Commit dd4d607e authored by Peter Xu's avatar Peter Xu Committed by Eduardo Habkost
Browse files

intel_iommu: enable remote IOTLB 

This patch is based on Aviv Ben-David (<bd.aviv@gmail.com>)'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: default avatarAviv Ben-David <bdaviv@cs.technion.ac.il>
Reviewed-by: default avatarJason Wang <jasowang@redhat.com>
Reviewed-by: default avatarDavid Gibson <david@gibson.dropbear.id.au>
Reviewed-by: default avatar\"Michael S. Tsirkin\" <mst@redhat.com>
Signed-off-by: default avatarPeter Xu <peterx@redhat.com>
Message-Id: <1491562755-23867-10-git-send-email-peterx@redhat.com>
Signed-off-by: default avatarEduardo Habkost <ehabkost@redhat.com>
parent 558e0024

hw/i386/intel_iommu.c

+178 −13
Original line number Diff line number Diff line
@@ -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;



    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.

     * 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) {

        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);

hw/i386/intel_iommu_internal.h

+1 −0
Original line number Diff line number Diff line
@@ -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)

hw/i386/trace-events

+1 −0
Original line number Diff line number Diff line
@@ -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

include/hw/i386/intel_iommu.h

+8 −0
Original line number Diff line number Diff line
@@ -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 */