diff --git a/block.h b/block.h
index 48d0bf3..7feda73 100644
--- a/block.h
+++ b/block.h
@@ -15,6 +15,10 @@ typedef struct BlockDriverInfo {
     int cluster_size;
     /* offset at which the VM state can be saved (0 if not possible) */
     int64_t vm_state_offset;
+    /* whether discard is guaranteed to zero bytes */
+    bool discard_zeroes_data;
+    /* discard granularity in sectors */
+    int discard_granularity;
 } BlockDriverInfo;
 
 typedef struct QEMUSnapshotInfo {
diff --git a/block/qcow2.c b/block/qcow2.c
index eb5ea48..2908484 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -1256,6 +1256,8 @@ static int qcow2_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
     BDRVQcowState *s = bs->opaque;
     bdi->cluster_size = s->cluster_size;
     bdi->vm_state_offset = qcow2_vm_state_offset(s);
+    bdi->discard_zeroes_data = (bs->backing_hd == NULL);
+    bdi->discard_granularity = s->cluster_size / BDRV_SECTOR_SIZE;
     return 0;
 }
 
diff --git a/qemu-io.c b/qemu-io.c
index 3189530..8f28b6a 100644
--- a/qemu-io.c
+++ b/qemu-io.c
@@ -1437,7 +1437,7 @@ static const cmdinfo_t length_cmd = {
 static int info_f(int argc, char **argv)
 {
     BlockDriverInfo bdi;
-    char s1[64], s2[64];
+    char s1[64], s2[64], s3[64];
     int ret;
 
     if (bs->drv && bs->drv->format_name) {
@@ -1454,9 +1454,12 @@ static int info_f(int argc, char **argv)
 
     cvtstr(bdi.cluster_size, s1, sizeof(s1));
     cvtstr(bdi.vm_state_offset, s2, sizeof(s2));
+    cvtstr(bdi.discard_granularity * BDRV_SECTOR_SIZE, s3, sizeof(s3));
 
     printf("cluster size: %s\n", s1);
     printf("vm state offset: %s\n", s2);
+    printf("discard zeroes: %s\n", bdi.discard_zeroes_data ? "yes" : "no");
+    printf("discard granularity: %s\n", s3);
 
     return 0;
 }