From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Raj, Ashok" Subject: Re: [RFC PATCH 03/20] intel_iommu: add "svm" option Date: Thu, 4 May 2017 13:37:50 -0700 Message-ID: <20170504203750.GA7308@otc-nc-03> References: <1493201210-14357-1-git-send-email-yi.l.liu@linux.intel.com> <1493201210-14357-4-git-send-email-yi.l.liu@linux.intel.com> <20170427105317.GE1542@pxdev.xzpeter.org> <20170504142853.1537028c@t450s.home> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <20170504142853.1537028c-1yVPhWWZRC1BDLzU/O5InQ@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Alex Williamson Cc: tianyu.lan-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, "Liu, Yi L" , kevin.tian-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, kvm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, jasowang-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, qemu-devel-qX2TKyscuCcdnm+yROfE0A@public.gmane.org, iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, jacob.jun.pan-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org List-Id: iommu@lists.linux-foundation.org On Thu, May 04, 2017 at 02:28:53PM -0600, Alex Williamson wrote: > On Thu, 27 Apr 2017 18:53:17 +0800 > Peter Xu wrote: > > > On Wed, Apr 26, 2017 at 06:06:33PM +0800, Liu, Yi L wrote: > > > Expose "Shared Virtual Memory" to guest by using "svm" option. > > > Also use "svm" to expose SVM related capabilities to guest. > > > e.g. "-device intel-iommu, svm=on" > > > > > > Signed-off-by: Liu, Yi L > > > --- > > > hw/i386/intel_iommu.c | 10 ++++++++++ > > > hw/i386/intel_iommu_internal.h | 5 +++++ > > > include/hw/i386/intel_iommu.h | 1 + > > > 3 files changed, 16 insertions(+) > > > > > > diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c > > > index bf98fa5..ba1e7eb 100644 > > > --- a/hw/i386/intel_iommu.c > > > +++ b/hw/i386/intel_iommu.c > > > @@ -2453,6 +2453,7 @@ static Property vtd_properties[] = { > > > DEFINE_PROP_BOOL("x-buggy-eim", IntelIOMMUState, buggy_eim, false), > > > DEFINE_PROP_BOOL("caching-mode", IntelIOMMUState, caching_mode, FALSE), > > > DEFINE_PROP_BOOL("ecs", IntelIOMMUState, ecs, FALSE), > > > + DEFINE_PROP_BOOL("svm", IntelIOMMUState, svm, FALSE), > > > DEFINE_PROP_END_OF_LIST(), > > > }; > > > > > > @@ -2973,6 +2974,15 @@ static void vtd_init(IntelIOMMUState *s) > > > s->ecap |= VTD_ECAP_ECS; > > > } > > > > > > + if (s->svm) { > > > + if (!s->ecs || !x86_iommu->pt_supported || !s->caching_mode) { > > > + error_report("Need to set ecs, pt, caching-mode for svm"); > > > + exit(1); > > > + } > > > + s->cap |= VTD_CAP_DWD | VTD_CAP_DRD; > > > + s->ecap |= VTD_ECAP_PRS | VTD_ECAP_PTS | VTD_ECAP_PASID28; > > > + } > > > + > > > if (s->caching_mode) { > > > s->cap |= VTD_CAP_CM; > > > } > > > diff --git a/hw/i386/intel_iommu_internal.h b/hw/i386/intel_iommu_internal.h > > > index 71a1c1e..f2a7d12 100644 > > > --- a/hw/i386/intel_iommu_internal.h > > > +++ b/hw/i386/intel_iommu_internal.h > > > @@ -191,6 +191,9 @@ > > > #define VTD_ECAP_PT (1ULL << 6) > > > #define VTD_ECAP_MHMV (15ULL << 20) > > > #define VTD_ECAP_ECS (1ULL << 24) > > > +#define VTD_ECAP_PASID28 (1ULL << 28) > > > > Could I ask what's this bit? On my spec, it says this bit is reserved > > and defunct (spec version: June 2016). > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=d42fde70849c5ba2f00c37a0666305eb507a47b8 > > Do we really need to emulate the buggy implementation? Seems like we > could just pretend bit28 never happened here and use bit40 instead. > Agree, bit28 can be gone.