[PATCH v4 12/12] iommu/arm-smmu-v3: Support IOMMU_HWPT_INVALIDATE using a VIOMMU object

Jason Gunthorpe
2024-10-31T00:21:11Z

From: Nicolin Chen <nicolinc@nvidia.com>

Implement the vIOMMU's cache_invalidate op for user space to invalidate
the IOTLB entries, Device ATS and CD entries that are cached by hardware.

Add struct iommu_viommu_arm_smmuv3_invalidate defining invalidation
entries that are simply in the native format of a 128-bit TLBI
command. Scan those commands against the permitted command list and fix
their VMID/SID fields to match what is stored in the vIOMMU.

Co-developed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Eric Auger <eric.auger@redhat.com>
Co-developed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
---
.../arm/arm-smmu-v3/arm-smmu-v3-iommufd.c | 134 ++++++++++++++++++
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 6 +-
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 5 +
include/uapi/linux/iommufd.h | 24 ++++
4 files changed, 166 insertions(+), 3 deletions(-)

diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-iommufd.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-iommufd.c
index ab515706d48463..2cfa1557817bc1 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-iommufd.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-iommufd.c
@@ -209,8 +209,134 @@ arm_vsmmu_alloc_domain_nested(struct iommufd_viommu *viommu, u32 flags,
return &nested_domain->domain;
}

+static int arm_vsmmu_vsid_to_sid(struct arm_vsmmu *vsmmu, u32 vsid, u32 *sid)
+{
+ struct arm_smmu_master *master;
+ struct device *dev;
+ int ret = 0;
+
+ xa_lock(&vsmmu->core.vdevs);
+ dev = iommufd_viommu_find_dev(&vsmmu->core, (unsigned long)vsid);
+ if (!dev) {
+ ret = -EIO;
+ goto unlock;
+ }
+ master = dev_iommu_priv_get(dev);
+
+ /* At this moment, iommufd only supports PCI device that has one SID */
+ if (sid)
+ *sid = master->streams[0].id;
+unlock:
+ xa_unlock(&vsmmu->core.vdevs);
+ return ret;
+}
+
+/* This is basically iommu_viommu_arm_smmuv3_invalidate in u64 for conversion */
+struct arm_vsmmu_invalidation_cmd {
+ union {
+ u64 cmd[2];
+ struct iommu_viommu_arm_smmuv3_invalidate ucmd;
+ };
+};
+
+/*
+ * Convert, in place, the raw invalidation command into an internal format that
+ * can be passed to arm_smmu_cmdq_issue_cmdlist(). Internally commands are
+ * stored in CPU endian.
+ *
+ * Enforce the VMID or SID on the command.
+ */
+static int arm_vsmmu_convert_user_cmd(struct arm_vsmmu *vsmmu,
+ struct arm_vsmmu_invalidation_cmd *cmd)
+{
+ /* Commands are le64 stored in u64 */
+ cmd->cmd[0] = le64_to_cpu(cmd->ucmd.cmd[0]);
+ cmd->cmd[1] = le64_to_cpu(cmd->ucmd.cmd[1]);
+
+ switch (cmd->cmd[0] & CMDQ_0_OP) {
+ case CMDQ_OP_TLBI_NSNH_ALL:
+ /* Convert to NH_ALL */
+ cmd->cmd[0] = CMDQ_OP_TLBI_NH_ALL |
+ FIELD_PREP(CMDQ_TLBI_0_VMID, vsmmu->vmid);
+ cmd->cmd[1] = 0;
+ break;
+ case CMDQ_OP_TLBI_NH_VA:
+ case CMDQ_OP_TLBI_NH_VAA:
+ case CMDQ_OP_TLBI_NH_ALL:
+ case CMDQ_OP_TLBI_NH_ASID:
+ cmd->cmd[0] &= ~CMDQ_TLBI_0_VMID;
+ cmd->cmd[0] |= FIELD_PREP(CMDQ_TLBI_0_VMID, vsmmu->vmid);
+ break;
+ case CMDQ_OP_ATC_INV:
+ case CMDQ_OP_CFGI_CD:
+ case CMDQ_OP_CFGI_CD_ALL: {
+ u32 sid, vsid = FIELD_GET(CMDQ_CFGI_0_SID, cmd->cmd[0]);
+
+ if (arm_vsmmu_vsid_to_sid(vsmmu, vsid, &sid))
+ return -EIO;
+ cmd->cmd[0] &= ~CMDQ_CFGI_0_SID;
+ cmd->cmd[0] |= FIELD_PREP(CMDQ_CFGI_0_SID, sid);
+ break;
+ }
+ default:
+ return -EIO;
+ }
+ return 0;
+}
+
+static int arm_vsmmu_cache_invalidate(struct iommufd_viommu *viommu,
+ struct iommu_user_data_array *array)
+{
+ struct arm_vsmmu *vsmmu = container_of(viommu, struct arm_vsmmu, core);
+ struct arm_smmu_device *smmu = vsmmu->smmu;
+ struct arm_vsmmu_invalidation_cmd *last;
+ struct arm_vsmmu_invalidation_cmd *cmds;
+ struct arm_vsmmu_invalidation_cmd *cur;
+ struct arm_vsmmu_invalidation_cmd *end;
+ int ret;
+
+ cmds = kcalloc(array->entry_num, sizeof(*cmds), GFP_KERNEL);
+ if (!cmds)
+ return -ENOMEM;
+ cur = cmds;
+ end = cmds + array->entry_num;
+
+ static_assert(sizeof(*cmds) == 2 * sizeof(u64));
+ ret = iommu_copy_struct_from_full_user_array(
+ cmds, sizeof(*cmds), array,
+ IOMMU_VIOMMU_INVALIDATE_DATA_ARM_SMMUV3);
+ if (ret)
+ goto out;
+
+ last = cmds;
+ while (cur != end) {
+ ret = arm_vsmmu_convert_user_cmd(vsmmu, cur);
+ if (ret)
+ goto out;
+
+ /* FIXME work in blocks of CMDQ_BATCH_ENTRIES and copy each block? */
+ cur++;
+ if (cur != end && (cur - last) != CMDQ_BATCH_ENTRIES - 1)
+ continue;
+
+ /* FIXME always uses the main cmdq rather than trying to group by type */
+ ret = arm_smmu_cmdq_issue_cmdlist(smmu, &smmu->cmdq, last->cmd,
+ cur - last, true);
+ if (ret) {
+ cur--;
+ goto out;
+ }
+ last = cur;
+ }
+out:
+ array->entry_num = cur - cmds;
+ kfree(cmds);
+ return ret;
+}
+
static const struct iommufd_viommu_ops arm_vsmmu_ops = {
.alloc_domain_nested = arm_vsmmu_alloc_domain_nested,
+ .cache_invalidate = arm_vsmmu_cache_invalidate,
};

struct iommufd_viommu *arm_vsmmu_alloc(struct device *dev,
@@ -233,6 +359,14 @@ struct iommufd_viommu *arm_vsmmu_alloc(struct device *dev,
if (s2_parent->smmu != master->smmu)
return ERR_PTR(-EINVAL);

+ /*
+ * FORCE_SYNC is not set with FEAT_NESTING. Some study of the exact HW
+ * defect is needed to determine if arm_vsmmu_cache_invalidate() needs
+ * any change to remove this.
+ */
+ if (WARN_ON(smmu->options & ARM_SMMU_OPT_CMDQ_FORCE_SYNC))
+ return ERR_PTR(-EOPNOTSUPP);
+
/*
* Must support some way to prevent the VM from bypassing the cache
* because VFIO currently does not do any cache maintenance. canwbs
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
index b47f80224781ba..2a9f2d1d3ed910 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -766,9 +766,9 @@ static void arm_smmu_cmdq_write_entries(struct arm_smmu_cmdq *cmdq, u64 *cmds,
* insert their own list of commands then all of the commands from one
* CPU will appear before any of the commands from the other CPU.
*/
-static int arm_smmu_cmdq_issue_cmdlist(struct arm_smmu_device *smmu,
- struct arm_smmu_cmdq *cmdq,
- u64 *cmds, int n, bool sync)
+int arm_smmu_cmdq_issue_cmdlist(struct arm_smmu_device *smmu,
+ struct arm_smmu_cmdq *cmdq, u64 *cmds, int n,
+ bool sync)
{
u64 cmd_sync[CMDQ_ENT_DWORDS];
u32 prod;
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
index 01c1d16dc0c81a..af25f092303f10 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
@@ -529,6 +529,7 @@ struct arm_smmu_cmdq_ent {
#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_NH_VAA 0x13
#define CMDQ_OP_TLBI_EL2_ALL 0x20
#define CMDQ_OP_TLBI_EL2_ASID 0x21
#define CMDQ_OP_TLBI_EL2_VA 0x22
@@ -951,6 +952,10 @@ void arm_smmu_attach_commit(struct arm_smmu_attach_state *state);
void arm_smmu_install_ste_for_dev(struct arm_smmu_master *master,
const struct arm_smmu_ste *target);

+int arm_smmu_cmdq_issue_cmdlist(struct arm_smmu_device *smmu,
+ struct arm_smmu_cmdq *cmdq, u64 *cmds, int n,
+ bool sync);
+
#ifdef CONFIG_ARM_SMMU_V3_SVA
bool arm_smmu_sva_supported(struct arm_smmu_device *smmu);
bool arm_smmu_master_sva_supported(struct arm_smmu_master *master);
diff --git a/include/uapi/linux/iommufd.h b/include/uapi/linux/iommufd.h
index 125b51b78ad8f9..2a492e054fb7c9 100644
--- a/include/uapi/linux/iommufd.h
+++ b/include/uapi/linux/iommufd.h
@@ -688,9 +688,11 @@ struct iommu_hwpt_get_dirty_bitmap {
* enum iommu_hwpt_invalidate_data_type - IOMMU HWPT Cache Invalidation
* Data Type
* @IOMMU_HWPT_INVALIDATE_DATA_VTD_S1: Invalidation data for VTD_S1
+ * @IOMMU_VIOMMU_INVALIDATE_DATA_ARM_SMMUV3: Invalidation data for ARM SMMUv3
*/
enum iommu_hwpt_invalidate_data_type {
IOMMU_HWPT_INVALIDATE_DATA_VTD_S1 = 0,
+ IOMMU_VIOMMU_INVALIDATE_DATA_ARM_SMMUV3 = 1,
};

/**
@@ -729,6 +731,28 @@ struct iommu_hwpt_vtd_s1_invalidate {
__u32 __reserved;
};

+/**
+ * struct iommu_viommu_arm_smmuv3_invalidate - ARM SMMUv3 cahce invalidation
+ * (IOMMU_VIOMMU_INVALIDATE_DATA_ARM_SMMUV3)
+ * @cmd: 128-bit cache invalidation command that runs in SMMU CMDQ.
+ * Must be little-endian.
+ *
+ * Supported command list only when passing in a vIOMMU via @hwpt_id:
+ * CMDQ_OP_TLBI_NSNH_ALL
+ * CMDQ_OP_TLBI_NH_VA
+ * CMDQ_OP_TLBI_NH_VAA
+ * CMDQ_OP_TLBI_NH_ALL
+ * CMDQ_OP_TLBI_NH_ASID
+ * CMDQ_OP_ATC_INV
+ * CMDQ_OP_CFGI_CD
+ * CMDQ_OP_CFGI_CD_ALL
+ *
+ * -EIO will be returned if the command is not supported.
+ */
+struct iommu_viommu_arm_smmuv3_invalidate {
+ __aligned_le64 cmd[2];
+};
+
/**
* struct iommu_hwpt_invalidate - ioctl(IOMMU_HWPT_INVALIDATE)
* @size: sizeof(struct iommu_hwpt_invalidate)
--
2.43.0