[PATCH 1/2] hw/arm/smmuv3: Sanitize SMMU_S_STRTAB_BASE_CFG.SPLIT

[Eric Auger <eric.auger@redhat.com>]

Currently the guest value for the SPLIT field is not checked.
Also the spec says that values different from 6, 8, 10, respectively
meaning 4KB, 16kB and 64kB leaf tables are reserved and behave as 6.

Signed-off-by: Eric Auger <eric.auger@redhat.com>
---
 hw/arm/smmuv3.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/hw/arm/smmuv3.c b/hw/arm/smmuv3.c
index 5e5a6a960c9..0a8d2fbb6a7 100644
--- a/hw/arm/smmuv3.c
+++ b/hw/arm/smmuv3.c
@@ -1688,6 +1688,13 @@ static MemTxResult smmu_writel(SMMUv3State *s, hwaddr offset,
         s->strtab_base_cfg = data;
         if (FIELD_EX32(data, STRTAB_BASE_CFG, FMT) == 1) {
             s->sid_split = FIELD_EX32(data, STRTAB_BASE_CFG, SPLIT);
+            if (s->sid_split != 6 && s->sid_split != 8 && s->sid_split != 10) {
+                /* Other values are reserved, behave as 6 */
+                qemu_log_mask(LOG_GUEST_ERROR,
+                              "Invalid STRTAB_BASE_CFG.SPLIT=0x%b, use 0b0110\n",
+                              s->sid_split);
+                s->sid_split = 6;
+            }
             s->features |= SMMU_FEATURE_2LVL_STE;
         }
         break;
-- 
2.53.0