platform(x86): report features via platform_info

Report via platform_info the capabilities of the kernel, e.g. ACPI and MSI.

With the commit the try-catch pattern on IRQ session creation by the platform
driver is avoided.

Issue #4016

repos/base-foc/src/core/platform.cc

@@ -493,7 +493,11 @@ Platform::Platform()
 		                  pages << get_page_size_log2(),
 		                  "platform_info", [&] ()
 		{
-			xml.node("kernel", [&] () { xml.attribute("name", "foc"); });
+			xml.node("kernel", [&] () {
+				xml.attribute("name", "foc");
+				xml.attribute("acpi", true);
+				xml.attribute("msi" , true);
+			});
 			xml.node("hardware", [&] () {
 				_setup_platform_info(xml, sigma0_map_kip()); });
 

repos/base-hw/src/core/platform.cc

@@ -132,7 +132,10 @@ void Platform::_init_platform_info()
 	Genode::Xml_generator xml(reinterpret_cast<char *>(virt_addr),
 	                          rom_size, rom_name, [&] ()
 	{
-		xml.node("kernel", [&] () { xml.attribute("name", "hw"); });
+		xml.node("kernel", [&] () {
+			xml.attribute("name", "hw");
+			xml.attribute("acpi", true);
+		});
 		_init_additional_platform_info(xml);
 		xml.node("affinity-space", [&] () {
 			xml.attribute("width", affinity_space().width());

repos/base-nova/src/core/platform.cc

@@ -680,7 +680,11 @@ Platform::Platform()
 				                          pages << get_page_size_log2(),
 				                          "platform_info", [&] ()
 				{
-					xml.node("kernel", [&] () { xml.attribute("name", "nova"); });
+					xml.node("kernel", [&] () {
+						xml.attribute("name", "nova");
+						xml.attribute("acpi", true);
+						xml.attribute("msi" , true);
+					});
 					if (efi_sys_tab_phy) {
 						xml.node("efi-system-table", [&] () {
 							xml.attribute("address", String<32>(Hex(efi_sys_tab_phy)));

repos/base-sel4/src/core/platform.cc

@@ -404,7 +404,10 @@ void Platform::_init_rom_modules()
 
 				tsc_freq const * boot_freq = reinterpret_cast<tsc_freq const *>(reinterpret_cast<addr_t>(element) + sizeof(* element));
 
-				xml.node("kernel", [&] () { xml.attribute("name", "sel4"); });
+				xml.node("kernel", [&] () {
+					xml.attribute("name", "sel4");
+					xml.attribute("acpi", true);
+				});
 				xml.node("hardware", [&] () {
 					xml.node("features", [&] () {
 						#ifdef CONFIG_VTX

repos/os/src/drivers/platform/spec/x86/main.cc

@@ -50,7 +50,6 @@ struct Platform::Main
 
 	Capability<Typed_root<Platform::Session_component> > root_cap { };
 
-	bool const _acpi_platform;
 	bool _acpi_ready    = false;
 
 	void _attempt_acpi_reset();
@@ -63,8 +62,20 @@ struct Platform::Main
 			if (!acpi_rom->valid())
 				return;
 
+			bool msi_platform  = false;
+			bool acpi_platform = false;
+
+			try {
+				Attached_rom_dataspace info { _env, "platform_info" };
+				info.xml().with_sub_node("kernel", [&] (Xml_node const &node) {
+					acpi_platform = node.attribute_value("acpi", acpi_platform);
+					msi_platform  = node.attribute_value("msi" , msi_platform);
+				});
+			} catch (...) { }
+
 			root.construct(_env, sliced_heap, _config,
-			               acpi_rom->local_addr<const char>(), _acpi_platform);
+			               acpi_rom->local_addr<const char>(), acpi_platform,
+			               msi_platform);
 		}
 
 		if (root_cap.valid())
@@ -134,25 +145,7 @@ struct Platform::Main
 		}
 	}
 
-	static bool acpi_platform(Env & env)
+	Main(Env &env) : _env(env)
-	{
-		using Name = String<32>;
-		try {
-			Attached_rom_dataspace info { env, "platform_info" };
-			Name kernel =
-				info.xml().sub_node("kernel").attribute_value("name", Name());
-			if (kernel == "hw"   ||
-			    kernel == "nova" ||
-			    kernel == "foc"  ||
-			    kernel == "sel4") { return true; }
-		} catch (...) {}
-		return false;
-	}
-
-	Main(Env &env)
-	:
-		_env(env),
-		_acpi_platform(acpi_platform(env))
 	{
 		_config.sigh(_config_handler);
 

repos/os/src/drivers/platform/spec/x86/pci_session_component.h

@@ -220,7 +220,8 @@ class Platform::Session_component : public Rpc_object<Session>
 		Heap                      &_global_heap;
 		Pci::Config::Delayer      &_delayer;
 		Device_bars_pool          &_devices_bars;
-		bool                       _iommu;
+		bool const                 _iommu;
+		bool const                 _msi_avail;
 		bool                       _msi_usage  { true };
 		bool                       _msix_usage { true };
 
@@ -474,7 +475,8 @@ class Platform::Session_component : public Rpc_object<Session>
 		                  Pci::Config::Delayer      &delayer,
 		                  Device_bars_pool          &devices_bars,
 		                  char               const *args,
-		                  bool               const  iommu)
+		                  bool               const  iommu,
+		                  bool               const  msi)
 		:
 			_env(env),
 			_config(config),
@@ -488,7 +490,8 @@ class Platform::Session_component : public Rpc_object<Session>
 			_global_heap(global_heap),
 			_delayer(delayer),
 			_devices_bars(devices_bars),
-			_iommu(iommu)
+			_iommu(iommu),
+			_msi_avail(msi)
 		{
 			/* subtract the RPC session and session dataspace capabilities */
 			_cap_guard.withdraw(Cap_quota{2});
@@ -500,9 +503,12 @@ class Platform::Session_component : public Rpc_object<Session>
 		{
 			Session_policy const policy { _label, _config.xml() };
 
-			_msi_usage  = policy.attribute_value("msi", _msi_usage);
+			if (_msi_avail) {
-			_msix_usage = _msi_usage &&
+				_msi_usage  = policy.attribute_value("msi", _msi_usage);
-			              policy.attribute_value("msix", _msix_usage);
+				_msix_usage = _msi_usage &&
+				              policy.attribute_value("msix", _msix_usage);
+			} else
+				_msi_usage = _msix_usage = false;
 
 			/* check policy for non-pci devices */
 			policy.for_each_sub_node("device", [&] (Xml_node device_node) {
@@ -875,6 +881,7 @@ class Platform::Root : public Root_component<Session_component>
 
 		bool _iommu        { false };
 		bool _pci_reported { false };
+		bool _msi_platform;
 
 		struct Timer_delayer : Pci::Config::Delayer, Timer::Connection
 		{
@@ -1074,7 +1081,8 @@ class Platform::Root : public Root_component<Session_component>
 					                              *_pci_confspace,
 					                               _pci_confspace_base,
 					                              *_buses, _heap, _delayer,
-					                              _devices_bars, args, _iommu);
+					                              _devices_bars, args, _iommu,
+					                              _msi_platform);
 			}
 			catch (Session_policy::No_policy_defined) {
 				error("Invalid session request, no matching policy for ",
@@ -1097,10 +1105,12 @@ class Platform::Root : public Root_component<Session_component>
 		 *                  components and PCI-device components
 		 */
 		Root(Env &env, Allocator &md_alloc, Attached_rom_dataspace &config,
-		     char const *acpi_rom, bool acpi_platform)
+		     char const *acpi_rom, bool acpi_platform, bool msi_platform)
 		:
 			Root_component<Session_component>(&env.ep().rpc_ep(), &md_alloc),
-			_env(env), _config(config)
+			_env(env),
+			_config(config),
+			_msi_platform(msi_platform)
 		{
 			try {
 				_parse_report_rom(env, acpi_rom, acpi_platform);