From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Liu, Yi L" Subject: Re: [RFC PATCH 7/8] VFIO: Add new IOCTL for IOMMU TLB invalidate propagation Date: Sun, 14 May 2017 18:55:07 +0800 Message-ID: <20170514105507.GB22110@gmail.com> References: <1493201525-14418-1-git-send-email-yi.l.liu@intel.com> <1493201525-14418-8-git-send-email-yi.l.liu@intel.com> <20170512155843.5abeb4bd@t450s.home> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: "Liu, Yi L" , kvm@vger.kernel.org, iommu@lists.linux-foundation.org, peterx@redhat.com, jasowang@redhat.com, qemu-devel@nongnu.org, kevin.tian@intel.com, ashok.raj@intel.com, jacob.jun.pan@intel.com, tianyu.lan@intel.com, jean-philippe.brucker@arm.com To: Alex Williamson Return-path: Received: from mga04.intel.com ([192.55.52.120]:7102 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933297AbdEOLJI (ORCPT ); Mon, 15 May 2017 07:09:08 -0400 Content-Disposition: inline In-Reply-To: <20170512155843.5abeb4bd@t450s.home> Sender: kvm-owner@vger.kernel.org List-ID: On Fri, May 12, 2017 at 03:58:43PM -0600, Alex Williamson wrote: > On Wed, 26 Apr 2017 18:12:04 +0800 > "Liu, Yi L" wrote: > > > From: "Liu, Yi L" > > > > This patch adds VFIO_IOMMU_TLB_INVALIDATE to propagate IOMMU TLB > > invalidate request from guest to host. > > > > In the case of SVM virtualization on VT-d, host IOMMU driver has > > no knowledge of caching structure updates unless the guest > > invalidation activities are passed down to the host. So a new > > IOCTL is needed to propagate the guest cache invalidation through > > VFIO. > > > > Signed-off-by: Liu, Yi L > > --- > > include/uapi/linux/vfio.h | 9 +++++++++ > > 1 file changed, 9 insertions(+) > > > > diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h > > index 6b97987..50c51f8 100644 > > --- a/include/uapi/linux/vfio.h > > +++ b/include/uapi/linux/vfio.h > > @@ -564,6 +564,15 @@ struct vfio_device_svm { > > > > #define VFIO_IOMMU_SVM_BIND_TASK _IO(VFIO_TYPE, VFIO_BASE + 22) > > > > +/* For IOMMU TLB Invalidation Propagation */ > > +struct vfio_iommu_tlb_invalidate { > > + __u32 argsz; > > + __u32 length; > > + __u8 data[]; > > +}; > > + > > +#define VFIO_IOMMU_TLB_INVALIDATE _IO(VFIO_TYPE, VFIO_BASE + 23) > > I'm kind of wondering why this isn't just a new flag bit on > vfio_device_svm, the data structure is so similar. Of course data > needs to be fully specified in uapi. Hi Alex, For this part, it depends on using opaque structure or not. The following link mentioned it in [Open] session. http://www.spinics.net/lists/kvm/msg148798.html If we pick the full opaque solution for iommu tlb invalidate propagation. Then I may add a flag bit on vfio_device_svm and also add definition in uapi as you suggested. Thanks, Yi L > > + > > /* -------- Additional API for SPAPR TCE (Server POWERPC) IOMMU -------- */ > > > > /* > From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:35835) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dADsG-0004qJ-HF for qemu-devel@nongnu.org; Mon, 15 May 2017 07:09:13 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dADsD-00048k-Bl for qemu-devel@nongnu.org; Mon, 15 May 2017 07:09:12 -0400 Received: from mga03.intel.com ([134.134.136.65]:60229) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dADsD-00048J-0m for qemu-devel@nongnu.org; Mon, 15 May 2017 07:09:09 -0400 Date: Sun, 14 May 2017 18:55:07 +0800 From: "Liu, Yi L" Message-ID: <20170514105507.GB22110@gmail.com> References: <1493201525-14418-1-git-send-email-yi.l.liu@intel.com> <1493201525-14418-8-git-send-email-yi.l.liu@intel.com> <20170512155843.5abeb4bd@t450s.home> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170512155843.5abeb4bd@t450s.home> Subject: Re: [Qemu-devel] [RFC PATCH 7/8] VFIO: Add new IOCTL for IOMMU TLB invalidate propagation List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alex Williamson Cc: "Liu, Yi L" , kvm@vger.kernel.org, iommu@lists.linux-foundation.org, peterx@redhat.com, jasowang@redhat.com, qemu-devel@nongnu.org, kevin.tian@intel.com, ashok.raj@intel.com, jacob.jun.pan@intel.com, tianyu.lan@intel.com, jean-philippe.brucker@arm.com On Fri, May 12, 2017 at 03:58:43PM -0600, Alex Williamson wrote: > On Wed, 26 Apr 2017 18:12:04 +0800 > "Liu, Yi L" wrote: > > > From: "Liu, Yi L" > > > > This patch adds VFIO_IOMMU_TLB_INVALIDATE to propagate IOMMU TLB > > invalidate request from guest to host. > > > > In the case of SVM virtualization on VT-d, host IOMMU driver has > > no knowledge of caching structure updates unless the guest > > invalidation activities are passed down to the host. So a new > > IOCTL is needed to propagate the guest cache invalidation through > > VFIO. > > > > Signed-off-by: Liu, Yi L > > --- > > include/uapi/linux/vfio.h | 9 +++++++++ > > 1 file changed, 9 insertions(+) > > > > diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h > > index 6b97987..50c51f8 100644 > > --- a/include/uapi/linux/vfio.h > > +++ b/include/uapi/linux/vfio.h > > @@ -564,6 +564,15 @@ struct vfio_device_svm { > > > > #define VFIO_IOMMU_SVM_BIND_TASK _IO(VFIO_TYPE, VFIO_BASE + 22) > > > > +/* For IOMMU TLB Invalidation Propagation */ > > +struct vfio_iommu_tlb_invalidate { > > + __u32 argsz; > > + __u32 length; > > + __u8 data[]; > > +}; > > + > > +#define VFIO_IOMMU_TLB_INVALIDATE _IO(VFIO_TYPE, VFIO_BASE + 23) > > I'm kind of wondering why this isn't just a new flag bit on > vfio_device_svm, the data structure is so similar. Of course data > needs to be fully specified in uapi. Hi Alex, For this part, it depends on using opaque structure or not. The following link mentioned it in [Open] session. http://www.spinics.net/lists/kvm/msg148798.html If we pick the full opaque solution for iommu tlb invalidate propagation. Then I may add a flag bit on vfio_device_svm and also add definition in uapi as you suggested. Thanks, Yi L > > + > > /* -------- Additional API for SPAPR TCE (Server POWERPC) IOMMU -------- */ > > > > /* >