[Qemu-devel] [PATCH v4 03/13] target-arm: Add support for AArch32 S2 negative t0sz

["Edgar E. Iglesias" <edgar.iglesias@gmail.com>]

From: "Edgar E. Iglesias" <edgar.iglesias@xilinx.com>

Add support for AArch32 S2 negative t0sz. In preparation for
using 40bit IPAs on AArch32.

Signed-off-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
---
 target-arm/helper.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/target-arm/helper.c b/target-arm/helper.c
index 4e19838..a8a46db 100644
--- a/target-arm/helper.c
+++ b/target-arm/helper.c
@@ -6475,6 +6475,17 @@ static bool get_phys_addr_lpae(CPUARMState *env, target_ulong address,
     if (va_size == 64) {
         t0sz = MIN(t0sz, 39);
         t0sz = MAX(t0sz, 16);
+    } else {
+        bool sext = extract32(t0sz, 4, 1);
+        bool sign = extract32(t0sz, 3, 1);
+        t0sz = sextract32(t0sz, 0, 4);
+
+        /* If the sign-extend bit is not the same as t0sz[3], the result
+         * is unpredictable. Flag this as a guest error.  */
+        if (sign != sext) {
+            qemu_log_mask(LOG_GUEST_ERROR,
+                          "AArch32: VTCR.S / VTCR.T0SZ[3] missmatch\n");
+        }
     }
     int32_t t1sz = extract32(tcr->raw_tcr, 16, 6);
     if (va_size == 64) {
-- 
1.9.1