Re: [Qemu-devel] [PATCH v8 4/9] memory: introduce memory_region_notify_one()

["Michael S. Tsirkin" <mst@redhat.com>]

On Thu, Apr 06, 2017 at 03:08:39PM +0800, Peter Xu wrote:
> Generalizing the notify logic in memory_region_notify_iommu() into a
> single function. This can be further used in customized replay()
> functions for IOMMUs.
> 
> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
> Signed-off-by: Peter Xu <peterx@redhat.com>

Reviewed-by: Michael S. Tsirkin <mst@redhat.com>

> ---
>  include/exec/memory.h | 15 +++++++++++++++
>  memory.c              | 40 ++++++++++++++++++++++++----------------
>  2 files changed, 39 insertions(+), 16 deletions(-)
> 
> diff --git a/include/exec/memory.h b/include/exec/memory.h
> index fb7dff3..055b3a8 100644
> --- a/include/exec/memory.h
> +++ b/include/exec/memory.h
> @@ -688,6 +688,21 @@ void memory_region_notify_iommu(MemoryRegion *mr,
>                                  IOMMUTLBEntry entry);
>  
>  /**
> + * memory_region_notify_one: notify a change in an IOMMU translation
> + *                           entry to a single notifier
> + *
> + * This works just like memory_region_notify_iommu(), but it only
> + * notifies a specific notifier, not all of them.
> + *
> + * @notifier: the notifier to be notified
> + * @entry: the new entry in the IOMMU translation table.  The entry
> + *         replaces all old entries for the same virtual I/O address range.
> + *         Deleted entries have .@perm == 0.
> + */
> +void memory_region_notify_one(IOMMUNotifier *notifier,
> +                              IOMMUTLBEntry *entry);
> +
> +/**
>   * memory_region_register_iommu_notifier: register a notifier for changes to
>   * IOMMU translation entries.
>   *
> diff --git a/memory.c b/memory.c
> index b4ed67b..ded4bf1 100644
> --- a/memory.c
> +++ b/memory.c
> @@ -1662,32 +1662,40 @@ void memory_region_unregister_iommu_notifier(MemoryRegion *mr,
>      memory_region_update_iommu_notify_flags(mr);
>  }
>  
> -void memory_region_notify_iommu(MemoryRegion *mr,
> -                                IOMMUTLBEntry entry)
> +void memory_region_notify_one(IOMMUNotifier *notifier,
> +                              IOMMUTLBEntry *entry)
>  {
> -    IOMMUNotifier *iommu_notifier;
>      IOMMUNotifierFlag request_flags;
>  
> -    assert(memory_region_is_iommu(mr));
> +    /*
> +     * Skip the notification if the notification does not overlap
> +     * with registered range.
> +     */
> +    if (notifier->start > entry->iova + entry->addr_mask + 1 ||
> +        notifier->end < entry->iova) {
> +        return;
> +    }
>  
> -    if (entry.perm & IOMMU_RW) {
> +    if (entry->perm & IOMMU_RW) {
>          request_flags = IOMMU_NOTIFIER_MAP;
>      } else {
>          request_flags = IOMMU_NOTIFIER_UNMAP;
>      }
>  
> +    if (notifier->notifier_flags & request_flags) {
> +        notifier->notify(notifier, entry);
> +    }
> +}
> +
> +void memory_region_notify_iommu(MemoryRegion *mr,
> +                                IOMMUTLBEntry entry)
> +{
> +    IOMMUNotifier *iommu_notifier;
> +
> +    assert(memory_region_is_iommu(mr));
> +
>      IOMMU_NOTIFIER_FOREACH(iommu_notifier, mr) {
> -        /*
> -         * Skip the notification if the notification does not overlap
> -         * with registered range.
> -         */
> -        if (iommu_notifier->start > entry.iova + entry.addr_mask + 1 ||
> -            iommu_notifier->end < entry.iova) {
> -            continue;
> -        }
> -        if (iommu_notifier->notifier_flags & request_flags) {
> -            iommu_notifier->notify(iommu_notifier, &entry);
> -        }
> +        memory_region_notify_one(iommu_notifier, &entry);
>      }
>  }
>  
> -- 
> 2.7.4