diff options
Diffstat (limited to 'src/arch/x86/pagetable_walker.cc')
-rw-r--r-- | src/arch/x86/pagetable_walker.cc | 170 |
1 files changed, 97 insertions, 73 deletions
diff --git a/src/arch/x86/pagetable_walker.cc b/src/arch/x86/pagetable_walker.cc index b0b9209b5..fe3a4c3bb 100644 --- a/src/arch/x86/pagetable_walker.cc +++ b/src/arch/x86/pagetable_walker.cc @@ -84,7 +84,7 @@ BitUnion64(PageTableEntry) Bitfield<0> p; EndBitUnion(PageTableEntry) -void +Fault Walker::doNext(PacketPtr &read, PacketPtr &write) { assert(state != Ready && state != Waiting); @@ -106,11 +106,11 @@ Walker::doNext(PacketPtr &read, PacketPtr &write) pte.a = 1; entry.writable = pte.w; entry.user = pte.u; - if (badNX) - panic("NX violation!\n"); + if (badNX || !pte.p) { + stop(); + return pageFault(pte.p); + } entry.noExec = pte.nx; - if (!pte.p) - panic("Page at %#x not present!\n", entry.vaddr); nextState = LongPDP; break; case LongPDP: @@ -119,10 +119,10 @@ Walker::doNext(PacketPtr &read, PacketPtr &write) pte.a = 1; entry.writable = entry.writable && pte.w; entry.user = entry.user && pte.u; - if (badNX) - panic("NX violation!\n"); - if (!pte.p) - panic("Page at %#x not present!\n", entry.vaddr); + if (badNX || !pte.p) { + stop(); + return pageFault(pte.p); + } nextState = LongPD; break; case LongPD: @@ -130,10 +130,10 @@ Walker::doNext(PacketPtr &read, PacketPtr &write) pte.a = 1; entry.writable = entry.writable && pte.w; entry.user = entry.user && pte.u; - if (badNX) - panic("NX violation!\n"); - if (!pte.p) - panic("Page at %#x not present!\n", entry.vaddr); + if (badNX || !pte.p) { + stop(); + return pageFault(pte.p); + } if (!pte.ps) { // 4 KB page entry.size = 4 * (1 << 10); @@ -150,36 +150,32 @@ Walker::doNext(PacketPtr &read, PacketPtr &write) entry.patBit = bits(pte, 12); entry.vaddr = entry.vaddr & ~((2 * (1 << 20)) - 1); tlb->insert(entry.vaddr, entry); - nextState = Ready; - delete read->req; - delete read; - read = NULL; - return; + stop(); + return NoFault; } case LongPTE: doWrite = !pte.a; pte.a = 1; entry.writable = entry.writable && pte.w; entry.user = entry.user && pte.u; - if (badNX) - panic("NX violation!\n"); - if (!pte.p) - panic("Page at %#x not present!\n", entry.vaddr); + if (badNX || !pte.p) { + stop(); + return pageFault(pte.p); + } entry.paddr = (uint64_t)pte & (mask(40) << 12); entry.uncacheable = uncacheable; entry.global = pte.g; entry.patBit = bits(pte, 12); entry.vaddr = entry.vaddr & ~((4 * (1 << 10)) - 1); tlb->insert(entry.vaddr, entry); - nextState = Ready; - delete read->req; - delete read; - read = NULL; - return; + stop(); + return NoFault; case PAEPDP: nextRead = ((uint64_t)pte & (mask(40) << 12)) + vaddr.pael2 * size; - if (!pte.p) - panic("Page at %#x not present!\n", entry.vaddr); + if (!pte.p) { + stop(); + return pageFault(pte.p); + } nextState = PAEPD; break; case PAEPD: @@ -187,10 +183,10 @@ Walker::doNext(PacketPtr &read, PacketPtr &write) pte.a = 1; entry.writable = pte.w; entry.user = pte.u; - if (badNX) - panic("NX violation!\n"); - if (!pte.p) - panic("Page at %#x not present!\n", entry.vaddr); + if (badNX || !pte.p) { + stop(); + return pageFault(pte.p); + } if (!pte.ps) { // 4 KB page entry.size = 4 * (1 << 10); @@ -206,39 +202,35 @@ Walker::doNext(PacketPtr &read, PacketPtr &write) entry.patBit = bits(pte, 12); entry.vaddr = entry.vaddr & ~((2 * (1 << 20)) - 1); tlb->insert(entry.vaddr, entry); - nextState = Ready; - delete read->req; - delete read; - read = NULL; - return; + stop(); + return NoFault; } case PAEPTE: doWrite = !pte.a; pte.a = 1; entry.writable = entry.writable && pte.w; entry.user = entry.user && pte.u; - if (badNX) - panic("NX violation!\n"); - if (!pte.p) - panic("Page at %#x not present!\n", entry.vaddr); + if (badNX || !pte.p) { + stop(); + return pageFault(pte.p); + } entry.paddr = (uint64_t)pte & (mask(40) << 12); entry.uncacheable = uncacheable; entry.global = pte.g; entry.patBit = bits(pte, 7); entry.vaddr = entry.vaddr & ~((4 * (1 << 10)) - 1); tlb->insert(entry.vaddr, entry); - nextState = Ready; - delete read->req; - delete read; - read = NULL; - return; + stop(); + return NoFault; case PSEPD: doWrite = !pte.a; pte.a = 1; entry.writable = pte.w; entry.user = pte.u; - if (!pte.p) - panic("Page at %#x not present!\n", entry.vaddr); + if (!pte.p) { + stop(); + return pageFault(pte.p); + } if (!pte.ps) { // 4 KB page entry.size = 4 * (1 << 10); @@ -255,44 +247,40 @@ Walker::doNext(PacketPtr &read, PacketPtr &write) entry.patBit = bits(pte, 12); entry.vaddr = entry.vaddr & ~((4 * (1 << 20)) - 1); tlb->insert(entry.vaddr, entry); - nextState = Ready; - delete read->req; - delete read; - read = NULL; - return; + stop(); + return NoFault; } case PD: doWrite = !pte.a; pte.a = 1; entry.writable = pte.w; entry.user = pte.u; - if (!pte.p) - panic("Page at %#x not present!\n", entry.vaddr); + if (!pte.p) { + stop(); + return pageFault(pte.p); + } // 4 KB page entry.size = 4 * (1 << 10); nextRead = ((uint64_t)pte & (mask(20) << 12)) + vaddr.norml2 * size; nextState = PTE; break; - nextState = PTE; - break; case PTE: doWrite = !pte.a; pte.a = 1; entry.writable = pte.w; entry.user = pte.u; - if (!pte.p) - panic("Page at %#x not present!\n", entry.vaddr); + if (!pte.p) { + stop(); + return pageFault(pte.p); + } entry.paddr = (uint64_t)pte & (mask(20) << 12); entry.uncacheable = uncacheable; entry.global = pte.g; entry.patBit = bits(pte, 7); entry.vaddr = entry.vaddr & ~((4 * (1 << 10)) - 1); tlb->insert(entry.vaddr, entry); - nextState = Ready; - delete read->req; - delete read; - read = NULL; - return; + stop(); + return NoFault; default: panic("Unknown page table walker state %d!\n"); } @@ -316,16 +304,21 @@ Walker::doNext(PacketPtr &read, PacketPtr &write) delete oldRead->req; delete oldRead; } + return NoFault; } -void -Walker::start(ThreadContext * _tc, Addr vaddr, bool _write, bool _execute) +Fault +Walker::start(ThreadContext * _tc, BaseTLB::Translation *_translation, + RequestPtr _req, bool _write, bool _execute) { assert(state == Ready); assert(!tc); tc = _tc; + req = _req; + Addr vaddr = req->getVaddr(); execute = _execute; write = _write; + translation = _translation; VAddr addr = vaddr; @@ -339,6 +332,7 @@ Walker::start(ThreadContext * _tc, Addr vaddr, bool _write, bool _execute) // Do long mode. state = LongPML4; top = (cr3.longPdtb << 12) + addr.longl4 * size; + enableNX = efer.nxe; } else { // We're in some flavor of legacy mode. CR4 cr4 = tc->readMiscRegNoEffect(MISCREG_CR4); @@ -346,6 +340,7 @@ Walker::start(ThreadContext * _tc, Addr vaddr, bool _write, bool _execute) // Do legacy PAE. state = PAEPDP; top = (cr3.paePdtb << 5) + addr.pael3 * size; + enableNX = efer.nxe; } else { size = 4; top = (cr3.pdtb << 12) + addr.norml2 * size; @@ -356,14 +351,13 @@ Walker::start(ThreadContext * _tc, Addr vaddr, bool _write, bool _execute) // Do legacy non PSE. state = PD; } + enableNX = false; } } nextState = Ready; entry.vaddr = vaddr; - enableNX = efer.nxe; - Request::Flags flags = Request::PHYSICAL; if (cr3.pcd) flags.set(Request::UNCACHEABLE); @@ -372,13 +366,15 @@ Walker::start(ThreadContext * _tc, Addr vaddr, bool _write, bool _execute) read->allocate(); Enums::MemoryMode memMode = sys->getMemoryMode(); if (memMode == Enums::timing) { - tc->suspend(); + timingFault = NoFault; port.sendTiming(read); } else if (memMode == Enums::atomic) { + Fault fault; do { port.sendAtomic(read); PacketPtr write = NULL; - doNext(read, write); + fault = doNext(read, write); + assert(fault == NoFault || read == NULL); state = nextState; nextState = Ready; if (write) @@ -387,9 +383,11 @@ Walker::start(ThreadContext * _tc, Addr vaddr, bool _write, bool _execute) tc = NULL; state = Ready; nextState = Waiting; + return fault; } else { panic("Unrecognized memory system mode.\n"); } + return NoFault; } bool @@ -410,9 +408,10 @@ Walker::recvTiming(PacketPtr pkt) state = nextState; nextState = Ready; PacketPtr write = NULL; - doNext(pkt, write); + timingFault = doNext(pkt, write); state = Waiting; read = pkt; + assert(timingFault == NoFault || read == NULL); if (write) { writes.push_back(write); } @@ -421,10 +420,27 @@ Walker::recvTiming(PacketPtr pkt) sendPackets(); } if (inflight == 0 && read == NULL && writes.size() == 0) { - tc->activate(0); tc = NULL; state = Ready; nextState = Waiting; + if (timingFault == NoFault) { + /* + * Finish the translation. Now that we now the right entry is + * in the TLB, this should work with no memory accesses. + * There could be new faults unrelated to the table walk like + * permissions violations, so we'll need the return value as + * well. + */ + bool delayedResponse; + Fault fault = tlb->translate(req, tc, NULL, write, execute, + delayedResponse, true); + assert(!delayedResponse); + // Let the CPU continue. + translation->finish(fault, req, tc, write); + } else { + // There was a fault during the walk. Let the CPU know. + translation->finish(timingFault, req, tc, write); + } } } else if (pkt->wasNacked()) { pkt->reinitNacked(); @@ -525,6 +541,14 @@ Walker::getPort(const std::string &if_name, int idx) panic("No page table walker port named %s!\n", if_name); } +Fault +Walker::pageFault(bool present) +{ + HandyM5Reg m5reg = tc->readMiscRegNoEffect(MISCREG_M5_REG); + return new PageFault(entry.vaddr, present, write, + m5reg.cpl == 3, false, execute && enableNX); +} + } X86ISA::Walker * |