[PATCH v3 21/29] iommu/arm-smmu-v3-kvm: Setup stream table
Mostafa Saleh
smostafa at google.com
Mon Jul 28 10:53:08 PDT 2025
Map the stream table allocated by the host into the hypervisor address
space. When the host mappings are finalized, the table is unmapped from
the host. Depending on the host configuration, the stream table may have
one or two levels. Populate the level-2 stream table lazily.
Also, add accessors for STEs.
Signed-off-by: Mostafa Saleh <smostafa at google.com>
Signed-off-by: Jean-Philippe Brucker <jean-philippe at linaro.org>
---
.../arm/arm-smmu-v3/arm-smmu-v3-common.h | 16 +++
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 16 ---
.../iommu/arm/arm-smmu-v3/pkvm/arm-smmu-v3.c | 102 +++++++++++++++++-
.../iommu/arm/arm-smmu-v3/pkvm/arm_smmu_v3.h | 2 +
4 files changed, 119 insertions(+), 17 deletions(-)
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-common.h b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-common.h
index ab6db8b4b9f2..a24fdbdaeb74 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-common.h
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-common.h
@@ -499,6 +499,22 @@ struct arm_smmu_queue {
Q_IDX(&((q)->llq), p) * \
(q)->ent_dwords)
+struct arm_smmu_strtab_cfg {
+ union {
+ struct {
+ struct arm_smmu_ste *table;
+ dma_addr_t ste_dma;
+ unsigned int num_ents;
+ } linear;
+ struct {
+ struct arm_smmu_strtab_l1 *l1tab;
+ struct arm_smmu_strtab_l2 **l2ptrs;
+ dma_addr_t l1_dma;
+ unsigned int num_l1_ents;
+ } l2;
+ };
+};
+
static inline void arm_smmu_write_strtab_l1_desc(struct arm_smmu_strtab_l1 *dst,
dma_addr_t l2ptr_dma)
{
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 f9a496e0bd94..480463ec118a 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
@@ -232,22 +232,6 @@ struct arm_smmu_s2_cfg {
u16 vmid;
};
-struct arm_smmu_strtab_cfg {
- union {
- struct {
- struct arm_smmu_ste *table;
- dma_addr_t ste_dma;
- unsigned int num_ents;
- } linear;
- struct {
- struct arm_smmu_strtab_l1 *l1tab;
- struct arm_smmu_strtab_l2 **l2ptrs;
- dma_addr_t l1_dma;
- unsigned int num_l1_ents;
- } l2;
- };
-};
-
struct arm_smmu_impl_ops {
int (*device_reset)(struct arm_smmu_device *smmu);
void (*device_remove)(struct arm_smmu_device *smmu);
diff --git a/drivers/iommu/arm/arm-smmu-v3/pkvm/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/pkvm/arm-smmu-v3.c
index c3d67c603619..74e6dfb53528 100644
--- a/drivers/iommu/arm/arm-smmu-v3/pkvm/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/pkvm/arm-smmu-v3.c
@@ -119,7 +119,6 @@ static int smmu_sync_cmd(struct hyp_arm_smmu_v3_device *smmu)
return smmu_wait_event(smmu, smmu_cmdq_empty(&smmu->cmdq));
}
-__maybe_unused
static int smmu_send_cmd(struct hyp_arm_smmu_v3_device *smmu,
struct arm_smmu_cmdq_ent *cmd)
{
@@ -131,6 +130,80 @@ static int smmu_send_cmd(struct hyp_arm_smmu_v3_device *smmu,
return smmu_sync_cmd(smmu);
}
+__maybe_unused
+static int smmu_sync_ste(struct hyp_arm_smmu_v3_device *smmu, u32 sid, unsigned long ste)
+{
+ struct arm_smmu_cmdq_ent cmd = {
+ .opcode = CMDQ_OP_CFGI_STE,
+ .cfgi.sid = sid,
+ .cfgi.leaf = true,
+ };
+
+ /*
+ * In case of 2 level STEs, L2 is allocated as cacheable, so flush it everytime
+ * we update the STE.
+ */
+ if (!(smmu->features & ARM_SMMU_FEAT_COHERENCY) &&
+ (smmu->features & ARM_SMMU_FEAT_2_LVL_STRTAB))
+ kvm_flush_dcache_to_poc(ste, sizeof(struct arm_smmu_ste));
+ return smmu_send_cmd(smmu, &cmd);
+}
+
+static int smmu_alloc_l2_strtab(struct hyp_arm_smmu_v3_device *smmu, u32 sid)
+{
+ struct arm_smmu_strtab_cfg *cfg = &smmu->strtab_cfg;
+ struct arm_smmu_strtab_l1 *l1_desc;
+ struct arm_smmu_strtab_l2 *l2table;
+
+ l1_desc = &cfg->l2.l1tab[arm_smmu_strtab_l1_idx(sid)];
+ if (l1_desc->l2ptr)
+ return 0;
+
+ l2table = kvm_iommu_donate_pages(get_order(sizeof(*l2table)));
+ if (!l2table)
+ return -ENOMEM;
+
+ arm_smmu_write_strtab_l1_desc(l1_desc, hyp_virt_to_phys(l2table));
+ if (!(smmu->features & ARM_SMMU_FEAT_COHERENCY))
+ kvm_flush_dcache_to_poc(l1_desc, sizeof(*l1_desc));
+ return 0;
+}
+
+static struct arm_smmu_ste *
+smmu_get_ste_ptr(struct hyp_arm_smmu_v3_device *smmu, u32 sid)
+{
+ struct arm_smmu_strtab_cfg *cfg = &smmu->strtab_cfg;
+
+ if (smmu->features & ARM_SMMU_FEAT_2_LVL_STRTAB) {
+ u32 l1_idx = arm_smmu_strtab_l1_idx(sid);
+ struct arm_smmu_strtab_l2 *l2ptr;
+
+ if (l1_idx >= cfg->l2.num_l1_ents)
+ return NULL;
+ l2ptr = hyp_phys_to_virt(cfg->l2.l1tab[l1_idx].l2ptr & STRTAB_L1_DESC_L2PTR_MASK);
+ /* Two-level walk */
+ return &l2ptr->stes[arm_smmu_strtab_l2_idx(sid)];
+ }
+
+ if (sid >= cfg->linear.num_ents)
+ return NULL;
+ /* Simple linear lookup */
+ return &cfg->linear.table[sid];
+}
+
+__maybe_unused
+static struct arm_smmu_ste *
+smmu_get_alloc_ste_ptr(struct hyp_arm_smmu_v3_device *smmu, u32 sid)
+{
+ if (smmu->features & ARM_SMMU_FEAT_2_LVL_STRTAB) {
+ int ret = smmu_alloc_l2_strtab(smmu, sid);
+
+ if (ret)
+ return NULL;
+ }
+ return smmu_get_ste_ptr(smmu, sid);
+}
+
static int smmu_init_registers(struct hyp_arm_smmu_v3_device *smmu)
{
u64 val, old;
@@ -205,6 +278,29 @@ static int smmu_init_cmdq(struct hyp_arm_smmu_v3_device *smmu)
return 0;
}
+static int smmu_init_strtab(struct hyp_arm_smmu_v3_device *smmu)
+{
+ size_t strtab_size;
+ u64 strtab_base;
+ struct arm_smmu_strtab_cfg *cfg = &smmu->strtab_cfg;
+ enum kvm_pgtable_prot prot = PAGE_HYP;
+
+ if (!(smmu->features & ARM_SMMU_FEAT_COHERENCY))
+ prot |= KVM_PGTABLE_PROT_NORMAL_NC;
+
+ if (smmu->features & ARM_SMMU_FEAT_2_LVL_STRTAB) {
+ strtab_size = PAGE_ALIGN(cfg->l2.num_l1_ents * sizeof(struct arm_smmu_strtab_l1));
+ strtab_base = (u64)cfg->l2.l1_dma;
+ cfg->linear.table = hyp_phys_to_virt(strtab_base);
+ } else {
+ strtab_size = PAGE_ALIGN(cfg->linear.num_ents * sizeof(struct arm_smmu_ste));
+ strtab_base = (u64)cfg->linear.ste_dma;
+ cfg->l2.l1tab = hyp_phys_to_virt(strtab_base);
+ }
+ return ___pkvm_host_donate_hyp(hyp_phys_to_pfn(strtab_base),
+ strtab_size >> PAGE_SHIFT, prot);
+}
+
static int smmu_init_device(struct hyp_arm_smmu_v3_device *smmu)
{
int i;
@@ -233,6 +329,10 @@ static int smmu_init_device(struct hyp_arm_smmu_v3_device *smmu)
if (ret)
goto out_err;
+ ret = smmu_init_strtab(smmu);
+ if (ret)
+ goto out_err;
+
return ret;
out_err:
diff --git a/drivers/iommu/arm/arm-smmu-v3/pkvm/arm_smmu_v3.h b/drivers/iommu/arm/arm-smmu-v3/pkvm/arm_smmu_v3.h
index f639312cf295..d188537545b1 100644
--- a/drivers/iommu/arm/arm-smmu-v3/pkvm/arm_smmu_v3.h
+++ b/drivers/iommu/arm/arm-smmu-v3/pkvm/arm_smmu_v3.h
@@ -13,6 +13,7 @@
* @base Virtual address of SMMU registers
* @features SMMUv3 features as defined in arm-smmu-v3-common.h
* @cmdq CMDQ queue struct
+ * @strtab_cfg stream table config, strtab_cfg.l2.l2ptrs is not used
* Other members are filled and used at runtime by the SMMU driver.
*/
struct hyp_arm_smmu_v3_device {
@@ -21,6 +22,7 @@ struct hyp_arm_smmu_v3_device {
void __iomem *base;
unsigned long features;
struct arm_smmu_queue cmdq;
+ struct arm_smmu_strtab_cfg strtab_cfg;
};
extern size_t kvm_nvhe_sym(kvm_hyp_arm_smmu_v3_count);
--
2.50.1.552.g942d659e1b-goog
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