base: support phys range specifier in ram_session

Fixes #696

repos/base/include/ram_session/connection.h

@@ -18,23 +18,26 @@
 #include <base/connection.h>
 
 namespace Genode {
-
+	struct Ram_connection;
-	struct Ram_connection : Connection<Ram_session>, Ram_session_client
-	{
-		enum { RAM_QUOTA = 64*1024 };
-		/**
-		 * Constructor
-		 *
-		 * \param label  session label
-		 */
-		Ram_connection(const char *label = "")
-		:
-			Connection<Ram_session>(
-				session("ram_quota=64K, label=\"%s\"", label)),
-
-			Ram_session_client(cap())
-		{ }
-	};
 }
 
+struct Genode::Ram_connection : Connection<Ram_session>, Ram_session_client
+{
+	enum { RAM_QUOTA = 64*1024 };
+	/**
+	 * Constructor
+	 *
+	 * \param label  session label
+	 */
+	Ram_connection(const char *label = "", unsigned long phys_start = 0UL,
+	               unsigned long phys_size = 0UL)
+	:
+		Connection<Ram_session>(
+			session("ram_quota=64K, phys_start=0x%lx, phys_size=0x%lx, "
+			        "label=\"%s\"", phys_start, phys_size, label)),
+
+		Ram_session_client(cap())
+	{ }
+};
+
 #endif /* _INCLUDE__RAM_SESSION__CONNECTION_H_ */

repos/base/src/core/include/ram_session_component.h

@@ -51,6 +51,8 @@ namespace Genode {
 			Allocator_guard         _md_alloc;     /* guarded meta-data allocator */
 			Ds_slab                 _ds_slab;      /* meta-data allocator         */
 			Ram_session_component  *_ref_account;  /* reference ram session       */
+			addr_t                  _phys_start;
+			addr_t                  _phys_end;
 
 			enum { MAX_LABEL_LEN = 64 };
 			char _label[MAX_LABEL_LEN];

repos/base/src/core/ram_session_component.cc

@@ -146,7 +146,8 @@ Ram_dataspace_capability Ram_session_component::alloc(size_t ds_size, Cache_attr
 	void *ds_addr = 0;
 	bool alloc_succeeded = false;
 	for (size_t align_log2 = log2(ds_size); align_log2 >= 12; align_log2--) {
-		if (_ram_alloc->alloc_aligned(ds_size, &ds_addr, align_log2).is_ok()) {
+		if (_ram_alloc->alloc_aligned(ds_size, &ds_addr, align_log2,
+		                              _phys_start, _phys_end).is_ok()) {
 			alloc_succeeded = true;
 			break;
 		}
@@ -265,9 +266,17 @@ Ram_session_component::Ram_session_component(Rpc_entrypoint  *ds_ep,
 	_ds_ep(ds_ep), _ram_session_ep(ram_session_ep), _ram_alloc(ram_alloc),
 	_quota_limit(quota_limit), _payload(0),
 	_md_alloc(md_alloc, Arg_string::find_arg(args, "ram_quota").long_value(0)),
-	_ds_slab(&_md_alloc), _ref_account(0)
+	_ds_slab(&_md_alloc), _ref_account(0),
+	_phys_start(Arg_string::find_arg(args, "phys_start").long_value(0))
 {
 	Arg_string::find_arg(args, "label").string(_label, sizeof(_label), "");
+
+	size_t phys_size = Arg_string::find_arg(args, "phys_size").long_value(0);
+	/* sanitize overflow and interpret phys_size==0 as maximum phys address */
+	if (_phys_start + phys_size <= _phys_start)
+		_phys_end = ~0UL;
+	else
+		_phys_end = _phys_start + phys_size - 1;
 }
 
 

repos/os/include/init/child.h

@@ -396,17 +396,21 @@ namespace Init {
 					Genode::printf("         Proceeding with a quota of %zu.\n", avail);
 				}
 
-				Read_quota(Genode::Xml_node start_node, Genode::size_t & ram_quota,
+				Read_quota(Genode::Xml_node start_node,
-				           Genode::size_t & cpu_quota)
+				           Genode::size_t & ram_quota,
+				           Genode::size_t & cpu_quota,
+				           bool           & constrain_phys)
 				{
 					Genode::Number_of_bytes ram_bytes = 0;
 					Genode::size_t          cpu_percent = 0;
+
 					try {
 						Genode::Xml_node rsc = start_node.sub_node("resource");
 						for (;; rsc = rsc.next("resource")) {
 							try {
 								if (rsc.attribute("name").has_value("RAM")) {
 									rsc.attribute("quantum").value(&ram_bytes);
+									constrain_phys = rsc.attribute("constrain_phys").has_value("yes");
 								} else if (rsc.attribute("name").has_value("CPU")) {
 									rsc.attribute("quantum").value(&cpu_percent); }
 							} catch (...) { }
@@ -445,6 +449,7 @@ namespace Init {
 				Genode::Affinity       affinity;
 				Genode::size_t         ram_quota;
 				Genode::size_t         cpu_quota;
+				bool                   constrain_phys;
 				Genode::Ram_connection ram;
 				Genode::Cpu_connection cpu;
 				Genode::Rm_connection  rm;
@@ -453,7 +458,7 @@ namespace Init {
 				          long prio_levels_log2,
 				          Genode::Affinity::Space const &affinity_space)
 				:
-					Read_quota(start_node, ram_quota, cpu_quota),
+					Read_quota(start_node, ram_quota, cpu_quota, constrain_phys),
 					prio_levels_log2(prio_levels_log2),
 					priority(read_priority(start_node)),
 					affinity(affinity_space,
@@ -517,6 +522,7 @@ namespace Init {
 			Init::Child_policy_provide_rom_file      _binary_policy;
 			Init::Child_policy_redirect_rom_file     _configfile_policy;
 			Init::Child_policy_pd_args               _pd_args_policy;
+			Init::Child_policy_ram_phys              _ram_session_policy;
 
 		public:
 
@@ -550,7 +556,8 @@ namespace Init {
 				_config_policy("config", _config.dataspace(), &_entrypoint),
 				_binary_policy("binary", _binary_rom_ds, &_entrypoint),
 				_configfile_policy("config", _config.filename()),
-				_pd_args_policy(&_pd_args)
+				_pd_args_policy(&_pd_args),
+				_ram_session_policy(_resources.constrain_phys)
 			{
 				using namespace Genode;
 
@@ -706,6 +713,7 @@ namespace Init {
 				_priority_policy.  filter_session_args(service, args, args_len);
 				_configfile_policy.filter_session_args(service, args, args_len);
 				_pd_args_policy.   filter_session_args(service, args, args_len);
+				_ram_session_policy.filter_session_args(service, args, args_len);
 			}
 
 			Genode::Affinity filter_session_affinity(Genode::Affinity const &session_affinity)

repos/os/include/init/child_policy.h

@@ -23,6 +23,41 @@
 
 namespace Init {
 
+	class Child_policy_ram_phys
+	{
+		private:
+
+			bool _constrain_phys;
+
+		public:
+
+			Child_policy_ram_phys(bool constrain_phys)
+			: _constrain_phys(constrain_phys) { }
+
+			/**
+			 * Filter arguments of session request
+			 *
+			 * This function removes phys_start and phys_size ram_session
+			 * parameters if the child configuration does not explicitly
+			 * permits this.
+			 */
+			void filter_session_args(const char *service, char *args,
+			                         Genode::size_t args_len)
+			{
+				using namespace Genode;
+
+				/* intercept only RAM session requests */
+				if (Genode::strcmp(service, "RAM"))
+					return;
+
+				if (_constrain_phys)
+					return;
+
+				Arg_string::remove_arg(args, "phys_start");
+				Arg_string::remove_arg(args, "phys_size");
+			}
+	};
+
 	/**
 	 * Policy for prepending the child name to the 'label' argument
 	 *