> -----Original Message----- > From: Alex Williamson [mailto:alex.williamson@xxxxxxxxxx] > Sent: Friday, February 16, 2018 9:18 PM > To: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@xxxxxxxxxx> > Cc: eric.auger@xxxxxxxxxx; pmorel@xxxxxxxxxxxxxxxxxx; > kvm@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Linuxarm > <linuxarm@xxxxxxxxxx>; John Garry <john.garry@xxxxxxxxxx>; xuwei (O) > <xuwei5@xxxxxxxxxx> > Subject: Re: [PATCH v3 2/6] vfio/type1: Check reserve region conflict and > update iova list > > On Thu, 15 Feb 2018 09:45:00 +0000 > Shameer Kolothum <shameerali.kolothum.thodi@xxxxxxxxxx> wrote: > > > This retrieves the reserved regions associated with dev group and > > checks for conflicts with any existing dma mappings. Also update > > the iova list excluding the reserved regions. > > > > Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@xxxxxxxxxx> > > --- > > drivers/vfio/vfio_iommu_type1.c | 86 > ++++++++++++++++++++++++++++++++++++++++- > > 1 file changed, 85 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/vfio/vfio_iommu_type1.c > b/drivers/vfio/vfio_iommu_type1.c > > index 4726f55..4db87a9 100644 > > --- a/drivers/vfio/vfio_iommu_type1.c > > +++ b/drivers/vfio/vfio_iommu_type1.c > > @@ -1303,6 +1303,72 @@ static int vfio_iommu_aper_resize(struct > list_head *iova, > > return 0; > > } > > > > +/* > > + * Check reserved region conflicts with existing dma mappings > > + */ > > +static bool vfio_iommu_resv_conflict(struct vfio_iommu *iommu, > > + struct list_head *resv_regions) > > +{ > > + struct iommu_resv_region *region; > > + > > + /* Check for conflict with existing dma mappings */ > > + list_for_each_entry(region, resv_regions, list) { > > + if (vfio_find_dma(iommu, region->start, region->length)) > > + return true; > > + } > > + > > + return false; > > +} > > + > > +/* > > + * Check iova region overlap with reserved regions and > > + * exclude them from the iommu iova range > > + */ > > +static int vfio_iommu_resv_exclude(struct list_head *iova, > > + struct list_head *resv_regions) > > +{ > > + struct iommu_resv_region *resv; > > + struct vfio_iova *n, *next; > > + > > + list_for_each_entry(resv, resv_regions, list) { > > + phys_addr_t start, end; > > + > > + start = resv->start; > > + end = resv->start + resv->length - 1; > > + > > + list_for_each_entry_safe(n, next, iova, list) { > > + int ret = 0; > > + > > + /* No overlap */ > > + if ((start > n->end) || (end < n->start)) > > + continue; > > + /* > > + * Insert a new node if current node overlaps with the > > + * reserve region to exlude that from valid iova range. > > + * Note that, new node is inserted before the current > > + * node and finally the current node is deleted keeping > > + * the list updated and sorted. > > + */ > > + if (start > n->start) > > + ret = vfio_insert_iova(n->start, start - 1, > > + &n->list); > > + if (!ret && end < n->end) > > + ret = vfio_insert_iova(end + 1, n->end, > > + &n->list); > > + if (ret) > > + return ret; > > + > > + list_del(&n->list); > > + kfree(n); > > + } > > + } > > + > > + if (list_empty(iova)) > > + return -EINVAL; > > + > > + return 0; > > +} > > + > > static int vfio_iommu_get_iova_copy(struct vfio_iommu *iommu, > > struct list_head *iova_copy) > > { > > @@ -1346,7 +1412,8 @@ static int vfio_iommu_type1_attach_group(void > *iommu_data, > > bool resv_msi, msi_remap; > > phys_addr_t resv_msi_base; > > struct iommu_domain_geometry geo; > > - struct list_head iova_copy; > > + struct list_head iova_copy, group_resv_regions; > > + struct iommu_resv_region *resv, *resv_next; > > struct vfio_iova *iova, *iova_next; > > > > mutex_lock(&iommu->lock); > > @@ -1426,6 +1493,14 @@ static int vfio_iommu_type1_attach_group(void > *iommu_data, > > goto out_detach; > > } > > > > + INIT_LIST_HEAD(&group_resv_regions); > > LIST_HEAD() Ok. > > + iommu_get_group_resv_regions(iommu_group, &group_resv_regions); > > + > > + if (vfio_iommu_resv_conflict(iommu, &group_resv_regions)) { > > + ret = -EINVAL; > > + goto out_detach; > > + } > > + > > /* Get a copy of the current iova list and work on it */ > > INIT_LIST_HEAD(&iova_copy); > > ret = vfio_iommu_get_iova_copy(iommu, &iova_copy); > > @@ -1437,6 +1512,10 @@ static int vfio_iommu_type1_attach_group(void > *iommu_data, > > if (ret) > > goto out_detach; > > > > + ret = vfio_iommu_resv_exclude(&iova_copy, &group_resv_regions); > > + if (ret) > > + goto out_detach; > > + > > resv_msi = vfio_iommu_has_sw_msi(iommu_group, &resv_msi_base); > > > > INIT_LIST_HEAD(&domain->group_list); > > @@ -1497,6 +1576,9 @@ static int vfio_iommu_type1_attach_group(void > *iommu_data, > > /* Delete the old one and insert new iova list */ > > vfio_iommu_insert_iova_copy(iommu, &iova_copy); > > > > + list_for_each_entry_safe(resv, resv_next, &group_resv_regions, list) > > + kfree(resv); > > list_del() here and below, also this can be done after the mutex unlock. Ok. I thought that as the reserved regions are local to this function, list_del() is not required. Same for the iova_copy in the first patch as well(which I missed to comment there). Thanks, Shameer > > + > > mutex_unlock(&iommu->lock); > > > > return 0; > > @@ -1507,6 +1589,8 @@ static int vfio_iommu_type1_attach_group(void > *iommu_data, > > iommu_domain_free(domain->domain); > > list_for_each_entry_safe(iova, iova_next, &iova_copy, list) > > kfree(iova); > > + list_for_each_entry_safe(resv, resv_next, &group_resv_regions, list) > > + kfree(resv); > > out_free: > > kfree(domain); > > kfree(group);
