Hi Bharat,
On 3/18/20 11:11 AM, Bharat Bhushan wrote:
> Add optional interface to set page size mask.
> Currently this is set global configuration and not
> per endpoint.
>
> Signed-off-by: Bharat Bhushan <[email protected]>
> ---
> v7->v8:
> - new patch
>
> hw/virtio/virtio-iommu.c | 10 ++++++++++
> 1 file changed, 10 insertions(+)
>
> diff --git a/hw/virtio/virtio-iommu.c b/hw/virtio/virtio-iommu.c
> index 4cee8083bc..c00a55348d 100644
> --- a/hw/virtio/virtio-iommu.c
> +++ b/hw/virtio/virtio-iommu.c
> @@ -650,6 +650,15 @@ static gint int_cmp(gconstpointer a, gconstpointer b,
> gpointer user_data)
> return (ua > ub) - (ua < ub);
> }
>
> +static void virtio_iommu_set_page_size_mask(IOMMUMemoryRegion *mr,
> + uint64_t page_size_mask)
> +{
> + IOMMUDevice *sdev = container_of(mr, IOMMUDevice, iommu_mr);
> + VirtIOIOMMU *s = sdev->viommu;
> +
> + s->config.page_size_mask = page_size_mask;
The problem is page_size_mask is global to the VIRTIO-IOMMU.
- Can't different VFIO containers impose different/inconsistent settings?
- VFIO devices can be hotplugged. So we may start with some default
page_size_mask which is latter overriden by a host imposed one. Assume
you first launch the VM with a virtio NIC. This uses 64K. Then you
hotplug a VFIO device behind a physical IOMMU which only supports 4K
pages. Isn't it a valid scenario?
Thanks
Eric
> +}
> +
> static void virtio_iommu_device_realize(DeviceState *dev, Error **errp)
> {
> VirtIODevice *vdev = VIRTIO_DEVICE(dev);
> @@ -865,6 +874,7 @@ static void
> virtio_iommu_memory_region_class_init(ObjectClass *klass,
> IOMMUMemoryRegionClass *imrc = IOMMU_MEMORY_REGION_CLASS(klass);
>
> imrc->translate = virtio_iommu_translate;
> + imrc->iommu_set_page_size_mask = virtio_iommu_set_page_size_mask;
> }
>
> static const TypeInfo virtio_iommu_info = {
>
