typeof(x) __wrap_##x __attribute__((weak, alias(#x)))
+
 #endif /* LIB_MUSER_COMMON_H */
 
 /* ex: set tabstop=4 shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/lib/dma.c b/lib/dma.c
index b47652d..bcc6128 100644
--- a/lib/dma.c
+++ b/lib/dma.c
@@ -90,7 +90,7 @@ dma_controller_create(lm_ctx_t *lm_ctx, int max_regions)
     return dma;
 }
 
-static void
+void
 _dma_controller_do_remove_region(dma_controller_t *dma,
                                  dma_memory_region_t *region)
 {
@@ -111,6 +111,14 @@ _dma_controller_do_remove_region(dma_controller_t *dma,
         }
     }
 }
+UNIT_TEST_SYMBOL(_dma_controller_do_remove_region);
+
+/*
+ * FIXME super ugly, but without this functions within the same compilation
+ * unit don't call the wrapped version, making unit testing impossible.
+ * Ideally we'd like the UNIT_TEST_SYMBOL macro to solve this.
+ */
+#define _dma_controller_do_remove_region __wrap__dma_controller_do_remove_region
 
 /*
  * FIXME no longer used. Also, it doesn't work for addresses that span two
@@ -173,6 +181,7 @@ dma_controller_remove_region(dma_controller_t *dma,
     }
     return -ENOENT;
 }
+UNIT_TEST_SYMBOL(dma_controller_remove_region);
 
 static inline void
 dma_controller_remove_regions(dma_controller_t *dma)
@@ -292,6 +301,8 @@ dma_controller_add_region(dma_controller_t *dma,
             }
             goto err;
         }
+    } else {
+        region->virt_addr = NULL;
     }
     dma->nregions++;
 
@@ -300,6 +311,7 @@ dma_controller_add_region(dma_controller_t *dma,
 err:
     return -idx - 1;
 }
+UNIT_TEST_SYMBOL(dma_controller_add_region);
 
 static inline void
 mmap_round(size_t *offset, size_t *size, size_t page_size)
@@ -334,6 +346,7 @@ dma_map_region(dma_memory_region_t *region, int prot, size_t offset, size_t len)
 
     return mmap_base + (offset - mmap_offset);
 }
+UNIT_TEST_SYMBOL(dma_map_region);
 
 int
 dma_unmap_region(dma_memory_region_t *region, void *virt_addr, size_t len)
diff --git a/lib/muser_ctx.c b/lib/muser_ctx.c
index e00a55a..d80e952 100644
--- a/lib/muser_ctx.c
+++ b/lib/muser_ctx.c
@@ -519,7 +519,7 @@ handle_dma_map_or_unmap(lm_ctx_t *lm_ctx, uint32_t size, bool map,
                         struct vfio_user_dma_region *dma_regions)
 {
     int nr_dma_regions;
-    int ret, i;
+    int ret, i, fdi;
 
     assert(lm_ctx != NULL);
     assert(fds != NULL);
@@ -534,43 +534,35 @@ handle_dma_map_or_unmap(lm_ctx_t *lm_ctx, uint32_t size, bool map,
     }
 
     nr_dma_regions = (int)(size / sizeof(struct vfio_user_dma_region));
-    if (map && nr_fds > 0 && nr_dma_regions != nr_fds) {
-        lm_log(lm_ctx, LM_ERR, "expected %d fds but got %d instead",
-               nr_dma_regions, nr_fds);
-        return -EINVAL;
-    }
 
-    for (i = 0; i < nr_dma_regions; i++) {
+    for (i = 0, fdi = 0; i < nr_dma_regions; i++) {
         if (map) {
+            int fd = -1;
             if (dma_regions[i].flags == VFIO_USER_F_DMA_REGION_MAPPABLE) {
-                if (nr_fds == 0) {
-                    return -EINVAL;
-                }
-            } else {
-                if (nr_fds != 0) {
+                if (fdi == nr_fds) {
                     return -EINVAL;
                 }
-                fds[i] = -1;
+                fd = fds[fdi++];
             }
 
             ret = dma_controller_add_region(lm_ctx->dma,
                                             dma_regions[i].addr,
                                             dma_regions[i].size,
-                                            fds[i],
+                                            fd,
                                             dma_regions[i].offset);
             if (ret < 0) {
                 lm_log(lm_ctx, LM_INF,
                        "failed to add DMA region %#lx-%#lx offset=%#lx fd=%d: %s",
                        dma_regions[i].addr,
                        dma_regions[i].addr + dma_regions[i].size - 1,
-                       dma_regions[i].offset, fds[i],
+                       dma_regions[i].offset, fd,
                        strerror(-ret));
             } else {
                 lm_log(lm_ctx, LM_DBG,
                        "added DMA region %#lx-%#lx offset=%#lx fd=%d",
                        dma_regions[i].addr,
                        dma_regions[i].addr + dma_regions[i].size - 1,
-                       dma_regions[i].offset, fds[i]);
+                       dma_regions[i].offset, fd);
             }
         } else {
             ret = dma_controller_remove_region(lm_ctx->dma,
diff --git a/lib/muser_priv.h b/lib/muser_priv.h
index 2d47d1a..ea44237 100644
--- a/lib/muser_priv.h
+++ b/lib/muser_priv.h
@@ -208,6 +208,10 @@ handle_dma_map_or_unmap(lm_ctx_t *lm_ctx, uint32_t size, bool map,
                         int *fds, int nr_fds,
                         struct vfio_user_dma_region *dma_regions);
 
+void
+_dma_controller_do_remove_region(dma_controller_t *dma,
+                                 dma_memory_region_t *region);
+
 #endif /* LIB_MUSER_PRIV_H */
 
 /* ex: set tabstop=4 shiftwidth=4 softtabstop=4 expandtab: */