Re: [Qemu-devel] [PATCH RFC v4 18/20] intel_iommu: enable vfio devices

[Jason Wang <jasowang@redhat.com>]

On 2017年01月20日 21:08, Peter Xu wrote:
> 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.
>
> Signed-off-by: Peter Xu<peterx@redhat.com>
> ---
>   hw/i386/intel_iommu.c         | 66 +++++++++++++++++++++++++++++++++++++------
>   include/hw/i386/intel_iommu.h |  8 ++++++
>   2 files changed, 65 insertions(+), 9 deletions(-)

A good side effect of this patch is that it makes vhost device IOTLB 
works without ATS (though may be slow). We probably need a better title :)

And I think we should block notifiers during PSI/DSI/GLOBAL for device 
with ATS enabled.

Thanks