[PATCH v5 2/9] iommu/vt-d: Add set domain DOMAIN_ATTR_NESTING attr

Lu Baolu
2019-12-24T07:46:19Z

This adds the Intel VT-d specific callback of setting
DOMAIN_ATTR_NESTING domain attribution. It is necessary
to let the VT-d driver know that the domain represents
a virtual machine which requires the IOMMU hardware to
support nested translation mode. Return success if the
IOMMU hardware suports nested mode, otherwise failure.

Signed-off-by: Yi Sun <yi.y.sun@linux.intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
drivers/iommu/intel-iommu.c | 56 +++++++++++++++++++++++++++++++++++++
1 file changed, 56 insertions(+)

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 71ad5e5feae2..35f65628202c 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -315,6 +315,12 @@ static int hw_pass_through = 1;
*/
#define DOMAIN_FLAG_USE_FIRST_LEVEL BIT(2)

+/*
+ * Domain represents a virtual machine which demands iommu nested
+ * translation mode support.
+ */
+#define DOMAIN_FLAG_NESTING_MODE BIT(3)
+
#define for_each_domain_iommu(idx, domain) \
for (idx = 0; idx < g_num_of_iommus; idx++) \
if (domain->iommu_refcnt[idx])
@@ -5640,6 +5646,24 @@ static inline bool iommu_pasid_support(void)
return ret;
}

+static inline bool nested_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) || !ecap_nest(iommu->ecap)) {
+ ret = false;
+ break;
+ }
+ }
+ rcu_read_unlock();
+
+ return ret;
+}
+
static bool intel_iommu_capable(enum iommu_cap cap)
{
if (cap == IOMMU_CAP_CACHE_COHERENCY)
@@ -6018,10 +6042,42 @@ static bool intel_iommu_is_attach_deferred(struct iommu_domain *domain,
return dev->archdata.iommu == DEFER_DEVICE_DOMAIN_INFO;
}

+static int
+intel_iommu_domain_set_attr(struct iommu_domain *domain,
+ enum iommu_attr attr, void *data)
+{
+ struct dmar_domain *dmar_domain = to_dmar_domain(domain);
+ unsigned long flags;
+ int ret = 0;
+
+ if (domain->type != IOMMU_DOMAIN_UNMANAGED)
+ return -EINVAL;
+
+ switch (attr) {
+ case DOMAIN_ATTR_NESTING:
+ spin_lock_irqsave(&device_domain_lock, flags);
+ if (nested_mode_support() &&
+ list_empty(&dmar_domain->devices)) {
+ dmar_domain->flags |= DOMAIN_FLAG_NESTING_MODE;
+ dmar_domain->flags &= ~DOMAIN_FLAG_USE_FIRST_LEVEL;
+ } else {
+ ret = -ENODEV;
+ }
+ spin_unlock_irqrestore(&device_domain_lock, flags);
+ break;
+ default:
+ ret = -EINVAL;
+ break;
+ }
+
+ return ret;
+}
+
const struct iommu_ops intel_iommu_ops = {
.capable = intel_iommu_capable,
.domain_alloc = intel_iommu_domain_alloc,
.domain_free = intel_iommu_domain_free,
+ .domain_set_attr = intel_iommu_domain_set_attr,
.attach_dev = intel_iommu_attach_device,
.detach_dev = intel_iommu_detach_device,
.aux_attach_dev = intel_iommu_aux_attach_device,