[PATCH 2/5] hw/arm/smmuv3: Check stream IDs against actual table LOG2SIZE

[Simon Veith <sveith@amazon.de>]

When checking whether a stream ID is in range of the stream table, we
have so far been only checking it against our implementation limit
(SMMU_IDR1_SIDSIZE). However, the guest can program the
STRTAB_BASE_CFG.LOG2SIZE field to a size that is smaller than this
limit.

Check the stream ID against this limit as well to match the hardware
behavior of raising C_BAD_STREAMID events in case the limit is exceeded.

ref. ARM IHI 0070C, section 6.3.24.

Signed-off-by: Simon Veith <sveith@amazon.de>
Cc: Eric Auger <eric.auger@redhat.com>
Cc: qemu-devel@nongnu.org
Cc: qemu-arm@nongnu.org
---
 hw/arm/smmuv3.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/hw/arm/smmuv3.c b/hw/arm/smmuv3.c
index eef9a18..aad4639 100644
--- a/hw/arm/smmuv3.c
+++ b/hw/arm/smmuv3.c
@@ -377,11 +377,15 @@ static int smmu_find_ste(SMMUv3State *s, uint32_t sid, STE *ste,
                          SMMUEventInfo *event)
 {
     dma_addr_t addr;
+    uint32_t log2size;
     int ret;
 
     trace_smmuv3_find_ste(sid, s->features, s->sid_split);
-    /* Check SID range */
-    if (sid > (1 << SMMU_IDR1_SIDSIZE)) {
+    log2size = FIELD_EX32(s->strtab_base_cfg, STRTAB_BASE_CFG, LOG2SIZE);
+    /*
+     * Check SID range against both guest-configured and implementation limits
+     */
+    if (sid > (1 << MIN(log2size, SMMU_IDR1_SIDSIZE))) {
         event->type = SMMU_EVT_C_BAD_STREAMID;
         return -EINVAL;
     }
-- 
2.7.4