Modern platforms have more than one IOMMU. Each IOMMU has its own
feature set. Some of these features must be consistent among IOMMUs.
Otherwise, these differences can lead to improper behavior in the system.
On the other hand, for some features, each IOMMU can have different
capacity values. So, different actions are required to deal with the
inconsistencies depending on the IOMMU features.
Currently, some inconsistencies are ignored by the IOMMU driver.
This patchset checks IOMMU capabilities and extended capabilities
centralizedly during boot and take different actions according to
the impacts caused by the mismatches.
For example:
1. Disable Shared Virtual Memory.
2. Use common capacity values (normally the lowest capacity value) for
all IOMMUs.
3. Report feature mismatches.
Detailed information on the IOMMU Capability / Extended Capability can
be found in Intel VT-d Specification.
Link: https://software.intel.com/sites/default/files/managed/c5/15/vt-directed-io-spec.pdf
Kyung Min Park (4):
iommu/vt-d: Disable SVM in the platform when IOMMUs have
inconsistencies
iommu/vt-d: Report out when IOMMU features have inconsistencies
iommu/vt-d: Audit IOMMUs for Interrupt Remapping features
iommu/vt-d: Scale capability to the lowest supported between the
IOMMUs
drivers/iommu/intel/Makefile | 4 +-
drivers/iommu/intel/audit.c | 193 ++++++++++++++++++++++++++++
drivers/iommu/intel/audit.h | 103 +++++++++++++++
drivers/iommu/intel/iommu.c | 12 +-
drivers/iommu/intel/irq_remapping.c | 8 ++
include/linux/intel-iommu.h | 3 +
6 files changed, 320 insertions(+), 3 deletions(-)
create mode 100644 drivers/iommu/intel/audit.c
create mode 100644 drivers/iommu/intel/audit.h
--
2.17.1
IOMMU features as below can have incompatibilities among IOMMUs.
Audit IOMMU Capability/Extended Capability and check if the IOMMUs have
the consistent value for features as below. Report out when features as
below have incompatibility among IOMMUs.
Report out features when below features are mismatched:
- First Level 5 Level Paging Support (FL5LP)
- First Level 1 GByte Page Support (FL1GP)
- Read Draining (DRD)
- Write Draining (DWD)
- Page Selective Invalidation (PSI)
- Caching Mode (CM)
- Protected High/Low-Memory Region (PHMR/PLMR)
- Scalable Mode Page Walk Coherency (SMPWC)
- First Level Translation Support (FLTS)
- Second Level Translation Support (SLTS)
- Second Level Accessed/Dirty Support (SLADS)
- Virtual Command Support (VCS)
- Scalable Mode Translation Support (SMTS)
- Device TLB Invalidation Throttle (DIT)
- Page Drain Support (PDS)
- Nested Translation Support (NEST)
- Snoop Control (SC)
- Pass Through (PT)
- Device TLB Support (DT)
- Queued Invalidation (QI)
- Page walk Coherency (C)
Signed-off-by: Kyung Min Park <[email protected]>
---
drivers/iommu/intel/audit.c | 48 +++++++++++++++++++++++++++++++++++++
drivers/iommu/intel/audit.h | 43 +++++++++++++++++++++++++++++++++
include/linux/intel-iommu.h | 2 ++
3 files changed, 93 insertions(+)
diff --git a/drivers/iommu/intel/audit.c b/drivers/iommu/intel/audit.c
index 2893170f5b6c..f783acabb402 100644
--- a/drivers/iommu/intel/audit.c
+++ b/drivers/iommu/intel/audit.c
@@ -13,6 +13,8 @@
#include "audit.h"
static bool svm_sanity_check = true;
+/* global variables that hold feature consistency and minimum features */
+static u64 intel_iommu_cap_sanity = ~0ULL;
static u64 intel_iommu_ecap_sanity = ~0ULL;
static void set_cap_audit_svm_sanity(bool svm_sanity)
@@ -30,12 +32,58 @@ static inline void check_dmar_capabilities(struct intel_iommu *a,
{
if (MINIMAL_SVM_ECAP & (a->ecap ^ b->ecap))
set_cap_audit_svm_sanity(false);
+
+ CHECK_FEATURE_MISMATCH(a, b, cap, 5lp_support, CAP_FL5LP_MASK);
+ CHECK_FEATURE_MISMATCH(a, b, cap, fl1gp_support, CAP_FL1GP_MASK);
+ CHECK_FEATURE_MISMATCH(a, b, cap, read_drain, CAP_RD_MASK);
+ CHECK_FEATURE_MISMATCH(a, b, cap, write_drain, CAP_WD_MASK);
+ CHECK_FEATURE_MISMATCH(a, b, cap, pgsel_inv, CAP_PSI_MASK);
+ CHECK_FEATURE_MISMATCH(a, b, cap, caching_mode, CAP_CM_MASK);
+ CHECK_FEATURE_MISMATCH(a, b, cap, phmr, CAP_PHMR_MASK);
+ CHECK_FEATURE_MISMATCH(a, b, cap, plmr, CAP_PLMR_MASK);
+ CHECK_FEATURE_MISMATCH(a, b, ecap, smpwc, ECAP_SMPWC_MASK);
+ CHECK_FEATURE_MISMATCH(a, b, ecap, flts, ECAP_FLTS_MASK);
+ CHECK_FEATURE_MISMATCH(a, b, ecap, slts, ECAP_SLTS_MASK);
+ CHECK_FEATURE_MISMATCH(a, b, ecap, slads, ECAP_SLADS_MASK);
+ CHECK_FEATURE_MISMATCH(a, b, ecap, vcs, ECAP_VCS_MASK);
+ CHECK_FEATURE_MISMATCH(a, b, ecap, smts, ECAP_SMTS_MASK);
+ CHECK_FEATURE_MISMATCH(a, b, ecap, pds, ECAP_PDS_MASK);
+ CHECK_FEATURE_MISMATCH(a, b, ecap, dit, ECAP_DIT_MASK);
+ CHECK_FEATURE_MISMATCH(a, b, ecap, nest, ECAP_NEST_MASK);
+ CHECK_FEATURE_MISMATCH(a, b, ecap, sc_support, ECAP_SC_MASK);
+ CHECK_FEATURE_MISMATCH(a, b, ecap, pass_through, ECAP_PT_MASK);
+ CHECK_FEATURE_MISMATCH(a, b, ecap, dev_iotlb_support, ECAP_DT_MASK);
+ CHECK_FEATURE_MISMATCH(a, b, ecap, qis, ECAP_QI_MASK);
+ CHECK_FEATURE_MISMATCH(a, b, ecap, coherent, ECAP_C_MASK);
}
static int audit_iommu_capabilities_hotplug(struct intel_iommu *hot_iommu)
{
bool mismatch = false;
+ CHECK_FEATURE_MISMATCH_HOTPLUG(hot_iommu, cap, 5lp_support, CAP_FL5LP_MASK);
+ CHECK_FEATURE_MISMATCH_HOTPLUG(hot_iommu, cap, fl1gp_support, CAP_FL1GP_MASK);
+ CHECK_FEATURE_MISMATCH_HOTPLUG(hot_iommu, cap, read_drain, CAP_RD_MASK);
+ CHECK_FEATURE_MISMATCH_HOTPLUG(hot_iommu, cap, write_drain, CAP_WD_MASK);
+ CHECK_FEATURE_MISMATCH_HOTPLUG(hot_iommu, cap, pgsel_inv, CAP_PSI_MASK);
+ CHECK_FEATURE_MISMATCH_HOTPLUG(hot_iommu, cap, caching_mode, CAP_CM_MASK);
+ CHECK_FEATURE_MISMATCH_HOTPLUG(hot_iommu, cap, phmr, CAP_PHMR_MASK);
+ CHECK_FEATURE_MISMATCH_HOTPLUG(hot_iommu, cap, plmr, CAP_PLMR_MASK);
+ CHECK_FEATURE_MISMATCH_HOTPLUG(hot_iommu, ecap, smpwc, ECAP_SMPWC_MASK);
+ CHECK_FEATURE_MISMATCH_HOTPLUG(hot_iommu, ecap, flts, ECAP_FLTS_MASK);
+ CHECK_FEATURE_MISMATCH_HOTPLUG(hot_iommu, ecap, slts, ECAP_SLTS_MASK);
+ CHECK_FEATURE_MISMATCH_HOTPLUG(hot_iommu, ecap, slads, ECAP_SLADS_MASK);
+ CHECK_FEATURE_MISMATCH_HOTPLUG(hot_iommu, ecap, vcs, ECAP_VCS_MASK);
+ CHECK_FEATURE_MISMATCH_HOTPLUG(hot_iommu, ecap, smts, ECAP_SMTS_MASK);
+ CHECK_FEATURE_MISMATCH_HOTPLUG(hot_iommu, ecap, pds, ECAP_PDS_MASK);
+ CHECK_FEATURE_MISMATCH_HOTPLUG(hot_iommu, ecap, dit, ECAP_DIT_MASK);
+ CHECK_FEATURE_MISMATCH_HOTPLUG(hot_iommu, ecap, nest, ECAP_NEST_MASK);
+ CHECK_FEATURE_MISMATCH_HOTPLUG(hot_iommu, ecap, sc_support, ECAP_SC_MASK);
+ CHECK_FEATURE_MISMATCH_HOTPLUG(hot_iommu, ecap, pass_through, ECAP_PT_MASK);
+ CHECK_FEATURE_MISMATCH_HOTPLUG(hot_iommu, ecap, dev_iotlb_support, ECAP_DT_MASK);
+ CHECK_FEATURE_MISMATCH_HOTPLUG(hot_iommu, ecap, qis, ECAP_QI_MASK);
+ CHECK_FEATURE_MISMATCH_HOTPLUG(hot_iommu, ecap, coherent, ECAP_C_MASK);
+
if (!IS_ENABLED(CONFIG_INTEL_IOMMU_SVM))
goto out;
diff --git a/drivers/iommu/intel/audit.h b/drivers/iommu/intel/audit.h
index 887900d9517d..e3a370405f82 100644
--- a/drivers/iommu/intel/audit.h
+++ b/drivers/iommu/intel/audit.h
@@ -7,19 +7,62 @@
* Author: Kyung Min Park <[email protected]>
*/
+/*
+ * Capability Register Mask
+ */
+#define CAP_FL5LP_MASK BIT(60)
+#define CAP_FL1GP_MASK BIT(56)
+#define CAP_RD_MASK BIT(55)
+#define CAP_WD_MASK BIT(54)
+#define CAP_PSI_MASK BIT(39)
+#define CAP_CM_MASK BIT(7)
+#define CAP_PHMR_MASK BIT(6)
+#define CAP_PLMR_MASK BIT(5)
+
/*
* Extended Capability Register Mask
*/
+#define ECAP_SMPWC_MASK BIT(48)
#define ECAP_FLTS_MASK BIT(47)
+#define ECAP_SLTS_MASK BIT(46)
+#define ECAP_SLADS_MASK BIT(45)
+#define ECAP_VCS_MASK BIT(44)
+#define ECAP_SMTS_MASK BIT(43)
+#define ECAP_PDS_MASK BIT(42)
+#define ECAP_DIT_MASK BIT(41)
#define ECAP_PASID_MASK BIT(40)
#define ECAP_EAFS_MASK BIT(34)
#define ECAP_SRS_MASK BIT(31)
#define ECAP_ERS_MASK BIT(30)
#define ECAP_PRS_MASK BIT(29)
+#define ECAP_NEST_MASK BIT(26)
+#define ECAP_SC_MASK BIT(7)
+#define ECAP_PT_MASK BIT(6)
+#define ECAP_DT_MASK BIT(2)
+#define ECAP_QI_MASK BIT(1)
+#define ECAP_C_MASK BIT(0)
#define MINIMAL_SVM_ECAP (ECAP_FLTS_MASK | ECAP_PASID_MASK | ECAP_EAFS_MASK | \
ECAP_SRS_MASK | ECAP_ERS_MASK | ECAP_PRS_MASK)
+#define DO_CHECK_FEATURE_MISMATCH(a, b, cap, feature, MASK) \
+do { \
+ if (cap##_##feature(a) != cap##_##feature(b)) { \
+ intel_iommu_##cap##_sanity &= ~(MASK); \
+ pr_info("IOMMU feature %s inconsistent.", #feature); \
+ } \
+} while (0)
+
+#define CHECK_FEATURE_MISMATCH(a, b, cap, feature, MASK) \
+ DO_CHECK_FEATURE_MISMATCH((a)->cap, (b)->cap, cap, feature, MASK)
+
+#define CHECK_FEATURE_MISMATCH_HOTPLUG(b, cap, feature, MASK) \
+do { \
+ if (cap##_##feature(intel_iommu_##cap##_sanity)) \
+ DO_CHECK_FEATURE_MISMATCH(intel_iommu_##cap##_sanity, \
+ (b)->cap, cap, feature, MASK); \
+} while (0)
+
enum cap_audit_type {
CAP_AUDIT_STATIC_DMAR,
CAP_AUDIT_HOTPLUG_DMAR,
diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h
index b1ed2f25f7c0..6744f00a144a 100644
--- a/include/linux/intel-iommu.h
+++ b/include/linux/intel-iommu.h
@@ -171,8 +171,10 @@
#define ecap_smpwc(e) (((e) >> 48) & 0x1)
#define ecap_flts(e) (((e) >> 47) & 0x1)
#define ecap_slts(e) (((e) >> 46) & 0x1)
+#define ecap_slads(e) (((e) >> 45) & 0x1)
#define ecap_vcs(e) (((e) >> 44) & 0x1)
#define ecap_smts(e) (((e) >> 43) & 0x1)
+#define ecap_pds(e) (((e) >> 42) & 0x1)
#define ecap_dit(e) ((e >> 41) & 0x1)
#define ecap_pasid(e) ((e >> 40) & 0x1)
#define ecap_pss(e) ((e >> 35) & 0x1f)
--
2.17.1