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Re: [Qemu-devel] [PATCH v8 9/9] intel_iommu: enable remote IOTLB
From: |
Michael S. Tsirkin |
Subject: |
Re: [Qemu-devel] [PATCH v8 9/9] intel_iommu: enable remote IOTLB |
Date: |
Thu, 6 Apr 2017 14:58:26 +0300 |
On Thu, Apr 06, 2017 at 03:08:44PM +0800, Peter Xu wrote:
> This patch is based on Aviv Ben-David (<address@hidden>)'s patch
> upstream:
>
> "IOMMU: enable intel_iommu map and unmap notifiers"
> https://lists.gnu.org/archive/html/qemu-devel/2016-11/msg01453.html
>
> However I removed/fixed some content, and added my own codes.
>
> Instead of translate() every page for iotlb invalidations (which is
> slower), we walk the pages when needed and notify in a hook function.
>
> This patch enables vfio devices for VT-d emulation.
>
> And, since we already have vhost DMAR support via device-iotlb, a
> natural benefit that this patch brings is that vt-d enabled vhost can
> live even without ATS capability now. Though more tests are needed.
>
> Signed-off-by: Aviv Ben-David <address@hidden>
> Reviewed-by: Jason Wang <address@hidden>
> Reviewed-by: David Gibson <address@hidden>
> Signed-off-by: Peter Xu <address@hidden>
Reviewed-by: Michael S. Tsirkin <address@hidden>
> ---
> hw/i386/intel_iommu.c | 191
> ++++++++++++++++++++++++++++++++++++++---
> hw/i386/intel_iommu_internal.h | 1 +
> hw/i386/trace-events | 1 +
> include/hw/i386/intel_iommu.h | 8 ++
> 4 files changed, 188 insertions(+), 13 deletions(-)
>
> diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
> index f7dec82..02f047c 100644
> --- a/hw/i386/intel_iommu.c
> +++ b/hw/i386/intel_iommu.c
> @@ -806,7 +806,8 @@ next:
> * @private: private data for the hook function
> */
> static int vtd_page_walk(VTDContextEntry *ce, uint64_t start, uint64_t end,
> - vtd_page_walk_hook hook_fn, void *private)
> + vtd_page_walk_hook hook_fn, void *private,
> + bool notify_unmap)
> {
> dma_addr_t addr = vtd_get_slpt_base_from_context(ce);
> uint32_t level = vtd_get_level_from_context_entry(ce);
> @@ -821,7 +822,7 @@ static int vtd_page_walk(VTDContextEntry *ce, uint64_t
> start, uint64_t end,
> }
>
> return vtd_page_walk_level(addr, start, end, hook_fn, private,
> - level, true, true, false);
> + level, true, true, notify_unmap);
> }
>
> /* Map a device to its corresponding domain (context-entry) */
> @@ -1038,6 +1039,15 @@ static void
> vtd_interrupt_remap_table_setup(IntelIOMMUState *s)
> s->intr_root, s->intr_size);
> }
>
> +static void vtd_iommu_replay_all(IntelIOMMUState *s)
> +{
> + IntelIOMMUNotifierNode *node;
> +
> + QLIST_FOREACH(node, &s->notifiers_list, next) {
> + memory_region_iommu_replay_all(&node->vtd_as->iommu);
> + }
> +}
> +
> static void vtd_context_global_invalidate(IntelIOMMUState *s)
> {
> trace_vtd_inv_desc_cc_global();
> @@ -1045,6 +1055,14 @@ static void
> vtd_context_global_invalidate(IntelIOMMUState *s)
> if (s->context_cache_gen == VTD_CONTEXT_CACHE_GEN_MAX) {
> vtd_reset_context_cache(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
> + * be safe even without this. Hoewever, let's replay the region as
> + * well to be safer, and go back here when we need finer tunes for
> + * VT-d emulation codes.
> + */
> + vtd_iommu_replay_all(s);
> }
>
>
> @@ -1111,6 +1129,16 @@ static void
> vtd_context_device_invalidate(IntelIOMMUState *s,
> trace_vtd_inv_desc_cc_device(bus_n, VTD_PCI_SLOT(devfn_it),
> VTD_PCI_FUNC(devfn_it));
> vtd_as->context_cache_entry.context_cache_gen = 0;
> + /*
> + * 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.
> + * This won't bring bad even if we have no such
> + * notifier registered - the IOMMU notification
> + * framework will skip MAP notifications if that
> + * happened.
> + */
> + memory_region_iommu_replay_all(&vtd_as->iommu);
> }
> }
> }
> @@ -1152,12 +1180,53 @@ static void
> vtd_iotlb_global_invalidate(IntelIOMMUState *s)
> {
> trace_vtd_iotlb_reset("global invalidation recved");
> vtd_reset_iotlb(s);
> + vtd_iommu_replay_all(s);
> }
>
> static void vtd_iotlb_domain_invalidate(IntelIOMMUState *s, uint16_t
> domain_id)
> {
> + IntelIOMMUNotifierNode *node;
> + VTDContextEntry ce;
> + VTDAddressSpace *vtd_as;
> +
> g_hash_table_foreach_remove(s->iotlb, vtd_hash_remove_by_domain,
> &domain_id);
> +
> + QLIST_FOREACH(node, &s->notifiers_list, next) {
> + vtd_as = node->vtd_as;
> + if (!vtd_dev_to_context_entry(s, pci_bus_num(vtd_as->bus),
> + vtd_as->devfn, &ce) &&
> + domain_id == VTD_CONTEXT_ENTRY_DID(ce.hi)) {
> + memory_region_iommu_replay_all(&vtd_as->iommu);
> + }
> + }
> +}
> +
> +static int vtd_page_invalidate_notify_hook(IOMMUTLBEntry *entry,
> + void *private)
> +{
> + memory_region_notify_iommu((MemoryRegion *)private, *entry);
> + return 0;
> +}
> +
> +static void vtd_iotlb_page_invalidate_notify(IntelIOMMUState *s,
> + uint16_t domain_id, hwaddr addr,
> + uint8_t am)
> +{
> + IntelIOMMUNotifierNode *node;
> + VTDContextEntry ce;
> + int ret;
> +
> + QLIST_FOREACH(node, &(s->notifiers_list), next) {
> + VTDAddressSpace *vtd_as = node->vtd_as;
> + ret = vtd_dev_to_context_entry(s, pci_bus_num(vtd_as->bus),
> + vtd_as->devfn, &ce);
> + if (!ret && domain_id == VTD_CONTEXT_ENTRY_DID(ce.hi)) {
> + vtd_page_walk(&ce, addr, addr + (1 << am) * VTD_PAGE_SIZE,
> + vtd_page_invalidate_notify_hook,
> + (void *)&vtd_as->iommu, true);
> + }
> + }
> }
>
> static void vtd_iotlb_page_invalidate(IntelIOMMUState *s, uint16_t domain_id,
> @@ -1170,6 +1239,7 @@ static void vtd_iotlb_page_invalidate(IntelIOMMUState
> *s, uint16_t domain_id,
> info.addr = addr;
> info.mask = ~((1 << am) - 1);
> g_hash_table_foreach_remove(s->iotlb, vtd_hash_remove_by_page, &info);
> + vtd_iotlb_page_invalidate_notify(s, domain_id, addr, am);
> }
>
> /* Flush IOTLB
> @@ -2187,15 +2257,33 @@ static void
> vtd_iommu_notify_flag_changed(MemoryRegion *iommu,
> IOMMUNotifierFlag new)
> {
> VTDAddressSpace *vtd_as = container_of(iommu, VTDAddressSpace, iommu);
> + IntelIOMMUState *s = vtd_as->iommu_state;
> + IntelIOMMUNotifierNode *node = NULL;
> + IntelIOMMUNotifierNode *next_node = NULL;
>
> - if (new & IOMMU_NOTIFIER_MAP) {
> - error_report("Device at bus %s addr %02x.%d requires iommu "
> - "notifier which is currently not supported by "
> - "intel-iommu emulation",
> - vtd_as->bus->qbus.name, PCI_SLOT(vtd_as->devfn),
> - PCI_FUNC(vtd_as->devfn));
> + if (!s->caching_mode && new & IOMMU_NOTIFIER_MAP) {
> + error_report("We need to set cache_mode=1 for intel-iommu to enable "
> + "device assignment with IOMMU protection.");
> exit(1);
> }
> +
> + if (old == IOMMU_NOTIFIER_NONE) {
> + node = g_malloc0(sizeof(*node));
> + node->vtd_as = vtd_as;
> + QLIST_INSERT_HEAD(&s->notifiers_list, node, next);
> + return;
> + }
> +
> + /* update notifier node with new flags */
> + QLIST_FOREACH_SAFE(node, &s->notifiers_list, next, next_node) {
> + if (node->vtd_as == vtd_as) {
> + if (new == IOMMU_NOTIFIER_NONE) {
> + QLIST_REMOVE(node, next);
> + g_free(node);
> + }
> + return;
> + }
> + }
> }
>
> static const VMStateDescription vtd_vmstate = {
> @@ -2613,6 +2701,74 @@ VTDAddressSpace *vtd_find_add_as(IntelIOMMUState *s,
> PCIBus *bus, int devfn)
> return vtd_dev_as;
> }
>
> +/* Unmap the whole range in the notifier's scope. */
> +static void vtd_address_space_unmap(VTDAddressSpace *as, IOMMUNotifier *n)
> +{
> + IOMMUTLBEntry entry;
> + hwaddr size;
> + hwaddr start = n->start;
> + hwaddr end = n->end;
> +
> + /*
> + * Note: all the codes in this function has a assumption that IOVA
> + * bits are no more than VTD_MGAW bits (which is restricted by
> + * VT-d spec), otherwise we need to consider overflow of 64 bits.
> + */
> +
> + if (end > VTD_ADDRESS_SIZE) {
> + /*
> + * Don't need to unmap regions that is bigger than the whole
> + * VT-d supported address space size
> + */
> + end = VTD_ADDRESS_SIZE;
> + }
> +
> + assert(start <= end);
> + size = end - start;
> +
> + if (ctpop64(size) != 1) {
> + /*
> + * This size cannot format a correct mask. Let's enlarge it to
> + * suite the minimum available mask.
> + */
> + int n = 64 - clz64(size);
> + if (n > VTD_MGAW) {
> + /* should not happen, but in case it happens, limit it */
> + n = VTD_MGAW;
> + }
> + size = 1ULL << n;
> + }
> +
> + entry.target_as = &address_space_memory;
> + /* Adjust iova for the size */
> + entry.iova = n->start & ~(size - 1);
> + /* This field is meaningless for unmap */
> + entry.translated_addr = 0;
> + entry.perm = IOMMU_NONE;
> + entry.addr_mask = size - 1;
> +
> + trace_vtd_as_unmap_whole(pci_bus_num(as->bus),
> + VTD_PCI_SLOT(as->devfn),
> + VTD_PCI_FUNC(as->devfn),
> + entry.iova, size);
> +
> + memory_region_notify_one(n, &entry);
> +}
> +
> +static void vtd_address_space_unmap_all(IntelIOMMUState *s)
> +{
> + IntelIOMMUNotifierNode *node;
> + VTDAddressSpace *vtd_as;
> + IOMMUNotifier *n;
> +
> + QLIST_FOREACH(node, &s->notifiers_list, next) {
> + vtd_as = node->vtd_as;
> + IOMMU_NOTIFIER_FOREACH(n, &vtd_as->iommu) {
> + vtd_address_space_unmap(vtd_as, n);
> + }
> + }
> +}
> +
> static int vtd_replay_hook(IOMMUTLBEntry *entry, void *private)
> {
> memory_region_notify_one((IOMMUNotifier *)private, entry);
> @@ -2626,16 +2782,19 @@ static void vtd_iommu_replay(MemoryRegion *mr,
> IOMMUNotifier *n)
> uint8_t bus_n = pci_bus_num(vtd_as->bus);
> VTDContextEntry ce;
>
> + /*
> + * The replay can be triggered by either a invalidation or a newly
> + * created entry. No matter what, we release existing mappings
> + * (it means flushing caches for UNMAP-only registers).
> + */
> + vtd_address_space_unmap(vtd_as, n);
> +
> if (vtd_dev_to_context_entry(s, bus_n, vtd_as->devfn, &ce) == 0) {
> - /*
> - * Scanned a valid context entry, walk over the pages and
> - * notify when needed.
> - */
> trace_vtd_replay_ce_valid(bus_n, PCI_SLOT(vtd_as->devfn),
> PCI_FUNC(vtd_as->devfn),
> VTD_CONTEXT_ENTRY_DID(ce.hi),
> ce.hi, ce.lo);
> - vtd_page_walk(&ce, 0, ~0ULL, vtd_replay_hook, (void *)n);
> + vtd_page_walk(&ce, 0, ~0ULL, vtd_replay_hook, (void *)n, false);
> } else {
> trace_vtd_replay_ce_invalid(bus_n, PCI_SLOT(vtd_as->devfn),
> PCI_FUNC(vtd_as->devfn));
> @@ -2754,6 +2913,11 @@ static void vtd_reset(DeviceState *dev)
>
> VTD_DPRINTF(GENERAL, "");
> vtd_init(s);
> +
> + /*
> + * When device reset, throw away all mappings and external caches
> + */
> + vtd_address_space_unmap_all(s);
> }
>
> static AddressSpace *vtd_host_dma_iommu(PCIBus *bus, void *opaque, int devfn)
> @@ -2817,6 +2981,7 @@ static void vtd_realize(DeviceState *dev, Error **errp)
> return;
> }
>
> + QLIST_INIT(&s->notifiers_list);
> memset(s->vtd_as_by_bus_num, 0, sizeof(s->vtd_as_by_bus_num));
> memory_region_init_io(&s->csrmem, OBJECT(s), &vtd_mem_ops, s,
> "intel_iommu", DMAR_REG_SIZE);
> diff --git a/hw/i386/intel_iommu_internal.h b/hw/i386/intel_iommu_internal.h
> index 4104121..29d6707 100644
> --- a/hw/i386/intel_iommu_internal.h
> +++ b/hw/i386/intel_iommu_internal.h
> @@ -197,6 +197,7 @@
> #define VTD_DOMAIN_ID_MASK ((1UL << VTD_DOMAIN_ID_SHIFT) - 1)
> #define VTD_CAP_ND (((VTD_DOMAIN_ID_SHIFT - 4) / 2) & 7ULL)
> #define VTD_MGAW 39 /* Maximum Guest Address Width */
> +#define VTD_ADDRESS_SIZE (1ULL << VTD_MGAW)
> #define VTD_CAP_MGAW (((VTD_MGAW - 1) & 0x3fULL) << 16)
> #define VTD_MAMV 18ULL
> #define VTD_CAP_MAMV (VTD_MAMV << 48)
> diff --git a/hw/i386/trace-events b/hw/i386/trace-events
> index 3c3a167..04a6980 100644
> --- a/hw/i386/trace-events
> +++ b/hw/i386/trace-events
> @@ -37,6 +37,7 @@ vtd_page_walk_skip_read(uint64_t iova, uint64_t next) "Page
> walk skip iova 0x%"P
> vtd_page_walk_skip_perm(uint64_t iova, uint64_t next) "Page walk skip iova
> 0x%"PRIx64" - 0x%"PRIx64" due to perm empty"
> 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
>
> # 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/include/hw/i386/intel_iommu.h b/include/hw/i386/intel_iommu.h
> index 8f212a1..3e51876 100644
> --- a/include/hw/i386/intel_iommu.h
> +++ b/include/hw/i386/intel_iommu.h
> @@ -63,6 +63,7 @@ typedef union VTD_IR_TableEntry VTD_IR_TableEntry;
> typedef union VTD_IR_MSIAddress VTD_IR_MSIAddress;
> typedef struct VTDIrq VTDIrq;
> typedef struct VTD_MSIMessage VTD_MSIMessage;
> +typedef struct IntelIOMMUNotifierNode IntelIOMMUNotifierNode;
>
> /* Context-Entry */
> struct VTDContextEntry {
> @@ -249,6 +250,11 @@ struct VTD_MSIMessage {
> /* When IR is enabled, all MSI/MSI-X data bits should be zero */
> #define VTD_IR_MSI_DATA (0)
>
> +struct IntelIOMMUNotifierNode {
> + VTDAddressSpace *vtd_as;
> + QLIST_ENTRY(IntelIOMMUNotifierNode) next;
> +};
> +
> /* The iommu (DMAR) device state struct */
> struct IntelIOMMUState {
> X86IOMMUState x86_iommu;
> @@ -286,6 +292,8 @@ struct IntelIOMMUState {
> MemoryRegionIOMMUOps iommu_ops;
> GHashTable *vtd_as_by_busptr; /* VTDBus objects indexed by PCIBus*
> reference */
> VTDBus *vtd_as_by_bus_num[VTD_PCI_BUS_MAX]; /* VTDBus objects indexed by
> bus number */
> + /* list of registered notifiers */
> + QLIST_HEAD(, IntelIOMMUNotifierNode) notifiers_list;
>
> /* interrupt remapping */
> bool intr_enabled; /* Whether guest enabled IR */
> --
> 2.7.4
- [Qemu-devel] [PATCH v8 5/9] memory: add MemoryRegionIOMMUOps.replay() callback, (continued)
- [Qemu-devel] [PATCH v8 5/9] memory: add MemoryRegionIOMMUOps.replay() callback, Peter Xu, 2017/04/06
- [Qemu-devel] [PATCH v8 6/9] intel_iommu: use the correct memory region for device IOTLB notification, Peter Xu, 2017/04/06
- [Qemu-devel] [PATCH v8 7/9] intel_iommu: provide its own replay() callback, Peter Xu, 2017/04/06
- [Qemu-devel] [PATCH v8 8/9] intel_iommu: allow dynamic switch of IOMMU region, Peter Xu, 2017/04/06
- [Qemu-devel] [PATCH v8 9/9] intel_iommu: enable remote IOTLB, Peter Xu, 2017/04/06
- Re: [Qemu-devel] [PATCH v8 9/9] intel_iommu: enable remote IOTLB,
Michael S. Tsirkin <=
- Re: [Qemu-devel] [PATCH v8 0/9] VT-d: vfio enablement and misc enhances, Michael S. Tsirkin, 2017/04/06
- Re: [Qemu-devel] [PATCH v8 0/9] VT-d: vfio enablement and misc enhances, Michael S. Tsirkin, 2017/04/06