From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marc Zyngier Subject: Re: [PATCH 2/3] KVM: arm/arm64: Add ARM arch timer interrupts ABI Date: Tue, 01 Nov 2016 16:56:47 +0000 Message-ID: <86d1ifkuk0.fsf@arm.com> References: <20160927190806.22988-1-christoffer.dall@linaro.org> <20160927190806.22988-3-christoffer.dall@linaro.org> <20161101145019.GB13677@cbox> Mime-Version: 1.0 Content-Type: text/plain Cc: Christoffer Dall , Alexander Graf , kvm-devel , arm-mail-list , Paolo Bonzini , "kvmarm\@lists.cs.columbia.edu" To: Peter Maydell Return-path: Received: from foss.arm.com ([217.140.101.70]:55688 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751389AbcKAQ4u (ORCPT ); Tue, 1 Nov 2016 12:56:50 -0400 In-Reply-To: (Peter Maydell's message of "Tue, 1 Nov 2016 14:54:11 +0000") Sender: kvm-owner@vger.kernel.org List-ID: On Tue, Nov 01 2016 at 02:54:11 PM, Peter Maydell wrote: > On 1 November 2016 at 14:50, Christoffer Dall > wrote: >> On Tue, Nov 01, 2016 at 11:26:54AM +0000, Peter Maydell wrote: >>> Possible current and future outbound interrupt lines (some of these >>> would only show up in some unlikely or lots-of-implementation-needed >>> cases, I'm just trying to produce an exhaustive list): >>> * virtual timer >>> * physical timer >>> * hyp timer (nested virtualization case) >>> * secure timer (unlikely but maybe if EL3 is ever supported inside a VM) >>> * gic maintenance interrupt (nested virt again) >>> * PMU interrupt >> >> Thanks for the list, that's good to have around for the future. >> >> There's also the potential of the EL2 virtual timer for nested VHE >> support, right? > > That's the one I meant by "hyp timer". VHE also adds an extra virtual timer, for symmetry with what EL1 provides (and on which CNTVOFF doesn't have any effect) - see section B8.1.1 of the ARMv8.1 addendum. So we effectively have: - Secure physical EL3 - Non-secure physical EL1 - Non-secure virtual EL1 - Non-secure physical EL2 - Non-secure virtual EL2 Thanks, M. -- Jazz is not dead. It just smells funny.