]> git.ipfire.org Git - thirdparty/kernel/linux.git/commitdiff
iommu/arm-smmu-v3: Support IOMMU_DOMAIN_NESTED
authorJason Gunthorpe <jgg@nvidia.com>
Thu, 31 Oct 2024 00:20:53 +0000 (21:20 -0300)
committerJason Gunthorpe <jgg@nvidia.com>
Tue, 12 Nov 2024 18:11:03 +0000 (14:11 -0400)
For SMMUv3 a IOMMU_DOMAIN_NESTED is composed of a S2 iommu_domain acting
as the parent and a user provided STE fragment that defines the CD table
and related data with addresses translated by the S2 iommu_domain.

The kernel only permits userspace to control certain allowed bits of the
STE that are safe for user/guest control.

IOTLB maintenance is a bit subtle here, the S1 implicitly includes the S2
translation, but there is no way of knowing which S1 entries refer to a
range of S2.

For the IOTLB we follow ARM's guidance and issue a CMDQ_OP_TLBI_NH_ALL to
flush all ASIDs from the VMID after flushing the S2 on any change to the
S2.

The IOMMU_DOMAIN_NESTED can only be created from inside a VIOMMU as the
invalidation path relies on the VIOMMU to translate virtual stream ID used
in the invalidation commands for the CD table and ATS.

Link: https://patch.msgid.link/r/9-v4-9e99b76f3518+3a8-smmuv3_nesting_jgg@nvidia.com
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
Reviewed-by: Donald Dutile <ddutile@redhat.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-iommufd.c
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
include/uapi/linux/iommufd.h

index 60dd9e907595712d437bf599180ff52ce283ae70..91247a2a2d2c8f0f28585a7b2a89e3bdc8430863 100644 (file)
@@ -30,7 +30,170 @@ void *arm_smmu_hw_info(struct device *dev, u32 *length, u32 *type)
        return info;
 }
 
+static void arm_smmu_make_nested_cd_table_ste(
+       struct arm_smmu_ste *target, struct arm_smmu_master *master,
+       struct arm_smmu_nested_domain *nested_domain, bool ats_enabled)
+{
+       arm_smmu_make_s2_domain_ste(
+               target, master, nested_domain->vsmmu->s2_parent, ats_enabled);
+
+       target->data[0] = cpu_to_le64(STRTAB_STE_0_V |
+                                     FIELD_PREP(STRTAB_STE_0_CFG,
+                                                STRTAB_STE_0_CFG_NESTED));
+       target->data[0] |= nested_domain->ste[0] &
+                          ~cpu_to_le64(STRTAB_STE_0_CFG);
+       target->data[1] |= nested_domain->ste[1];
+}
+
+/*
+ * Create a physical STE from the virtual STE that userspace provided when it
+ * created the nested domain. Using the vSTE userspace can request:
+ * - Non-valid STE
+ * - Abort STE
+ * - Bypass STE (install the S2, no CD table)
+ * - CD table STE (install the S2 and the userspace CD table)
+ */
+static void arm_smmu_make_nested_domain_ste(
+       struct arm_smmu_ste *target, struct arm_smmu_master *master,
+       struct arm_smmu_nested_domain *nested_domain, bool ats_enabled)
+{
+       unsigned int cfg =
+               FIELD_GET(STRTAB_STE_0_CFG, le64_to_cpu(nested_domain->ste[0]));
+
+       /*
+        * Userspace can request a non-valid STE through the nesting interface.
+        * We relay that into an abort physical STE with the intention that
+        * C_BAD_STE for this SID can be generated to userspace.
+        */
+       if (!(nested_domain->ste[0] & cpu_to_le64(STRTAB_STE_0_V)))
+               cfg = STRTAB_STE_0_CFG_ABORT;
+
+       switch (cfg) {
+       case STRTAB_STE_0_CFG_S1_TRANS:
+               arm_smmu_make_nested_cd_table_ste(target, master, nested_domain,
+                                                 ats_enabled);
+               break;
+       case STRTAB_STE_0_CFG_BYPASS:
+               arm_smmu_make_s2_domain_ste(target, master,
+                                           nested_domain->vsmmu->s2_parent,
+                                           ats_enabled);
+               break;
+       case STRTAB_STE_0_CFG_ABORT:
+       default:
+               arm_smmu_make_abort_ste(target);
+               break;
+       }
+}
+
+static int arm_smmu_attach_dev_nested(struct iommu_domain *domain,
+                                     struct device *dev)
+{
+       struct arm_smmu_nested_domain *nested_domain =
+               to_smmu_nested_domain(domain);
+       struct arm_smmu_master *master = dev_iommu_priv_get(dev);
+       struct arm_smmu_attach_state state = {
+               .master = master,
+               .old_domain = iommu_get_domain_for_dev(dev),
+               .ssid = IOMMU_NO_PASID,
+               /* Currently invalidation of ATC is not supported */
+               .disable_ats = true,
+       };
+       struct arm_smmu_ste ste;
+       int ret;
+
+       if (nested_domain->vsmmu->smmu != master->smmu)
+               return -EINVAL;
+       if (arm_smmu_ssids_in_use(&master->cd_table))
+               return -EBUSY;
+
+       mutex_lock(&arm_smmu_asid_lock);
+       ret = arm_smmu_attach_prepare(&state, domain);
+       if (ret) {
+               mutex_unlock(&arm_smmu_asid_lock);
+               return ret;
+       }
+
+       arm_smmu_make_nested_domain_ste(&ste, master, nested_domain,
+                                       state.ats_enabled);
+       arm_smmu_install_ste_for_dev(master, &ste);
+       arm_smmu_attach_commit(&state);
+       mutex_unlock(&arm_smmu_asid_lock);
+       return 0;
+}
+
+static void arm_smmu_domain_nested_free(struct iommu_domain *domain)
+{
+       kfree(to_smmu_nested_domain(domain));
+}
+
+static const struct iommu_domain_ops arm_smmu_nested_ops = {
+       .attach_dev = arm_smmu_attach_dev_nested,
+       .free = arm_smmu_domain_nested_free,
+};
+
+static int arm_smmu_validate_vste(struct iommu_hwpt_arm_smmuv3 *arg)
+{
+       unsigned int cfg;
+
+       if (!(arg->ste[0] & cpu_to_le64(STRTAB_STE_0_V))) {
+               memset(arg->ste, 0, sizeof(arg->ste));
+               return 0;
+       }
+
+       /* EIO is reserved for invalid STE data. */
+       if ((arg->ste[0] & ~STRTAB_STE_0_NESTING_ALLOWED) ||
+           (arg->ste[1] & ~STRTAB_STE_1_NESTING_ALLOWED))
+               return -EIO;
+
+       cfg = FIELD_GET(STRTAB_STE_0_CFG, le64_to_cpu(arg->ste[0]));
+       if (cfg != STRTAB_STE_0_CFG_ABORT && cfg != STRTAB_STE_0_CFG_BYPASS &&
+           cfg != STRTAB_STE_0_CFG_S1_TRANS)
+               return -EIO;
+       return 0;
+}
+
+static struct iommu_domain *
+arm_vsmmu_alloc_domain_nested(struct iommufd_viommu *viommu, u32 flags,
+                             const struct iommu_user_data *user_data)
+{
+       struct arm_vsmmu *vsmmu = container_of(viommu, struct arm_vsmmu, core);
+       const u32 SUPPORTED_FLAGS = IOMMU_HWPT_FAULT_ID_VALID;
+       struct arm_smmu_nested_domain *nested_domain;
+       struct iommu_hwpt_arm_smmuv3 arg;
+       int ret;
+
+       /*
+        * Faults delivered to the nested domain are faults that originated by
+        * the S1 in the domain. The core code will match all PASIDs when
+        * delivering the fault due to user_pasid_table
+        */
+       if (flags & ~SUPPORTED_FLAGS)
+               return ERR_PTR(-EOPNOTSUPP);
+
+       ret = iommu_copy_struct_from_user(&arg, user_data,
+                                         IOMMU_HWPT_DATA_ARM_SMMUV3, ste);
+       if (ret)
+               return ERR_PTR(ret);
+
+       ret = arm_smmu_validate_vste(&arg);
+       if (ret)
+               return ERR_PTR(ret);
+
+       nested_domain = kzalloc(sizeof(*nested_domain), GFP_KERNEL_ACCOUNT);
+       if (!nested_domain)
+               return ERR_PTR(-ENOMEM);
+
+       nested_domain->domain.type = IOMMU_DOMAIN_NESTED;
+       nested_domain->domain.ops = &arm_smmu_nested_ops;
+       nested_domain->vsmmu = vsmmu;
+       nested_domain->ste[0] = arg.ste[0];
+       nested_domain->ste[1] = arg.ste[1] & ~cpu_to_le64(STRTAB_STE_1_EATS);
+
+       return &nested_domain->domain;
+}
+
 static const struct iommufd_viommu_ops arm_vsmmu_ops = {
+       .alloc_domain_nested = arm_vsmmu_alloc_domain_nested,
 };
 
 struct iommufd_viommu *arm_vsmmu_alloc(struct device *dev,
index c425fb923eb3deb1ad60362de2314c1d1105296c..53f12b9d78ab213745aa923ff883f670a42036e2 100644 (file)
@@ -295,6 +295,7 @@ static int arm_smmu_cmdq_build_cmd(u64 *cmd, struct arm_smmu_cmdq_ent *ent)
        case CMDQ_OP_TLBI_NH_ASID:
                cmd[0] |= FIELD_PREP(CMDQ_TLBI_0_ASID, ent->tlbi.asid);
                fallthrough;
+       case CMDQ_OP_TLBI_NH_ALL:
        case CMDQ_OP_TLBI_S12_VMALL:
                cmd[0] |= FIELD_PREP(CMDQ_TLBI_0_VMID, ent->tlbi.vmid);
                break;
@@ -2230,6 +2231,15 @@ static void arm_smmu_tlb_inv_range_domain(unsigned long iova, size_t size,
        }
        __arm_smmu_tlb_inv_range(&cmd, iova, size, granule, smmu_domain);
 
+       if (smmu_domain->nest_parent) {
+               /*
+                * When the S2 domain changes all the nested S1 ASIDs have to be
+                * flushed too.
+                */
+               cmd.opcode = CMDQ_OP_TLBI_NH_ALL;
+               arm_smmu_cmdq_issue_cmd_with_sync(smmu_domain->smmu, &cmd);
+       }
+
        /*
         * Unfortunately, this can't be leaf-only since we may have
         * zapped an entire table.
@@ -2644,6 +2654,8 @@ to_smmu_domain_devices(struct iommu_domain *domain)
        if ((domain->type & __IOMMU_DOMAIN_PAGING) ||
            domain->type == IOMMU_DOMAIN_SVA)
                return to_smmu_domain(domain);
+       if (domain->type == IOMMU_DOMAIN_NESTED)
+               return to_smmu_nested_domain(domain)->vsmmu->s2_parent;
        return NULL;
 }
 
@@ -2716,7 +2728,8 @@ int arm_smmu_attach_prepare(struct arm_smmu_attach_state *state,
                 * enabled if we have arm_smmu_domain, those always have page
                 * tables.
                 */
-               state->ats_enabled = arm_smmu_ats_supported(master);
+               state->ats_enabled = !state->disable_ats &&
+                                    arm_smmu_ats_supported(master);
        }
 
        if (smmu_domain) {
@@ -3122,6 +3135,7 @@ arm_smmu_domain_alloc_user(struct device *dev, u32 flags,
                        goto err_free;
                }
                smmu_domain->stage = ARM_SMMU_DOMAIN_S2;
+               smmu_domain->nest_parent = true;
        }
 
        smmu_domain->domain.type = IOMMU_DOMAIN_UNMANAGED;
@@ -3518,6 +3532,7 @@ static struct iommu_ops arm_smmu_ops = {
        .page_response          = arm_smmu_page_response,
        .def_domain_type        = arm_smmu_def_domain_type,
        .viommu_alloc           = arm_vsmmu_alloc,
+       .user_pasid_table       = 1,
        .pgsize_bitmap          = -1UL, /* Restricted during device attach */
        .owner                  = THIS_MODULE,
        .default_domain_ops = &(const struct iommu_domain_ops) {
index 3b8013afcec0de88e785cf497ecf7271a80d0ee0..3fabe187ea78158f8ff04886469ae7dfea1c06ed 100644 (file)
@@ -244,6 +244,7 @@ static inline u32 arm_smmu_strtab_l2_idx(u32 sid)
 #define STRTAB_STE_0_CFG_BYPASS                4
 #define STRTAB_STE_0_CFG_S1_TRANS      5
 #define STRTAB_STE_0_CFG_S2_TRANS      6
+#define STRTAB_STE_0_CFG_NESTED                7
 
 #define STRTAB_STE_0_S1FMT             GENMASK_ULL(5, 4)
 #define STRTAB_STE_0_S1FMT_LINEAR      0
@@ -295,6 +296,15 @@ static inline u32 arm_smmu_strtab_l2_idx(u32 sid)
 
 #define STRTAB_STE_3_S2TTB_MASK                GENMASK_ULL(51, 4)
 
+/* These bits can be controlled by userspace for STRTAB_STE_0_CFG_NESTED */
+#define STRTAB_STE_0_NESTING_ALLOWED                                         \
+       cpu_to_le64(STRTAB_STE_0_V | STRTAB_STE_0_CFG | STRTAB_STE_0_S1FMT | \
+                   STRTAB_STE_0_S1CTXPTR_MASK | STRTAB_STE_0_S1CDMAX)
+#define STRTAB_STE_1_NESTING_ALLOWED                            \
+       cpu_to_le64(STRTAB_STE_1_S1DSS | STRTAB_STE_1_S1CIR |   \
+                   STRTAB_STE_1_S1COR | STRTAB_STE_1_S1CSH |   \
+                   STRTAB_STE_1_S1STALLD)
+
 /*
  * Context descriptors.
  *
@@ -514,6 +524,7 @@ struct arm_smmu_cmdq_ent {
                        };
                } cfgi;
 
+               #define CMDQ_OP_TLBI_NH_ALL     0x10
                #define CMDQ_OP_TLBI_NH_ASID    0x11
                #define CMDQ_OP_TLBI_NH_VA      0x12
                #define CMDQ_OP_TLBI_EL2_ALL    0x20
@@ -815,10 +826,18 @@ struct arm_smmu_domain {
        struct list_head                devices;
        spinlock_t                      devices_lock;
        bool                            enforce_cache_coherency : 1;
+       bool                            nest_parent : 1;
 
        struct mmu_notifier             mmu_notifier;
 };
 
+struct arm_smmu_nested_domain {
+       struct iommu_domain domain;
+       struct arm_vsmmu *vsmmu;
+
+       __le64 ste[2];
+};
+
 /* The following are exposed for testing purposes. */
 struct arm_smmu_entry_writer_ops;
 struct arm_smmu_entry_writer {
@@ -863,6 +882,12 @@ static inline struct arm_smmu_domain *to_smmu_domain(struct iommu_domain *dom)
        return container_of(dom, struct arm_smmu_domain, domain);
 }
 
+static inline struct arm_smmu_nested_domain *
+to_smmu_nested_domain(struct iommu_domain *dom)
+{
+       return container_of(dom, struct arm_smmu_nested_domain, domain);
+}
+
 extern struct xarray arm_smmu_asid_xa;
 extern struct mutex arm_smmu_asid_lock;
 
@@ -909,6 +934,7 @@ struct arm_smmu_attach_state {
        struct iommu_domain *old_domain;
        struct arm_smmu_master *master;
        bool cd_needs_ats;
+       bool disable_ats;
        ioasid_t ssid;
        /* Resulting state */
        bool ats_enabled;
index 7cb13a29969d62457281139752a6435727596c65..b6baaa1e55b12664c0c95d5518a094c57e4f955c 100644 (file)
@@ -421,6 +421,26 @@ struct iommu_hwpt_vtd_s1 {
        __u32 __reserved;
 };
 
+/**
+ * struct iommu_hwpt_arm_smmuv3 - ARM SMMUv3 nested STE
+ *                                (IOMMU_HWPT_DATA_ARM_SMMUV3)
+ *
+ * @ste: The first two double words of the user space Stream Table Entry for
+ *       the translation. Must be little-endian.
+ *       Allowed fields: (Refer to "5.2 Stream Table Entry" in SMMUv3 HW Spec)
+ *       - word-0: V, Cfg, S1Fmt, S1ContextPtr, S1CDMax
+ *       - word-1: S1DSS, S1CIR, S1COR, S1CSH, S1STALLD
+ *
+ * -EIO will be returned if @ste is not legal or contains any non-allowed field.
+ * Cfg can be used to select a S1, Bypass or Abort configuration. A Bypass
+ * nested domain will translate the same as the nesting parent. The S1 will
+ * install a Context Descriptor Table pointing at userspace memory translated
+ * by the nesting parent.
+ */
+struct iommu_hwpt_arm_smmuv3 {
+       __aligned_le64 ste[2];
+};
+
 /**
  * enum iommu_hwpt_data_type - IOMMU HWPT Data Type
  * @IOMMU_HWPT_DATA_NONE: no data