Re: [PATCH v2 03/12] vfio: Collect container iova range info

["Cédric Le Goater" <clg@redhat.com>]

On 9/13/23 10:01, Eric Auger wrote:
> Collect iova range information if VFIO_IOMMU_TYPE1_INFO_CAP_IOVA_RANGE
> capability is supported.
> 
> This allows to propagate the information though the IOMMU MR
> set_iova_ranges() callback so that virtual IOMMUs
> get aware of those aperture constraints.
> 
> Signed-off-by: Eric Auger <eric.auger@redhat.com>
> ---
>   include/hw/vfio/vfio-common.h |  2 ++
>   hw/vfio/common.c              | 45 +++++++++++++++++++++++++++++++++--
>   2 files changed, 45 insertions(+), 2 deletions(-)
> 
> diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
> index da43d27352..74b9b27270 100644
> --- a/include/hw/vfio/vfio-common.h
> +++ b/include/hw/vfio/vfio-common.h
> @@ -98,6 +98,8 @@ typedef struct VFIOContainer {
>       QLIST_HEAD(, VFIOGroup) group_list;
>       QLIST_HEAD(, VFIORamDiscardListener) vrdl_list;
>       QLIST_ENTRY(VFIOContainer) next;
> +    unsigned nr_iovas;
> +    struct  vfio_iova_range *iova_ranges;
>   } VFIOContainer;
>   
>   typedef struct VFIOGuestIOMMU {
> diff --git a/hw/vfio/common.c b/hw/vfio/common.c
> index 9aac21abb7..26da38de05 100644
> --- a/hw/vfio/common.c
> +++ b/hw/vfio/common.c
> @@ -1157,6 +1157,14 @@ static void vfio_listener_region_add(MemoryListener *listener,
>               goto fail;
>           }
>   
> +        ret = memory_region_iommu_set_iova_ranges(giommu->iommu_mr,
> +                container->nr_iovas, (struct Range *)container->iova_ranges,
> +                &err);
> +        if (ret) {
> +            g_free(giommu);
> +            goto fail;
> +        }
> +
>           ret = memory_region_register_iommu_notifier(section->mr, &giommu->n,
>                                                       &err);
>           if (ret) {
> @@ -1981,6 +1989,29 @@ bool vfio_get_info_dma_avail(struct vfio_iommu_type1_info *info,
>       return true;
>   }
>   
> +static void vfio_get_info_iova_range(struct vfio_iommu_type1_info *info,
> +                                     unsigned int *nr_iovas,
> +                                     struct  vfio_iova_range **iova_ranges)

I guess there is no point in returning an error since we can not
assign default values.

> +{
> +    struct vfio_info_cap_header *hdr;
> +    struct vfio_iommu_type1_info_cap_iova_range *cap;
> +
> +    hdr = vfio_get_iommu_type1_info_cap(info,
> +                                        VFIO_IOMMU_TYPE1_INFO_CAP_IOVA_RANGE);
> +    if (hdr == NULL) {

May be :

     if (!hdr) {


> +        return;
> +    }
> +
> +    cap = (void *)hdr;
> +    *nr_iovas = cap->nr_iovas;
> +

I would add a trace event with the #iovas.

Thanks,

C.


> +    if (*nr_iovas == 0) {
> +        return;
> +    }
> +    *iova_ranges = g_memdup2(cap->iova_ranges,
> +                             *nr_iovas * sizeof(struct  vfio_iova_range));
> +}
> +
>   static int vfio_setup_region_sparse_mmaps(VFIORegion *region,
>                                             struct vfio_region_info *info)
>   {
> @@ -2433,6 +2464,12 @@ static void vfio_get_iommu_info_migration(VFIOContainer *container,
>       }
>   }
>   
> +static void vfio_free_container(VFIOContainer *container)
> +{
> +    g_free(container->iova_ranges);
> +    g_free(container);
> +}
> +
>   static int vfio_connect_container(VFIOGroup *group, AddressSpace *as,
>                                     Error **errp)
>   {
> @@ -2550,6 +2587,10 @@ static int vfio_connect_container(VFIOGroup *group, AddressSpace *as,
>           if (!vfio_get_info_dma_avail(info, &container->dma_max_mappings)) {
>               container->dma_max_mappings = 65535;
>           }
> +
> +        vfio_get_info_iova_range(info, &container->nr_iovas,
> +                                 &container->iova_ranges);
> +
>           vfio_get_iommu_info_migration(container, info);
>           g_free(info);
>   
> @@ -2663,7 +2704,7 @@ enable_discards_exit:
>       vfio_ram_block_discard_disable(container, false);
>   
>   free_container_exit:
> -    g_free(container);
> +    vfio_free_container(container);
>   
>   close_fd_exit:
>       close(fd);
> @@ -2717,7 +2758,7 @@ static void vfio_disconnect_container(VFIOGroup *group)
>   
>           trace_vfio_disconnect_container(container->fd);
>           close(container->fd);
> -        g_free(container);
> +        vfio_free_container(container);
>   
>           vfio_put_address_space(space);
>       }