respond to Swapnil's review

Signed-off-by: William Henderson <william.henderson@nutanix.com>

samples/client.c

@@ -563,7 +563,7 @@ set_migration_state(int sock, uint32_t state)
  return ret;
 }
 
-static int
+static ssize_t
 read_migr_data(int sock, void *buf, size_t len)
 {
  static int msg_id = 0x6904;
@@ -584,9 +584,9 @@ read_migr_data(int sock, void *buf, size_t len)
  }
 
  pthread_mutex_lock(&mutex);
- int ret = tran_sock_msg_iovec(sock, msg_id--, VFIO_USER_MIG_DATA_READ,
- send_iovecs, 2, NULL, 0, NULL,
- res, sizeof(req) + len, NULL, 0);
+ ssize_t ret = tran_sock_msg_iovec(sock, msg_id--, VFIO_USER_MIG_DATA_READ,
+  send_iovecs, 2, NULL, 0, NULL,
+  res, sizeof(req) + len, NULL, 0);
  pthread_mutex_unlock(&mutex);
 
  if (ret < 0) {
@@ -596,14 +596,14 @@ read_migr_data(int sock, void *buf, size_t len)
 
  memcpy(buf, res->data, res->size);
 
- uint32_t size = res->size;
+ ssize_t size = res->size;
 
  free(res);
 
  return size;
 }
 
-static int
+static ssize_t
 write_migr_data(int sock, void *buf, size_t len)
 {
  static int msg_id = 0x2023;
@@ -623,9 +623,9 @@ write_migr_data(int sock, void *buf, size_t len)
  };
 
  pthread_mutex_lock(&mutex);
- int ret = tran_sock_msg_iovec(sock, msg_id--, VFIO_USER_MIG_DATA_WRITE,
- send_iovecs, 3, NULL, 0, NULL,
- &req, sizeof(req), NULL, 0);
+ ssize_t ret = tran_sock_msg_iovec(sock, msg_id--, VFIO_USER_MIG_DATA_WRITE,
+  send_iovecs, 3, NULL, 0, NULL,
+  &req, sizeof(req), NULL, 0);
  pthread_mutex_unlock(&mutex);
 
  return ret;
@@ -793,15 +793,14 @@ handle_dma_io(int sock, struct vfio_user_dma_map *dma_regions,
 static void
 get_dirty_bitmap(int sock, struct vfio_user_dma_map *dma_region)
 {
- uint64_t bitmap_size = _get_bitmap_size(dma_region->size,
- sysconf(_SC_PAGESIZE));
-
  struct vfio_user_device_feature *res;
  struct vfio_user_device_feature_dma_logging_report *report;
-
  char *bitmap;
  int ret;
 
+ uint64_t bitmap_size = _get_bitmap_size(dma_region->size,
+ sysconf(_SC_PAGESIZE));
+
  size_t size = sizeof(*res) + sizeof(*report) + bitmap_size;
 
  void *data = calloc(1, size);
@@ -858,11 +857,10 @@ static size_t
 do_migrate(int sock, size_t nr_iters, size_t max_iter_size,
  struct iovec *migr_iter)
 {
- int ret;
- bool is_more = true;
+ ssize_t ret;
  size_t i = 0;
 
- for (i = 0; i < nr_iters && is_more; i++) {
+ for (i = 0; i < nr_iters; i++) {
 
  migr_iter[i].iov_len = max_iter_size;
  migr_iter[i].iov_base = malloc(migr_iter[i].iov_len);
@@ -881,7 +879,7 @@ do_migrate(int sock, size_t nr_iters, size_t max_iter_size,
 
  // We know we've finished transferring data when we read 0 bytes.
  if (ret == 0) {
- is_more = false;
+ break;
  }
  }
  return i;
@@ -932,6 +930,7 @@ migrate_from(int sock, size_t *nr_iters, struct iovec **migr_iters,
  uint32_t *crcp, size_t bar1_size, size_t max_iter_size)
 {
  uint32_t device_state;
+ size_t iters;
  int ret;
  pthread_t thread;
  struct fake_guest_data fake_guest_data = {
@@ -968,10 +967,8 @@ migrate_from(int sock, size_t *nr_iters, struct iovec **migr_iters,
  err(EXIT_FAILURE, "failed to write to device state");
  }
 
- ret = do_migrate(sock, *nr_iters, max_iter_size, *migr_iters);
- if (ret < 0) {
- err(EXIT_FAILURE, "failed to do migration in pre-copy state");
- }
+ iters = do_migrate(sock, *nr_iters, max_iter_size, *migr_iters);
+ assert(iters == 12);
 
  printf("client: stopping fake guest thread\n");
  fake_guest_data.done = true;
@@ -990,10 +987,8 @@ migrate_from(int sock, size_t *nr_iters, struct iovec **migr_iters,
  err(EXIT_FAILURE, "failed to write to device state");
  }
 
- size_t iters = do_migrate(sock, *nr_iters, max_iter_size, *migr_iters);
- if (ret < 0) {
- err(EXIT_FAILURE, "failed to do migration in stop-and-copy state");
- }
+ iters = do_migrate(sock, *nr_iters, max_iter_size, *migr_iters);
+ assert(iters == 13);
 
  /* XXX read device state, migration must have finished now */
  device_state = VFIO_USER_DEVICE_STATE_STOP;
@@ -1011,7 +1006,8 @@ migrate_to(char *old_sock_path, int *server_max_fds,
  struct iovec *migr_iters, char *path_to_server,
  uint32_t src_crc, size_t bar1_size)
 {
- int ret, sock;
+ ssize_t ret;
+ int sock;
  char *sock_path;
  struct stat sb;
  uint32_t device_state = VFIO_USER_DEVICE_STATE_RESUMING;

samples/server.c

@@ -320,10 +320,8 @@ migration_read_data(vfu_ctx_t *vfu_ctx, void *buf, uint64_t size)
  // TODO check the following is always allowed
 
  memcpy(buf, server_data->bar1 + read_start, bytes_read);
- } else if (
- read_start < server_data->bar1_size // starts in bar1
- && read_end > server_data->bar1_size // ends in bar0
- ) {
+ } else if (read_start < server_data->bar1_size // starts in bar1
+ && read_end > server_data->bar1_size) { // ends in bar0
  // case 2: part of the read in bar1 and part of the read in bar0
  // TODO check the following is always allowed