RE: [PATCH 2/5] iommu/virtio: Support bypass domains

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



> From: Jean-Philippe Brucker <jean-philippe@xxxxxxxxxx>
> Sent: Wednesday, October 13, 2021 8:11 PM
> 
> The VIRTIO_IOMMU_F_BYPASS_CONFIG feature adds a new flag to the
> ATTACH
> request, that creates a bypass domain. Use it to enable identity
> domains.
> 
> When VIRTIO_IOMMU_F_BYPASS_CONFIG is not supported by the device,
> we
> currently fail attaching to an identity domain. Future patches will
> instead create identity mappings in this case.
> 
> Signed-off-by: Jean-Philippe Brucker <jean-philippe@xxxxxxxxxx>
> ---
>  drivers/iommu/virtio-iommu.c | 20 +++++++++++++++++++-
>  1 file changed, 19 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/iommu/virtio-iommu.c b/drivers/iommu/virtio-iommu.c
> index 80930ce04a16..ee8a7afd667b 100644
> --- a/drivers/iommu/virtio-iommu.c
> +++ b/drivers/iommu/virtio-iommu.c
> @@ -71,6 +71,7 @@ struct viommu_domain {
>  	struct rb_root_cached		mappings;
> 
>  	unsigned long			nr_endpoints;
> +	bool				bypass;
>  };
> 
>  struct viommu_endpoint {
> @@ -587,7 +588,9 @@ static struct iommu_domain
> *viommu_domain_alloc(unsigned type)
>  {
>  	struct viommu_domain *vdomain;
> 
> -	if (type != IOMMU_DOMAIN_UNMANAGED && type !=
> IOMMU_DOMAIN_DMA)
> +	if (type != IOMMU_DOMAIN_UNMANAGED &&
> +	    type != IOMMU_DOMAIN_DMA &&
> +	    type != IOMMU_DOMAIN_IDENTITY)
>  		return NULL;
> 
>  	vdomain = kzalloc(sizeof(*vdomain), GFP_KERNEL);
> @@ -630,6 +633,17 @@ static int viommu_domain_finalise(struct
> viommu_endpoint *vdev,
>  	vdomain->map_flags	= viommu->map_flags;
>  	vdomain->viommu		= viommu;
> 
> +	if (domain->type == IOMMU_DOMAIN_IDENTITY) {
> +		if (!virtio_has_feature(viommu->vdev,
> +					VIRTIO_IOMMU_F_BYPASS_CONFIG))
> {
> +			ida_free(&viommu->domain_ids, vdomain->id);
> +			vdomain->viommu = 0;
> +			return -EOPNOTSUPP;
> +		}
> +
> +		vdomain->bypass = true;
> +	}
> +

move to the start of the function, then no need for above cleanup.

>  	return 0;
>  }
> 
> @@ -691,6 +705,9 @@ static int viommu_attach_dev(struct iommu_domain
> *domain, struct device *dev)
>  		.domain		= cpu_to_le32(vdomain->id),
>  	};
> 
> +	if (vdomain->bypass)
> +		req.flags |=
> cpu_to_le32(VIRTIO_IOMMU_ATTACH_F_BYPASS);
> +
>  	for (i = 0; i < fwspec->num_ids; i++) {
>  		req.endpoint = cpu_to_le32(fwspec->ids[i]);
> 
> @@ -1132,6 +1149,7 @@ static unsigned int features[] = {
>  	VIRTIO_IOMMU_F_DOMAIN_RANGE,
>  	VIRTIO_IOMMU_F_PROBE,
>  	VIRTIO_IOMMU_F_MMIO,
> +	VIRTIO_IOMMU_F_BYPASS_CONFIG,
>  };
> 
>  static struct virtio_device_id id_table[] = {
> --
> 2.33.0

_______________________________________________
Virtualization mailing list
Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx
https://lists.linuxfoundation.org/mailman/listinfo/virtualization



[Index of Archives]     [KVM Development]     [Libvirt Development]     [Libvirt Users]     [CentOS Virtualization]     [Netdev]     [Ethernet Bridging]     [Linux Wireless]     [Kernel Newbies]     [Security]     [Linux for Hams]     [Netfilter]     [Bugtraq]     [Yosemite Forum]     [MIPS Linux]     [ARM Linux]     [Linux RAID]     [Linux Admin]     [Samba]

  Powered by Linux