volatile bool timerOverflowed = false;
-static void
-onTimerOverflow(int signo, siginfo_t *si, void *data)
-{
- timerOverflowed = true;
-}
-
BaseKvmCPU::BaseKvmCPU(BaseKvmCPUParams *params)
: BaseCPU(params),
vm(*params->kvmVM),
_kvmRun(NULL), mmioRing(NULL),
pageSize(sysconf(_SC_PAGE_SIZE)),
tickEvent(*this),
+ activeInstPeriod(0),
perfControlledByTimer(params->usePerfOverflow),
- hostFreq(params->hostFreq),
hostFactor(params->hostFactor),
drainManager(NULL),
ctrInsts(0)
case RunningServiceCompletion:
case Running: {
- Tick ticksToExecute(mainEventQueue.nextTick() - curTick());
+ EventQueue *q = curEventQueue();
+ Tick ticksToExecute(q->nextTick() - curTick());
// We might need to update the KVM state.
syncKvmState();
+ // Setup any pending instruction count breakpoints using
+ // PerfEvent.
+ setupInstStop();
+
DPRINTF(KvmRun, "Entering KVM...\n");
if (drainManager) {
// Force an immediate exit from KVM after completing
_status = Running;
}
+ // Service any pending instruction events. The vCPU should
+ // have exited in time for the event using the instruction
+ // counter configured by setupInstStop().
+ comInstEventQueue[0]->serviceEvents(ctrInsts);
+ system->instEventQueue.serviceEvents(system->totalNumInsts);
+
if (tryDrain())
_status = Idle;
} break;
// sure we don't deliver it immediately next time we try to
// enter into KVM.
discardPendingSignal(KVM_TIMER_SIGNAL);
+ discardPendingSignal(KVM_INST_SIGNAL);
const uint64_t hostCyclesExecuted(getHostCycles() - baseCycles);
const uint64_t simCyclesExecuted(hostCyclesExecuted * hostFactor);
const Cycles ipr_delay(write ?
TheISA::handleIprWrite(tc, &pkt) :
TheISA::handleIprRead(tc, &pkt));
- return clockEdge(ipr_delay);
+ return clockPeriod() * ipr_delay;
} else {
return dataPort.sendAtomic(&pkt);
}
return ticks;
}
+/**
+ * Cycle timer overflow when running in KVM. Forces the KVM syscall to
+ * exit with EINTR and allows us to run the event queue.
+ */
+static void
+onTimerOverflow(int signo, siginfo_t *si, void *data)
+{
+ timerOverflowed = true;
+}
+
+/**
+ * Instruction counter overflow when running in KVM. Forces the KVM
+ * syscall to exit with EINTR and allows us to handle instruction
+ * count events.
+ */
+static void
+onInstEvent(int signo, siginfo_t *si, void *data)
+{
+}
+
void
BaseKvmCPU::setupSignalHandler()
{
sa.sa_sigaction = onTimerOverflow;
sa.sa_flags = SA_SIGINFO | SA_RESTART;
if (sigaction(KVM_TIMER_SIGNAL, &sa, NULL) == -1)
- panic("KVM: Failed to setup vCPU signal handler\n");
+ panic("KVM: Failed to setup vCPU timer signal handler\n");
+
+ memset(&sa, 0, sizeof(sa));
+ sa.sa_sigaction = onInstEvent;
+ sa.sa_flags = SA_SIGINFO | SA_RESTART;
+ if (sigaction(KVM_INST_SIGNAL, &sa, NULL) == -1)
+ panic("KVM: Failed to setup vCPU instruction signal handler\n");
sigset_t sigset;
if (sigprocmask(SIG_BLOCK, NULL, &sigset) == -1)
// requests. See kvmRun().
setSignalMask(&sigset);
- // Mask the KVM_TIMER_SIGNAL so it isn't delivered unless we're
+ // Mask our control signals so they aren't delivered unless we're
// actually executing inside KVM.
sigaddset(&sigset, KVM_TIMER_SIGNAL);
+ sigaddset(&sigset, KVM_INST_SIGNAL);
if (sigprocmask(SIG_SETMASK, &sigset, NULL) == -1)
- panic("KVM: Failed mask the KVM timer signal\n");
+ panic("KVM: Failed mask the KVM control signals\n");
}
bool
cfgCycles.disabled(true)
.pinned(true);
+ // Try to exclude the host. We set both exclude_hv and
+ // exclude_host since different architectures use slightly
+ // different APIs in the kernel.
+ cfgCycles.exclude_hv(true)
+ .exclude_host(true);
+
if (perfControlledByTimer) {
// We need to configure the cycles counter to send overflows
// since we are going to use it to trigger timer signals that
hwCycles.attach(cfgCycles,
0); // TID (0 => currentThread)
- DPRINTF(Kvm, "Attaching instruction counter...\n");
- PerfKvmCounterConfig cfgInstructions(PERF_TYPE_HARDWARE,
- PERF_COUNT_HW_INSTRUCTIONS);
- hwInstructions.attach(cfgInstructions,
- 0, // TID (0 => currentThread)
- hwCycles);
+ setupInstCounter();
}
bool
errno);
}
}
+
+void
+BaseKvmCPU::setupInstStop()
+{
+ if (comInstEventQueue[0]->empty()) {
+ setupInstCounter(0);
+ } else {
+ const uint64_t next(comInstEventQueue[0]->nextTick());
+
+ assert(next > ctrInsts);
+ setupInstCounter(next - ctrInsts);
+ }
+}
+
+void
+BaseKvmCPU::setupInstCounter(uint64_t period)
+{
+ // No need to do anything if we aren't attaching for the first
+ // time or the period isn't changing.
+ if (period == activeInstPeriod && hwInstructions.attached())
+ return;
+
+ PerfKvmCounterConfig cfgInstructions(PERF_TYPE_HARDWARE,
+ PERF_COUNT_HW_INSTRUCTIONS);
+
+ // Try to exclude the host. We set both exclude_hv and
+ // exclude_host since different architectures use slightly
+ // different APIs in the kernel.
+ cfgInstructions.exclude_hv(true)
+ .exclude_host(true);
+
+ if (period) {
+ // Setup a sampling counter if that has been requested.
+ cfgInstructions.wakeupEvents(1)
+ .samplePeriod(period);
+ }
+
+ // We need to detach and re-attach the counter to reliably change
+ // sampling settings. See PerfKvmCounter::period() for details.
+ if (hwInstructions.attached())
+ hwInstructions.detach();
+ assert(hwCycles.attached());
+ hwInstructions.attach(cfgInstructions,
+ 0, // TID (0 => currentThread)
+ hwCycles);
+
+ if (period)
+ hwInstructions.enableSignals(KVM_INST_SIGNAL);
+
+ activeInstPeriod = period;
+}
projects / gem5.git / blobdiff