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authorJean-Philippe Brucker <jean-philippe@linaro.org>2021-12-01 20:33:22 +0300
committerJoerg Roedel <jroedel@suse.de>2021-12-06 17:03:05 +0300
commitf0f07a8462dc2a889745b9e436b4d86d66ccc787 (patch)
tree659d89892bc258ef31b5584f11ad6b8962a46296 /drivers/iommu
parent063ebb19d962b45a1b505748d464bd12b5074797 (diff)
downloadlinux-f0f07a8462dc2a889745b9e436b4d86d66ccc787.tar.xz
iommu/virtio: Support bypass domains
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. Reviewed-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org> Reviewed-by: Eric Auger <eric.auger@redhat.com> Link: https://lore.kernel.org/r/20211201173323.1045819-3-jean-philippe@linaro.org Signed-off-by: Joerg Roedel <jroedel@suse.de>
Diffstat (limited to 'drivers/iommu')
-rw-r--r--drivers/iommu/virtio-iommu.c20
1 files changed, 19 insertions, 1 deletions
diff --git a/drivers/iommu/virtio-iommu.c b/drivers/iommu/virtio-iommu.c
index 80930ce04a16..14dfee76fd19 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 = NULL;
+ return -EOPNOTSUPP;
+ }
+
+ vdomain->bypass = true;
+ }
+
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[] = {