[RFC v5 08/28] hw/arm/smmu-common: Key configuration cache on SMMUDevice and SEC_SID

Adapt the configuration cache to distinguish entries decoded through
different SEC_SID-selected programming interfaces by introducing a
composite SMMUConfigKey. The key combines SMMUDevice with SEC_SID,
preventing Secure and Non-secure configuration entries from aliasing in
the cache and leaving the key extensible for a future Realm SEC_SID
namespace.

The cache lookup, insertion, and invalidation mechanisms are updated to
use this new keying infrastructure.

Signed-off-by: Tao Tang <[email protected]>
Reviewed-by: Eric Auger <[email protected]>
Reviewed-by: Pierrick Bouvier <[email protected]>
Link: https://lore.kernel.org/qemu-devel/[email protected]/
---
 hw/arm/smmu-common.c         | 45 ++++++++++++++++++++++++++++++++++--
 hw/arm/smmuv3.c              | 12 ++++++----
 include/hw/arm/smmu-common.h |  7 ++++++
 3 files changed, 57 insertions(+), 7 deletions(-)

diff --git a/hw/arm/smmu-common.c b/hw/arm/smmu-common.c
index 89e1e2826d4..63c36329a98 100644
--- a/hw/arm/smmu-common.c
+++ b/hw/arm/smmu-common.c
@@ -30,6 +30,26 @@
 #include "hw/arm/smmu-common.h"
 #include "smmu-internal.h"
 
+/* Configuration Cache Management */
+static guint smmu_config_key_hash(gconstpointer key)
+{
+    const SMMUConfigKey *k = key;
+    return g_direct_hash(k->sdev) ^ (guint)k->sec_sid;
+}
+
+static gboolean smmu_config_key_equal(gconstpointer a, gconstpointer b)
+{
+    const SMMUConfigKey *ka = a;
+    const SMMUConfigKey *kb = b;
+    return ka->sdev == kb->sdev && ka->sec_sid == kb->sec_sid;
+}
+
+SMMUConfigKey smmu_get_config_key(SMMUDevice *sdev, SMMUSecSID sec_sid)
+{
+    SMMUConfigKey key = {.sdev = sdev, .sec_sid = sec_sid};
+    return key;
+}
+
 ARMSecuritySpace smmu_get_security_space(SMMUSecSID sec_sid)
 {
     switch (sec_sid) {
@@ -265,7 +285,8 @@ static gboolean smmu_hash_remove_by_vmid_ipa(gpointer key, gpointer value,
 static gboolean
 smmu_hash_remove_by_sid_range(gpointer key, gpointer value, gpointer user_data)
 {
-    SMMUDevice *sdev = (SMMUDevice *)key;
+    SMMUConfigKey *config_key = (SMMUConfigKey *)key;
+    SMMUDevice *sdev = config_key->sdev;
     uint32_t sid = smmu_get_sid(sdev);
     SMMUSIDRange *sid_range = (SMMUSIDRange *)user_data;
 
@@ -283,6 +304,24 @@ void smmu_configs_inv_sid_range(SMMUState *s, SMMUSIDRange sid_range)
                                 &sid_range);
 }
 
+static gboolean smmu_hash_remove_by_sdev(gpointer key, gpointer value,
+                                         gpointer user_data)
+{
+    SMMUConfigKey *config_key = (SMMUConfigKey *)key;
+    SMMUDevice *target = (SMMUDevice *)user_data;
+
+    if (config_key->sdev != target) {
+        return false;
+    }
+    trace_smmu_config_cache_inv(smmu_get_sid(target));
+    return true;
+}
+
+void smmu_configs_inv_sdev(SMMUState *s, SMMUDevice *sdev)
+{
+    g_hash_table_foreach_remove(s->configs, smmu_hash_remove_by_sdev, sdev);
+}
+
 void smmu_iotlb_inv_iova(SMMUState *s, int asid, int vmid, dma_addr_t iova,
                          uint8_t tg, uint64_t num_pages, uint8_t ttl)
 {
@@ -979,7 +1018,9 @@ static void smmu_base_realize(DeviceState *dev, Error **errp)
         error_propagate(errp, local_err);
         return;
     }
-    s->configs = g_hash_table_new_full(NULL, NULL, NULL, g_free);
+    s->configs = g_hash_table_new_full(smmu_config_key_hash,
+                                       smmu_config_key_equal,
+                                       g_free, g_free);
     s->iotlb = g_hash_table_new_full(smmu_iotlb_key_hash, smmu_iotlb_key_equal,
                                      g_free, g_free);
     s->smmu_pcibus_by_busptr = g_hash_table_new(NULL, NULL);
diff --git a/hw/arm/smmuv3.c b/hw/arm/smmuv3.c
index 3ff2f498a3b..a01175cc672 100644
--- a/hw/arm/smmuv3.c
+++ b/hw/arm/smmuv3.c
@@ -952,7 +952,7 @@ static int smmuv3_decode_config(IOMMUMemoryRegion *mr, SMMUTransCfg *cfg,
  *
  * The configuration cache contains data resulting from both STE and CD
  * decoding under the form of an SMMUTransCfg struct. The hash table is indexed
- * by the SMMUDevice handle.
+ * by a composite key of the SMMUDevice and the sec_sid.
  */
 static SMMUTransCfg *smmuv3_get_config(SMMUDevice *sdev, SMMUEventInfo *event,
                                        SMMUSecSID sec_sid)
@@ -960,8 +960,9 @@ static SMMUTransCfg *smmuv3_get_config(SMMUDevice *sdev, SMMUEventInfo *event,
     SMMUv3State *s = sdev->smmu;
     SMMUState *bc = &s->smmu_state;
     SMMUTransCfg *cfg;
+    SMMUConfigKey lookup_key = smmu_get_config_key(sdev, sec_sid);
 
-    cfg = g_hash_table_lookup(bc->configs, sdev);
+    cfg = g_hash_table_lookup(bc->configs, &lookup_key);
     if (cfg) {
         sdev->cfg_cache_hits++;
         trace_smmuv3_config_cache_hit(smmu_get_sid(sdev),
@@ -977,7 +978,9 @@ static SMMUTransCfg *smmuv3_get_config(SMMUDevice *sdev, SMMUEventInfo *event,
         cfg = g_new0(SMMUTransCfg, 1);
 
         if (!smmuv3_decode_config(&sdev->iommu, cfg, event, sec_sid)) {
-            g_hash_table_insert(bc->configs, sdev, cfg);
+            SMMUConfigKey *persistent_key = g_new(SMMUConfigKey, 1);
+            *persistent_key = lookup_key;
+            g_hash_table_insert(bc->configs, persistent_key, cfg);
         } else {
             g_free(cfg);
             cfg = NULL;
@@ -991,8 +994,7 @@ static void smmuv3_flush_config(SMMUDevice *sdev)
     SMMUv3State *s = sdev->smmu;
     SMMUState *bc = &s->smmu_state;
 
-    trace_smmu_config_cache_inv(smmu_get_sid(sdev));
-    g_hash_table_remove(bc->configs, sdev);
+    smmu_configs_inv_sdev(bc, sdev);
 }
 
 /* Do translation with TLB lookup. */
diff --git a/include/hw/arm/smmu-common.h b/include/hw/arm/smmu-common.h
index a31ffcf6e71..bd83648b14c 100644
--- a/include/hw/arm/smmu-common.h
+++ b/include/hw/arm/smmu-common.h
@@ -153,6 +153,11 @@ typedef struct SMMUIOTLBKey {
     uint8_t level;
 } SMMUIOTLBKey;
 
+typedef struct SMMUConfigKey {
+    SMMUDevice *sdev;
+    SMMUSecSID sec_sid;
+} SMMUConfigKey;
+
 typedef struct SMMUSIDRange {
     uint32_t start;
     uint32_t end;
@@ -247,6 +252,7 @@ SMMUTLBEntry *smmu_iotlb_lookup(SMMUState *bs, SMMUTransCfg *cfg,
 void smmu_iotlb_insert(SMMUState *bs, SMMUTransCfg *cfg, SMMUTLBEntry *entry);
 SMMUIOTLBKey smmu_get_iotlb_key(int asid, int vmid, uint64_t iova,
                                 uint8_t tg, uint8_t level);
+SMMUConfigKey smmu_get_config_key(SMMUDevice *sdev, SMMUSecSID sec_sid);
 void smmu_iotlb_inv_all(SMMUState *s);
 void smmu_iotlb_inv_asid_vmid(SMMUState *s, int asid, int vmid);
 void smmu_iotlb_inv_vmid(SMMUState *s, int vmid);
@@ -256,6 +262,7 @@ void smmu_iotlb_inv_iova(SMMUState *s, int asid, int vmid, dma_addr_t iova,
 void smmu_iotlb_inv_ipa(SMMUState *s, int vmid, dma_addr_t ipa, uint8_t tg,
                         uint64_t num_pages, uint8_t ttl);
 void smmu_configs_inv_sid_range(SMMUState *s, SMMUSIDRange sid_range);
+void smmu_configs_inv_sdev(SMMUState *s, SMMUDevice *sdev);
 /* Unmap the range of all the notifiers registered to any IOMMU mr */
 void smmu_inv_notifiers_all(SMMUState *s);
 
-- 
2.34.1