[PATCH v5 15/15] iommu/vt-d: Support reporting nesting capability info

Liu Yi L
2020-07-12T11:14:49Z

Cc: Kevin Tian <kevin.tian@intel.com>
CC: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Eric Auger <eric.auger@redhat.com>
Cc: Jean-Philippe Brucker <jean-philippe@linaro.org>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Liu Yi L <yi.l.liu@intel.com>
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
---
v2 -> v3:
*) remove cap/ecap_mask in iommu_nesting_info.
---
drivers/iommu/intel/iommu.c | 81 +++++++++++++++++++++++++++++++++++++++++++--
include/linux/intel-iommu.h | 16 +++++++++
2 files changed, 95 insertions(+), 2 deletions(-)

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index a9504cb..9f7ad1a 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -5659,12 +5659,16 @@ static inline bool iommu_pasid_support(void)
static inline bool nested_mode_support(void)
{
struct dmar_drhd_unit *drhd;
- struct intel_iommu *iommu;
+ struct intel_iommu *iommu, *prev = NULL;
bool ret = true;

rcu_read_lock();
for_each_active_iommu(iommu, drhd) {
- if (!sm_supported(iommu) || !ecap_nest(iommu->ecap)) {
+ if (!prev)
+ prev = iommu;
+ if (!sm_supported(iommu) || !ecap_nest(iommu->ecap) ||
+ (VTD_CAP_MASK & (iommu->cap ^ prev->cap)) ||
+ (VTD_ECAP_MASK & (iommu->ecap ^ prev->ecap))) {
ret = false;
break;
}
@@ -6079,6 +6083,78 @@ intel_iommu_domain_set_attr(struct iommu_domain *domain,
return ret;
}

+static int intel_iommu_get_nesting_info(struct iommu_domain *domain,
+ struct iommu_nesting_info *info)
+{
+ struct dmar_domain *dmar_domain = to_dmar_domain(domain);
+ u64 cap = VTD_CAP_MASK, ecap = VTD_ECAP_MASK;
+ struct device_domain_info *domain_info;
+ struct iommu_nesting_info_vtd vtd;
+ unsigned long flags;
+ unsigned int size;
+
+ if (domain->type != IOMMU_DOMAIN_UNMANAGED ||
+ !(dmar_domain->flags & DOMAIN_FLAG_NESTING_MODE))
+ return -ENODEV;
+
+ if (!info)
+ return -EINVAL;
+
+ size = sizeof(struct iommu_nesting_info) +
+ sizeof(struct iommu_nesting_info_vtd);
+ /*
+ * if provided buffer size is smaller than expected, should
+ * return 0 and also the expected buffer size to caller.
+ */
+ if (info->size < size) {
+ info->size = size;
+ return 0;
+ }
+
+ spin_lock_irqsave(&device_domain_lock, flags);
+ /*
+ * arbitrary select the first domain_info as all nesting
+ * related capabilities should be consistent across iommu
+ * units.
+ */
+ domain_info = list_first_entry(&dmar_domain->devices,
+ struct device_domain_info, link);
+ cap &= domain_info->iommu->cap;
+ ecap &= domain_info->iommu->ecap;
+ spin_unlock_irqrestore(&device_domain_lock, flags);
+
+ info->format = IOMMU_PASID_FORMAT_INTEL_VTD;
+ info->features = IOMMU_NESTING_FEAT_SYSWIDE_PASID |
+ IOMMU_NESTING_FEAT_BIND_PGTBL |
+ IOMMU_NESTING_FEAT_CACHE_INVLD;
+ info->addr_width = dmar_domain->gaw;
+ info->pasid_bits = ilog2(intel_pasid_max_id);
+ info->padding = 0;
+ vtd.flags = 0;
+ vtd.padding = 0;
+ vtd.cap_reg = cap;
+ vtd.ecap_reg = ecap;
+
+ memcpy(info->data, &vtd, sizeof(vtd));
+ return 0;
+}
+
+static int intel_iommu_domain_get_attr(struct iommu_domain *domain,
+ enum iommu_attr attr, void *data)
+{
+ switch (attr) {
+ case DOMAIN_ATTR_NESTING:
+ {
+ struct iommu_nesting_info *info =
+ (struct iommu_nesting_info *)data;
+
+ return intel_iommu_get_nesting_info(domain, info);
+ }
+ default:
+ return -ENODEV;
+ }
+}
+
/*
* Check that the device does not live on an external facing PCI port that is
* marked as untrusted. Such devices should not be able to apply quirks and
@@ -6101,6 +6177,7 @@ const struct iommu_ops intel_iommu_ops = {
.domain_alloc = intel_iommu_domain_alloc,
.domain_free = intel_iommu_domain_free,
.domain_set_attr = intel_iommu_domain_set_attr,
+ .domain_get_attr = intel_iommu_domain_get_attr,
.attach_dev = intel_iommu_attach_device,
.detach_dev = intel_iommu_detach_device,
.aux_attach_dev = intel_iommu_aux_attach_device,
diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h
index 18f292e..c4ed0d4 100644
--- a/include/linux/intel-iommu.h
+++ b/include/linux/intel-iommu.h
@@ -197,6 +197,22 @@
#define ecap_max_handle_mask(e) ((e >> 20) & 0xf)
#define ecap_sc_support(e) ((e >> 7) & 0x1) /* Snooping Control */

+/* Nesting Support Capability Alignment */
+#define VTD_CAP_FL1GP BIT_ULL(56)
+#define VTD_CAP_FL5LP BIT_ULL(60)
+#define VTD_ECAP_PRS BIT_ULL(29)
+#define VTD_ECAP_ERS BIT_ULL(30)
+#define VTD_ECAP_SRS BIT_ULL(31)
+#define VTD_ECAP_EAFS BIT_ULL(34)
+#define VTD_ECAP_PASID BIT_ULL(40)
+
+/* Only capabilities marked in below MASKs are reported */
+#define VTD_CAP_MASK (VTD_CAP_FL1GP | VTD_CAP_FL5LP)
+
+#define VTD_ECAP_MASK (VTD_ECAP_PRS | VTD_ECAP_ERS | \
+ VTD_ECAP_SRS | VTD_ECAP_EAFS | \
+ VTD_ECAP_PASID)
+
/* Virtual command interface capability */
#define vccap_pasid(v) (((v) & DMA_VCS_PAS)) /* PASID allocation */

--
2.7.4