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kvm, arm: Switch to the device EQ when accessing ISA devices

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ISA devices typically run in the device event queue. Previously, we
assumed that devices would perform their own EQ migrations as
needed. This isn't ideal since it means we have different conventions
for IO devices and ISA devices. Switch to doing migrations in the KVM
CPU instead to make the behavior consistent.

Change-Id: I33b74480fb2126b0786dbdbfdcfa86083384250c
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/4288
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
This commit is contained in:
Andreas Sandberg
2017-07-27 09:26:07 +00:00
parent 1935cec529
commit db85b8ff32
2 changed files with 18 additions and 13 deletions
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21
src/arch/arm/kvm/armv8_cpu.cc
View File

@@ -260,7 +260,17 @@ ArmV8KvmCPU::updateKvmState()
}
for (const auto &ri : getSysRegMap()) {
const uint64_t value(tc->readMiscReg(ri.idx));
uint64_t value;
if (ri.is_device) {
// This system register is backed by a device. This means
// we need to lock the device event queue.
EventQueue::ScopedMigration migrate(deviceEventQueue());
value = tc->readMiscReg(ri.idx);
} else {
value = tc->readMiscReg(ri.idx);
}
DPRINTF(KvmContext, " %s := 0x%x\n", ri.name, value);
setOneReg(ri.kvm, value);
}
@@ -323,10 +333,15 @@ ArmV8KvmCPU::updateThreadContext()
for (const auto &ri : getSysRegMap()) {
const auto value(getOneRegU64(ri.kvm));
DPRINTF(KvmContext, " %s := 0x%x\n", ri.name, value);
if (ri.is_device)
if (ri.is_device) {
// This system register is backed by a device. This means
// we need to lock the device event queue.
EventQueue::ScopedMigration migrate(deviceEventQueue());
tc->setMiscReg(ri.idx, value);
else
} else {
tc->setMiscRegNoEffect(ri.idx, value);
}
}
PCState pc(getOneRegU64(INT_REG(regs.pc)));

10
src/dev/arm/generic_timer.cc
View File

@@ -318,11 +318,6 @@ GenericTimer::createTimers(unsigned cpus)
void
GenericTimer::setMiscReg(int reg, unsigned cpu, MiscReg val)
{
// This method might have been called from another context if we
// are running in multi-core KVM. Migrate to the SimObject's event
// queue to prevent surprising race conditions.
EventQueue::ScopedMigration migrate(eventQueue());
CoreTimers &core(getTimers(cpu));
switch (reg) {
@@ -415,11 +410,6 @@ GenericTimer::setMiscReg(int reg, unsigned cpu, MiscReg val)
MiscReg
GenericTimer::readMiscReg(int reg, unsigned cpu)
{
// This method might have been called from another context if we
// are running in multi-core KVM. Migrate to the SimObject's event
// queue to prevent surprising race conditions.
EventQueue::ScopedMigration migrate(eventQueue());
CoreTimers &core(getTimers(cpu));
switch (reg) {