From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Chalamarla, Tirumalesh" Subject: Re: [PATCH] arm64/kvm: Add generic v8 KVM target Date: Mon, 29 Jun 2015 17:13:37 +0000 Message-ID: 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> <20150626095318.GG28244@cbox> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: kvm-devel , Marc Zyngier , "timur@codeaurora.org" , "vgandhi@codeaurora.org" , "kvmarm@lists.cs.columbia.edu" , arm-mail-list To: Christoffer Dall Return-path: In-Reply-To: <20150626095318.GG28244@cbox> Content-Language: en-US Content-ID: 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 List-Id: kvm.vger.kernel.org > On Jun 26, 2015, at 2:53 AM, Christoffer Dall wrote: > > 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. > Will this also prevents migrating between same implementations, if no how is this identified. This seems to be making emulation a requirment for ARM64 KVM. Thanks, Tirumalesh. > -Christoffer > _______________________________________________ > kvmarm mailing list > kvmarm@lists.cs.columbia.edu > https://lists.cs.columbia.edu/mailman/listinfo/kvmarm From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tirumalesh.Chalamarla@caviumnetworks.com (Chalamarla, Tirumalesh) Date: Mon, 29 Jun 2015 17:13:37 +0000 Subject: [PATCH] arm64/kvm: Add generic v8 KVM target In-Reply-To: <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> <20150626095318.GG28244@cbox> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org > On Jun 26, 2015, at 2:53 AM, Christoffer Dall wrote: > > 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. > Will this also prevents migrating between same implementations, if no how is this identified. This seems to be making emulation a requirment for ARM64 KVM. Thanks, Tirumalesh. > -Christoffer > _______________________________________________ > kvmarm mailing list > kvmarm at lists.cs.columbia.edu > https://lists.cs.columbia.edu/mailman/listinfo/kvmarm