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Diffstat (limited to 'src/arch/x86/pagetable_walker.cc')
-rw-r--r--src/arch/x86/pagetable_walker.cc249
1 files changed, 146 insertions, 103 deletions
diff --git a/src/arch/x86/pagetable_walker.cc b/src/arch/x86/pagetable_walker.cc
index e70c16b1d..f625cf4bd 100644
--- a/src/arch/x86/pagetable_walker.cc
+++ b/src/arch/x86/pagetable_walker.cc
@@ -84,8 +84,8 @@ BitUnion64(PageTableEntry)
Bitfield<0> p;
EndBitUnion(PageTableEntry)
-void
-Walker::doNext(PacketPtr &read, PacketPtr &write)
+Fault
+Walker::doNext(PacketPtr &write)
{
assert(state != Ready && state != Waiting);
write = NULL;
@@ -101,39 +101,45 @@ Walker::doNext(PacketPtr &read, PacketPtr &write)
bool badNX = pte.nx && (!tlb->allowNX() || !enableNX);
switch(state) {
case LongPML4:
+ DPRINTF(PageTableWalker,
+ "Got long mode PML4 entry %#016x.\n", (uint64_t)pte);
nextRead = ((uint64_t)pte & (mask(40) << 12)) + vaddr.longl3 * size;
doWrite = !pte.a;
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:
+ DPRINTF(PageTableWalker,
+ "Got long mode PDP entry %#016x.\n", (uint64_t)pte);
nextRead = ((uint64_t)pte & (mask(40) << 12)) + vaddr.longl2 * size;
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);
+ }
nextState = LongPD;
break;
case LongPD:
+ DPRINTF(PageTableWalker,
+ "Got long mode PD entry %#016x.\n", (uint64_t)pte);
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);
+ }
if (!pte.ps) {
// 4 KB page
entry.size = 4 * (1 << 10);
@@ -150,47 +156,49 @@ 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:
+ DPRINTF(PageTableWalker,
+ "Got long mode PTE entry %#016x.\n", (uint64_t)pte);
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:
+ DPRINTF(PageTableWalker,
+ "Got legacy mode PAE PDP entry %#08x.\n", (uint32_t)pte);
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:
+ DPRINTF(PageTableWalker,
+ "Got legacy mode PAE PD entry %#08x.\n", (uint32_t)pte);
doWrite = !pte.a;
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 +214,39 @@ 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:
+ DPRINTF(PageTableWalker,
+ "Got legacy mode PAE PTE entry %#08x.\n", (uint32_t)pte);
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:
+ DPRINTF(PageTableWalker,
+ "Got legacy mode PSE PD entry %#08x.\n", (uint32_t)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);
+ }
if (!pte.ps) {
// 4 KB page
entry.size = 4 * (1 << 10);
@@ -255,54 +263,51 @@ 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:
+ DPRINTF(PageTableWalker,
+ "Got legacy mode PD entry %#08x.\n", (uint32_t)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);
+ }
// 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:
+ DPRINTF(PageTableWalker,
+ "Got legacy mode PTE entry %#08x.\n", (uint32_t)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");
}
PacketPtr oldRead = read;
//If we didn't return, we're setting up another read.
- uint32_t flags = oldRead->req->getFlags();
- if (uncacheable)
- flags |= UNCACHEABLE;
- else
- flags &= ~UNCACHEABLE;
+ Request::Flags flags = oldRead->req->getFlags();
+ flags.set(Request::UNCACHEABLE, uncacheable);
RequestPtr request =
new Request(nextRead, oldRead->getSize(), flags);
read = new Packet(request, MemCmd::ReadExReq, Packet::Broadcast);
@@ -319,14 +324,20 @@ Walker::doNext(PacketPtr &read, PacketPtr &write)
delete oldRead->req;
delete oldRead;
}
+ return NoFault;
}
-void
-Walker::start(ThreadContext * _tc, Addr vaddr)
+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;
@@ -340,6 +351,7 @@ Walker::start(ThreadContext * _tc, Addr vaddr)
// 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);
@@ -347,6 +359,7 @@ Walker::start(ThreadContext * _tc, Addr vaddr)
// 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;
@@ -357,38 +370,44 @@ Walker::start(ThreadContext * _tc, Addr vaddr)
// Do legacy non PSE.
state = PD;
}
+ enableNX = false;
}
}
nextState = Ready;
entry.vaddr = vaddr;
- enableNX = efer.nxe;
-
- RequestPtr request =
- new Request(top, size, PHYSICAL | cr3.pcd ? UNCACHEABLE : 0);
+ Request::Flags flags = Request::PHYSICAL;
+ if (cr3.pcd)
+ flags.set(Request::UNCACHEABLE);
+ RequestPtr request = new Request(top, size, flags);
read = new Packet(request, MemCmd::ReadExReq, Packet::Broadcast);
read->allocate();
Enums::MemoryMode memMode = sys->getMemoryMode();
if (memMode == Enums::timing) {
- tc->suspend();
- port.sendTiming(read);
+ nextState = state;
+ state = Waiting;
+ timingFault = NoFault;
+ sendPackets();
} else if (memMode == Enums::atomic) {
+ Fault fault;
do {
port.sendAtomic(read);
PacketPtr write = NULL;
- doNext(read, write);
+ fault = doNext(write);
+ assert(fault == NoFault || read == NULL);
state = nextState;
nextState = Ready;
if (write)
port.sendAtomic(write);
} while(read);
- tc = NULL;
state = Ready;
nextState = Waiting;
+ return fault;
} else {
panic("Unrecognized memory system mode.\n");
}
+ return NoFault;
}
bool
@@ -400,18 +419,19 @@ Walker::WalkerPort::recvTiming(PacketPtr pkt)
bool
Walker::recvTiming(PacketPtr pkt)
{
- inflight--;
if (pkt->isResponse() && !pkt->wasNacked()) {
+ assert(inflight);
+ assert(state == Waiting);
+ assert(!read);
+ inflight--;
if (pkt->isRead()) {
- assert(inflight);
- assert(state == Waiting);
- assert(!read);
state = nextState;
nextState = Ready;
PacketPtr write = NULL;
- doNext(pkt, write);
- state = Waiting;
read = pkt;
+ timingFault = doNext(write);
+ state = Waiting;
+ assert(timingFault == NoFault || read == NULL);
if (write) {
writes.push_back(write);
}
@@ -420,14 +440,31 @@ 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();
if (!port.sendTiming(pkt)) {
+ inflight--;
retrying = true;
if (pkt->isWrite()) {
writes.push_back(pkt);
@@ -435,8 +472,6 @@ Walker::recvTiming(PacketPtr pkt)
assert(!read);
read = pkt;
}
- } else {
- inflight++;
}
}
return true;
@@ -490,27 +525,26 @@ Walker::sendPackets()
//Reads always have priority
if (read) {
- if (!port.sendTiming(read)) {
+ PacketPtr pkt = read;
+ read = NULL;
+ inflight++;
+ if (!port.sendTiming(pkt)) {
retrying = true;
+ read = pkt;
+ inflight--;
return;
- } else {
- inflight++;
- delete read->req;
- delete read;
- read = NULL;
}
}
//Send off as many of the writes as we can.
while (writes.size()) {
PacketPtr write = writes.back();
+ writes.pop_back();
+ inflight++;
if (!port.sendTiming(write)) {
retrying = true;
+ writes.push_back(write);
+ inflight--;
return;
- } else {
- inflight++;
- delete write->req;
- delete write;
- writes.pop_back();
}
}
}
@@ -524,6 +558,15 @@ 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)
+{
+ DPRINTF(PageTableWalker, "Raising page fault.\n");
+ HandyM5Reg m5reg = tc->readMiscRegNoEffect(MISCREG_M5_REG);
+ return new PageFault(entry.vaddr, present, write,
+ m5reg.cpl == 3, false, execute && enableNX);
+}
+
}
X86ISA::Walker *
generated by cgit v1.2.3 (git 2.25.1) at 2024-09-29 16:56:54 +0000