Hi Zhenzhong, On 1/15/24 11:13, Zhenzhong Duan wrote: > From: Yi Liu <yi.l....@intel.com> > > Add a framework to check and synchronize host IOMMU cap/ecap with > vIOMMU cap/ecap. > > Currently only stage-2 translation is supported which is backed by > shadow page table on host side. So we don't need exact matching of > each bit of cap/ecap between vIOMMU and host. However, we can still > utilize this framework to ensure compatibility of host and vIOMMU's > address width at least, i.e., vIOMMU's aw_bits <= host aw_bits, > which is missed before. > > When stage-1 translation is supported in future, a.k.a. scalable > modern mode, we need to ensure compatibility of each bits. Some > bits are user controllable, they should be checked with host side > to ensure compatibility. Other bits are not, they should be synced > into vIOMMU cap/ecap for compatibility. > > The sequence will be: > > vtd_cap_init() initializes iommu->cap/ecap. ---- vtd_cap_init() > iommu->host_cap/ecap is initialized as iommu->cap/ecap. ---- vtd_init() > iommu->host_cap/ecap is checked and updated some bits with host cap/ecap. > ---- vtd_sync_hw_info() > iommu->cap/ecap is finalized as iommu->host_cap/ecap. ---- > vtd_machine_done_hook() > > iommu->host_cap/ecap is a temporary storage to hold intermediate value > when synthesize host cap/ecap and vIOMMU's initial configured cap/ecap. > > Signed-off-by: Yi Liu <yi.l....@intel.com> > Signed-off-by: Yi Sun <yi.y....@linux.intel.com> > Signed-off-by: Zhenzhong Duan <zhenzhong.d...@intel.com> > --- > include/hw/i386/intel_iommu.h | 4 ++ > hw/i386/intel_iommu.c | 78 +++++++++++++++++++++++++++++++---- > 2 files changed, 75 insertions(+), 7 deletions(-) > > diff --git a/include/hw/i386/intel_iommu.h b/include/hw/i386/intel_iommu.h > index c65fdde56f..b8abbcce12 100644 > --- a/include/hw/i386/intel_iommu.h > +++ b/include/hw/i386/intel_iommu.h > @@ -292,6 +292,9 @@ struct IntelIOMMUState { > uint64_t cap; /* The value of capability reg */ > uint64_t ecap; /* The value of extended capability reg > */ > > + uint64_t host_cap; /* The value of host capability reg */ > + uint64_t host_ecap; /* The value of host ext-capability reg > */ > + > uint32_t context_cache_gen; /* Should be in [1,MAX] */ > GHashTable *iotlb; /* IOTLB */ > > @@ -314,6 +317,7 @@ struct IntelIOMMUState { > bool dma_translation; /* Whether DMA translation supported */ > bool pasid; /* Whether to support PASID */ > > + bool cap_finalized; /* Whether VTD capability finalized */ > /* > * Protects IOMMU states in general. Currently it protects the > * per-IOMMU IOTLB cache, and context entry cache in VTDAddressSpace. > diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c > index 4c1d058ebd..be03fcbf52 100644 > --- a/hw/i386/intel_iommu.c > +++ b/hw/i386/intel_iommu.c > @@ -3819,6 +3819,47 @@ VTDAddressSpace *vtd_find_add_as(IntelIOMMUState *s, > PCIBus *bus, > return vtd_dev_as; > } > > +static bool vtd_sync_hw_info(IntelIOMMUState *s, struct iommu_hw_info_vtd > *vtd, > + Error **errp) > +{ > + uint64_t addr_width; > + > + addr_width = (vtd->cap_reg >> 16) & 0x3fULL; > + if (s->aw_bits > addr_width) { > + error_setg(errp, "User aw-bits: %u > host address width: %lu", > + s->aw_bits, addr_width); > + return false; > + } > + > + /* TODO: check and sync host cap/ecap into vIOMMU cap/ecap */ > + > + return true; > +} > + > +/* > + * virtual VT-d which wants nested needs to check the host IOMMU > + * nesting cap info behind the assigned devices. Thus that vIOMMU > + * could bind guest page table to host. > + */ > +static bool vtd_check_idev(IntelIOMMUState *s, IOMMUFDDevice *idev, > + Error **errp) > +{ > + struct iommu_hw_info_vtd vtd; > + enum iommu_hw_info_type type = IOMMU_HW_INFO_TYPE_INTEL_VTD; > + > + if (iommufd_device_get_info(idev, &type, sizeof(vtd), &vtd)) { > + error_setg(errp, "Failed to get IOMMU capability!!!"); > + return false; > + } > + > + if (type != IOMMU_HW_INFO_TYPE_INTEL_VTD) { > + error_setg(errp, "IOMMU hardware is not compatible!!!"); > + return false; > + } > + > + return vtd_sync_hw_info(s, &vtd, errp); > +} > + > static int vtd_dev_set_iommu_device(PCIBus *bus, void *opaque, int32_t devfn, > IOMMUFDDevice *idev, Error **errp) > { > @@ -3837,6 +3878,10 @@ static int vtd_dev_set_iommu_device(PCIBus *bus, void > *opaque, int32_t devfn, > return 0; > } > > + if (!vtd_check_idev(s, idev, errp)) {In In [RFC 0/7] VIRTIO-IOMMU/VFIO: Fix host iommu geometry handling for hotplugged devices https://lore.kernel.org/all/20240117080414.316890-1-eric.au...@redhat.com/
I also attempt to pass host iommu info to the virtio-iommu but with legacy BE. In my case I want to pass the reserved memory regions which also model the aw. So this is a pretty similar use case. Why don't we pass the pointer to an opaque iommu_hw_info instead, through the PCIIOMMUOps? > + return -1; > + } > + > vtd_iommu_lock(s); > > vtd_idev = g_hash_table_lookup(s->vtd_iommufd_dev, &key); > @@ -4071,10 +4116,11 @@ static void vtd_init(IntelIOMMUState *s) > { > X86IOMMUState *x86_iommu = X86_IOMMU_DEVICE(s); > > - memset(s->csr, 0, DMAR_REG_SIZE); > - memset(s->wmask, 0, DMAR_REG_SIZE); > - memset(s->w1cmask, 0, DMAR_REG_SIZE); > - memset(s->womask, 0, DMAR_REG_SIZE); > + /* CAP/ECAP are initialized in machine create done stage */ > + memset(s->csr + DMAR_GCMD_REG, 0, DMAR_REG_SIZE - DMAR_GCMD_REG); > + memset(s->wmask + DMAR_GCMD_REG, 0, DMAR_REG_SIZE - DMAR_GCMD_REG); > + memset(s->w1cmask + DMAR_GCMD_REG, 0, DMAR_REG_SIZE - DMAR_GCMD_REG); > + memset(s->womask + DMAR_GCMD_REG, 0, DMAR_REG_SIZE - DMAR_GCMD_REG); This change is not documented in the commit msg. Sorry I don't get why this is needed? > > s->root = 0; > s->root_scalable = false; > @@ -4110,13 +4156,16 @@ static void vtd_init(IntelIOMMUState *s) > vtd_spte_rsvd_large[3] &= ~VTD_SPTE_SNP; > } > > - vtd_cap_init(s); > + if (!s->cap_finalized) { > + vtd_cap_init(s); > + s->host_cap = s->cap; > + s->host_ecap = s->ecap; > + } > + > vtd_reset_caches(s); > > /* Define registers with default values and bit semantics */ > vtd_define_long(s, DMAR_VER_REG, 0x10UL, 0, 0); > - vtd_define_quad(s, DMAR_CAP_REG, s->cap, 0, 0); > - vtd_define_quad(s, DMAR_ECAP_REG, s->ecap, 0, 0); > vtd_define_long(s, DMAR_GCMD_REG, 0, 0xff800000UL, 0); > vtd_define_long_wo(s, DMAR_GCMD_REG, 0xff800000UL); > vtd_define_long(s, DMAR_GSTS_REG, 0, 0, 0); > @@ -4241,6 +4290,12 @@ static bool vtd_decide_config(IntelIOMMUState *s, > Error **errp) > return true; > } > > +static void vtd_setup_capability_reg(IntelIOMMUState *s) > +{ > + vtd_define_quad(s, DMAR_CAP_REG, s->cap, 0, 0); > + vtd_define_quad(s, DMAR_ECAP_REG, s->ecap, 0, 0); > +} > + > static int vtd_machine_done_notify_one(Object *child, void *unused) > { > IntelIOMMUState *iommu = INTEL_IOMMU_DEVICE(x86_iommu_get_default()); > @@ -4259,6 +4314,14 @@ static int vtd_machine_done_notify_one(Object *child, > void *unused) > > static void vtd_machine_done_hook(Notifier *notifier, void *unused) > { > + IntelIOMMUState *iommu = INTEL_IOMMU_DEVICE(x86_iommu_get_default()); > + > + iommu->cap = iommu->host_cap; > + iommu->ecap = iommu->host_ecap; > + iommu->cap_finalized = true; I don't think you can change the defaults like this without taking care of compats (migration). Thanks Eric > + > + vtd_setup_capability_reg(iommu); > + > object_child_foreach_recursive(object_get_root(), > vtd_machine_done_notify_one, NULL); > } > @@ -4292,6 +4355,7 @@ static void vtd_realize(DeviceState *dev, Error **errp) > > QLIST_INIT(&s->vtd_as_with_notifiers); > qemu_mutex_init(&s->iommu_lock); > + s->cap_finalized = false; > memory_region_init_io(&s->csrmem, OBJECT(s), &vtd_mem_ops, s, > "intel_iommu", DMAR_REG_SIZE); > memory_region_add_subregion(get_system_memory(),