From dbaabb25f441264d9029dc53e84a156269ecd275 Mon Sep 17 00:00:00 2001 From: Peter Xu Date: Fri, 19 May 2017 11:19:47 +0800 Subject: intel_iommu: support passthrough (PT) Hardware support for VT-d device passthrough. Although current Linux can live with iommu=pt even without this, but this is faster than when using software passthrough. Signed-off-by: Peter Xu Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin Reviewed-by: Liu, Yi L Reviewed-by: Jason Wang --- hw/i386/intel_iommu.c | 231 ++++++++++++++++++++++++++++++----------- hw/i386/intel_iommu_internal.h | 1 + hw/i386/trace-events | 2 + hw/i386/x86-iommu.c | 1 + include/hw/i386/x86-iommu.h | 1 + 5 files changed, 177 insertions(+), 59 deletions(-) diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c index aac2cc7..15610b9 100644 --- a/hw/i386/intel_iommu.c +++ b/hw/i386/intel_iommu.c @@ -613,6 +613,11 @@ static inline bool vtd_ce_type_check(X86IOMMUState *x86_iommu, return false; } break; + case VTD_CONTEXT_TT_PASS_THROUGH: + if (!x86_iommu->pt_supported) { + return false; + } + break; default: /* Unknwon type */ return false; @@ -660,6 +665,29 @@ static bool vtd_slpte_nonzero_rsvd(uint64_t slpte, uint32_t level) } } +/* Find the VTD address space associated with a given bus number */ +static VTDBus *vtd_find_as_from_bus_num(IntelIOMMUState *s, uint8_t bus_num) +{ + VTDBus *vtd_bus = s->vtd_as_by_bus_num[bus_num]; + if (!vtd_bus) { + /* + * Iterate over the registered buses to find the one which + * currently hold this bus number, and update the bus_num + * lookup table: + */ + GHashTableIter iter; + + g_hash_table_iter_init(&iter, s->vtd_as_by_busptr); + while (g_hash_table_iter_next(&iter, NULL, (void **)&vtd_bus)) { + if (pci_bus_num(vtd_bus->bus) == bus_num) { + s->vtd_as_by_bus_num[bus_num] = vtd_bus; + return vtd_bus; + } + } + } + return vtd_bus; +} + /* Given the @iova, get relevant @slptep. @slpte_level will be the last level * of the translation, can be used for deciding the size of large page. */ @@ -906,6 +934,91 @@ static int vtd_dev_to_context_entry(IntelIOMMUState *s, uint8_t bus_num, return 0; } +/* + * Fetch translation type for specific device. Returns <0 if error + * happens, otherwise return the shifted type to check against + * VTD_CONTEXT_TT_*. + */ +static int vtd_dev_get_trans_type(VTDAddressSpace *as) +{ + IntelIOMMUState *s; + VTDContextEntry ce; + int ret; + + s = as->iommu_state; + + ret = vtd_dev_to_context_entry(s, pci_bus_num(as->bus), + as->devfn, &ce); + if (ret) { + return ret; + } + + return vtd_ce_get_type(&ce); +} + +static bool vtd_dev_pt_enabled(VTDAddressSpace *as) +{ + int ret; + + assert(as); + + ret = vtd_dev_get_trans_type(as); + if (ret < 0) { + /* + * Possibly failed to parse the context entry for some reason + * (e.g., during init, or any guest configuration errors on + * context entries). We should assume PT not enabled for + * safety. + */ + return false; + } + + return ret == VTD_CONTEXT_TT_PASS_THROUGH; +} + +/* Return whether the device is using IOMMU translation. */ +static bool vtd_switch_address_space(VTDAddressSpace *as) +{ + bool use_iommu; + + assert(as); + + use_iommu = as->iommu_state->dmar_enabled & !vtd_dev_pt_enabled(as); + + trace_vtd_switch_address_space(pci_bus_num(as->bus), + VTD_PCI_SLOT(as->devfn), + VTD_PCI_FUNC(as->devfn), + use_iommu); + + /* Turn off first then on the other */ + if (use_iommu) { + memory_region_set_enabled(&as->sys_alias, false); + memory_region_set_enabled(&as->iommu, true); + } else { + memory_region_set_enabled(&as->iommu, false); + memory_region_set_enabled(&as->sys_alias, true); + } + + return use_iommu; +} + +static void vtd_switch_address_space_all(IntelIOMMUState *s) +{ + GHashTableIter iter; + VTDBus *vtd_bus; + int i; + + g_hash_table_iter_init(&iter, s->vtd_as_by_busptr); + while (g_hash_table_iter_next(&iter, NULL, (void **)&vtd_bus)) { + for (i = 0; i < X86_IOMMU_PCI_DEVFN_MAX; i++) { + if (!vtd_bus->dev_as[i]) { + continue; + } + vtd_switch_address_space(vtd_bus->dev_as[i]); + } + } +} + static inline uint16_t vtd_make_source_id(uint8_t bus_num, uint8_t devfn) { return ((bus_num & 0xffUL) << 8) | (devfn & 0xffUL); @@ -943,6 +1056,31 @@ static inline bool vtd_is_interrupt_addr(hwaddr addr) return VTD_INTERRUPT_ADDR_FIRST <= addr && addr <= VTD_INTERRUPT_ADDR_LAST; } +static void vtd_pt_enable_fast_path(IntelIOMMUState *s, uint16_t source_id) +{ + VTDBus *vtd_bus; + VTDAddressSpace *vtd_as; + bool success = false; + + vtd_bus = vtd_find_as_from_bus_num(s, VTD_SID_TO_BUS(source_id)); + if (!vtd_bus) { + goto out; + } + + vtd_as = vtd_bus->dev_as[VTD_SID_TO_DEVFN(source_id)]; + if (!vtd_as) { + goto out; + } + + if (vtd_switch_address_space(vtd_as) == false) { + /* We switched off IOMMU region successfully. */ + success = true; + } + +out: + trace_vtd_pt_enable_fast_path(source_id, success); +} + /* Map dev to context-entry then do a paging-structures walk to do a iommu * translation. * @@ -1014,6 +1152,30 @@ static void vtd_do_iommu_translate(VTDAddressSpace *vtd_as, PCIBus *bus, cc_entry->context_cache_gen = s->context_cache_gen; } + /* + * We don't need to translate for pass-through context entries. + * Also, let's ignore IOTLB caching as well for PT devices. + */ + if (vtd_ce_get_type(&ce) == VTD_CONTEXT_TT_PASS_THROUGH) { + entry->translated_addr = entry->iova; + entry->addr_mask = VTD_PAGE_SIZE - 1; + entry->perm = IOMMU_RW; + trace_vtd_translate_pt(source_id, entry->iova); + + /* + * When this happens, it means firstly caching-mode is not + * enabled, and this is the first passthrough translation for + * the device. Let's enable the fast path for passthrough. + * + * When passthrough is disabled again for the device, we can + * capture it via the context entry invalidation, then the + * IOMMU region can be swapped back. + */ + vtd_pt_enable_fast_path(s, source_id); + + return; + } + ret_fr = vtd_iova_to_slpte(&ce, addr, is_write, &slpte, &level, &reads, &writes); if (ret_fr) { @@ -1083,6 +1245,7 @@ static void vtd_context_global_invalidate(IntelIOMMUState *s) if (s->context_cache_gen == VTD_CONTEXT_CACHE_GEN_MAX) { vtd_reset_context_cache(s); } + vtd_switch_address_space_all(s); /* * From VT-d spec 6.5.2.1, a global context entry invalidation * should be followed by a IOTLB global invalidation, so we should @@ -1093,29 +1256,6 @@ static void vtd_context_global_invalidate(IntelIOMMUState *s) vtd_iommu_replay_all(s); } - -/* Find the VTD address space currently associated with a given bus number, - */ -static VTDBus *vtd_find_as_from_bus_num(IntelIOMMUState *s, uint8_t bus_num) -{ - VTDBus *vtd_bus = s->vtd_as_by_bus_num[bus_num]; - if (!vtd_bus) { - /* Iterate over the registered buses to find the one - * which currently hold this bus number, and update the bus_num lookup table: - */ - GHashTableIter iter; - - g_hash_table_iter_init(&iter, s->vtd_as_by_busptr); - while (g_hash_table_iter_next (&iter, NULL, (void**)&vtd_bus)) { - if (pci_bus_num(vtd_bus->bus) == bus_num) { - s->vtd_as_by_bus_num[bus_num] = vtd_bus; - return vtd_bus; - } - } - } - return vtd_bus; -} - /* Do a context-cache device-selective invalidation. * @func_mask: FM field after shifting */ @@ -1158,6 +1298,11 @@ static void vtd_context_device_invalidate(IntelIOMMUState *s, VTD_PCI_FUNC(devfn_it)); vtd_as->context_cache_entry.context_cache_gen = 0; /* + * Do switch address space when needed, in case if the + * device passthrough bit is switched. + */ + vtd_switch_address_space(vtd_as); + /* * So a device is moving out of (or moving into) a * domain, a replay() suites here to notify all the * IOMMU_NOTIFIER_MAP registers about this change. @@ -1389,42 +1534,6 @@ static void vtd_handle_gcmd_sirtp(IntelIOMMUState *s) vtd_set_clear_mask_long(s, DMAR_GSTS_REG, 0, VTD_GSTS_IRTPS); } -static void vtd_switch_address_space(VTDAddressSpace *as) -{ - assert(as); - - trace_vtd_switch_address_space(pci_bus_num(as->bus), - VTD_PCI_SLOT(as->devfn), - VTD_PCI_FUNC(as->devfn), - as->iommu_state->dmar_enabled); - - /* Turn off first then on the other */ - if (as->iommu_state->dmar_enabled) { - memory_region_set_enabled(&as->sys_alias, false); - memory_region_set_enabled(&as->iommu, true); - } else { - memory_region_set_enabled(&as->iommu, false); - memory_region_set_enabled(&as->sys_alias, true); - } -} - -static void vtd_switch_address_space_all(IntelIOMMUState *s) -{ - GHashTableIter iter; - VTDBus *vtd_bus; - int i; - - g_hash_table_iter_init(&iter, s->vtd_as_by_busptr); - while (g_hash_table_iter_next(&iter, NULL, (void **)&vtd_bus)) { - for (i = 0; i < X86_IOMMU_PCI_DEVFN_MAX; i++) { - if (!vtd_bus->dev_as[i]) { - continue; - } - vtd_switch_address_space(vtd_bus->dev_as[i]); - } - } -} - /* Handle Translation Enable/Disable */ static void vtd_handle_gcmd_te(IntelIOMMUState *s, bool en) { @@ -2872,6 +2981,10 @@ static void vtd_init(IntelIOMMUState *s) s->ecap |= VTD_ECAP_DT; } + if (x86_iommu->pt_supported) { + s->ecap |= VTD_ECAP_PT; + } + 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 29d6707..0e73a65 100644 --- a/hw/i386/intel_iommu_internal.h +++ b/hw/i386/intel_iommu_internal.h @@ -187,6 +187,7 @@ /* Interrupt Remapping support */ #define VTD_ECAP_IR (1ULL << 3) #define VTD_ECAP_EIM (1ULL << 4) +#define VTD_ECAP_PT (1ULL << 6) #define VTD_ECAP_MHMV (15ULL << 20) /* CAP_REG */ diff --git a/hw/i386/trace-events b/hw/i386/trace-events index 04a6980..72556da 100644 --- a/hw/i386/trace-events +++ b/hw/i386/trace-events @@ -38,6 +38,8 @@ vtd_page_walk_skip_perm(uint64_t iova, uint64_t next) "Page walk skip iova 0x%"P vtd_page_walk_skip_reserve(uint64_t iova, uint64_t next) "Page walk skip iova 0x%"PRIx64" - 0x%"PRIx64" due to rsrv set" vtd_switch_address_space(uint8_t bus, uint8_t slot, uint8_t fn, bool on) "Device %02x:%02x.%x switching address space (iommu enabled=%d)" vtd_as_unmap_whole(uint8_t bus, uint8_t slot, uint8_t fn, uint64_t iova, uint64_t size) "Device %02x:%02x.%x start 0x%"PRIx64" size 0x%"PRIx64 +vtd_translate_pt(uint16_t sid, uint64_t addr) "source id 0x%"PRIu16", iova 0x%"PRIx64 +vtd_pt_enable_fast_path(uint16_t sid, bool success) "sid 0x%"PRIu16" %d" # hw/i386/amd_iommu.c amdvi_evntlog_fail(uint64_t addr, uint32_t head) "error: fail to write at addr 0x%"PRIx64" + offset 0x%"PRIx32 diff --git a/hw/i386/x86-iommu.c b/hw/i386/x86-iommu.c index 02b8825..293caf8 100644 --- a/hw/i386/x86-iommu.c +++ b/hw/i386/x86-iommu.c @@ -91,6 +91,7 @@ static void x86_iommu_realize(DeviceState *dev, Error **errp) static Property x86_iommu_properties[] = { DEFINE_PROP_BOOL("intremap", X86IOMMUState, intr_supported, false), DEFINE_PROP_BOOL("device-iotlb", X86IOMMUState, dt_supported, false), + DEFINE_PROP_BOOL("pt", X86IOMMUState, pt_supported, true), DEFINE_PROP_END_OF_LIST(), }; diff --git a/include/hw/i386/x86-iommu.h b/include/hw/i386/x86-iommu.h index 361c07c..ef89c0c 100644 --- a/include/hw/i386/x86-iommu.h +++ b/include/hw/i386/x86-iommu.h @@ -74,6 +74,7 @@ struct X86IOMMUState { SysBusDevice busdev; bool intr_supported; /* Whether vIOMMU supports IR */ bool dt_supported; /* Whether vIOMMU supports DT */ + bool pt_supported; /* Whether vIOMMU supports pass-through */ IommuType type; /* IOMMU type - AMD/Intel */ QLIST_HEAD(, IEC_Notifier) iec_notifiers; /* IEC notify list */ }; -- cgit v1.1