[PATCH] target/riscv: Fix Guest Physical Address Translation

[Irina Ryapolova]

According to specification:
For Sv39x4, address bits of the guest physical address 63:41 must all be zeros, 
or else a
guest-page-fault exception occurs.

Likewise for Sv48x4 and Sv57x4.
For Sv48x4 address bits 63:50 must all be zeros, or else a guest-page-fault 
exception occurs.
For Sv57x4 address bits 63:59 must all be zeros, or else a guest-page-fault 
exception occurs.

Signed-off-by: Irina Ryapolova <irina.ryapol...@syntacore.com>
---
 target/riscv/cpu_helper.c | 25 ++++++++++++++++---------
 1 file changed, 16 insertions(+), 9 deletions(-)

diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
index f88c503cf4..27289f2305 100644
--- a/target/riscv/cpu_helper.c
+++ b/target/riscv/cpu_helper.c
@@ -863,17 +863,24 @@ static int get_physical_address(CPURISCVState *env, 
hwaddr *physical,
 
     CPUState *cs = env_cpu(env);
     int va_bits = PGSHIFT + levels * ptidxbits + widened;
-    target_ulong mask, masked_msbs;
 
-    if (TARGET_LONG_BITS > (va_bits - 1)) {
-        mask = (1L << (TARGET_LONG_BITS - (va_bits - 1))) - 1;
-    } else {
-        mask = 0;
-    }
-    masked_msbs = (addr >> (va_bits - 1)) & mask;
+    if (first_stage == true) {
+        target_ulong mask, masked_msbs;
+
+        if (TARGET_LONG_BITS > (va_bits - 1)) {
+            mask = (1L << (TARGET_LONG_BITS - (va_bits - 1))) - 1;
+        } else {
+            mask = 0;
+        }
+        masked_msbs = (addr >> (va_bits - 1)) & mask;
 
-    if (masked_msbs != 0 && masked_msbs != mask) {
-        return TRANSLATE_FAIL;
+        if (masked_msbs != 0 && masked_msbs != mask) {
+            return TRANSLATE_FAIL;
+        }
+    } else {
+        if (vm != VM_1_10_SV32 && addr >> va_bits != 0) {
+            return TRANSLATE_FAIL;
+        }
     }
 
     int ptshift = (levels - 1) * ptidxbits;
-- 
2.25.1