On 17 April 2018 at 08:03, Ard Biesheuvel ard.biesheuvel@linaro.org wrote:
When we first ported EDK2 to KVM/arm, we implemented a workaround for the quirky timer handling on the KVM side. This has been fixed in Linux commit f120cd6533d2 ("KVM: arm/arm64: timer: Allow the timer to control the active state") dated 23 June 2014, which was incorporated into Linux release 4.3.
So almost 4 years later, it should be safe to drop this workaround on the EDK2 side.
This reverts commit b1a633434ddc.
Cc: cross-distro@lists.linaro.org Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Ard Biesheuvel ard.biesheuvel@linaro.org Acked-by: Marc Zyngier marc.zyngier@arm.com Reviewed-by: Leif Lindholm leif.lindholm@linaro.org Acked-by: Laszlo Ersek lersek@redhat.com
Pushed as 411a373ed6426fb1bff253905b6a59ada44e18ad
Thanks all
v2: add acks
Note to cross-distro readers: this means guest firmware built with this patch will not work on KVM/ARM hosts using kernel v4.2 or earlier.
ArmPkg/Drivers/TimerDxe/TimerDxe.c | 1 - ArmPkg/Library/ArmGenericTimerVirtCounterLib/ArmGenericTimerVirtCounterLib.c | 10 ---------- 2 files changed, 11 deletions(-)
diff --git a/ArmPkg/Drivers/TimerDxe/TimerDxe.c b/ArmPkg/Drivers/TimerDxe/TimerDxe.c index a3202fa056f3..bd616d2efc73 100644 --- a/ArmPkg/Drivers/TimerDxe/TimerDxe.c +++ b/ArmPkg/Drivers/TimerDxe/TimerDxe.c @@ -337,7 +337,6 @@ TimerInterruptHandler (
// Set next compare value ArmGenericTimerSetCompareVal (CompareValue);
- ArmGenericTimerEnableTimer (); ArmInstructionSynchronizationBarrier (); }
diff --git a/ArmPkg/Library/ArmGenericTimerVirtCounterLib/ArmGenericTimerVirtCounterLib.c b/ArmPkg/Library/ArmGenericTimerVirtCounterLib/ArmGenericTimerVirtCounterLib.c index 69a4ceb62db6..c941895a3574 100644 --- a/ArmPkg/Library/ArmGenericTimerVirtCounterLib/ArmGenericTimerVirtCounterLib.c +++ b/ArmPkg/Library/ArmGenericTimerVirtCounterLib/ArmGenericTimerVirtCounterLib.c @@ -26,16 +26,6 @@ ArmGenericTimerEnableTimer (
TimerCtrlReg = ArmReadCntvCtl (); TimerCtrlReg |= ARM_ARCH_TIMER_ENABLE;
- //
- // When running under KVM, we need to unmask the interrupt on the timer side
- // as KVM will mask it when servicing the interrupt at the hypervisor level
- // and delivering the virtual timer interrupt to the guest. Otherwise, the
- // interrupt will fire again, trapping into the hypervisor again, etc. etc.
- // This is scheduled to be fixed on the KVM side, but there is no harm in
- // leaving this in once KVM gets fixed.
- //
- TimerCtrlReg &= ~ARM_ARCH_TIMER_IMASK; ArmWriteCntvCtl (TimerCtrlReg);
}
-- 2.17.0