> From: Williamson < alex.williamson@xxxxxxxxxx >
> Sent: Friday, July 3, 2020 5:20 AM
>
> On Wed, 24 Jun 2020 01:55:23 -0700
> Liu Yi L <yi.l.liu@xxxxxxxxx> wrote:
>
> > This patch provides an interface allowing the userspace to invalidate
> > IOMMU cache for first-level page table. It is required when the first
> > level IOMMU page table is not managed by the host kernel in the nested
> > translation setup.
> >
> > Cc: Kevin Tian <kevin.tian@xxxxxxxxx>
> > CC: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx>
> > Cc: Alex Williamson <alex.williamson@xxxxxxxxxx>
> > Cc: Eric Auger <eric.auger@xxxxxxxxxx>
> > Cc: Jean-Philippe Brucker <jean-philippe@xxxxxxxxxx>
> > Cc: Joerg Roedel <joro@xxxxxxxxxx>
> > Cc: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
> > Signed-off-by: Liu Yi L <yi.l.liu@xxxxxxxxx>
> > Signed-off-by: Eric Auger <eric.auger@xxxxxxxxxx>
> > Signed-off-by: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx>
> > ---
> > v1 -> v2:
> > *) rename from "vfio/type1: Flush stage-1 IOMMU cache for nesting type"
> > *) rename vfio_cache_inv_fn() to vfio_dev_cache_invalidate_fn()
> > *) vfio_dev_cache_inv_fn() always successful
> > *) remove VFIO_IOMMU_CACHE_INVALIDATE, and reuse
> VFIO_IOMMU_NESTING_OP
> > ---
> > drivers/vfio/vfio_iommu_type1.c | 52
> +++++++++++++++++++++++++++++++++++++++++
> > include/uapi/linux/vfio.h | 3 +++
> > 2 files changed, 55 insertions(+)
> >
> > diff --git a/drivers/vfio/vfio_iommu_type1.c
> > b/drivers/vfio/vfio_iommu_type1.c index 5926533..4c21300 100644
> > --- a/drivers/vfio/vfio_iommu_type1.c
> > +++ b/drivers/vfio/vfio_iommu_type1.c
> > @@ -3080,6 +3080,53 @@ static long vfio_iommu_handle_pgtbl_op(struct
> vfio_iommu *iommu,
> > return ret;
> > }
> >
> > +static int vfio_dev_cache_invalidate_fn(struct device *dev, void
> > +*data) {
> > + struct domain_capsule *dc = (struct domain_capsule *)data;
> > + unsigned long arg = *(unsigned long *) dc->data;
> > +
> > + iommu_cache_invalidate(dc->domain, dev, (void __user *) arg);
> > + return 0;
> > +}
> > +
> > +static long vfio_iommu_invalidate_cache(struct vfio_iommu *iommu,
> > + unsigned long arg)
> > +{
> > + struct domain_capsule dc = { .data = &arg };
> > + struct vfio_group *group;
> > + struct vfio_domain *domain;
> > + int ret = 0;
> > + struct iommu_nesting_info *info;
> > +
> > + mutex_lock(&iommu->lock);
> > + /*
> > + * Cache invalidation is required for any nesting IOMMU,
> > + * so no need to check system-wide PASID support.
> > + */
> > + info = iommu->nesting_info;
> > + if (!info || !(info->features & IOMMU_NESTING_FEAT_CACHE_INVLD)) {
> > + ret = -ENOTSUPP;
> > + goto out_unlock;
> > + }
> > +
> > + group = vfio_find_nesting_group(iommu);
> > + if (!group) {
> > + ret = -EINVAL;
> > + goto out_unlock;
> > + }
> > +
> > + domain = list_first_entry(&iommu->domain_list,
> > + struct vfio_domain, next);
> > + dc.group = group;
> > + dc.domain = domain->domain;
> > + iommu_group_for_each_dev(group->iommu_group, &dc,
> > + vfio_dev_cache_invalidate_fn);
> > +
> > +out_unlock:
> > + mutex_unlock(&iommu->lock);
> > + return ret;
> > +}
> > +
> > static long vfio_iommu_type1_nesting_op(struct vfio_iommu *iommu,
> > unsigned long arg)
> > {
> > @@ -3102,6 +3149,11 @@ static long vfio_iommu_type1_nesting_op(struct
> vfio_iommu *iommu,
> > case VFIO_IOMMU_NESTING_OP_UNBIND_PGTBL:
> > ret = vfio_iommu_handle_pgtbl_op(iommu, false, arg + minsz);
> > break;
> > + case VFIO_IOMMU_NESTING_OP_CACHE_INVLD:
> > + {
> > + ret = vfio_iommu_invalidate_cache(iommu, arg + minsz);
> > + break;
> > + }
>
>
> Why the {} brackets? Thanks,
should be removed. will do it.
Regards,
Yi Liu
> Alex
>
>
> > default:
> > ret = -EINVAL;
> > }
> > diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
> > index 2c9def8..7f8678e 100644
> > --- a/include/uapi/linux/vfio.h
> > +++ b/include/uapi/linux/vfio.h
> > @@ -1213,6 +1213,8 @@ struct vfio_iommu_type1_pasid_request {
> > * +-----------------+-----------------------------------------------+
> > * | UNBIND_PGTBL | struct iommu_gpasid_bind_data |
> > *
> > +-----------------+-----------------------------------------------+
> > + * | CACHE_INVLD | struct iommu_cache_invalidate_info |
> > + *
> > + +-----------------+-----------------------------------------------+
> > *
> > * returns: 0 on success, -errno on failure.
> > */
> > @@ -1225,6 +1227,7 @@ struct vfio_iommu_type1_nesting_op {
> >
> > #define VFIO_IOMMU_NESTING_OP_BIND_PGTBL (0)
> > #define VFIO_IOMMU_NESTING_OP_UNBIND_PGTBL (1)
> > +#define VFIO_IOMMU_NESTING_OP_CACHE_INVLD (2)
> >
> > #define VFIO_IOMMU_NESTING_OP _IO(VFIO_TYPE,
> VFIO_BASE + 19)
> >
