From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received-SPF: Pass (sender SPF authorized) identity=mailfrom; client-ip=217.140.101.70; helo=foss.arm.com; envelope-from=julien.grall@arm.com; receiver=edk2-devel@lists.01.org Received: from foss.arm.com (usa-sjc-mx-foss1.foss.arm.com [217.140.101.70]) by ml01.01.org (Postfix) with ESMTP id 569102277AF02 for ; Mon, 23 Apr 2018 03:27:15 -0700 (PDT) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id C54BB1435; Mon, 23 Apr 2018 03:27:14 -0700 (PDT) Received: from [10.1.206.53] (e108454-lin.cambridge.arm.com [10.1.206.53]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id D15F33F4FF; Mon, 23 Apr 2018 03:27:13 -0700 (PDT) To: Ard Biesheuvel Cc: "edk2-devel@lists.01.org" , Marc Zyngier , cross-distro@lists.linaro.org, Laszlo Ersek References: <20180417060320.29090-1-ard.biesheuvel@linaro.org> From: Julien Grall Message-ID: Date: Mon, 23 Apr 2018 11:27:12 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 MIME-Version: 1.0 In-Reply-To: Subject: Re: [PATCH v2] ArmPkg/TimerDxe: remove workaround for KVM timer handling X-BeenThere: edk2-devel@lists.01.org X-Mailman-Version: 2.1.26 Precedence: list List-Id: EDK II Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 23 Apr 2018 10:27:15 -0000 Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit On 19/04/18 15:34, Ard Biesheuvel wrote: > On 19 April 2018 at 16:23, Julien Grall wrote: >> Hi Ard, >> >> Sorry for the late reply. >> >> On 19/04/18 09:16, Ard Biesheuvel wrote: >>> >>> On 17 April 2018 at 08:03, Ard Biesheuvel >>> 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 >>>> Acked-by: Marc Zyngier >>>> Reviewed-by: Leif Lindholm >>>> Acked-by: Laszlo Ersek >>> >>> >>> Pushed as 411a373ed6426fb1bff253905b6a59ada44e18ad >> >> >> While this was added for KVM, I believe that code is also needed by Xen. >> Indeed before injecting the interrupt the hypervisor will mask the >> interrupt. >> >> So would it be possible to revert that patch? >> > > Given that this is now a Xen-only quirk, I'd rather work around it by > creating a separate ArmGenericTimerCounterLib implementation for Xen. That would work for me. > > I will try to put something together beginning of next week. I am happy to test it. Cheers, -- Julien Grall