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

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/*
* \brief Pager framework
* \author Norman Feske
* \author Sebastian Sumpf
* \author Alexander Boettcher
* \date 2010-01-25
*/
/*
* Copyright (C) 2010-2015 Genode Labs GmbH
*
* This file is part of the Genode OS framework, which is distributed
* under the terms of the GNU General Public License version 2.
*/
/* Genode includes */
#include <base/pager.h>
#include <base/sleep.h>
#include <util/construct_at.h>
#include <rm_session/rm_session.h>
/* NOVA includes */
#include <nova/syscalls.h>
#include <nova_util.h> /* map_local */
using namespace Genode;
using namespace Nova;
extern Genode::addr_t __core_pd_sel;
static Nova::Hip * kernel_hip()
{
/**
* Initial value of esp register, saved by the crt0 startup code.
* This value contains the address of the hypervisor information page.
*/
extern addr_t __initial_sp;
return reinterpret_cast<Hip *>(__initial_sp);
}
/* pager activation threads storage and handling - one thread per CPU */
enum { PAGER_CPUS = 128, PAGER_STACK_SIZE = 2*4096 };
static char pager_activation_mem[sizeof (Pager_activation<PAGER_STACK_SIZE>) * PAGER_CPUS];
static Pager_activation_base * pager_threads[PAGER_CPUS];
static unsigned which_cpu(Pager_activation_base * pager)
{
Pager_activation_base * start = reinterpret_cast<Pager_activation_base *>(&pager_activation_mem);
Pager_activation_base * end = start + PAGER_CPUS;
if (start <= pager && pager < end) {
/* pager of one of the non boot CPUs */
unsigned cpu_id = pager - start;
return cpu_id;
}
/* pager of boot CPU */
return Affinity::Location().xpos();
}
void Pager_object::_page_fault_handler(addr_t pager_obj)
{
Ipc_pager ipc_pager;
ipc_pager.wait_for_fault();
Thread_base * myself = Thread_base::myself();
Pager_object * obj = reinterpret_cast<Pager_object *>(pager_obj);
Utcb * utcb = reinterpret_cast<Utcb *>(myself->utcb());
Pager_activation_base * pager_thread = static_cast<Pager_activation_base *>(myself);
/* lookup fault address and decide what to do */
int ret = obj->pager(ipc_pager);
/* don't open receive window for pager threads */
if (utcb->crd_rcv.value())
nova_die();
/* good case - found a valid region which is mappable */
if (!ret)
ipc_pager.reply_and_wait_for_fault();
obj->_state.thread.ip = ipc_pager.fault_ip();
obj->_state.thread.sp = 0;
obj->_state.thread.trapno = PT_SEL_PAGE_FAULT;
obj->_state.block();
char const * client = reinterpret_cast<char const *>(obj->_badge);
/* region manager fault - to be handled */
if (ret == 1) {
PDBG("page fault, thread '%s', cpu %u, ip=%lx, fault address=0x%lx",
client, which_cpu(pager_thread), ipc_pager.fault_ip(),
ipc_pager.fault_addr());
utcb->set_msg_word(0);
utcb->mtd = 0;
/* block the faulting thread until region manager is done */
ipc_pager.reply_and_wait_for_fault(obj->sel_sm_block());
}
/* unhandled case */
obj->_state.mark_dead();
PWRN("unresolvable page fault, thread '%s', cpu %u, ip=%lx, "
"fault address=0x%lx ret=%u", client, which_cpu(pager_thread),
ipc_pager.fault_ip(), ipc_pager.fault_addr(), ret);
Native_capability pager_cap = obj->Object_pool<Pager_object>::Entry::cap();
revoke(pager_cap.dst());
revoke(Obj_crd(obj->exc_pt_sel_client(), NUM_INITIAL_PT_LOG2));
utcb->set_msg_word(0);
utcb->mtd = 0;
ipc_pager.reply_and_wait_for_fault();
}
void Pager_object::exception(uint8_t exit_id)
{
Thread_base *myself = Thread_base::myself();
Utcb * utcb = reinterpret_cast<Utcb *>(myself->utcb());
Pager_activation_base * pager_thread = static_cast<Pager_activation_base *>(myself);
if (exit_id > PT_SEL_PARENT || !pager_thread)
nova_die();
addr_t fault_ip = utcb->ip;
uint8_t res = 0xFF;
addr_t mtd = 0;
if (_state.skip_requested()) {
_state.skip_reset();
utcb->set_msg_word(0);
utcb->mtd = 0;
reply(myself->stack_top());
}
/* remember exception type for cpu_session()->state() calls */
_state.thread.trapno = exit_id;
_state.thread.ip = fault_ip;
if (_exception_sigh.valid()) {
_state.submit_signal();
res = client_recall();
}
if (res != NOVA_OK) {
/* nobody handles this exception - so thread will be stopped finally */
_state.mark_dead();
char const * client = reinterpret_cast<char const *>(_badge);
PWRN("unresolvable exception %u, thread '%s', cpu %u, ip=0x%lx, %s",
exit_id, client, which_cpu(pager_thread), fault_ip,
res == 0xFF ? "no signal handler" :
(res == NOVA_OK ? "" : "recall failed"));
Nova::revoke(Obj_crd(exc_pt_sel_client(), NUM_INITIAL_PT_LOG2));
enum { TRAP_BREAKPOINT = 3 };
if (exit_id == TRAP_BREAKPOINT) {
utcb->ip = fault_ip - 1;
mtd = Mtd::EIP;
}
}
utcb->set_msg_word(0);
utcb->mtd = mtd;
reply(myself->stack_top());
}
void Pager_object::_recall_handler(addr_t pager_obj)
{
Thread_base * myself = Thread_base::myself();
Pager_object * obj = reinterpret_cast<Pager_object *>(pager_obj);
Utcb * utcb = reinterpret_cast<Utcb *>(myself->utcb());
/* save state - can be requested via cpu_session->state */
obj->_copy_state(utcb);
obj->_state.thread.ip = utcb->ip;
obj->_state.thread.sp = utcb->sp;
obj->_state.thread.eflags = utcb->flags;
/* thread becomes blocked */
obj->_state.block();
/* deliver signal if it was requested */
if (obj->_state.to_submit())
obj->submit_exception_signal();
/* notify callers of cpu_session()->pause that the state is now valid */
if (obj->_state.notify_requested()) {
obj->_state.notify_cancel();
if (sm_ctrl(obj->sel_sm_notify(), SEMAPHORE_UP) != NOVA_OK)
PWRN("paused notification failed");
}
/* switch on/off single step */
bool singlestep_state = obj->_state.thread.eflags & 0x100UL;
if (obj->_state.singlestep() && !singlestep_state) {
utcb->flags = obj->_state.thread.eflags | 0x100UL;
utcb->mtd = Nova::Mtd(Mtd::EFL).value();
} else {
if (!obj->_state.singlestep() && singlestep_state) {
utcb->flags = obj->_state.thread.eflags & ~0x100UL;
utcb->mtd = Nova::Mtd(Mtd::EFL).value();
} else
utcb->mtd = 0;
}
/* block until cpu_session()->resume() respectively wake_up() call */
utcb->set_msg_word(0);
reply(myself->stack_top(), obj->sel_sm_block());
}
void Pager_object::_startup_handler(addr_t pager_obj)
{
Thread_base *myself = Thread_base::myself();
Pager_object * obj = reinterpret_cast<Pager_object *>(pager_obj);
Utcb * utcb = reinterpret_cast<Utcb *>(myself->utcb());
utcb->ip = obj->_initial_eip;
utcb->sp = obj->_initial_esp;
utcb->mtd = Mtd::EIP | Mtd::ESP;
utcb->set_msg_word(0);
reply(myself->stack_top());
}
void Pager_object::_invoke_handler(addr_t pager_obj)
{
Thread_base *myself = Thread_base::myself();
Pager_object * obj = reinterpret_cast<Pager_object *>(pager_obj);
Utcb * utcb = reinterpret_cast<Utcb *>(myself->utcb());
/* receive window must be closed - otherwise implementation bug */
if (utcb->crd_rcv.value())
nova_die();
addr_t const event = utcb->msg[0];
addr_t const logcount = utcb->msg[1];
/* check for translated vCPU portals */
unsigned const items_count = 1U << (Nova::NUM_INITIAL_VCPU_PT_LOG2 - 1);
if ((obj->_client_exc_vcpu != Native_thread::INVALID_INDEX) &&
(utcb->msg_items() == items_count) &&
(utcb->msg_words() == 1 && (event == 0UL || event == 1UL))) {
/* check all translated item and remap if valid */
for (unsigned i = 0; i < items_count; i++) {
Nova::Utcb::Item * item = utcb->get_item(i);
if (!item)
break;
Nova::Crd cap(item->crd);
if (cap.is_null() || item->is_del())
continue;
/**
* Remap portal to dense packed region - required for vCPU running
* in separate PD (non-colocated case)
*/
Obj_crd snd(cap.base(), 0);
Obj_crd rcv(obj->_client_exc_vcpu + event * items_count + i, 0);
if (map_local(utcb, snd, rcv))
PWRN("could not remap vCPU portal 0x%x", i);
}
}
/* if protocol is violated ignore request */
if (utcb->msg_words() != 2) {
utcb->mtd = 0;
utcb->set_msg_word(0);
reply(myself->stack_top());
}
utcb->mtd = 0;
utcb->set_msg_word(0);
/* native ec cap requested */
if (event == ~0UL) {
/**
* Return native EC cap with specific rights mask set.
* If the cap is mapped the kernel will demote the
* rights of the EC as specified by the rights mask.
*
* The cap is supposed to be returned to clients,
* which they have to use as argument to identify
* the thread to which they want attach portals.
*
* The demotion by the kernel during the map operation
* takes care that the EC cap itself contains
* no usable rights for the clients.
*/
bool res = utcb->append_item(Obj_crd(obj->_state.sel_client_ec, 0,
Obj_crd::RIGHT_EC_RECALL), 0);
/* if logcount > 0 then the pager cap should also be mapped */
if (logcount)
res = utcb->append_item(Obj_crd(obj->Object_pool<Pager_object>::Entry::cap().local_name(), 0), 1);
(void)res;
reply(myself->stack_top());
}
/* semaphore for signaling thread is requested, reuse PT_SEL_STARTUP. */
if (event == ~0UL - 1) {
/* create semaphore only once */
if (!obj->_state.has_signal_sm()) {
revoke(Obj_crd(obj->exc_pt_sel_client() + PT_SEL_STARTUP, 0));
bool res = Nova::create_sm(obj->exc_pt_sel_client() + PT_SEL_STARTUP,
__core_pd_sel, 0);
if (res != Nova::NOVA_OK)
reply(myself->stack_top());
obj->_state.mark_signal_sm();
}
bool res = utcb->append_item(Obj_crd(obj->exc_pt_sel_client() +
PT_SEL_STARTUP, 0), 0);
(void)res;
reply(myself->stack_top());
}
/* sanity check, if event is not valid return nothing */
if (logcount > NUM_INITIAL_PT_LOG2 || event > 1UL << NUM_INITIAL_PT_LOG2 ||
event + (1UL << logcount) > (1UL << NUM_INITIAL_PT_LOG2))
reply(myself->stack_top());
/* valid event portal is requested, delegate it to caller */
bool res = utcb->append_item(Obj_crd(obj->exc_pt_sel_client() + event,
logcount), 0);
(void)res;
reply(myself->stack_top());
}
void Pager_object::wake_up()
{
if (!_state.blocked())
return;
_state.unblock();
uint8_t res = sm_ctrl(sel_sm_block(), SEMAPHORE_UP);
if (res != NOVA_OK)
PWRN("canceling blocked client failed (thread sm)");
}
void Pager_object::client_cancel_blocking()
{
uint8_t res = sm_ctrl(exc_pt_sel_client() + SM_SEL_EC, SEMAPHORE_UP);
if (res != NOVA_OK)
PWRN("canceling blocked client failed (thread sm)");
if (!_state.has_signal_sm())
return;
res = sm_ctrl(exc_pt_sel_client() + PT_SEL_STARTUP, SEMAPHORE_UP);
if (res != NOVA_OK)
PWRN("canceling blocked client failed (signal sm)");
}
uint8_t Pager_object::client_recall()
{
return ec_ctrl(EC_RECALL, _state.sel_client_ec);
}
void Pager_object::cleanup_call()
{
_state.mark_dissolved();
/* revoke all portals handling the client. */
revoke(Obj_crd(exc_pt_sel_client(), NUM_INITIAL_PT_LOG2));
/* if we are paused or waiting for a page fault nothing is in-flight */
if (_state.blocked())
return;
Utcb *utcb = reinterpret_cast<Utcb *>(Thread_base::myself()->utcb());
utcb->set_msg_word(0);
utcb->mtd = 0;
if (uint8_t res = call(sel_pt_cleanup()))
PERR("%8p - cleanup call to pager failed res=%d", utcb, res);
}
static uint8_t create_portal(addr_t pt, addr_t pd, addr_t ec, Mtd mtd,
addr_t eip, addr_t localname)
{
uint8_t res = create_pt(pt, pd, ec, mtd, eip);
if (res != NOVA_OK)
return res;
res = pt_ctrl(pt, localname);
if (res == NOVA_OK)
revoke(Obj_crd(pt, 0, Obj_crd::RIGHT_PT_CTRL));
else
revoke(Obj_crd(pt, 0));
return res;
}
/************************
** Exception handlers **
************************/
template <uint8_t EV>
void Exception_handlers::register_handler(Pager_object *obj, Mtd mtd,
void (* __attribute__((regparm(1))) func)(addr_t))
{
unsigned use_cpu = obj->location.xpos();
if (!kernel_hip()->is_cpu_enabled(use_cpu) || !pager_threads[use_cpu])
throw Rm_session::Invalid_thread();
addr_t const ec_sel = pager_threads[use_cpu]->tid().ec_sel;
/* compiler generates instance of exception entry if not specified */
addr_t entry = func ? (addr_t)func : (addr_t)(&_handler<EV>);
uint8_t res = create_portal(obj->exc_pt_sel_client() + EV,
__core_pd_sel, ec_sel, mtd, entry,
reinterpret_cast<addr_t>(obj));
if (res != Nova::NOVA_OK)
throw Rm_session::Invalid_thread();
}
template <uint8_t EV>
void Exception_handlers::_handler(addr_t obj)
{
Pager_object * pager_obj = reinterpret_cast<Pager_object *>(obj);
pager_obj->exception(EV);
}
Exception_handlers::Exception_handlers(Pager_object *obj)
{
register_handler<0>(obj, Mtd(Mtd::EIP));
register_handler<1>(obj, Mtd(Mtd::EIP));
register_handler<2>(obj, Mtd(Mtd::EIP));
register_handler<3>(obj, Mtd(Mtd::EIP));
register_handler<4>(obj, Mtd(Mtd::EIP));
register_handler<5>(obj, Mtd(Mtd::EIP));
register_handler<6>(obj, Mtd(Mtd::EIP));
register_handler<7>(obj, Mtd(Mtd::EIP));
register_handler<8>(obj, Mtd(Mtd::EIP));
register_handler<9>(obj, Mtd(Mtd::EIP));
register_handler<10>(obj, Mtd(Mtd::EIP));
register_handler<11>(obj, Mtd(Mtd::EIP));
register_handler<12>(obj, Mtd(Mtd::EIP));
register_handler<13>(obj, Mtd(Mtd::EIP));
register_handler<15>(obj, Mtd(Mtd::EIP));
register_handler<16>(obj, Mtd(Mtd::EIP));
register_handler<17>(obj, Mtd(Mtd::EIP));
register_handler<18>(obj, Mtd(Mtd::EIP));
register_handler<19>(obj, Mtd(Mtd::EIP));
register_handler<20>(obj, Mtd(Mtd::EIP));
register_handler<21>(obj, Mtd(Mtd::EIP));
register_handler<22>(obj, Mtd(Mtd::EIP));
register_handler<23>(obj, Mtd(Mtd::EIP));
register_handler<24>(obj, Mtd(Mtd::EIP));
register_handler<25>(obj, Mtd(Mtd::EIP));
}
/******************
** Pager object **
******************/
Pager_object::Pager_object(unsigned long badge, Affinity::Location location)
:
_badge(badge),
_selectors(cap_map()->insert(2)),
_client_exc_pt_sel(cap_map()->insert(NUM_INITIAL_PT_LOG2)),
_client_exc_vcpu(Native_thread::INVALID_INDEX),
_exceptions(this),
location(location)
{
uint8_t res;
addr_t pd_sel = __core_pd_sel;
_state._status = 0;
_state.sel_client_ec = Native_thread::INVALID_INDEX;
if (Native_thread::INVALID_INDEX == _selectors ||
Native_thread::INVALID_INDEX == _client_exc_pt_sel)
throw Rm_session::Invalid_thread();
/* ypos information not supported by now */
if (location.ypos()) {
PWRN("Unsupported location %ux%u", location.xpos(), location.ypos());
throw Rm_session::Invalid_thread();
}
/* place Pager_object on specified CPU by selecting proper pager thread */
unsigned use_cpu = location.xpos();
if (!kernel_hip()->is_cpu_enabled(use_cpu) || !pager_threads[use_cpu])
throw Rm_session::Invalid_thread();
addr_t ec_sel = pager_threads[use_cpu]->tid().ec_sel;
/* create portal for page-fault handler - 14 */
_exceptions.register_handler<14>(this, Mtd::QUAL | Mtd::EIP,
_page_fault_handler);
/* create portal for startup handler - 26 */
Mtd const mtd_startup(Mtd::ESP | Mtd::EIP);
_exceptions.register_handler<PT_SEL_STARTUP>(this, mtd_startup,
_startup_handler);
/* create portal for recall handler - 31 */
Mtd const mtd_recall(Mtd::ESP | Mtd::EIP | Mtd::ACDB | Mtd::EFL |
Mtd::EBSD | Mtd::FSGS);
_exceptions.register_handler<PT_SEL_RECALL>(this, mtd_recall,
_recall_handler);
/*
* Create semaphore required for Genode locking. It can be later on
* requested by the thread the same way as all exception portals.
*/
res = Nova::create_sm(exc_pt_sel_client() + SM_SEL_EC, pd_sel, 0);
if (res != Nova::NOVA_OK) {
throw Rm_session::Invalid_thread();
}
/* create portal for final cleanup call used during destruction */
res = create_portal(sel_pt_cleanup(), pd_sel, ec_sel, Mtd(0),
reinterpret_cast<addr_t>(_invoke_handler),
reinterpret_cast<addr_t>(this));
if (res != Nova::NOVA_OK) {
PERR("could not create pager cleanup portal, error = %u\n", res);
throw Rm_session::Invalid_thread();
}
/* used to notify caller of as soon as pause succeeded */
res = Nova::create_sm(sel_sm_notify(), pd_sel, 0);
if (res != Nova::NOVA_OK) {
throw Rm_session::Invalid_thread();
}
/* semaphore used to block paged thread during page fault or recall */
res = Nova::create_sm(sel_sm_block(), pd_sel, 0);
if (res != Nova::NOVA_OK) {
throw Rm_session::Invalid_thread();
}
}
Pager_object::~Pager_object()
{
/* sanity check that object got dissolved already - otherwise bug */
if (!_state.dissolved())
nova_die();
/* revoke portal used for the cleanup call and sm cap for blocking state */
revoke(Obj_crd(_selectors, 2));
cap_map()->remove(_selectors, 2, 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);
}
/**********************
** Pager activation **
**********************/
Pager_activation_base::Pager_activation_base(const char *name, size_t stack_size)
:
Thread_base(Cpu_session::DEFAULT_WEIGHT, name, stack_size),
_cap(Native_capability()), _ep(0), _cap_valid(Lock::LOCKED)
{
/* tell thread starting code on which CPU to let run the pager */
reinterpret_cast<Affinity::Location *>(stack_base())[0] = Affinity::Location(which_cpu(this), 0);
/* creates local EC */
Thread_base::start();
reinterpret_cast<Nova::Utcb *>(Thread_base::utcb())->crd_xlt = Obj_crd(0, ~0UL);
}
void Pager_activation_base::entry() { }
/**********************
** Pager entrypoint **
**********************/
Pager_entrypoint::Pager_entrypoint(Cap_session *cap_session,
Pager_activation_base *a)
: _activation(a), _cap_session(cap_session)
{
/* sanity check space for pager threads */
if (kernel_hip()->cpu_max() > PAGER_CPUS) {
PERR("kernel supports more CPUs (%u) than Genode (%u)",
kernel_hip()->cpu_max(), PAGER_CPUS);
nova_die();
}
/* determine boot cpu */
unsigned master_cpu = boot_cpu();
/* detect enabled CPUs and create per CPU a pager thread */
typedef Pager_activation<PAGER_STACK_SIZE> Pager;
Pager * pager_of_cpu = reinterpret_cast<Pager *>(&pager_activation_mem);
for (unsigned i = 0; i < kernel_hip()->cpu_max(); i++, pager_of_cpu++) {
if (i == master_cpu) {
pager_threads[master_cpu] = a;
a->ep(this);
continue;
}
if (!kernel_hip()->is_cpu_enabled(i))
continue;
pager_threads[i] = pager_of_cpu;
construct_at<Pager>(pager_threads[i]);
pager_threads[i]->ep(this);
}
}
Pager_capability Pager_entrypoint::manage(Pager_object *obj)
{
/* let handle pager_object of pager thread on same CPU */
unsigned use_cpu = obj->location.xpos();
if (!kernel_hip()->is_cpu_enabled(use_cpu) || !pager_threads[use_cpu]) {
PWRN("invalid CPU parameter used in pager object");
return Pager_capability();
}
Native_capability pager_thread_cap(pager_threads[use_cpu]->tid().ec_sel);
/* request creation of portal bind to pager thread */
Native_capability cap_session =
_cap_session->alloc(pager_thread_cap, obj->handler_address());
if (NOVA_OK != pt_ctrl(cap_session.local_name(), reinterpret_cast<mword_t>(obj)))
nova_die();
/* disable the feature for security reasons now */
revoke(Obj_crd(cap_session.local_name(), 0, Obj_crd::RIGHT_PT_CTRL));
/* add server object to object pool */
obj->Object_pool<Pager_object>::Entry::cap(cap_session);
insert(obj);
/* return capability that uses the object id as badge */
return reinterpret_cap_cast<Pager_object>(
obj->Object_pool<Pager_object>::Entry::cap());
}
void Pager_entrypoint::dissolve(Pager_object *obj)
{
Native_capability pager_obj = obj->Object_pool<Pager_object>::Entry::cap();
/* cleanup at cap session */
_cap_session->free(pager_obj);
/* revoke cap selector locally */
revoke(pager_obj.dst(), true);
/* remove object from pool */
remove_locked(obj);
/* take care that no faults are in-flight */
obj->cleanup_call();
}
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