gpu/intel: handle double insertion in PPGTT

As the PPGTT is populated by the client, the client has to account for
guard pages and so forth.

Issue #4148 #4233

repos/os/include/gpu_session/connection.h

@@ -30,7 +30,8 @@ struct Gpu::Connection : Genode::Connection<Session>, Session_client
 	Genode::Capability<Gpu::Session> _session(Genode::Parent &parent,
 	                                          char const *label, Genode::size_t quota)
 	{
-		return session(parent, "ram_quota=%ld, label=\"%s\"", quota, label);
+		return session(parent, "ram_quota=%ld, cap_quota=%ld, label=\"%s\"",
+		               quota, CAP_QUOTA, label);
 	}
 
 	/**

repos/os/include/gpu_session/gpu_session.h

@@ -65,6 +65,7 @@ struct Gpu::Session : public Genode::Session
 	struct Out_of_ram    : Genode::Exception { };
 	struct Out_of_caps   : Genode::Exception { };
 	struct Invalid_state : Genode::Exception { };
+	struct Mapping_buffer_failed  : Genode::Exception { };
 
 	enum { REQUIRED_QUOTA = 1024 * 1024, CAP_QUOTA = 8, };
 
@@ -124,6 +125,8 @@ struct Gpu::Session : public Genode::Session
 	 * \param ds        dataspace capability for buffer
 	 * \param aperture  if true create CPU accessible mapping through
 	 *                  GGTT window, otherwise create PPGTT mapping
+	 *
+	 * \throw Mapping_buffer_failed
 	 */
 	virtual Genode::Dataspace_capability map_buffer(Genode::Dataspace_capability ds,
 	                                                bool aperture) = 0;
@@ -140,6 +143,9 @@ struct Gpu::Session : public Genode::Session
 	 *
 	 * \param ds  dataspace capability for buffer
 	 * \param va  virtual address
+	 *
+	 * \throw Mapping_buffer_failed
+	 * \throw Out_of_ram
 	 */
 	virtual bool map_buffer_ppgtt(Genode::Dataspace_capability ds,
 	                              Gpu::addr_t va) = 0;
@@ -174,12 +180,12 @@ struct Gpu::Session : public Genode::Session
 	                 Genode::size_t);
 	GENODE_RPC(Rpc_free_buffer, void, free_buffer, Genode::Dataspace_capability);
 	GENODE_RPC_THROW(Rpc_map_buffer, Genode::Dataspace_capability, map_buffer,
-	                 GENODE_TYPE_LIST(Out_of_ram),
+	                 GENODE_TYPE_LIST(Mapping_buffer_failed, Out_of_ram),
 	                 Genode::Dataspace_capability, bool);
 	GENODE_RPC(Rpc_unmap_buffer, void, unmap_buffer,
 	           Genode::Dataspace_capability);
 	GENODE_RPC_THROW(Rpc_map_buffer_ppgtt, bool, map_buffer_ppgtt,
-	                 GENODE_TYPE_LIST(Out_of_ram),
+	                 GENODE_TYPE_LIST(Mapping_buffer_failed, Out_of_ram),
 	                 Genode::Dataspace_capability, Gpu::addr_t);
 	GENODE_RPC(Rpc_unmap_buffer_ppgtt, void, unmap_buffer_ppgtt,
 	           Genode::Dataspace_capability, Gpu::addr_t);

repos/os/src/drivers/gpu/intel/main.cc

@@ -796,8 +796,8 @@ struct Igd::Device
 			} catch (Igd::Ppgtt_allocator::Out_of_memory) {
 				throw Igd::Device::Out_of_ram();
 			} catch (...) {
-				Genode::log(__func__, ": unknown exception");
-				throw;
+				/* Double_insertion and the like */
+				throw Igd::Device::Could_not_map_buffer();
 			}
 		}
 
@@ -1560,21 +1560,21 @@ class Gpu::Session_component : public Genode::Session_object<Gpu::Session>
 					buffer.ppgtt_va_valid = true;
 					result = OK;
 				} catch (Igd::Device::Could_not_map_buffer) {
-					/* FIXME do not result in Out_of_ram */
-					Genode::error("could not map buffer object into PPGTT");
+					Genode::error("could not map buffer object (", Genode::Hex(va), ") into PPGTT");
 					result = MAP_FAILED;
 					return;
 				}
-				/* will throw below */
-				catch (Igd::Device::Out_of_ram) { return; }
+				catch (Igd::Device::Out_of_ram) {
+					result = ALLOC_FAILED;
+					return;
+				}
 			};
 			_buffer_registry.for_each(lookup_and_map);
 
 			switch (result) {
-			case ALLOC_FAILED:
-				throw Gpu::Session::Out_of_ram();
-			case OK:
-				return true;
+			case ALLOC_FAILED: throw Gpu::Session::Out_of_ram();
+			case MAP_FAILED:   throw Gpu::Session::Mapping_buffer_failed();
+			case OK: return true;
 			default:
 				return false;
 			}