From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH] KVM: VMX cannot yet handle migration-after-preemption, so disable it Date: Wed, 25 Jul 2007 06:20:30 +0300 Message-ID: <46A6C17E.9030307@qumranet.com> References: <20070724204022.5456.72025.stgit@novell1.haskins.net> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org To: Gregory Haskins Return-path: In-Reply-To: <20070724204022.5456.72025.stgit-sLgBBP33vUGnsjUZhwzVf9HuzzzSOjJt@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Errors-To: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: kvm.vger.kernel.org Gregory Haskins wrote: > This patch applies to the preempt-hooks branch to enable KVM to function > properly on VMX. With preemption enabled, the KVM context can get scheduled > out at arbitrary points. The preempt-hooks allow us to correctly restore > the host state while being preemptible, but preemption causes problems on the > schedule-in side if the vcpu-task migrates to a new pCPU. > > Ideally we can handle the migration scenario better (patch for this in > progress). However, this patch provides correctness in the interim at the > expense of a small amount of flexibility. E.g. we can only migrate when the > vcpu_lock is not held. > > I'd rather wait for the real fix, especially as this is an experimental branch. Can you provide details of the issue? -- Do not meddle in the internals of kernels, for they are subtle and quick to panic. ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/