From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoffer Dall Subject: Re: [PATCH] arm64/kvm: Add generic v8 KVM target Date: Fri, 26 Jun 2015 11:53:18 +0200 Message-ID: <20150626095318.GG28244@cbox> References: <1434531646-4873-1-git-send-email-suzuki.poulose@arm.com> <558A6A84.5020603@arm.com> <20150624085128.GA22785@cbox> <558A7936.7020109@arm.com> <20150625123034.GE28244@cbox> <558BF6C9.3000009@arm.com> <558C05A9.8080201@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Marc Zyngier , Suzuki Poulose , "timur@codeaurora.org" , "vgandhi@codeaurora.org" , kvm-devel , arm-mail-list , "kvmarm@lists.cs.columbia.edu" To: Peter Maydell Return-path: Received: from mail-lb0-f176.google.com ([209.85.217.176]:33186 "EHLO mail-lb0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751828AbbFZJxQ (ORCPT ); Fri, 26 Jun 2015 05:53:16 -0400 Received: by lbbvz5 with SMTP id vz5so61207794lbb.0 for ; Fri, 26 Jun 2015 02:53:15 -0700 (PDT) Content-Disposition: inline In-Reply-To: Sender: kvm-owner@vger.kernel.org List-ID: On Thu, Jun 25, 2015 at 02:49:08PM +0100, Peter Maydell wrote: > On 25 June 2015 at 14:44, Marc Zyngier wrote: > > It should always be possible to emulate a "known" CPU on a generic host, > > and it should be able to migrate. The case we can't migrate is when we > > let the guest be generic (which I guess should really be unknown, and > > not generic). > > > > So if the user specify "-cpu cortex-a57" on the command line, the guest > > should be able to migrate from an A72 to an A53. if the user specified > > "-cpu host", the resulting guest won't be able to migrate. > > > > Does it make sense? > > Yes. We've always said "-cpu host" won't be cross-host migratable > from a QEMU point of view. > ok, this makes sense. It's basically up to userspace to mandate that trying to migrate something that used unknown cpu (via -cpu host or whatever) cannot be migrated. -Christoffer From mboxrd@z Thu Jan 1 00:00:00 1970 From: christoffer.dall@linaro.org (Christoffer Dall) Date: Fri, 26 Jun 2015 11:53:18 +0200 Subject: [PATCH] arm64/kvm: Add generic v8 KVM target In-Reply-To: References: <1434531646-4873-1-git-send-email-suzuki.poulose@arm.com> <558A6A84.5020603@arm.com> <20150624085128.GA22785@cbox> <558A7936.7020109@arm.com> <20150625123034.GE28244@cbox> <558BF6C9.3000009@arm.com> <558C05A9.8080201@arm.com> Message-ID: <20150626095318.GG28244@cbox> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Thu, Jun 25, 2015 at 02:49:08PM +0100, Peter Maydell wrote: > On 25 June 2015 at 14:44, Marc Zyngier wrote: > > It should always be possible to emulate a "known" CPU on a generic host, > > and it should be able to migrate. The case we can't migrate is when we > > let the guest be generic (which I guess should really be unknown, and > > not generic). > > > > So if the user specify "-cpu cortex-a57" on the command line, the guest > > should be able to migrate from an A72 to an A53. if the user specified > > "-cpu host", the resulting guest won't be able to migrate. > > > > Does it make sense? > > Yes. We've always said "-cpu host" won't be cross-host migratable > from a QEMU point of view. > ok, this makes sense. It's basically up to userspace to mandate that trying to migrate something that used unknown cpu (via -cpu host or whatever) cannot be migrated. -Christoffer