[RFC PATCH v3 06/10] hw/arm/smmuv3: Make TLB lookup work for stage-2

[Mostafa Saleh]

Right now, either stage-1 or stage-2 are supported, this simplifies
how we can deal with TLBs.
This patch makes TLB lookup work if stage-2 is enabled instead of
stage-1.
TLB lookup is done before a PTW, if a valid entry is found we won't
do the PTW.
To be able to do TLB lookup, we need the correct tagging info, as
granularity and input size, so we get this based on the supported
translation stage. The TLB entries are added correctly from each
stage PTW.

When nested translation is supported, this would need to change, for
example if we go with a combined TLB implementation, we would need to
use the min of the granularities in TLB.

As stage-2 shouldn't be tagged by ASID, it will be set to -1 if S1P
is not enabled.

Signed-off-by: Mostafa Saleh <smostafa@google.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
---
Changes in v3:
- Rename temp to tt_combined and move to top.
- Collected Reviewed-by tag.
Changes in v2:
- check if S1 is enabled(not supported) when reading S1 TT.
---
 hw/arm/smmuv3.c | 44 +++++++++++++++++++++++++++++++++-----------
 1 file changed, 33 insertions(+), 11 deletions(-)

diff --git a/hw/arm/smmuv3.c b/hw/arm/smmuv3.c
index 0f5429aed8..a1f4a4f902 100644
--- a/hw/arm/smmuv3.c
+++ b/hw/arm/smmuv3.c
@@ -727,6 +727,9 @@ static int smmuv3_decode_config(IOMMUMemoryRegion *mr, 
SMMUTransCfg *cfg,
     STE ste;
     CD cd;
 
+    /* ASID defaults to -1 (if s1 is not supported). */
+    cfg->asid = -1;
+
     ret = smmu_find_ste(s, sid, &ste, event);
     if (ret) {
         return ret;
@@ -824,6 +827,11 @@ static IOMMUTLBEntry smmuv3_translate(IOMMUMemoryRegion 
*mr, hwaddr addr,
         .addr_mask = ~(hwaddr)0,
         .perm = IOMMU_NONE,
     };
+    /*
+     * Combined attributes used for TLB lookup, as only one stage is supported,
+     * it will hold attributes based on the enabled stage.
+     */
+    SMMUTransTableInfo tt_combined;
 
     qemu_mutex_lock(&s->mutex);
 
@@ -852,21 +860,35 @@ static IOMMUTLBEntry smmuv3_translate(IOMMUMemoryRegion 
*mr, hwaddr addr,
         goto epilogue;
     }
 
-    tt = select_tt(cfg, addr);
-    if (!tt) {
-        if (cfg->record_faults) {
-            event.type = SMMU_EVT_F_TRANSLATION;
-            event.u.f_translation.addr = addr;
-            event.u.f_translation.rnw = flag & 0x1;
+    if (cfg->stage == 1) {
+        /* Select stage1 translation table. */
+        tt = select_tt(cfg, addr);
+        if (!tt) {
+            if (cfg->record_faults) {
+                event.type = SMMU_EVT_F_TRANSLATION;
+                event.u.f_translation.addr = addr;
+                event.u.f_translation.rnw = flag & 0x1;
+            }
+            status = SMMU_TRANS_ERROR;
+            goto epilogue;
         }
-        status = SMMU_TRANS_ERROR;
-        goto epilogue;
-    }
+        tt_combined.granule_sz = tt->granule_sz;
+        tt_combined.tsz = tt->tsz;
 
-    page_mask = (1ULL << (tt->granule_sz)) - 1;
+    } else {
+        /* Stage2. */
+        tt_combined.granule_sz = cfg->s2cfg.granule_sz;
+        tt_combined.tsz = cfg->s2cfg.tsz;
+    }
+    /*
+     * TLB lookup looks for granule and input size for a translation stage,
+     * as only one stage is supported right now, choose the right values
+     * from the configuration.
+     */
+    page_mask = (1ULL << tt_combined.granule_sz) - 1;
     aligned_addr = addr & ~page_mask;
 
-    cached_entry = smmu_iotlb_lookup(bs, cfg, tt, aligned_addr);
+    cached_entry = smmu_iotlb_lookup(bs, cfg, &tt_combined, aligned_addr);
     if (cached_entry) {
         if ((flag & IOMMU_WO) && !(cached_entry->entry.perm & IOMMU_WO)) {
             status = SMMU_TRANS_ERROR;
-- 
2.40.0.348.gf938b09366-goog