diff --git a/src/gallium/drivers/d3d12/d3d12_screen.cpp b/src/gallium/drivers/d3d12/d3d12_screen.cpp
index e1e9d719c4e..aeffeee5435 100644
--- a/src/gallium/drivers/d3d12/d3d12_screen.cpp
+++ b/src/gallium/drivers/d3d12/d3d12_screen.cpp
@@ -295,7 +295,8 @@ d3d12_get_param(struct pipe_screen *pscreen, enum pipe_cap param)
       return D3D12_REQ_GS_INVOCATION_32BIT_OUTPUT_COMPONENT_LIMIT;
 
    case PIPE_CAP_MAX_VARYINGS:
-      return D3D12_PS_INPUT_REGISTER_COUNT;
+      /* Subtract one so that implicit position can be added */
+      return D3D12_PS_INPUT_REGISTER_COUNT - 1;
 
    case PIPE_CAP_NIR_COMPACT_ARRAYS:
       return 1;
@@ -389,18 +390,28 @@ d3d12_get_shader_param(struct pipe_screen *pscreen,
       return 0;
 
    case PIPE_SHADER_CAP_MAX_INPUTS:
-      return screen->max_feature_level >= D3D_FEATURE_LEVEL_10_1 ? 32 : 16;
+      switch (shader) {
+      case PIPE_SHADER_VERTEX: return D3D12_VS_INPUT_REGISTER_COUNT;
+      case PIPE_SHADER_FRAGMENT: return D3D12_PS_INPUT_REGISTER_COUNT;
+      case PIPE_SHADER_GEOMETRY: return D3D12_GS_INPUT_REGISTER_COUNT;
+      case PIPE_SHADER_TESS_CTRL: return D3D12_HS_CONTROL_POINT_PHASE_INPUT_REGISTER_COUNT;
+      case PIPE_SHADER_TESS_EVAL: return D3D12_DS_INPUT_CONTROL_POINT_REGISTER_COUNT;
+      case PIPE_SHADER_COMPUTE: return 0;
+      default: unreachable("Unexpected shader");
+      }
+      break;
 
    case PIPE_SHADER_CAP_MAX_OUTPUTS:
-      if (shader == PIPE_SHADER_FRAGMENT) {
-         /* same as max MRTs (not sure if this is correct) */
-         if (screen->max_feature_level >= D3D_FEATURE_LEVEL_10_0)
-            return 8;
-         else if (screen->max_feature_level == D3D_FEATURE_LEVEL_9_3)
-            return 4;
-         return 1;
+      switch (shader) {
+      case PIPE_SHADER_VERTEX: return D3D12_VS_OUTPUT_REGISTER_COUNT;
+      case PIPE_SHADER_FRAGMENT: return D3D12_PS_OUTPUT_REGISTER_COUNT;
+      case PIPE_SHADER_GEOMETRY: return D3D12_GS_OUTPUT_REGISTER_COUNT;
+      case PIPE_SHADER_TESS_CTRL: return D3D12_HS_CONTROL_POINT_PHASE_OUTPUT_REGISTER_COUNT;
+      case PIPE_SHADER_TESS_EVAL: return D3D12_DS_OUTPUT_REGISTER_COUNT;
+      case PIPE_SHADER_COMPUTE: return 0;
+      default: unreachable("Unexpected shader");
       }
-      return screen->max_feature_level >= D3D_FEATURE_LEVEL_10_1 ? 32 : 16;
+      break;
 
    case PIPE_SHADER_CAP_MAX_TEXTURE_SAMPLERS:
       if (screen->opts.ResourceBindingTier == D3D12_RESOURCE_BINDING_TIER_1)