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: [email protected] Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Ard Biesheuvel <[email protected]> Acked-by: Marc Zyngier <[email protected]> Reviewed-by: Leif Lindholm <[email protected]> Acked-by: Laszlo Ersek <[email protected]> --- 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 _______________________________________________ cross-distro mailing list [email protected] https://lists.linaro.org/mailman/listinfo/cross-distro
