diff --git a/base-linux/src/base/env/platform_env.cc b/base-linux/src/base/env/platform_env.cc
index b6aa58768..a40df1b6b 100644
--- a/base-linux/src/base/env/platform_env.cc
+++ b/base-linux/src/base/env/platform_env.cc
@@ -56,7 +56,8 @@ Platform_env_base::Rm_session_mmap::_dataspace_writable(Dataspace_capability ds)
 
 Session_capability
 Platform_env::Local_parent::session(Service_name const &service_name,
-                                    Session_args const &args)
+                                    Session_args const &args,
+                                    Affinity     const &affinity)
 {
 	if (strcmp(service_name.string(),
 	    Rm_session::service_name()) == 0)
@@ -66,7 +67,7 @@ Platform_env::Local_parent::session(Service_name const &service_name,
 				.ulong_value(~0);
 
 		if (size == 0)
-			return Parent_client::session(service_name, args);
+			return Parent_client::session(service_name, args, affinity);
 
 		Rm_session_mmap *rm = new (env()->heap())
 		                      Rm_session_mmap(true, size);
@@ -74,7 +75,7 @@ Platform_env::Local_parent::session(Service_name const &service_name,
 		return Session_capability::local_cap(rm);
 	}
 
-	return Parent_client::session(service_name, args);
+	return Parent_client::session(service_name, args, affinity);
 }
 
 
diff --git a/base-linux/src/base/env/platform_env.h b/base-linux/src/base/env/platform_env.h
index a28a0d74f..a84ff9d9b 100644
--- a/base-linux/src/base/env/platform_env.h
+++ b/base-linux/src/base/env/platform_env.h
@@ -387,7 +387,8 @@ namespace Genode {
 					 **********************/
 
 					Session_capability session(Service_name const &,
-					                           Session_args const &);
+					                           Session_args const &,
+					                           Affinity     const & = Affinity());
 					void close(Session_capability);
 
 					/**
diff --git a/base/include/base/affinity.h b/base/include/base/affinity.h
index 19014029e..1f95f935c 100644
--- a/base/include/base/affinity.h
+++ b/base/include/base/affinity.h
@@ -117,6 +117,8 @@ namespace Genode {
 			Space    _space;
 			Location _location;
 
+		public:
+
 			Affinity(Space const &space, Location const &location)
 			: _space(space), _location(location) { }
 
diff --git a/base/include/base/child.h b/base/include/base/child.h
index e8ea04268..37479e35d 100644
--- a/base/include/base/child.h
+++ b/base/include/base/child.h
@@ -269,7 +269,8 @@ namespace Genode {
 			 **********************/
 
 			void announce(Service_name const &, Root_capability);
-			Session_capability session(Service_name const &, Session_args const &);
+			Session_capability session(Service_name const &, Session_args const &,
+			                           Affinity const &);
 			void upgrade(Session_capability, Upgrade_args const &);
 			void close(Session_capability);
 			void exit(int);
diff --git a/base/include/base/service.h b/base/include/base/service.h
index e5ddadcd0..32ca62877 100644
--- a/base/include/base/service.h
+++ b/base/include/base/service.h
@@ -126,13 +126,15 @@ namespace Genode {
 			/**
 			 * Create session
 			 *
-			 * \param args  session-construction arguments
+			 * \param args      session-construction arguments
+			 * \param affinity  preferred CPU affinity of session
 			 *
 			 * \throw Invalid_args
 			 * \throw Unavailable
 			 * \throw Quota_exceeded
 			 */
-			virtual Session_capability session(const char *args) = 0;
+			virtual Session_capability session(char const *args,
+			                                   Affinity const &affinity) = 0;
 
 			/**
 			 * Extend resource donation to an existing session
@@ -175,9 +177,9 @@ namespace Genode {
 			Local_service(const char *name, Root *root)
 			: Service(name), _root(root) { }
 
-			Session_capability session(const char *args)
+			Session_capability session(const char *args, Affinity const &affinity)
 			{
-				try { return _root->session(args); }
+				try { return _root->session(args, affinity); }
 				catch (Root::Invalid_args)   { throw Invalid_args(); }
 				catch (Root::Unavailable)    { throw Unavailable(); }
 				catch (Root::Quota_exceeded) { throw Quota_exceeded(); }
@@ -200,9 +202,9 @@ namespace Genode {
 
 			Parent_service(const char *name) : Service(name) { }
 
-			Session_capability session(const char *args)
+			Session_capability session(const char *args, Affinity const &affinity)
 			{
-				try { return env()->parent()->session(name(), args); }
+				try { return env()->parent()->session(name(), args, affinity); }
 				catch (Parent::Unavailable) {
 					PWRN("parent has no service \"%s\"", name());
 					throw Unavailable();
@@ -245,12 +247,12 @@ namespace Genode {
 
 			Server *server() const { return _server; }
 
-			Session_capability session(const char *args)
+			Session_capability session(const char *args, Affinity const &affinity)
 			{
 				if (!_root_cap.valid())
 					throw Unavailable();
 
-				try { return _root.session(args); }
+				try { return _root.session(args, affinity); }
 				catch (Root::Invalid_args)   { throw Invalid_args();   }
 				catch (Root::Unavailable)    { throw Unavailable();    }
 				catch (Root::Quota_exceeded) { throw Quota_exceeded(); }
diff --git a/base/include/parent/client.h b/base/include/parent/client.h
index 44b2ea1b8..cfc53ec2d 100644
--- a/base/include/parent/client.h
+++ b/base/include/parent/client.h
@@ -30,8 +30,9 @@ namespace Genode {
 			call<Rpc_announce>(service, root); }
 
 		Session_capability session(Service_name const &service,
-		                           Session_args const &args) {
-			return call<Rpc_session>(service, args); }
+		                           Session_args const &args,
+		                           Affinity     const &affinity) {
+			return call<Rpc_session>(service, args, affinity); }
 
 		void upgrade(Session_capability to_session, Upgrade_args const &args) {
 			call<Rpc_upgrade>(to_session, args); }
diff --git a/base/include/parent/parent.h b/base/include/parent/parent.h
index 2850488fb..448693c32 100644
--- a/base/include/parent/parent.h
+++ b/base/include/parent/parent.h
@@ -107,6 +107,7 @@ namespace Genode {
 			 *
 			 * \param service_name     name of the requested interface
 			 * \param args             session constructor arguments
+			 * \param affinity         preferred CPU affinity for the session
 			 *
 			 * \throw Service_denied   parent denies session request
 			 * \throw Quota_exceeded   our own quota does not suffice for
@@ -119,13 +120,15 @@ namespace Genode {
 			 * 'session()' template instead.
 			 */
 			virtual Session_capability session(Service_name const &service_name,
-			                                   Session_args const &args) = 0;
+			                                   Session_args const &args,
+			                                   Affinity     const &affinity = Affinity()) = 0;
 
 			/**
 			 * Create session to a service
 			 *
-			 * \param SESSION_TYPE  session interface type
-			 * \param args          session constructor arguments
+			 * \param SESSION_TYPE     session interface type
+			 * \param args             session constructor arguments
+			 * \param affinity         preferred CPU affinity for the session
 			 *
 			 * \throw Service_denied   parent denies session request
 			 * \throw Quota_exceeded   our own quota does not suffice for
@@ -135,9 +138,11 @@ namespace Genode {
 			 * \return                 capability to new session
 			 */
 			template <typename SESSION_TYPE>
-			Capability<SESSION_TYPE> session(Session_args const &args)
+			Capability<SESSION_TYPE> session(Session_args const &args,
+			                                 Affinity     const &affinity = Affinity())
 			{
-				Session_capability cap = session(SESSION_TYPE::service_name(), args);
+				Session_capability cap = session(SESSION_TYPE::service_name(),
+				                                 args, affinity);
 				return reinterpret_cap_cast<SESSION_TYPE>(cap);
 			}
 
@@ -176,7 +181,7 @@ namespace Genode {
 			           Service_name const &, Root_capability);
 			GENODE_RPC_THROW(Rpc_session, Session_capability, session,
 			                 GENODE_TYPE_LIST(Service_denied, Quota_exceeded, Unavailable),
-			                 Service_name const &, Session_args const &);
+			                 Service_name const &, Session_args const &, Affinity const &);
 			GENODE_RPC_THROW(Rpc_upgrade, void, upgrade,
 			                 GENODE_TYPE_LIST(Quota_exceeded),
 			                 Session_capability, Upgrade_args const &);
diff --git a/base/include/root/client.h b/base/include/root/client.h
index fbb5ac5c6..96b02ee85 100644
--- a/base/include/root/client.h
+++ b/base/include/root/client.h
@@ -24,8 +24,8 @@ namespace Genode {
 		explicit Root_client(Root_capability root)
 		: Rpc_client<Root>(root) { }
 
-		Session_capability session(Session_args const &args) {
-			return call<Rpc_session>(args); }
+		Session_capability session(Session_args const &args, Affinity const &affinity) {
+			return call<Rpc_session>(args, affinity); }
 
 		void upgrade(Session_capability session, Upgrade_args const &args) {
 			call<Rpc_upgrade>(session, args); }
diff --git a/base/include/root/component.h b/base/include/root/component.h
index bd33d2889..7706689bf 100644
--- a/base/include/root/component.h
+++ b/base/include/root/component.h
@@ -120,12 +120,25 @@ namespace Genode {
 			 * by 'Root_component' must be used for allocating the session
 			 * object.
 			 *
+			 * If the server implementation does not evaluate the session
+			 * affinity, it suffices to override the overload without the
+			 * affinity argument.
+			 *
 			 * \throw Allocator::Out_of_memory  typically caused by the
 			 *                                  meta-data allocator
 			 * \throw Root::Invalid_args        typically caused by the
 			 *                                  session-component constructor
 			 */
-			virtual SESSION_TYPE *_create_session(const char *args) = 0;
+			virtual SESSION_TYPE *_create_session(const char *args,
+			                                      Affinity const &)
+			{
+				return _create_session(args);
+			}
+
+			virtual SESSION_TYPE *_create_session(const char *args)
+			{
+				throw Root::Invalid_args();
+			}
 
 			/**
 			 * Inform session about a quota upgrade
@@ -175,7 +188,8 @@ namespace Genode {
 			 ** Root interface **
 			 ********************/
 
-			Session_capability session(Root::Session_args const &args)
+			Session_capability session(Root::Session_args const &args,
+			                           Affinity           const &affinity)
 			{
 				if (!args.is_valid_string()) throw Root::Invalid_args();
 
@@ -213,7 +227,7 @@ namespace Genode {
 				                    "ram_quota", ram_quota_buf);
 
 				SESSION_TYPE *s = 0;
-				try { s = _create_session(adjusted_args); }
+				try { s = _create_session(adjusted_args, affinity); }
 				catch (Allocator::Out_of_memory) { throw Root::Quota_exceeded(); }
 
 				return _ep->manage(s);
diff --git a/base/include/root/root.h b/base/include/root/root.h
index 5e67594cf..f11bf77c4 100644
--- a/base/include/root/root.h
+++ b/base/include/root/root.h
@@ -17,6 +17,7 @@
 #include <base/exception.h>
 #include <base/rpc.h>
 #include <base/rpc_args.h>
+#include <base/affinity.h>
 #include <session/capability.h>
 
 namespace Genode {
@@ -46,7 +47,8 @@ namespace Genode {
 		 *
 		 * \return capability to new session
 		 */
-		virtual Session_capability session(Session_args const &args) = 0;
+		virtual Session_capability session(Session_args const &args,
+		                                   Affinity     const &affinity) = 0;
 
 		/**
 		 * Extend resource donation to an existing session
@@ -65,7 +67,7 @@ namespace Genode {
 
 		GENODE_RPC_THROW(Rpc_session, Session_capability, session,
 		                 GENODE_TYPE_LIST(Unavailable, Quota_exceeded, Invalid_args),
-		                 Session_args const &);
+		                 Session_args const &, Affinity const &);
 		GENODE_RPC_THROW(Rpc_upgrade, void, upgrade,
 		                 GENODE_TYPE_LIST(Invalid_args),
 		                 Session_capability, Upgrade_args const &);
diff --git a/base/src/base/child/child.cc b/base/src/base/child/child.cc
index e2dffd295..ed8d3a12b 100644
--- a/base/src/base/child/child.cc
+++ b/base/src/base/child/child.cc
@@ -242,7 +242,8 @@ void Child::announce(Parent::Service_name const &name, Root_capability root)
 
 
 Session_capability Child::session(Parent::Service_name const &name,
-                                  Parent::Session_args const &args)
+                                  Parent::Session_args const &args,
+                                  Affinity             const &affinity)
 {
 	if (!name.is_valid_string() || !args.is_valid_string()) throw Unavailable();
 
@@ -273,7 +274,7 @@ Session_capability Child::session(Parent::Service_name const &name,
 
 	/* create session */
 	Session_capability cap;
-	try { cap = service->session(_args); }
+	try { cap = service->session(_args, affinity); }
 	catch (Service::Invalid_args)   { throw Service_denied(); }
 	catch (Service::Unavailable)    { throw Service_denied(); }
 	catch (Service::Quota_exceeded) { throw Quota_exceeded(); }
diff --git a/base/src/core/include/core_parent.h b/base/src/core/include/core_parent.h
index f7e7a2fcc..4c0dadb86 100644
--- a/base/src/core/include/core_parent.h
+++ b/base/src/core/include/core_parent.h
@@ -45,7 +45,8 @@ namespace Genode {
 				PDBG("implement me, please");
 			}
 
-			Session_capability session(Service_name const &, Session_args const &);
+			Session_capability session(Service_name const &, Session_args const &,
+			                           Affinity const &);
 
 			void upgrade(Session_capability, Upgrade_args const &)
 			{
diff --git a/base/src/core/include/irq_root.h b/base/src/core/include/irq_root.h
index e9bd3a5c8..c75ddaea0 100644
--- a/base/src/core/include/irq_root.h
+++ b/base/src/core/include/irq_root.h
@@ -56,7 +56,7 @@ namespace Genode {
 			 ** Root interface **
 			 ********************/
 
-			Session_capability session(Session_args const &args)
+			Session_capability session(Session_args const &args, Affinity const &affinity)
 			{
 				if (!args.is_valid_string()) throw Invalid_args();
 
diff --git a/base/src/core/include/rm_root.h b/base/src/core/include/rm_root.h
index fa854ae69..edb7afc00 100644
--- a/base/src/core/include/rm_root.h
+++ b/base/src/core/include/rm_root.h
@@ -56,9 +56,9 @@ namespace Genode {
 				                            size  ==  0   ? _vm_size  : size);
 			}
 
-			Session_capability session(Root::Session_args const &args)
+			Session_capability session(Root::Session_args const &args, Affinity const &affinity)
 			{
-				Session_capability cap = Root_component<Rm_session_component>::session(args);
+				Session_capability cap = Root_component<Rm_session_component>::session(args, affinity);
 
 				/* lookup rm_session_component object */
 				Object_pool<Rm_session_component>::Guard rm_session(ep()->lookup_and_lock(cap));
diff --git a/base/src/core/main.cc b/base/src/core/main.cc
index 0c314bb7b..4bb5ae7a5 100644
--- a/base/src/core/main.cc
+++ b/base/src/core/main.cc
@@ -84,12 +84,13 @@ Platform_generic *Genode::platform() { return platform_specific(); }
  *************************/
 
 Session_capability Core_parent::session(Parent::Service_name const &name,
-                                        Parent::Session_args const &args)
+                                        Parent::Session_args const &args,
+                                        Affinity             const &affinity)
 {
 	Service *service = local_services.find(name.string());
 
 	if (service)
-		return service->session(args.string());
+		return service->session(args.string(), affinity);
 
 	PWRN("service_name=\"%s\" arg=\"%s\" not handled", name.string(), args.string());
 	return Session_capability();
@@ -235,7 +236,7 @@ int main()
 
 	/* create ram session for init and transfer some of our own quota */
 	Ram_session_capability init_ram_session_cap
-		= static_cap_cast<Ram_session>(ram_root.session("ram_quota=32K"));
+		= static_cap_cast<Ram_session>(ram_root.session("ram_quota=32K", Affinity()));
 	Ram_session_client(init_ram_session_cap).ref_account(env()->ram_session_cap());
 
 	Cpu_connection init_cpu("init");
diff --git a/dde_ipxe/src/drivers/nic_stat/main.cc b/dde_ipxe/src/drivers/nic_stat/main.cc
index ea0ccf8d9..fcedf3f2d 100644
--- a/dde_ipxe/src/drivers/nic_stat/main.cc
+++ b/dde_ipxe/src/drivers/nic_stat/main.cc
@@ -156,7 +156,8 @@ int main(int, char **)
 	        6*4096 + tx_buf_size + rx_buf_size,
 	        tx_buf_size, rx_buf_size))
 */
-	nic_root.session("ram_quota=155648, tx_buf_size=65536, rx_buf_size=65536");
+	nic_root.session("ram_quota=155648, tx_buf_size=65536, rx_buf_size=65536",
+	                 Affinity());
 
 	sleep_forever();
 	return 0;
diff --git a/gems/src/server/d3m/block_service.h b/gems/src/server/d3m/block_service.h
index 367e5f5aa..5c384b891 100644
--- a/gems/src/server/d3m/block_service.h
+++ b/gems/src/server/d3m/block_service.h
@@ -51,7 +51,9 @@ class Iso9660_boot_probe
 			Proxy_service(Genode::Session_capability session)
 			: Genode::Service("proxy"), _session(session) { }
 
-			Genode::Session_capability session(const char *) { return _session; }
+			Genode::Session_capability session(char             const *,
+			                                   Genode::Affinity const &)
+			{ return _session; }
 
 			void upgrade(Genode::Session_capability session, const char *) { }
 
@@ -127,7 +129,8 @@ class Iso9660_boot_probe
 	{
 		char const *args = "ram_quota=140K, tx_buf_size=128K";
 		Genode::Root_client root(_block_root);
-		return Genode::static_cap_cast<Block::Session>(root.session(args));
+		return Genode::static_cap_cast<Block::Session>
+		       (root.session(args, Genode::Affinity()));
 	}
 
 	/**
@@ -152,7 +155,7 @@ class Iso9660_boot_probe
 		char args[Genode::Root::Session_args::MAX_SIZE];
 		Genode::snprintf(args, sizeof(args), "ram_quota=4K, filename=\"%s\"",
 		                 boot_tag_name);
-		rom_root.session(args);
+		rom_root.session(args, Genode::Affinity());
 	}
 
 	public:
@@ -297,11 +300,12 @@ namespace Block {
 			Root(Driver_registry &driver_registry)
 			: _driver_registry(driver_registry) { }
 
-			Genode::Session_capability session(Genode::Root::Session_args const &args)
+			Genode::Session_capability session(Genode::Root::Session_args const &args,
+			                                   Genode::Affinity           const &affinity)
 			{
 				PDBG("\nsession requested args=\"%s\"", args.string());
 				Genode::Root_capability root = _driver_registry.root();
-				return Genode::Root_client(root).session(args);
+				return Genode::Root_client(root).session(args, affinity);
 			}
 
 			void upgrade(Genode::Session_capability,
diff --git a/gems/src/server/d3m/input_service.h b/gems/src/server/d3m/input_service.h
index a81da2c9a..cd60bc1f2 100644
--- a/gems/src/server/d3m/input_service.h
+++ b/gems/src/server/d3m/input_service.h
@@ -55,7 +55,8 @@ namespace Input {
 
 				try {
 					using namespace Genode;
-					return static_cap_cast<Session>(Root_client(root).session(args));
+					return static_cap_cast<Session>
+					       (Root_client(root).session(args, Genode::Affinity()));
 				} catch (...) {
 					throw Source_unavailable();
 				}
diff --git a/gems/src/server/d3m/nic_service.h b/gems/src/server/d3m/nic_service.h
index 43c1b4d1d..89a4d45de 100644
--- a/gems/src/server/d3m/nic_service.h
+++ b/gems/src/server/d3m/nic_service.h
@@ -40,7 +40,8 @@ namespace Nic {
 
 		public:
 
-			Genode::Session_capability session(Session_args const &args)
+			Genode::Session_capability session(Session_args     const &args,
+			                                   Genode::Affinity const &affinity)
 			{
 				if (!args.is_valid_string()) throw Invalid_args();
 
@@ -48,7 +49,8 @@ namespace Nic {
 					throw Unavailable();
 
 				try {
-					return Genode::Root_client(_nic_provider.root()).session(args.string());
+					return Genode::Root_client(_nic_provider.root())
+					       .session(args.string(), affinity);
 				} catch (...) {
 					throw Unavailable();
 				}
diff --git a/os/include/init/child.h b/os/include/init/child.h
index 05321e25a..fb762ed85 100644
--- a/os/include/init/child.h
+++ b/os/include/init/child.h
@@ -229,7 +229,8 @@ namespace Init {
 				}
 			}
 
-			Genode::Session_capability session(const char *args)
+			Genode::Session_capability session(const char *args,
+			                                   Genode::Affinity const &affinity)
 			{
 				/*
 				 * This function is called from the context of the client's
@@ -246,7 +247,7 @@ namespace Init {
 					_applicants_lock.unlock();
 
 				Genode::Session_capability cap;
-				try { cap = Genode::Root_client(_root).session(args); }
+				try { cap = Genode::Root_client(_root).session(args, affinity); }
 				catch (Genode::Root::Invalid_args)   { throw Invalid_args();   }
 				catch (Genode::Root::Unavailable)    { throw Unavailable();    }
 				catch (Genode::Root::Quota_exceeded) { throw Quota_exceeded(); }
diff --git a/os/include/init/child_policy.h b/os/include/init/child_policy.h
index 5561a0644..5ac369112 100644
--- a/os/include/init/child_policy.h
+++ b/os/include/init/child_policy.h
@@ -171,7 +171,8 @@ namespace Init {
 				Local_rom_service(Genode::Rom_session_capability rom_cap, bool valid)
 				: Genode::Service("ROM"), _rom_cap(rom_cap), _valid(valid) { }
 
-				Genode::Session_capability session(const char * /*args*/)
+				Genode::Session_capability session(char const * /*args*/,
+				                                   Genode::Affinity const &)
 				{
 					if (!_valid)
 						throw Invalid_args();
diff --git a/os/include/os/child_policy_dynamic_rom.h b/os/include/os/child_policy_dynamic_rom.h
index 475317b2d..d8dd5b70c 100644
--- a/os/include/os/child_policy_dynamic_rom.h
+++ b/os/include/os/child_policy_dynamic_rom.h
@@ -135,7 +135,9 @@ namespace Genode {
 			 ** Service interface **
 			 ***********************/
 
-			Session_capability session(const char *) { return _rom_session_cap; }
+			Session_capability session(const char *, Affinity const &) {
+				return _rom_session_cap; }
+
 			void upgrade(Session_capability, const char *) { }
 			void close(Session_capability) { }
 
diff --git a/os/include/os/static_root.h b/os/include/os/static_root.h
index c2bfaf45b..d35577ad0 100644
--- a/os/include/os/static_root.h
+++ b/os/include/os/static_root.h
@@ -51,7 +51,7 @@ class Genode::Static_root : public Genode::Rpc_object<Genode::Typed_root<SESSION
 		 ** Root interface **
 		 ********************/
 
-		Capability<Session> session(Root::Session_args const &args)
+		Capability<Session> session(Root::Session_args const &args, Affinity const &)
 		{
 			return _session;
 		}
diff --git a/os/src/drivers/acpi/main.cc b/os/src/drivers/acpi/main.cc
index 24282b109..bbf21393d 100644
--- a/os/src/drivers/acpi/main.cc
+++ b/os/src/drivers/acpi/main.cc
@@ -74,7 +74,8 @@ namespace Irq {
 			/**
 			 * Remap IRQ number and create IRQ session at parent
 			 */
-			Genode::Session_capability session(Root::Session_args const &args)
+			Genode::Session_capability session(Root::Session_args const &args,
+			                                   Genode::Affinity   const &)
 			{
 				using namespace Genode;
 
@@ -127,7 +128,8 @@ namespace Pci {
 
 			Root(Provider &pci_provider) : _pci_provider(pci_provider) { }
 
-			Genode::Session_capability session(Session_args const &args)
+			Genode::Session_capability session(Session_args     const &args,
+			                                   Genode::Affinity const &affinity)
 			{
 				if (!args.is_valid_string()) throw Invalid_args();
 
@@ -135,7 +137,8 @@ namespace Pci {
 					throw Unavailable();
 
 				try {
-					return Genode::Root_client(_pci_provider.root()).session(args.string());
+					return Genode::Root_client(_pci_provider.root())
+					       .session(args.string(), affinity);
 				} catch (...) {
 					throw Unavailable();
 				}
@@ -179,7 +182,8 @@ class Pci_policy : public Genode::Slave_policy, public Pci::Provider
 
 			try {
 				using namespace Genode;
-				session = static_cap_cast<Pci::Session>(Root_client(_cap).session(args));
+				session = static_cap_cast<Pci::Session>(Root_client(_cap)
+				          .session(args, Genode::Affinity()));
 			} catch (...) { return; }
 
 			Acpi::configure_pci_devices(session);
diff --git a/os/src/drivers/pci/main.cc b/os/src/drivers/pci/main.cc
index 4ce6071dd..86927fe58 100644
--- a/os/src/drivers/pci/main.cc
+++ b/os/src/drivers/pci/main.cc
@@ -94,7 +94,7 @@ int main(int argc, char **argv)
 		static Device_pd_policy device_pd_policy(device_pd_ep);
 		static Genode::Slave    device_pd_slave(device_pd_ep, device_pd_policy,
 		                                        PCI_DEVICE_PD_RAM_QUOTA);
-		session_dev_pd = Genode::Root_client(device_pd_policy.root()).session("");
+		session_dev_pd = Genode::Root_client(device_pd_policy.root()).session("", Affinity());
 	} catch (...) {
 		PWRN("PCI device protection domain for IOMMU support is not available");
 	}
diff --git a/os/src/server/loader/child.h b/os/src/server/loader/child.h
index a748b3a87..2083f1d05 100644
--- a/os/src/server/loader/child.h
+++ b/os/src/server/loader/child.h
@@ -95,7 +95,7 @@ namespace Loader {
 				try {
 					char args[Session::Name::MAX_SIZE];
 					snprintf(args, sizeof(args), "ram_quota=4K, filename=\"%s\"", name);
-					return static_cap_cast<Rom_session>(_local_rom_service.session(args));
+					return static_cap_cast<Rom_session>(_local_rom_service.session(args, Affinity()));
 				} catch (Genode::Parent::Service_denied) {
 					PERR("Lookup for ROM module \"%s\" failed", name);
 					throw;
diff --git a/os/src/server/loader/main.cc b/os/src/server/loader/main.cc
index 14c490744..b0378192b 100644
--- a/os/src/server/loader/main.cc
+++ b/os/src/server/loader/main.cc
@@ -73,7 +73,8 @@ namespace Loader {
 						_close(_rom_sessions.first()); }
 				}
 
-				Genode::Session_capability session(const char *args)
+				Genode::Session_capability session(char     const *args,
+				                                   Affinity const &affinity)
 				{
 					/* try to find ROM module at local ROM service */
 					try {
@@ -97,7 +98,7 @@ namespace Loader {
 					} catch (...) { }
 
 					/* fall back to parent_rom_service */
-					return _parent_rom_service.session(args);
+					return _parent_rom_service.session(args, affinity);
 				}
 
 				void close(Session_capability session)
@@ -145,9 +146,10 @@ namespace Loader {
 			{
 				Local_cpu_service() : Intercepted_parent_service("CPU") { }
 
-				Genode::Session_capability session(const char *args)
+				Genode::Session_capability session(char     const *args,
+				                                   Affinity const &affinity)
 				{
-					Capability<Cpu_session> cap = env()->parent()->session<Cpu_session>(args);
+					Capability<Cpu_session> cap = env()->parent()->session<Cpu_session>(args, affinity);
 					Cpu_session_client(cap).exception_handler(Thread_capability(), fault_sigh);
 					return cap;
 				}
@@ -160,9 +162,10 @@ namespace Loader {
 			{
 				Local_rm_service() : Intercepted_parent_service("RM") { }
 
-				Genode::Session_capability session(const char *args)
+				Genode::Session_capability session(char     const *args,
+				                                   Affinity const &affinity)
 				{
-					Capability<Rm_session> cap = env()->parent()->session<Rm_session>(args);
+					Capability<Rm_session> cap = env()->parent()->session<Rm_session>(args, affinity);
 					Rm_session_client(cap).fault_handler(fault_sigh);
 					return cap;
 				}
@@ -195,7 +198,8 @@ namespace Loader {
 					destroy(&_md_alloc, open_session);
 				}
 
-				Genode::Session_capability session(const char *args)
+				Genode::Session_capability session(char     const *args,
+				                                   Affinity const &)
 				{
 					if (open_session)
 						throw Unavailable();
diff --git a/os/src/server/terminal_crosslink/terminal_root.h b/os/src/server/terminal_crosslink/terminal_root.h
index 0fb093b09..3da64732f 100644
--- a/os/src/server/terminal_crosslink/terminal_root.h
+++ b/os/src/server/terminal_crosslink/terminal_root.h
@@ -41,7 +41,8 @@ namespace Terminal {
 
 		public:
 
-			Session_capability session(Root::Session_args const &args)
+			Session_capability session(Root::Session_args const &args,
+			                           Genode::Affinity   const &)
 			{
 				if (!(_session_state & FIRST_SESSION_OPEN)) {
 					_session_state |= FIRST_SESSION_OPEN;
diff --git a/ports/src/app/gdb_monitor/app_child.h b/ports/src/app/gdb_monitor/app_child.h
index b6d0f1cd0..1ef53232c 100644
--- a/ports/src/app/gdb_monitor/app_child.h
+++ b/ports/src/app/gdb_monitor/app_child.h
@@ -85,9 +85,10 @@ namespace Gdb_monitor {
 						_rm_root(entrypoint, md_alloc, managed_ds_map)
 					{ }
 
-					Genode::Session_capability session(const char *args)
+					Genode::Session_capability session(const char *args,
+					                                   Genode::Affinity const &affinity)
 					{
-						return _rm_root.session(args);
+						return _rm_root.session(args, affinity);
 					}
 
 					void upgrade(Genode::Session_capability, const char *) { }
@@ -102,7 +103,7 @@ namespace Gdb_monitor {
 			{
 				_entrypoint.manage(&_rm_root);
 				Capability<Rm_session> cap = static_cap_cast<Rm_session>
-				                             (_rm_root.session("ram_quota=64K"));
+				                             (_rm_root.session("ram_quota=64K", Affinity()));
 				Rm_session_client rm(cap);
 
 				rm.fault_handler(_gdb_stub_thread.exception_signal_receiver()->manage(new (env()->heap()) Signal_context()));
@@ -114,7 +115,7 @@ namespace Gdb_monitor {
 				_entrypoint.manage(&_cpu_root);
 				char args[64];
 				Genode::snprintf(args, sizeof(args), "ram_quota=32K, label=\"%s\"", _unique_name);
-				return static_cap_cast<Cpu_session>(_cpu_root.session(args));
+				return static_cap_cast<Cpu_session>(_cpu_root.session(args, Affinity()));
 			}
 
 			/**
@@ -172,7 +173,8 @@ namespace Gdb_monitor {
 					 ** Root interface **
 					 ********************/
 
-					Session_capability session(Session_args const &args)
+					Session_capability session(Session_args const &args,
+					                           Affinity const &affinity)
 					{
 						using namespace Genode;
 
@@ -183,7 +185,7 @@ namespace Gdb_monitor {
 						/* forward session quota to child */
 						env()->ram_session()->transfer_quota(_child_ram, ram_quota);
 
-						Session_capability cap = _child_root.session(args);
+						Session_capability cap = _child_root.session(args, affinity);
 
 						/*
 						 * Keep information about donated quota in '_sessions'
diff --git a/ports/src/app/gdb_monitor/rom.h b/ports/src/app/gdb_monitor/rom.h
index 06a6fea15..1df8a6022 100644
--- a/ports/src/app/gdb_monitor/rom.h
+++ b/ports/src/app/gdb_monitor/rom.h
@@ -114,8 +114,8 @@ namespace Gdb_monitor {
 			: Service("ROM"), _root(entrypoint, md_alloc)
 			{ }
 
-			Capability<Session> session(char const *args) {
-				return _root.session(args); }
+			Capability<Session> session(char const *args, Affinity const &affinity) {
+				return _root.session(args, affinity); }
 
 			void upgrade(Capability<Session>, char const *) { }
 
diff --git a/ports/src/noux/local_cpu_service.h b/ports/src/noux/local_cpu_service.h
index 62c926c58..c070ecdf9 100644
--- a/ports/src/noux/local_cpu_service.h
+++ b/ports/src/noux/local_cpu_service.h
@@ -37,7 +37,7 @@ namespace Noux {
 				_cap(cap)
 			{ }
 
-			Genode::Session_capability session(const char *args)
+			Genode::Session_capability session(const char *args, Affinity const &)
 			{
 				PDBG("Implement me!");
 				return Genode::Session_capability();
diff --git a/ports/src/noux/local_noux_service.h b/ports/src/noux/local_noux_service.h
index 4a0a294b0..31c799d2e 100644
--- a/ports/src/noux/local_noux_service.h
+++ b/ports/src/noux/local_noux_service.h
@@ -33,7 +33,11 @@ namespace Noux {
 		Local_noux_service(Genode::Session_capability cap)
 		: Service(Session::service_name()), _cap(cap) { }
 
-		Genode::Session_capability session(const char *args) { return _cap; }
+		Genode::Session_capability session(const char *args, Affinity const &)
+		{
+			return _cap;
+		}
+
 		void upgrade(Genode::Session_capability, const char *args) { }
 		void close(Genode::Session_capability) { }
 	};
diff --git a/ports/src/noux/local_ram_service.h b/ports/src/noux/local_ram_service.h
index dbd057722..6f6f925f1 100644
--- a/ports/src/noux/local_ram_service.h
+++ b/ports/src/noux/local_ram_service.h
@@ -35,7 +35,7 @@ namespace Noux {
 				Service(Ram_session::service_name()), _ep(ep)
 			{ }
 
-			Genode::Session_capability session(const char *args)
+			Genode::Session_capability session(const char *args, Affinity const &)
 			{
 				PDBG("Implement me!");
 				return Genode::Session_capability();
diff --git a/ports/src/noux/local_rm_service.h b/ports/src/noux/local_rm_service.h
index 7edd8a20c..7217c1b57 100644
--- a/ports/src/noux/local_rm_service.h
+++ b/ports/src/noux/local_rm_service.h
@@ -103,7 +103,7 @@ namespace Noux {
 				_ds_registry(ds_registry)
 			{ }
 
-			Genode::Session_capability session(const char *args)
+			Genode::Session_capability session(const char *args, Affinity const &)
 			{
 				addr_t start = Arg_string::find_arg(args, "start").ulong_value(~0UL);
 				size_t size  = Arg_string::find_arg(args, "size").ulong_value(0);
diff --git a/ports/src/noux/local_rom_service.h b/ports/src/noux/local_rom_service.h
index c097cc3e8..51a7ec460 100644
--- a/ports/src/noux/local_rom_service.h
+++ b/ports/src/noux/local_rom_service.h
@@ -42,7 +42,7 @@ namespace Noux {
 				_ds_registry(ds_registry)
 			{ }
 
-			Genode::Session_capability session(const char *args)
+			Genode::Session_capability session(const char *args, Affinity const &)
 			{
 				enum { NAME_MAX_LEN = 128 };
 				char name[NAME_MAX_LEN];