hw: add support for VMX

Add support for Intel's Virtual Machine Extensions with nested paging.

Fixes genodelabs#5128

repos/base-hw/lib/mk/spec/x86_64/core-hw-pc.mk

@@ -21,6 +21,7 @@ SRC_CC += kernel/cpu_mp.cc
 SRC_CC += kernel/vm_thread_on.cc
 SRC_CC += spec/x86_64/virtualization/kernel/vm.cc
 SRC_CC += spec/x86_64/virtualization/kernel/svm.cc
+SRC_CC += spec/x86_64/virtualization/kernel/vmx.cc
 SRC_CC += spec/x86_64/virtualization/vm_session_component.cc
 SRC_CC += vm_session_common.cc
 SRC_CC += vm_session_component.cc

repos/base-hw/src/core/spec/x86_64/platform_support.cc

@@ -1,11 +1,12 @@
 /*
  * \brief   Platform implementations specific for x86_64
  * \author  Reto Buerki
+ * \author  Benjamin Lamowski
  * \date    2015-05-04
  */
 
 /*
- * Copyright (C) 2015-2017 Genode Labs GmbH
+ * Copyright (C) 2015-2024 Genode Labs GmbH
  *
  * This file is part of the Genode OS framework, which is distributed
  * under the terms of the GNU Affero General Public License version 3.
@@ -55,7 +56,7 @@ void Platform::_init_additional_platform_info(Xml_generator &xml)
 	xml.node("hardware", [&]() {
 		xml.node("features", [&] () {
 			xml.attribute("svm", Hw::Virtualization_support::has_svm());
-			xml.attribute("vmx", false);
+			xml.attribute("vmx", Hw::Virtualization_support::has_vmx());
 		});
 		xml.node("tsc", [&]() {
 			xml.attribute("invariant", Hw::Lapic::invariant_tsc());

repos/base-hw/src/core/spec/x86_64/virtualization/board.h

@@ -18,10 +18,12 @@
 #include <kernel/configuration.h>
 #include <kernel/irq.h>
 
+#include <cpu.h>
 #include <cpu/vcpu_state_virtualization.h>
 #include <hw/spec/x86_64/page_table.h>
+#include <hw/spec/x86_64/x86_64.h>
 #include <spec/x86_64/virtualization/svm.h>
-#include <cpu.h>
+#include <spec/x86_64/virtualization/vmx.h>
 
 
 using Genode::addr_t;;
@@ -52,6 +54,7 @@ namespace Board {
 	enum Custom_trapnos {
 		TRAP_VMEXIT = 256,
 		TRAP_VMSKIP = 257,
+		TRAP_VMERROR = 258,
 	};
 };
 
@@ -68,6 +71,7 @@ struct Board::Vcpu_context
 	void initialize(Kernel::Cpu &cpu, addr_t table_phys_addr);
 	void read_vcpu_state(Vcpu_state &state);
 	void write_vcpu_state(Vcpu_state &state);
+	bool handle_vm_exit(unsigned &irq);
 
 	Genode::Align_at<Core::Cpu::Context> regs;
 
@@ -80,9 +84,19 @@ struct Board::Vcpu_context
 	static Virt_interface &detect_virtualization(Vcpu_data &vcpu_data,
 	                                             unsigned   id)
 	{
-		return *Genode::construct_at<Vmcb>(
-			vcpu_data.virt_interface_ptr(),
-			vcpu_data, id);
+		if (Hw::Virtualization_support::has_svm())
+			return *Genode::construct_at<Vmcb>(
+				vcpu_data.virt_interface_ptr(),
+				vcpu_data,
+				id);
+		else if (Hw::Virtualization_support::has_vmx()) {
+			return *Genode::construct_at<Vmcs>(
+				vcpu_data.virt_interface_ptr(),
+				vcpu_data);
+		} else {
+			Genode::error( "No virtualization support detected.");
+			throw Core::Service_denied();
+		}
 	}
 };
 

repos/base-hw/src/core/spec/x86_64/virtualization/kernel/vm.cc

@@ -26,9 +26,10 @@
 #include <kernel/vm.h>
 #include <kernel/main.h>
 
+#include <hw/spec/x86_64/x86_64.h>
 #include <virtualization/hypervisor.h>
 #include <virtualization/svm.h>
-#include <hw/spec/x86_64/x86_64.h>
+#include <virtualization/vmx.h>
 
 using namespace Genode;
 
@@ -86,15 +87,26 @@ void Vm::exception(Cpu & cpu)
 {
 	using namespace Board;
 
+	bool pause = false;
+	addr_t table_phys_addr { 0 };
+	unsigned irq_id { TRAP_VMSKIP };
+
 	switch (_vcpu_context.regs->trapno) {
 		case Cpu_state::INTERRUPTS_START ... Cpu_state::INTERRUPTS_END:
 			_interrupt(_user_irq_pool, cpu.id());
-			break;
-		case TRAP_VMEXIT:
-			/* exception method was entered because of a VMEXIT */
-			break;
+			return;
 		case TRAP_VMSKIP:
-			/* exception method was entered without exception */
+			/* vCPU is running for the first time */
+			table_phys_addr =
+			    reinterpret_cast<addr_t>(_id.table);
+			_vcpu_context.initialize(cpu, table_phys_addr);
+			_vcpu_context.tsc_aux_host = cpu.id();
+			_vcpu_context.exitcode     = EXIT_STARTUP;
+			pause = true;
+			break;
+		case TRAP_VMEXIT: [[fallthrough]];
+		case TRAP_VMERROR:
+			pause = _vcpu_context.handle_vm_exit(irq_id);
 			break;
 		default:
 			error("VM: triggered unknown exception ",
@@ -107,24 +119,20 @@ void Vm::exception(Cpu & cpu)
 			return;
 	};
 
-	if (_vcpu_context.exitcode == EXIT_INIT) {
-			addr_t table_phys_addr =
-			    reinterpret_cast<addr_t>(_id.table);
-			_vcpu_context.initialize(cpu, table_phys_addr);
-			_vcpu_context.tsc_aux_host = cpu.id();
-			_vcpu_context.exitcode     = EXIT_STARTUP;
-			_pause_vcpu();
-			_context.submit(1);
-			return;
+	if ((pause == false) && (irq_id != TRAP_VMSKIP)) {
+		/* XXX consolidate with Cpu_job::_interrupt */
+		if (!_cpu->handle_if_cpu_local_interrupt(irq_id)) {
+			/* it isn't a CPU-local IRQ, so, it must be a user IRQ */
+			User_irq * irq = User_irq::object(_user_irq_pool, irq_id);
+			if (irq) irq->occurred();
+			else Genode::raw("Unknown interrupt ", irq_id);
+		}
+		_cpu->pic().finish_request();
 	}
 
-	unsigned irq { };
-	bool error { false };
-	_vcpu_context.exitcode = _vcpu_context.virt.handle_vm_exit(irq, error);
-
-	if (_vcpu_context.exitcode != EXIT_PAUSED) {
-			_pause_vcpu();
-			_context.submit(1);
+	if (pause) {
+		_pause_vcpu();
+		_context.submit(1);
 	}
 }
 
@@ -240,3 +248,14 @@ void Board::Vcpu_context::initialize(Kernel::Cpu &cpu, addr_t table_phys_addr)
 {
 	virt.initialize(cpu, table_phys_addr, *regs);
 }
+
+
+bool Board::Vcpu_context::handle_vm_exit(unsigned &irq)
+{
+	exitcode = virt.handle_vm_exit(irq, (regs->trapno == TRAP_VMERROR));
+
+	if (exitcode == EXIT_PAUSED)
+		return false;
+	else
+		return true;
+}