nova: support creation of vCPU in own PD

With the patch a VMM is not forced anymore to co-located the VMM and VM in same
PD.

Fixes #949

base-nova/include/base/pager.h

@@ -52,6 +52,7 @@ namespace Genode {
 			addr_t _initial_esp;
 			addr_t _initial_eip;
 			addr_t _client_exc_pt_sel;
+			addr_t _client_exc_vcpu;
 
 			struct
 			{
@@ -131,6 +132,7 @@ namespace Genode {
 			 */
 			addr_t exc_pt_sel() { return _tid.exc_pt_sel; }
 			addr_t exc_pt_sel_client() { return _client_exc_pt_sel; }
+			addr_t exc_pt_vcpu() { return _client_exc_vcpu; }
 
 			/**
 			 * Set initial stack pointer used by the startup handler
@@ -226,6 +228,18 @@ namespace Genode {
 			 * all remotely available portals had been revoked beforehand.
 			 */
 			void cleanup_call();
+
+			/**
+			 * Open receive window for initial portals for vCPU.
+			 */
+			void prepare_vCPU_portals()
+			{
+				_client_exc_vcpu = cap_map()->insert(Nova::NUM_INITIAL_VCPU_PT_LOG2);
+
+				Nova::Utcb *utcb = reinterpret_cast<Nova::Utcb *>(Thread_base::utcb());
+
+				utcb->crd_rcv = Nova::Obj_crd(_client_exc_vcpu, Nova::NUM_INITIAL_VCPU_PT_LOG2); 
+			}
 	};
 
 

base-nova/include/nova/syscall-generic.h

@@ -550,6 +550,7 @@ namespace Nova {
 		NUM_INITIAL_PT_LOG2 = 5,
 		NUM_INITIAL_PT = 1UL << NUM_INITIAL_PT_LOG2,
 		NUM_INITIAL_PT_RESERVED = 2 * NUM_INITIAL_PT,
+		NUM_INITIAL_VCPU_PT_LOG2 = 8, 
 	};
 
 	/**

base-nova/include/nova/util.h

@@ -64,4 +64,27 @@ inline void request_signal_sm_cap(Genode::Native_capability const &cap,
                                   Genode::addr_t sel) {
 	request_event_portal(cap, sel, ~0UL - 1, 0); }
 
+
+inline void delegate_vcpu_portals(Genode::Native_capability const &cap,
+                                  Genode::addr_t sel)
+{
+	using namespace Nova;
+	Utcb *utcb = reinterpret_cast<Utcb *>(Genode::Thread_base::myself()->utcb());
+
+	/* save original receive window */
+	Crd orig_crd = utcb->crd_rcv;
+
+	utcb->crd_rcv = Obj_crd();
+	utcb->set_msg_word(0);
+	uint8_t res = utcb->append_item(Obj_crd(sel, NUM_INITIAL_VCPU_PT_LOG2), 0);
+	(void)res;
+
+	res = call(cap.local_name());
+
+	/* restore original receive window */
+	utcb->crd_rcv = orig_crd;
+
+	if (res)
+		PERR("setting exception portals for vCPU failed %u", res);
+}
 #endif /* _NOVA__INCLUDE__UTIL_H_ */

base-nova/src/base/pager/pager.cc

@@ -194,6 +194,12 @@ void Pager_object::_invoke_handler()
 	Pager_object *obj;
 	Utcb         *utcb = _check_handler(myself, obj);
 
+	/* if protocol is violated ignore request and close receive window */
+	if (utcb->msg_words() != 2) {
+		utcb->crd_rcv = Obj_crd();
+		reply(myself->stack_top());
+	}
+
 	/* send single portal as reply */
 	addr_t const event    = utcb->msg[0];
 	addr_t const logcount = utcb->msg[1];
@@ -325,8 +331,10 @@ static uint8_t create_portal(addr_t pt, addr_t pd, addr_t ec, Mtd mtd,
 
 
 Pager_object::Pager_object(unsigned long badge, Affinity::Location location)
-: Thread_base("pager:", PF_HANDLER_STACK_SIZE),
+:
-  _badge(reinterpret_cast<unsigned long>(_context->name + 6))
+	Thread_base("pager:", PF_HANDLER_STACK_SIZE),
+	_badge(reinterpret_cast<unsigned long>(_context->name + 6)),
+	_client_exc_vcpu(Native_thread::INVALID_INDEX)
 {
 	class Create_exception_pt_failed { };
 	uint8_t res;
@@ -441,6 +449,13 @@ Pager_object::~Pager_object()
 
 	cap_map()->remove(_pt_cleanup, 1, false);
 	cap_map()->remove(exc_pt_sel_client(), NUM_INITIAL_PT_LOG2, false);
+
+	if (_client_exc_vcpu == Native_thread::INVALID_INDEX)
+		return;
+
+	/* revoke vCPU exception portals */
+	revoke(Obj_crd(_client_exc_vcpu, NUM_INITIAL_VCPU_PT_LOG2));
+	cap_map()->remove(_client_exc_vcpu, NUM_INITIAL_VCPU_PT_LOG2, false);
 }
 
 

base-nova/src/core/platform_thread.cc

@@ -100,38 +100,32 @@ int Platform_thread::start(void *ip, void *sp)
 		return -5;
 	}
 
-	/*
-	 * For the first thread of a new PD, use the initial stack pointer for
-	 * reporting the thread's UTCB address.
-	 */
-	addr_t pd_utcb = Native_config::context_area_virtual_base() +
-	                 Native_config::context_area_virtual_size() -
-	                 get_page_size();
-
-	_sel_exc_base = _pager->exc_pt_sel_client();
-
 	addr_t pd_core_sel  = Platform_pd::pd_core_sel();
+	addr_t pd_utcb      = 0;
+	_sel_exc_base       = is_vcpu() ? _pager->exc_pt_vcpu() : _pager->exc_pt_sel_client();
 
-	addr_t remap_src[] = { _pd->parent_pt_sel() };
+	if (!is_vcpu()) {
-	addr_t remap_dst[] = { PT_SEL_PARENT };
+		pd_utcb = Native_config::context_area_virtual_base() +
-	addr_t pd_sel;
+		          Native_config::context_area_virtual_size() - get_page_size();
 
-	Obj_crd initial_pts(_sel_exc_base, NUM_INITIAL_PT_LOG2);
+		addr_t remap_src[] = { _pd->parent_pt_sel() };
+		addr_t remap_dst[] = { PT_SEL_PARENT };
 
-	uint8_t res;
+		/* remap exception portals for first thread */
-
+		for (unsigned i = 0; i < sizeof(remap_dst)/sizeof(remap_dst[0]); i++) {
-	/* remap exception portals for first thread */
+			if (map_local((Utcb *)Thread_base::myself()->utcb(),
-	for (unsigned i = 0; i < sizeof(remap_dst)/sizeof(remap_dst[0]); i++) {
+		    	          Obj_crd(remap_src[i], 0),
-		if (map_local((Utcb *)Thread_base::myself()->utcb(),
+		        	      Obj_crd(_sel_exc_base + remap_dst[i], 0)))
-		              Obj_crd(remap_src[i], 0),
+				return -6;
-		              Obj_crd(_sel_exc_base + remap_dst[i], 0)))
+		}
-			return -6;
 	}
 
-	pd_sel = cap_map()->insert();
+	addr_t pd_sel = cap_map()->insert();
 
 	/* create task */
-	res = create_pd(pd_sel, pd_core_sel, initial_pts);
+	Obj_crd initial_pts(_sel_exc_base, is_vcpu() ?
+	                    NUM_INITIAL_VCPU_PT_LOG2 : NUM_INITIAL_PT_LOG2);
+	uint8_t res = create_pd(pd_sel, pd_core_sel, initial_pts);
 	if (res != NOVA_OK) {
 		PERR("create_pd returned %d", res);
 		goto cleanup_pd;
@@ -238,9 +232,6 @@ Thread_state Platform_thread::state()
 
 void Platform_thread::state(Thread_state s)
 {
-	/* not permitted for main thread */
-	if (is_main_thread()) throw Cpu_session::State_access_failed();
-
 	/* you can do it only once */
 	if (_sel_exc_base != Native_thread::INVALID_INDEX)
 		throw Cpu_session::State_access_failed();
@@ -251,8 +242,16 @@ void Platform_thread::state(Thread_state s)
 	 * s.is_vcpu      If true it will run as vCPU,
 	 *                otherwise it will be a thread.
 	 */
-	_sel_exc_base = s.sel_exc_base;
+	if (!is_main_thread())
-	if (s.is_vcpu) _features |= VCPU;
+		_sel_exc_base = s.sel_exc_base;
+
+	if (!s.is_vcpu)
+		return;
+
+	_features |= VCPU;
+
+	if (is_main_thread() && _pager)
+		_pager->prepare_vCPU_portals();
 }