kvm: Add a helper method to access device event queues

The VM's event queue is normally used for devices in multi-core KVM
mode. Add a helper method, BaseKvmCPU::deviceEventQueue(), to access
this queue. This makes the intention of code migrating to device event
queues clearer.

Change-Id: Ifb10f553a6d7445c8d562f658cf9d0b1f4c577ff
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/4287
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>

1 files changed, 3 insertions, 4 deletions

diff --git a/src/cpu/kvm/base.cc b/src/cpu/kvm/base.cc
index 6ea99ce4a..d0f7515de 100644
--- a/src/cpu/kvm/base.cc
+++ b/src/cpu/kvm/base.cc
@@ -1147,10 +1147,9 @@ BaseKvmCPU::doMMIOAccess(Addr paddr, void *data, int size, bool write)
         delete pkt;
         return clockPeriod() * ipr_delay;
     } else {
-        // Temporarily lock and migrate to the event queue of the
-        // VM. This queue is assumed to "own" all devices we need to
-        // access if running in multi-core mode.
-        EventQueue::ScopedMigration migrate(vm.eventQueue());
+        // Temporarily lock and migrate to the device event queue to
+        // prevent races in multi-core mode.
+        EventQueue::ScopedMigration migrate(deviceEventQueue());
 
         return dataPort.submitIO(pkt);
     }