Hi Shameer,
On 7/23/19 6:06 PM, Shameer Kolothum wrote:
> Get a copy of iova list on _group_detach and try to update the list.
> On success replace the current one with the copy. Leave the list as
> it is if update fails.
>
> Signed-off-by: Shameer Kolothum <shameerali.kolothum.th...@huawei.com>
Reviewed-by: Eric Auger <eric.au...@redhat.com>
Thanks
Eric
> ---
> v7 --> v8
> -Fixed possible invalid holes in iova list if there are no more
> reserved regions in vfio_iommu_resv_refresh().
> -Handled iommu_get_group_resv_regions() err case in
> vfio_iommu_resv_refresh()
> -Tidy up of iova_copy list fail case.
> ---
> drivers/vfio/vfio_iommu_type1.c | 94 +++++++++++++++++++++++++++++++++
> 1 file changed, 94 insertions(+)
>
> diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
> index a3c9794ccf83..7005a8cfca1b 100644
> --- a/drivers/vfio/vfio_iommu_type1.c
> +++ b/drivers/vfio/vfio_iommu_type1.c
> @@ -1867,12 +1867,93 @@ static void vfio_sanity_check_pfn_list(struct
> vfio_iommu *iommu)
> WARN_ON(iommu->notifier.head);
> }
>
> +/*
> + * Called when a domain is removed in detach. It is possible that
> + * the removed domain decided the iova aperture window. Modify the
> + * iova aperture with the smallest window among existing domains.
> + */
> +static void vfio_iommu_aper_expand(struct vfio_iommu *iommu,
> + struct list_head *iova_copy)
> +{
> + struct vfio_domain *domain;
> + struct iommu_domain_geometry geo;
> + struct vfio_iova *node;
> + dma_addr_t start = 0;
> + dma_addr_t end = (dma_addr_t)~0;
> +
> + if (list_empty(iova_copy))
> + return;
> +
> + list_for_each_entry(domain, &iommu->domain_list, next) {
> + iommu_domain_get_attr(domain->domain, DOMAIN_ATTR_GEOMETRY,
> + &geo);
> + if (geo.aperture_start > start)
> + start = geo.aperture_start;
> + if (geo.aperture_end < end)
> + end = geo.aperture_end;
> + }
> +
> + /* Modify aperture limits. The new aper is either same or bigger */
> + node = list_first_entry(iova_copy, struct vfio_iova, list);
> + node->start = start;
> + node = list_last_entry(iova_copy, struct vfio_iova, list);
> + node->end = end;
> +}
> +
> +/*
> + * Called when a group is detached. The reserved regions for that
> + * group can be part of valid iova now. But since reserved regions
> + * may be duplicated among groups, populate the iova valid regions
> + * list again.
> + */
> +static int vfio_iommu_resv_refresh(struct vfio_iommu *iommu,
> + struct list_head *iova_copy)
> +{
> + struct vfio_domain *d;
> + struct vfio_group *g;
> + struct vfio_iova *node;
> + dma_addr_t start, end;
> + LIST_HEAD(resv_regions);
> + int ret;
> +
> + if (list_empty(iova_copy))
> + return -EINVAL;
> +
> + list_for_each_entry(d, &iommu->domain_list, next) {
> + list_for_each_entry(g, &d->group_list, next) {
> + ret = iommu_get_group_resv_regions(g->iommu_group,
> + &resv_regions);
> + if (ret)
> + goto done;
> + }
> + }
> +
> + node = list_first_entry(iova_copy, struct vfio_iova, list);
> + start = node->start;
> + node = list_last_entry(iova_copy, struct vfio_iova, list);
> + end = node->end;
> +
> + /* purge the iova list and create new one */
> + vfio_iommu_iova_free(iova_copy);
> +
> + ret = vfio_iommu_aper_resize(iova_copy, start, end);
> + if (ret)
> + goto done;
> +
> + /* Exclude current reserved regions from iova ranges */
> + ret = vfio_iommu_resv_exclude(iova_copy, &resv_regions);
> +done:
> + vfio_iommu_resv_free(&resv_regions);
> + return ret;
> +}
> +
> static void vfio_iommu_type1_detach_group(void *iommu_data,
> struct iommu_group *iommu_group)
> {
> struct vfio_iommu *iommu = iommu_data;
> struct vfio_domain *domain;
> struct vfio_group *group;
> + LIST_HEAD(iova_copy);
>
> mutex_lock(&iommu->lock);
>
> @@ -1895,6 +1976,13 @@ static void vfio_iommu_type1_detach_group(void
> *iommu_data,
> }
> }
>
> + /*
> + * Get a copy of iova list. This will be used to update
> + * and to replace the current one later. Please note that
> + * we will leave the original list as it is if update fails.
> + */
> + vfio_iommu_iova_get_copy(iommu, &iova_copy);
> +
> list_for_each_entry(domain, &iommu->domain_list, next) {
> group = find_iommu_group(domain, iommu_group);
> if (!group)
> @@ -1920,10 +2008,16 @@ static void vfio_iommu_type1_detach_group(void
> *iommu_data,
> iommu_domain_free(domain->domain);
> list_del(&domain->next);
> kfree(domain);
> + vfio_iommu_aper_expand(iommu, &iova_copy);
> }
> break;
> }
>
> + if (!vfio_iommu_resv_refresh(iommu, &iova_copy))
> + vfio_iommu_iova_insert_copy(iommu, &iova_copy);
> + else
> + vfio_iommu_iova_free(&iova_copy);
> +
> detach_group_done:
> mutex_unlock(&iommu->lock);
> }
>
