> -----Original Message----- > From: Peter Xu [mailto:pet...@redhat.com] > Sent: Monday, December 19, 2016 6:01 PM > To: Liu, Yi L <yi.l....@intel.com> > Cc: bd.a...@gmail.com; qemu-devel@nongnu.org; Michael S. Tsirkin > <m...@redhat.com>; , Jan Kiszka <jan.kis...@siemens.com>; , Alex Williamson > <alex.william...@redhat.com>; , Jason Wang <jasow...@redhat.com>; Lan, > Tianyu <tianyu....@intel.com>; Tian, Kevin <kevin.t...@intel.com> > Subject: Re: [Qemu-devel] [PATCH v7 3/5] IOMMU: enable intel_iommu map > and unmap notifiers > > On Fri, Dec 16, 2016 at 09:12:05AM +0000, Liu, Yi L wrote: > > > From: "Aviv Ben-David" <address@hidden> > > > > > > Adds a list of registered vtd_as's to intel iommu state to save > > > iteration over each PCI device in a search of the corrosponding domain. > > > > > > Signed-off-by: Aviv Ben-David <address@hidden> > > > --- > > > hw/i386/intel_iommu.c | 94 > ++++++++++++++++++++++++++++++++++++++---- > > > hw/i386/intel_iommu_internal.h | 2 + > > > include/hw/i386/intel_iommu.h | 9 ++++ > > > 3 files changed, 98 insertions(+), 7 deletions(-) > > > > > > diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c > > > index 05973b9..d872969 100644 > > > --- a/hw/i386/intel_iommu.c > > > +++ b/hw/i386/intel_iommu.c > > > @@ -679,7 +679,7 @@ static int vtd_gpa_to_slpte(VTDContextEntry *ce, > uint64_t > > > gpa, > > > } > > > *reads = (*reads) && (slpte & VTD_SL_R); > > > *writes = (*writes) && (slpte & VTD_SL_W); > > > - if (!(slpte & access_right_check)) { > > > + if (!(slpte & access_right_check) && !(flags & IOMMU_NO_FAIL)) { > > > VTD_DPRINTF(GENERAL, "error: lack of %s permission for " > > > "gpa 0x%"PRIx64 " slpte 0x%"PRIx64, > > > (flags & IOMMU_WO ? "write" : "read"), gpa, > > > slpte); > > > @@ -978,6 +978,23 @@ static VTDBus > *vtd_find_as_from_bus_num(IntelIOMMUState > > > *s, uint8_t bus_num) > > > return vtd_bus; > > > } > > > > > > +static int vtd_get_did_dev(IntelIOMMUState *s, uint8_t bus_num, uint8_t > devfn, > > > + uint16_t *domain_id) > > > +{ > > > + VTDContextEntry ce; > > > + int ret_fr; > > > + > > > + assert(domain_id); > > > + > > > + ret_fr = vtd_dev_to_context_entry(s, bus_num, devfn, &ce); > > > + if (ret_fr) { > > > + return -1; > > > + } > > > + > > > + *domain_id = VTD_CONTEXT_ENTRY_DID(ce.hi); > > > + return 0; > > > +} > > > + > > > /* Do a context-cache device-selective invalidation. > > > * @func_mask: FM field after shifting > > > */ > > > @@ -1064,6 +1081,45 @@ static void > vtd_iotlb_domain_invalidate(IntelIOMMUState > > > *s, uint16_t domain_id) > > > &domain_id); > > > } > > > > > > +static void vtd_iotlb_page_invalidate_notify(IntelIOMMUState *s, > > > + uint16_t domain_id, hwaddr > > > addr, > > > + uint8_t am) > > > +{ > > > + IntelIOMMUNotifierNode *node; > > > + > > > + QLIST_FOREACH(node, &(s->notifiers_list), next) { > > Aviv, > > > > Regards to the s->notifiers_list, I didn't see the init op to it. Does it > > happen > > in another patch? If so, it may be better to move it in this patch since > > this > > patch introduces both the definition and usage of notifiers_list. > > > > If it is already clarified, then ignore it. > > I think it was missing. It IMHO accidentally worked since QLIST_INIT() > just set the head to NULL and that's what we did when we create the > IntelIOMMUState object. > > And what's worse - I found this approach may not work if we do > QLIST_INSERT() in the changed() hook, since if we have more than one > assigned devices we will only register the first one not the rest. A > better approach may be traversing the vt-d buses via > IntelIOMMUState.vtd_as_by_busptr. > Peter,
In Oct, I also mailed Aviv about using IntelIOMMUState.vtd_as_by_busptr when trying to connect the vfio notifiers(map/unmap) and vIOMMU. However, I reconsidered it later. If I remember correctly, IntelIOMMUState.vtd_as_by_busptr not only includes vtd_as for assigned devices, but also includes virtual devices. When iotlb invalidation comes to vIOMMU, there is no indication for which device in iotlb_inv_desc. So still need to have a list to record vtd_as which needs to be looped. So I keep silent on it after that thought. Now, you mentioned it may not work in multi-assigned scenario. Maybe it's time to reconsider it again. Regards, Yi L