From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH 3/4 V13] Add ioctl for KVM_KVMCLOCK_CTRL Date: Thu, 16 Feb 2012 16:11:40 +0200 Message-ID: <4F3D0E9C.8030302@redhat.com> References: <1328713666-11424-1-git-send-email-emunson@mgebm.net> <1328713666-11424-4-git-send-email-emunson@mgebm.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from mx1.redhat.com ([209.132.183.28]:56860 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751085Ab2BPOLy (ORCPT ); Thu, 16 Feb 2012 09:11:54 -0500 In-Reply-To: <1328713666-11424-4-git-send-email-emunson@mgebm.net> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Eric B Munson Cc: mingo@redhat.com, hpa@zytor.com, ryanh@linux.vnet.ibm.com, aliguori@us.ibm.com, mtosatti@redhat.com, kvm@vger.kernel.org, linux-arch@vger.kernel.org, x86@kernel.org, linux-kernel@vger.kernel.org On 02/08/2012 05:07 PM, Eric B Munson wrote: > Now that we have a flag that will tell the guest it was suspended, create an > interface for that communication using a KVM ioctl. > > + > +Capability: KVM_CAP_KVMCLOCK_CTRL > +Architectures: Any that implement pvclocks (currently x86 only) > +Type: vcpu ioctl > +Parameters: None > +Returns: 0 on success, -1 on error > + > +This signals to the host kernel that the specified guest is being paused by > +userspace. The host will set a flag in the pvclock structure that is checked > +from the soft lockup watchdog. This needs to be expanded. There is a protocol between the host and guest that needs to be documented, including the requirement to use a single instruction (or ll/sc) to clear the flag. See Documentation/virtual/kvm/msr.txt > This ioctl can be called during pause or > +unpause. > + After pausing the vcpu, but before resuming it. -- error compiling committee.c: too many arguments to function