fix: migration quiesce and short write

Signed-off-by: William Henderson <william.henderson@nutanix.com>
nutanix · Sep 15, 2023 · 5562eb7 · 5562eb7
1 parent 4b42857
commit 5562eb7
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Showing 3 changed files with 31 additions and 3 deletions.
diff --git a/lib/libvfio-user.c b/lib/libvfio-user.c
@@ -1522,6 +1522,7 @@ static bool
 command_needs_quiesce(vfu_ctx_t *vfu_ctx, const vfu_msg_t *msg)
 {
  struct vfio_user_region_access *reg;
+ struct vfio_user_device_feature *feature;
 
  if (vfu_ctx->quiesce == NULL) {
  return false;
@@ -1540,7 +1541,6 @@ command_needs_quiesce(vfu_ctx_t *vfu_ctx, const vfu_msg_t *msg)
  /*
  * bad request, it will be eventually failed by
  * handle_region_access
- *
  */
  return false;
  }
@@ -1549,8 +1549,23 @@ command_needs_quiesce(vfu_ctx_t *vfu_ctx, const vfu_msg_t *msg)
  return true;
  }
  break;
+
+ case VFIO_USER_DEVICE_FEATURE:
+ if (msg->in.iov.iov_len < sizeof(*feature)) {
+ /*
+ * bad request, it will be eventually failed by
+ * handle_region_access
+ */
+ return false;
+ }
+ feature = msg->in.iov.iov_base;
+ if (migration_feature_needs_quiesce(feature)) {
+ return true;
+ }
+ break;
  }
 
+
  return false;
 }
 

diff --git a/lib/migration.c b/lib/migration.c
@@ -385,6 +385,12 @@ handle_mig_data_write(vfu_ctx_t *vfu_ctx, vfu_msg_t *msg)
  return ERROR_INT(EINVAL);
  }
 
+ if (msg->in.iov.iov_len < sizeof(struct vfio_user_mig_data) + req->size) {
+ vfu_log(vfu_ctx, LOG_ERR, "short write (%d < %ld)",
+ req->argsz, sizeof(struct vfio_user_mig_data) + req->size);
+ return ERROR_INT(EINVAL);
+ }
+
  ssize_t ret = migr->callbacks.write_data(vfu_ctx, &req->data, req->size);
 
  if (ret < 0) {
@@ -434,4 +440,12 @@ migration_set_pgsize(struct migration *migr, size_t pgsize)
  return 0;
 }
 
+bool
+migration_feature_needs_quiesce(struct vfio_user_device_feature *feature)
+{
+ return ((feature->flags &
+ (VFIO_DEVICE_FEATURE_SET | VFIO_DEVICE_FEATURE_MIG_DEVICE_STATE)) != 0)
+ && !(feature->flags & VFIO_DEVICE_FEATURE_PROBE);
+}
+
 /* ex: set tabstop=4 shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/lib/migration.h b/lib/migration.h
@@ -85,8 +85,7 @@ MOCK_DECLARE(ssize_t, handle_device_state, vfu_ctx_t *vfu_ctx,
  struct migration *migr, uint32_t device_state, bool notify);
 
 bool
-access_migration_needs_quiesce(const vfu_ctx_t *vfu_ctx, size_t region_index,
- uint64_t offset);
+migration_feature_needs_quiesce(struct vfio_user_device_feature *feature);
 
 #endif /* LIB_VFIO_USER_MIGRATION_H */