On Fri, May 12, 2017 at 03:58:43PM -0600, Alex Williamson wrote:
> On Wed, 26 Apr 2017 18:12:04 +0800
> "Liu, Yi L" <yi.l.liu@xxxxxxxxx> wrote:
>
> > From: "Liu, Yi L" <yi.l.liu@xxxxxxxxxxxxxxx>
> >
> > This patch adds VFIO_IOMMU_TLB_INVALIDATE to propagate IOMMU TLB
> > invalidate request from guest to host.
> >
> > In the case of SVM virtualization on VT-d, host IOMMU driver has
> > no knowledge of caching structure updates unless the guest
> > invalidation activities are passed down to the host. So a new
> > IOCTL is needed to propagate the guest cache invalidation through
> > VFIO.
> >
> > Signed-off-by: Liu, Yi L <yi.l.liu@xxxxxxxxxxxxxxx>
> > ---
> > include/uapi/linux/vfio.h | 9 +++++++++
> > 1 file changed, 9 insertions(+)
> >
> > diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
> > index 6b97987..50c51f8 100644
> > --- a/include/uapi/linux/vfio.h
> > +++ b/include/uapi/linux/vfio.h
> > @@ -564,6 +564,15 @@ struct vfio_device_svm {
> >
> > #define VFIO_IOMMU_SVM_BIND_TASK _IO(VFIO_TYPE, VFIO_BASE + 22)
> >
> > +/* For IOMMU TLB Invalidation Propagation */
> > +struct vfio_iommu_tlb_invalidate {
> > + __u32 argsz;
> > + __u32 length;
> > + __u8 data[];
> > +};
> > +
> > +#define VFIO_IOMMU_TLB_INVALIDATE _IO(VFIO_TYPE, VFIO_BASE + 23)
>
> I'm kind of wondering why this isn't just a new flag bit on
> vfio_device_svm, the data structure is so similar. Of course data
> needs to be fully specified in uapi.
Hi Alex,
For this part, it depends on using opaque structure or not. The following
link mentioned it in [Open] session.
http://www.spinics.net/lists/kvm/msg148798.html
If we pick the full opaque solution for iommu tlb invalidate propagation.
Then I may add a flag bit on vfio_device_svm and also add definition in
uapi as you suggested.
Thanks,
Yi L
> > +
> > /* -------- Additional API for SPAPR TCE (Server POWERPC) IOMMU -------- */
> >
> > /*
>
