Re: [PATCH v4 2/8] iommu/vt-d: Add multiple domains per device query

From: Lu Baolu
Date: Sun Nov 25 2018 - 21:13:50 EST


Hi,

On 11/23/18 6:49 PM, Auger Eric wrote:
Hi,

On 11/5/18 8:34 AM, Lu Baolu wrote:
Add the response to IOMMU_DEV_ATTR_AUXD_CAPABILITY capability query
through iommu_get_dev_attr().

commit title: Advertise auxiliary domain capability?

Yes. I should make it consistent. Thanks.


Cc: Ashok Raj <ashok.raj@xxxxxxxxx>
Cc: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx>
Cc: Kevin Tian <kevin.tian@xxxxxxxxx>
Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
Signed-off-by: Liu Yi L <yi.l.liu@xxxxxxxxx>
---
drivers/iommu/intel-iommu.c | 38 +++++++++++++++++++++++++++++++++++++
1 file changed, 38 insertions(+)

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 5e149d26ea9b..298f7a3fafe8 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -5167,6 +5167,24 @@ static phys_addr_t intel_iommu_iova_to_phys(struct iommu_domain *domain,
return phys;
}
+static inline bool scalable_mode_support(void)
+{
+ struct dmar_drhd_unit *drhd;
+ struct intel_iommu *iommu;
+ bool ret = true;
+
+ rcu_read_lock();
+ for_each_active_iommu(iommu, drhd) {
+ if (!sm_supported(iommu)) {
+ ret = false;
+ break;
+ }
+ }
+ rcu_read_unlock();
+
+ return ret;
+}
+
static bool intel_iommu_capable(enum iommu_cap cap)
{
if (cap == IOMMU_CAP_CACHE_COHERENCY)
@@ -5331,6 +5349,25 @@ struct intel_iommu *intel_svm_device_to_iommu(struct device *dev)
}
#endif /* CONFIG_INTEL_IOMMU_SVM */
+static int intel_iommu_get_dev_attr(struct device *dev,
+ enum iommu_dev_attr attr, void *data)
+{
+ int ret = 0;
+ bool *auxd_capable;
nit: could be local to the case as other cases may use other datatypes.

I have thought about this. Making it local to the case needs extra "{}".
That's the reason I put it here. We can change it later when we need
other datatypes.

+
+ switch (attr) {
+ case IOMMU_DEV_ATTR_AUXD_CAPABILITY:
+ auxd_capable = data;
+ *auxd_capable = scalable_mode_support();
+ break;
+ default:
+ ret = -EINVAL;
+ break;
+ }
+
+ return ret;
+}
+
const struct iommu_ops intel_iommu_ops = {
.capable = intel_iommu_capable,
.domain_alloc = intel_iommu_domain_alloc,
@@ -5345,6 +5382,7 @@ const struct iommu_ops intel_iommu_ops = {
.get_resv_regions = intel_iommu_get_resv_regions,
.put_resv_regions = intel_iommu_put_resv_regions,
.device_group = pci_device_group,
+ .get_dev_attr = intel_iommu_get_dev_attr,
.pgsize_bitmap = INTEL_IOMMU_PGSIZES,
};

Thanks

Eric



Best regards,
Lu Baolu