Re: [Qemu-devel] [PATCH v5 15/18] intel_iommu: introduce IEC notifiers

[Jan Kiszka <jan.kiszka@web.de>]

On 2016-04-28 09:05, Peter Xu wrote:
> This patch introduces Intel VT-d IEC (Interrupt Entry Cache)
> invalidation notifier list. When vIOMMU receives IEC invalidate request,
> all the registered units will be notified with specific invalidation
> requests.

This should be designed to be IOMMU-agnostic, i.e. become reusable for
the AMD implementation. I suspect we will have the same need for route
invalidations there as well...

Jan

> 
> Signed-off-by: Peter Xu <peterx@redhat.com>
> ---
>  hw/i386/intel_iommu.c          | 56 ++++++++++++++++++++++++++++++++++++------
>  hw/i386/intel_iommu_internal.h | 24 +++++++++++++++---
>  include/hw/i386/intel_iommu.h  | 22 +++++++++++++++++
>  3 files changed, 91 insertions(+), 11 deletions(-)
> 
> diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
> index a8a57db..7122e5b 100644
> --- a/hw/i386/intel_iommu.c
> +++ b/hw/i386/intel_iommu.c
> @@ -900,6 +900,22 @@ static void vtd_root_table_setup(IntelIOMMUState *s)
>                  (s->root_extended ? "(extended)" : ""));
>  }
>  
> +static void vtd_iec_notify_all(IntelIOMMUState *s, bool global,
> +                               uint32_t index, uint32_t mask)
> +{
> +    VTD_IEC_Notifier *notifier;
> +
> +    VTD_DPRINTF(INV, "notify IEC invalidate: global=%d, index=%u, mask=%u",
> +                global, index, mask);
> +
> +    QLIST_FOREACH(notifier, &s->iec_notifiers, list) {
> +        if (notifier->iec_notify) {
> +            notifier->iec_notify(notifier->private, global,
> +                                 index, mask);
> +        }
> +    }
> +}
> +
>  static void vtd_interrupt_remap_table_setup(IntelIOMMUState *s)
>  {
>      uint64_t value = 0;
> @@ -907,7 +923,8 @@ static void vtd_interrupt_remap_table_setup(IntelIOMMUState *s)
>      s->intr_size = 1UL << ((value & VTD_IRTA_SIZE_MASK) + 1);
>      s->intr_root = value & VTD_IRTA_ADDR_MASK;
>  
> -    /* TODO: invalidate interrupt entry cache */
> +    /* Notify global invalidation */
> +    vtd_iec_notify_all(s, true, 0, 0);
>  
>      VTD_DPRINTF(CSR, "int remap table addr 0x%"PRIx64 " size %"PRIu32,
>                  s->intr_root, s->intr_size);
> @@ -1409,6 +1426,21 @@ static bool vtd_process_iotlb_desc(IntelIOMMUState *s, VTDInvDesc *inv_desc)
>      return true;
>  }
>  
> +static bool vtd_process_inv_iec_desc(IntelIOMMUState *s,
> +                                     VTDInvDesc *inv_desc)
> +{
> +    VTD_DPRINTF(INV, "inv ir glob %d index %d mask %d",
> +                inv_desc->iec.granularity,
> +                inv_desc->iec.index,
> +                inv_desc->iec.index_mask);
> +
> +    vtd_iec_notify_all(s, inv_desc->iec.granularity,
> +                       inv_desc->iec.index,
> +                       inv_desc->iec.index_mask);
> +
> +    return true;
> +}
> +
>  static bool vtd_process_inv_desc(IntelIOMMUState *s)
>  {
>      VTDInvDesc inv_desc;
> @@ -1449,12 +1481,12 @@ static bool vtd_process_inv_desc(IntelIOMMUState *s)
>          break;
>  
>      case VTD_INV_DESC_IEC:
> -        VTD_DPRINTF(INV, "Interrupt Entry Cache Invalidation "
> -                    "not implemented yet");
> -        /*
> -         * Since currently we do not cache interrupt entries, we can
> -         * just mark this descriptor as "good" and move on.
> -         */
> +        VTD_DPRINTF(INV, "Invalidation Interrupt Entry Cache "
> +                    "Descriptor hi 0x%"PRIx64 " lo 0x%"PRIx64,
> +                    inv_desc.hi, inv_desc.lo);
> +        if (!vtd_process_inv_iec_desc(s, &inv_desc)) {
> +            return false;
> +        }
>          break;
>  
>      default:
> @@ -2209,6 +2241,15 @@ static const MemoryRegionOps vtd_mem_ir_ops = {
>      },
>  };
>  
> +void vtd_iec_register_notifier(IntelIOMMUState *s, vtd_iec_notify_fn fn,
> +                               void *data)
> +{
> +    VTD_IEC_Notifier *notifier = g_new0(VTD_IEC_Notifier, 1);
> +    notifier->iec_notify = fn;
> +    notifier->private = data;
> +    QLIST_INSERT_HEAD(&s->iec_notifiers, notifier, list);
> +}
> +
>  VTDAddressSpace *vtd_find_add_as(IntelIOMMUState *s, PCIBus *bus, int devfn)
>  {
>      uintptr_t key = (uintptr_t)bus;
> @@ -2371,6 +2412,7 @@ static void vtd_realize(DeviceState *dev, Error **errp)
>                                       g_free, g_free);
>      s->vtd_as_by_busptr = g_hash_table_new_full(vtd_uint64_hash, vtd_uint64_equal,
>                                                g_free, g_free);
> +    QLIST_INIT(&s->iec_notifiers);
>      vtd_init(s);
>  }
>  
> diff --git a/hw/i386/intel_iommu_internal.h b/hw/i386/intel_iommu_internal.h
> index e1a08cb..10c20fe 100644
> --- a/hw/i386/intel_iommu_internal.h
> +++ b/hw/i386/intel_iommu_internal.h
> @@ -296,12 +296,28 @@ typedef enum VTDFaultReason {
>  
>  #define VTD_CONTEXT_CACHE_GEN_MAX       0xffffffffUL
>  
> +/* Interrupt Entry Cache Invalidation Descriptor: VT-d 6.5.2.7. */
> +struct VTDInvDescIEC {
> +    uint32_t type:4;            /* Should always be 0x4 */
> +    uint32_t granularity:1;     /* If set, it's global IR invalidation */
> +    uint32_t resved_1:22;
> +    uint32_t index_mask:5;      /* 2^N for continuous int invalidation */
> +    uint32_t index:16;          /* Start index to invalidate */
> +    uint32_t reserved_2:16;
> +};
> +typedef struct VTDInvDescIEC VTDInvDescIEC;
> +
>  /* Queued Invalidation Descriptor */
> -struct VTDInvDesc {
> -    uint64_t lo;
> -    uint64_t hi;
> +union VTDInvDesc {
> +    struct {
> +        uint64_t lo;
> +        uint64_t hi;
> +    };
> +    union {
> +        VTDInvDescIEC iec;
> +    };
>  };
> -typedef struct VTDInvDesc VTDInvDesc;
> +typedef union VTDInvDesc VTDInvDesc;
>  
>  /* Masks for struct VTDInvDesc */
>  #define VTD_INV_DESC_TYPE               0xf
> diff --git a/include/hw/i386/intel_iommu.h b/include/hw/i386/intel_iommu.h
> index 5910e6f..4fe92cf 100644
> --- a/include/hw/i386/intel_iommu.h
> +++ b/include/hw/i386/intel_iommu.h
> @@ -203,6 +203,24 @@ struct VTD_MSIMessage {
>  /* When IR is enabled, all MSI/MSI-X data bits should be zero */
>  #define VTD_IR_MSI_DATA          (0)
>  
> +/**
> + * vtd_iec_notify_fn - IEC (Interrupt Entry Cache) notifier hook,
> + *                     triggered when IR invalidation happens.
> + * @private: private data
> + * @global: whether this is a global IEC invalidation
> + * @index: IRTE index to invalidate (start from)
> + * @mask: invalidation mask
> + */
> +typedef void (*vtd_iec_notify_fn)(void *private, bool global,
> +                                  uint32_t index, uint32_t mask);
> +
> +struct VTD_IEC_Notifier {
> +    vtd_iec_notify_fn iec_notify;
> +    void *private;
> +    QLIST_ENTRY(VTD_IEC_Notifier) list;
> +};
> +typedef struct VTD_IEC_Notifier VTD_IEC_Notifier;
> +
>  /* The iommu (DMAR) device state struct */
>  struct IntelIOMMUState {
>      SysBusDevice busdev;
> @@ -243,6 +261,7 @@ struct IntelIOMMUState {
>      bool intr_enabled;              /* Whether guest enabled IR */
>      dma_addr_t intr_root;           /* Interrupt remapping table pointer */
>      uint32_t intr_size;             /* Number of IR table entries */
> +    QLIST_HEAD(, VTD_IEC_Notifier) iec_notifiers; /* IEC notify list */
>  };
>  
>  /* Find the VTD Address space associated with the given bus pointer,
> @@ -252,5 +271,8 @@ VTDAddressSpace *vtd_find_add_as(IntelIOMMUState *s, PCIBus *bus, int devfn);
>  /* Get default IOMMU object */
>  IntelIOMMUState *vtd_iommu_get(void);
>  int vtd_int_remap(void *iommu, MSIMessage *src, MSIMessage *dst);
> +/* Register IEC invalidate notifier */
> +void vtd_iec_register_notifier(IntelIOMMUState *s, vtd_iec_notify_fn fn,
> +                               void *data);
>  
>  #endif
>