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authorAndreas Sandberg <andreas@sandberg.pp.se>2013-05-14 16:02:45 +0200
committerAndreas Sandberg <andreas@sandberg.pp.se>2013-05-14 16:02:45 +0200
commit4e52789c6db91cd292e2de933c7c797e24fa870f (patch)
tree137cdcac6264cb1104fe2d1adb6330f7eff31873 /src
parent3ba93822ccae1dcc5e47c6909d7e690d784ec0e1 (diff)
downloadgem5-4e52789c6db91cd292e2de933c7c797e24fa870f.tar.xz
kvm: Add support for disabling coalesced MMIO
Add the option useCoalescedMMIO to the BaseKvmCPU. The default behavior is to disable coalesced MMIO since this hasn't been heavily tested.
Diffstat (limited to 'src')
-rw-r--r--src/cpu/kvm/BaseKvmCPU.py1
-rw-r--r--src/cpu/kvm/base.cc7
2 files changed, 7 insertions, 1 deletions
diff --git a/src/cpu/kvm/BaseKvmCPU.py b/src/cpu/kvm/BaseKvmCPU.py
index a8356ac5b..796a7794b 100644
--- a/src/cpu/kvm/BaseKvmCPU.py
+++ b/src/cpu/kvm/BaseKvmCPU.py
@@ -69,5 +69,6 @@ class BaseKvmCPU(BaseCPU):
return True
kvmVM = Param.KvmVM(Parent.any, 'KVM VM (i.e., shared memory domain)')
+ useCoalescedMMIO = Param.Bool(False, "Use coalesced MMIO (EXPERIMENTAL)")
usePerfOverflow = Param.Bool(False, "Use perf event overflow counters (EXPERIMENTAL)")
hostFactor = Param.Float(1.0, "Cycle scale factor")
diff --git a/src/cpu/kvm/base.cc b/src/cpu/kvm/base.cc
index 7435d4364..bc650aee9 100644
--- a/src/cpu/kvm/base.cc
+++ b/src/cpu/kvm/base.cc
@@ -133,6 +133,9 @@ BaseKvmCPU::init()
void
BaseKvmCPU::startup()
{
+ const BaseKvmCPUParams * const p(
+ dynamic_cast<const BaseKvmCPUParams *>(params()));
+
Kvm &kvm(vm.kvm);
BaseCPU::startup();
@@ -159,7 +162,9 @@ BaseKvmCPU::startup()
// available. The offset into the KVM's communication page is
// provided by the coalesced MMIO capability.
int mmioOffset(kvm.capCoalescedMMIO());
- if (mmioOffset) {
+ if (!p->useCoalescedMMIO) {
+ inform("KVM: Coalesced MMIO disabled by config.\n");
+ } else if (mmioOffset) {
inform("KVM: Coalesced IO available\n");
mmioRing = (struct kvm_coalesced_mmio_ring *)(
(char *)_kvmRun + (mmioOffset * pageSize));