From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:46387) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fiHED-0005HS-FH for qemu-devel@nongnu.org; Wed, 25 Jul 2018 06:41:15 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fiHEA-0000Ky-G8 for qemu-devel@nongnu.org; Wed, 25 Jul 2018 06:41:09 -0400 References: <000e01d3afad$b9a13830$2ce3a890$@codeaurora.org> <20180227104708.GA11391@cbox> <20180227124604.GA2373@cbox> <20180227132131.fipafmnb56a7fj76@kamzik.brq.redhat.com> From: Marc Zyngier Message-ID: <74427c65-b860-d576-04f9-766253285210@arm.com> Date: Wed, 25 Jul 2018 11:40:54 +0100 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-GB Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] VCPU hotplug on KVM/ARM List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Maran Wilson , kvmarm@lists.cs.columbia.edu, bthakur@codeaurora.org Cc: Andrew Jones , Christoffer Dall , Christoffer Dall , qemu-devel@nongnu.org, Christoffer Dall , qemu-arm@nongnu.org, imammedo@redhat.com, peter.maydell@linaro.org, david@redhat.com On 24/07/18 19:35, Maran Wilson wrote: > It's been a few months since this email thread died off. Has anyone > started working on a potential solution that would allow VCPU hotplug on > KVM/ARM ? Or is this a project that is still waiting for an owner who > has the time and inclination to get started? This is typically a project for someone who would have this particular itch to scratch, and who has a demonstrable need for this functionality. Work wise, it would have to include adding physical CPU hotplug support to the arm64 kernel as a precondition, before worrying about doing it in KVM. For KVM itself, particular area of interests would be: - Making GICv3 redistributors magically appear in the IPA space - Live resizing of GICv3 structures - Dynamic allocation of MPIDR, and mapping with vcpu_id This should keep someone busy for a good couple of weeks (give or take a few months). That being said, I'd rather see support in QEMU first, creating all the vcpu/redistributors upfront, and signalling the hotplug event via the virtual firmware. And then post some numbers to show that creating all the vcpus upfront is not acceptable. Thanks, M. -- Jazz is not dead. It just smells funny... From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marc Zyngier Subject: Re: VCPU hotplug on KVM/ARM Date: Wed, 25 Jul 2018 11:40:54 +0100 Message-ID: <74427c65-b860-d576-04f9-766253285210@arm.com> References: <000e01d3afad$b9a13830$2ce3a890$@codeaurora.org> <20180227104708.GA11391@cbox> <20180227124604.GA2373@cbox> <20180227132131.fipafmnb56a7fj76@kamzik.brq.redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id DC4B140A6E for ; Wed, 25 Jul 2018 06:40:59 -0400 (EDT) Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id jLDfAF2eLItO for ; Wed, 25 Jul 2018 06:40:58 -0400 (EDT) Received: from foss.arm.com (usa-sjc-mx-foss1.foss.arm.com [217.140.101.70]) by mm01.cs.columbia.edu (Postfix) with ESMTP id B8BE54045F for ; Wed, 25 Jul 2018 06:40:58 -0400 (EDT) In-Reply-To: Content-Language: en-GB List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu To: Maran Wilson , kvmarm@lists.cs.columbia.edu, bthakur@codeaurora.org Cc: Christoffer Dall , Christoffer Dall , david@redhat.com, qemu-devel@nongnu.org, Christoffer Dall , qemu-arm@nongnu.org, imammedo@redhat.com List-Id: kvmarm@lists.cs.columbia.edu On 24/07/18 19:35, Maran Wilson wrote: > It's been a few months since this email thread died off. Has anyone > started working on a potential solution that would allow VCPU hotplug on > KVM/ARM ? Or is this a project that is still waiting for an owner who > has the time and inclination to get started? This is typically a project for someone who would have this particular itch to scratch, and who has a demonstrable need for this functionality. Work wise, it would have to include adding physical CPU hotplug support to the arm64 kernel as a precondition, before worrying about doing it in KVM. For KVM itself, particular area of interests would be: - Making GICv3 redistributors magically appear in the IPA space - Live resizing of GICv3 structures - Dynamic allocation of MPIDR, and mapping with vcpu_id This should keep someone busy for a good couple of weeks (give or take a few months). That being said, I'd rather see support in QEMU first, creating all the vcpu/redistributors upfront, and signalling the hotplug event via the virtual firmware. And then post some numbers to show that creating all the vcpus upfront is not acceptable. Thanks, M. -- Jazz is not dead. It just smells funny...