PPU Page Faults (#3309)

I guess I'll merge it and fix some issues later myself.

Utilities/Thread.cpp

@@ -3,6 +3,8 @@
 #include "Emu/System.h"
 #include "Emu/IdManager.h"
 #include "Emu/Cell/RawSPUThread.h"
+#include "Emu/Cell/lv2/sys_mmapper.h"
+#include "Emu/Cell/lv2/sys_event.h"
 #include "Thread.h"
 #include <typeinfo>
 
@@ -1259,9 +1261,60 @@ bool handle_access_violation(u32 addr, bool is_writing, x64_context* context)
 		return true;
 	}
 
-	// TODO: allow recovering from a page fault as a feature of PS3 virtual memory
 	if (cpu)
 	{
+		if (fxm::check<page_fault_notification_entries>())
+		{
+			for (const auto& entry : fxm::get<page_fault_notification_entries>()->entries)
+			{
+				auto mem = vm::get(vm::any, entry.start_addr);
+				if (!mem)
+				{
+					continue;
+				}
+				if (entry.start_addr <= addr && addr <= addr + mem->size - 1)
+				{
+					// Place the page fault event onto table so that other functions [sys_mmapper_free_address and ppu pagefault funcs] 
+					// know that this thread is page faulted and where.
+
+					auto pf_entries = fxm::get_always<page_fault_event_entries>();
+					{
+						semaphore_lock pf_lock(pf_entries->pf_mutex);
+						page_fault_event pf_event{ cpu->id, addr };
+						pf_entries->events.emplace_back(pf_event);
+					}
+
+					// Now, we notify the game that a page fault occurred so it can rectify it.
+					// Note, for data3, were the memory readable AND we got a page fault, it must be due to a write violation since reads are allowed.
+					be_t<u64> data1 = addr;
+					be_t<u64> data2 = (SYS_MEMORY_PAGE_FAULT_TYPE_PPU_THREAD << 32) + cpu->id; // TODO: fix hack for now that assumes PPU thread always.
+					be_t<u64> data3 = vm::check_addr(addr, a_size, vm::page_readable) ? SYS_MEMORY_PAGE_FAULT_CAUSE_READ_ONLY : SYS_MEMORY_PAGE_FAULT_CAUSE_NON_MAPPED;
+
+					LOG_ERROR(MEMORY, "Page_fault %s location 0x%x because of %s memory", is_writing ? "writing" : "reading",
+						addr, data3 == SYS_MEMORY_PAGE_FAULT_CAUSE_READ_ONLY ? "writing read-only" : "using unmapped");
+
+					error_code sending_error = sys_event_port_send(entry.port_id, data1, data2, data3);
+					
+					// If we fail due to being busy, wait a bit and try again.
+					while (sending_error == CELL_EBUSY)
+					{
+						lv2_obj::sleep(*cpu, 1000);
+						thread_ctrl::wait_for(1000);
+						sending_error = sys_event_port_send(entry.port_id, data1, data2, data3);
+					}
+					
+					if (sending_error)
+					{
+						fmt::throw_exception("Unknown error %x while trying to pass page fault.", sending_error.value);
+					}
+
+					lv2_obj::sleep(*cpu);
+					thread_ctrl::wait();
+					return true;
+				}
+			}
+		}
+
 		LOG_FATAL(MEMORY, "Access violation %s location 0x%x", is_writing ? "writing" : "reading", addr);
 		cpu->state += cpu_flag::dbg_pause;
 		cpu->check_state();

rpcs3/Emu/Cell/lv2/lv2.cpp

@@ -106,8 +106,8 @@ const std::array<ppu_function_t, 1024> s_ppu_syscall_table
 	null_func,//BIND_FUNC(sys_ppu_...),                     //54  (0x036)  ROOT
 	null_func,//BIND_FUNC(sys_ppu_...),                     //55  (0x037)  ROOT
 	BIND_FUNC(sys_ppu_thread_rename),                       //56  (0x038)
-	null_func,//BIND_FUNC(sys_ppu_thread_recover_page_fault)//57  (0x039)
-	null_func,//BIND_FUNC(sys_ppu_thread_get_page_fault_context),//58 (0x03A)
+	BIND_FUNC(sys_ppu_thread_recover_page_fault),           //57  (0x039)
+	BIND_FUNC(sys_ppu_thread_get_page_fault_context),       //58  (0x03A)
 	null_func,                                              //59  (0x03B)  UNS
 	BIND_FUNC(sys_trace_create),                            //60  (0x03C)
 	BIND_FUNC(sys_trace_start),                             //61  (0x03D)

rpcs3/Emu/Cell/lv2/sys_mmapper.cpp

@@ -1,5 +1,8 @@
 #include "stdafx.h"
 #include "sys_mmapper.h"
+#include "Emu/Cell/PPUThread.h"
+#include "sys_ppu_thread.h"
+#include "Emu/Cell/lv2/sys_event.h"
 
 namespace vm { using namespace ps3; }
 
@@ -179,6 +182,19 @@ error_code sys_mmapper_free_address(u32 addr)
 {
 	sys_mmapper.error("sys_mmapper_free_address(addr=0x%x)", addr);
 
+	// If page fault notify exists and an address in this area is faulted, we can't free the memory.
+	auto pf_events = fxm::get_always<page_fault_event_entries>();
+	semaphore_lock pf_lock(pf_events->pf_mutex);
+
+	for (const auto& ev : pf_events->events)
+	{
+		auto mem = vm::get(vm::any, addr);
+		if (mem && addr <= ev.fault_addr && ev.fault_addr <= addr + mem->size - 1)
+		{
+			return CELL_EBUSY;
+		}
+	}
+
 	// Try to unmap area
 	const auto area = vm::unmap(addr, true);
 
@@ -192,6 +208,21 @@ error_code sys_mmapper_free_address(u32 addr)
 		return CELL_EBUSY;
 	}
 
+	// If a memory block is freed, remove it from page notification table.
+	auto pf_entries = fxm::get_always<page_fault_notification_entries>();
+	auto ind_to_remove = pf_entries->entries.begin();
+	for (; ind_to_remove != pf_entries->entries.end(); ++ind_to_remove)
+	{
+		if (addr == ind_to_remove->start_addr)
+		{
+			break;
+		}
+	}
+	if (ind_to_remove != pf_entries->entries.end())
+	{
+		pf_entries->entries.erase(ind_to_remove);
+	}
+
 	return CELL_OK;
 }
 
@@ -332,9 +363,47 @@ error_code sys_mmapper_unmap_shared_memory(u32 addr, vm::ptr<u32> mem_id)
 	return CELL_OK;
 }
 
-error_code sys_mmapper_enable_page_fault_notification(u32 addr, u32 eq)
+error_code sys_mmapper_enable_page_fault_notification(u32 start_addr, u32 event_queue_id)
 {
-	sys_mmapper.todo("sys_mmapper_enable_page_fault_notification(addr=0x%x, eq=0x%x)", addr, eq);
+	sys_mmapper.warning("sys_mmapper_enable_page_fault_notification(start_addr=0x%x, event_queue_id=0x%x)", start_addr, event_queue_id);
+
+	auto mem = vm::get(vm::any, start_addr);
+	if (!mem)
+	{
+		return CELL_EINVAL;
+	}
+
+	// TODO: Check memory region's flags to make sure the memory can be used for page faults.
+
+	auto queue = idm::get<lv2_obj, lv2_event_queue>(event_queue_id);
+
+	if (!queue)
+	{ // Can't connect the queue if it doesn't exist.
+		return CELL_ESRCH;
+	}
+
+	auto pf_entries = fxm::get_always<page_fault_notification_entries>();
+
+	// We're not allowed to have the same queue registered more than once for page faults.
+	for (const auto& entry : pf_entries->entries)
+	{
+		if (entry.event_queue_id == event_queue_id)
+		{
+			return CELL_ESRCH;
+		}
+	}
+
+	vm::ptr<u32> port_id = vm::make_var<u32>(0);
+	error_code res = sys_event_port_create(port_id, SYS_EVENT_PORT_LOCAL, SYS_MEMORY_PAGE_FAULT_EVENT_KEY);
+	sys_event_port_connect_local(port_id->value(), event_queue_id);
+
+	if (res == CELL_EAGAIN)
+	{ // Not enough system resources.
+		return CELL_EAGAIN;
+	}
+
+	page_fault_notification_entry entry{ start_addr, event_queue_id, port_id->value() };
+	pf_entries->entries.emplace_back(entry);
 
 	return CELL_OK;
 }

rpcs3/Emu/Cell/lv2/sys_mmapper.h

@@ -3,6 +3,8 @@
 #include "sys_sync.h"
 #include "sys_memory.h"
 
+#include <list>
+
 struct lv2_memory : lv2_obj
 {
 	static const u32 id_base = 0x08000000;
@@ -26,6 +28,45 @@ struct lv2_memory : lv2_obj
 	}
 };
 
+enum : u64
+{
+	SYS_MEMORY_PAGE_FAULT_EVENT_KEY	       = 0xfffe000000000000ULL,
+};
+
+enum : u32
+{
+	SYS_MEMORY_PAGE_FAULT_CAUSE_NON_MAPPED = 0x00000002U,
+	SYS_MEMORY_PAGE_FAULT_CAUSE_READ_ONLY  = 0x00000001U,
+	SYS_MEMORY_PAGE_FAULT_TYPE_PPU_THREAD  = 0x00000000U,
+	SYS_MEMORY_PAGE_FAULT_TYPE_SPU_THREAD  = 0x00000001U,
+	SYS_MEMORY_PAGE_FAULT_TYPE_RAW_SPU     = 0x00000002U,
+};
+
+struct page_fault_notification_entry
+{
+	u32 start_addr; // Starting address of region to monitor.
+	u32 event_queue_id; // Queue to be notified.
+	u32 port_id; // Port used to notify the queue.
+};
+
+// Used to hold list of queues to be notified on page fault event.
+struct page_fault_notification_entries
+{
+	std::list<page_fault_notification_entry> entries;
+};
+
+struct page_fault_event
+{
+	u32 thread_id;
+	u32 fault_addr;
+};
+
+struct page_fault_event_entries
+{
+	std::list<page_fault_event> events;
+	semaphore<> pf_mutex;
+};
+
 // SysCalls
 error_code sys_mmapper_allocate_address(u64 size, u64 flags, u64 alignment, vm::ps3::ptr<u32> alloc_addr);
 error_code sys_mmapper_allocate_fixed_address();
@@ -37,4 +78,4 @@ error_code sys_mmapper_free_shared_memory(u32 mem_id);
 error_code sys_mmapper_map_shared_memory(u32 addr, u32 mem_id, u64 flags);
 error_code sys_mmapper_search_and_map(u32 start_addr, u32 mem_id, u64 flags, vm::ps3::ptr<u32> alloc_addr);
 error_code sys_mmapper_unmap_shared_memory(u32 addr, vm::ps3::ptr<u32> mem_id);
-error_code sys_mmapper_enable_page_fault_notification(u32 addr, u32 eq);
+error_code sys_mmapper_enable_page_fault_notification(u32 start_addr, u32 event_queue_id);

rpcs3/Emu/Cell/lv2/sys_ppu_thread.cpp

@@ -7,6 +7,7 @@
 #include "Emu/Cell/PPUThread.h"
 #include "sys_ppu_thread.h"
 #include "sys_event.h"
+#include "sys_mmapper.h"
 
 namespace vm { using namespace ps3; }
 
@@ -381,3 +382,69 @@ error_code sys_ppu_thread_rename(u32 thread_id, vm::cptr<char> name)
 
 	return CELL_OK;
 }
+
+error_code sys_ppu_thread_recover_page_fault(u32 thread_id)
+{
+	sys_ppu_thread.warning("sys_ppu_thread_recover_page_fault(thread_id=0x%x)", thread_id);
+	const auto thread = idm::get<ppu_thread>(thread_id);
+	if (!thread)
+	{
+		return CELL_ESRCH;
+	}
+
+	// We can only wake a thread if it is being suspended for a page fault.
+	auto pf_events = fxm::get_always<page_fault_event_entries>();
+	auto pf_event_ind = pf_events->events.begin();
+
+	for (auto event_ind = pf_events->events.begin(); event_ind != pf_events->events.end(); ++event_ind)
+	{
+		if (event_ind->thread_id == thread_id)
+		{
+			pf_event_ind = event_ind;
+			break;
+		}
+	}
+
+	if (pf_event_ind == pf_events->events.end())
+	{ // if not found...
+		return CELL_EINVAL;
+	}
+
+	pf_events->events.erase(pf_event_ind);
+
+	lv2_obj::awake(*thread);
+	return CELL_OK;
+}
+
+error_code sys_ppu_thread_get_page_fault_context(u32 thread_id, vm::ptr<sys_ppu_thread_icontext_t> ctxt)
+{
+	sys_ppu_thread.todo("sys_ppu_thread_get_page_fault_context(thread_id=0x%x, ctxt=*0x%x)", thread_id, ctxt);
+
+	const auto thread = idm::get<ppu_thread>(thread_id);
+	if (!thread)
+	{
+		return CELL_ESRCH;
+	}
+
+	// We can only get a context if the thread is being suspended for a page fault.
+	auto pf_events = fxm::get_always<page_fault_event_entries>();
+
+	bool found = false;
+	for (const auto& ev : pf_events->events)
+	{
+		if (ev.thread_id == thread_id)
+		{
+			found = true;
+			break;
+		}
+	}
+	if (!found)
+	{
+		return CELL_EINVAL;
+	}
+
+	// TODO: Fill ctxt with proper information.
+
+	return CELL_OK;
+}
+

rpcs3/Emu/Cell/lv2/sys_ppu_thread.h

@@ -29,6 +29,17 @@ struct ppu_thread_param_t
 	be_t<u32> tls; // vm::ps3::bptr<void>
 };
 
+struct sys_ppu_thread_icontext_t
+{
+	be_t<u64> gpr[32];
+	be_t<u32> cr;
+	be_t<u32> rsv1;
+	be_t<u64> xer;
+	be_t<u64> lr;
+	be_t<u64> ctr;
+	be_t<u64> pc;
+};
+
 enum : u32
 {
 	PPU_THREAD_STATUS_IDLE,
@@ -56,3 +67,5 @@ error_code sys_ppu_thread_restart(u32 thread_id);
 error_code _sys_ppu_thread_create(vm::ps3::ptr<u64> thread_id, vm::ps3::ptr<ppu_thread_param_t> param, u64 arg, u64 arg4, s32 prio, u32 stacksize, u64 flags, vm::ps3::cptr<char> threadname);
 error_code sys_ppu_thread_start(ppu_thread& ppu, u32 thread_id);
 error_code sys_ppu_thread_rename(u32 thread_id, vm::ps3::cptr<char> name);
+error_code sys_ppu_thread_recover_page_fault(u32 thread_id);
+error_code sys_ppu_thread_get_page_fault_context(u32 thread_id, vm::ps3::ptr<sys_ppu_thread_icontext_t> ctxt);