From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53640) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1b1FMb-0000Ge-Rd for qemu-devel@nongnu.org; Fri, 13 May 2016 11:50:55 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1b1FMW-0004pz-KY for qemu-devel@nongnu.org; Fri, 13 May 2016 11:50:53 -0400 Received: from hqemgate15.nvidia.com ([216.228.121.64]:16896) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1b1FMW-0004pv-AQ for qemu-devel@nongnu.org; Fri, 13 May 2016 11:50:48 -0400 Date: Fri, 13 May 2016 08:50:45 -0700 From: Neo Jia Message-ID: <20160513155044.GB11236@nvidia.com> References: <20160512194924.GA24334@nvidia.com> <573572AD.2010407@intel.com> <20160513064357.GB30970@nvidia.com> <57358293.7060408@intel.com> <20160513074206.GC5749@nvidia.com> <20160513083107.GC6162@nvidia.com> <57359D20.6020305@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <57359D20.6020305@intel.com> Subject: Re: [Qemu-devel] [RFC PATCH v3 3/3] VFIO Type1 IOMMU change: to support with iommu and without iommu List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Jike Song Cc: "Tian, Kevin" , Jike Song , Alex Williamson , Kirti Wankhede , "pbonzini@redhat.com" , "kraxel@redhat.com" , "qemu-devel@nongnu.org" , "kvm@vger.kernel.org" , "Ruan, Shuai" , "Lv, Zhiyuan" On Fri, May 13, 2016 at 05:23:44PM +0800, Jike Song wrote: > On 05/13/2016 04:31 PM, Neo Jia wrote: > > On Fri, May 13, 2016 at 07:45:14AM +0000, Tian, Kevin wrote: > >> > >> We use page tracking framework, which is newly added to KVM recently, > >> to mark RAM pages as read-only so write accesses are intercepted to > >> device model. > > > > Yes, I am aware of that patchset from Guangrong. So far the interface are all > > requiring struct *kvm, copied from https://lkml.org/lkml/2015/11/30/644 > > > > - kvm_page_track_add_page(): add the page to the tracking pool after > > that later specified access on that page will be tracked > > > > - kvm_page_track_remove_page(): remove the page from the tracking pool, > > the specified access on the page is not tracked after the last user is > > gone > > > > void kvm_page_track_add_page(struct kvm *kvm, gfn_t gfn, > > enum kvm_page_track_mode mode); > > void kvm_page_track_remove_page(struct kvm *kvm, gfn_t gfn, > > enum kvm_page_track_mode mode); > > > > Really curious how you are going to have access to the struct kvm *kvm, or you > > are relying on the userfaultfd to track the write faults only as part of the > > QEMU userfault thread? > > > > Hi Neo, > > For the vGPU used as a device for KVM guest, there will be interfaces > wrapped or implemented in KVM layer, as a rival thing diverted from > the interfaces for Xen. That is where the KVM related code supposed to be. Hi Jike, Is this discussed anywhere on the mailing list already? Sorry if I have missed such conversation. Thanks, Neo > > -- > Thanks, > Jike