diff --git a/riscv/encoding.h b/riscv/encoding.h
index 1fb0e51d..776a2aed 100644
--- a/riscv/encoding.h
+++ b/riscv/encoding.h
@@ -4,7 +4,7 @@
 
 /*
  * This file is auto-generated by running 'make' in
- * https://github.com/riscv/riscv-opcodes (56f9011)
+ * https://github.com/riscv/riscv-opcodes (3deaa8c)
  */
 
 #ifndef RISCV_CSR_ENCODING_H
@@ -383,6 +383,9 @@
 #define PMP_NA4   0x10
 #define PMP_NAPOT 0x18
 
+#define SPMP_U      0x100
+#define SPMP_SHARED 0x200
+
 #define MCTRCTL_U          0x0000000000000001
 #define MCTRCTL_S          0x0000000000000002
 #define MCTRCTL_M          0x0000000000000004
@@ -492,7 +495,8 @@
 #define PTE_A     0x040 /* Accessed */
 #define PTE_D     0x080 /* Dirty */
 #define PTE_SOFT  0x300 /* Reserved for Software */
-#define PTE_RSVD  0x1FC0000000000000 /* Reserved for future standard use */
+#define PTE_SVRSW60T59B  0x1800000000000000 /* Svrsw60t59b: Reserved for software use */
+#define PTE_RSVD         0x07C0000000000000 /* Reserved for future standard use */
 #define PTE_PBMT  0x6000000000000000 /* Svpbmt: Page-based memory types */
 #define PTE_N     0x8000000000000000 /* Svnapot: NAPOT translation contiguity */
 #define PTE_ATTR  0xFFC0000000000000 /* All attributes and reserved bits */
diff --git a/riscv/isa_parser.h b/riscv/isa_parser.h
index 29bb1441..8815ec2d 100644
--- a/riscv/isa_parser.h
+++ b/riscv/isa_parser.h
@@ -49,6 +49,7 @@ typedef enum {
   EXT_SVPBMT,
   EXT_SVINVAL,
   EXT_SVUKTE,
+  EXT_SVRSW60T59B,
   EXT_ZDINX,
   EXT_ZFA,
   EXT_ZFBFMIN,
diff --git a/riscv/mmu.cc b/riscv/mmu.cc
index 7ca85bba..027c939a 100644
--- a/riscv/mmu.cc
+++ b/riscv/mmu.cc
@@ -561,6 +561,8 @@ reg_t mmu_t::s2xlate(reg_t gva, reg_t gpa, access_type type, access_type trap_ty
 
       if (pte & PTE_RSVD) {
         break;
+      } else if (!proc->extension_enabled(EXT_SVRSW60T59B) && (pte & PTE_SVRSW60T59B)) {
+        break;
       } else if (!proc->extension_enabled(EXT_SVNAPOT) && (pte & PTE_N)) {
         break;
       } else if (!pbmte && (pte & PTE_PBMT)) {
@@ -691,6 +693,8 @@ reg_t mmu_t::walk(mem_access_info_t access_info)
 
     if (pte & PTE_RSVD) {
       break;
+    } else if (!proc->extension_enabled(EXT_SVRSW60T59B) && (pte & PTE_SVRSW60T59B)) {
+        break;
     } else if (!proc->extension_enabled(EXT_SVNAPOT) && (pte & PTE_N)) {
       break;
     } else if (!pbmte && (pte & PTE_PBMT)) {