target/riscv: do not set mtval2 for non guest-page faults

Previous patch fixed the PMP priority in raise_mmu_exception() but we're still
setting mtval2 incorrectly. In riscv_cpu_tlb_fill(), after pmp check in 2 stage
translation part, mtval2 will be set in case of successes 2 stage translation but
failed pmp check.

In this case we gonna set mtval2 via env->guest_phys_fault_addr in context of
riscv_cpu_tlb_fill(), as this was a guest-page-fault, but it didn't and mtval2
should be zero, according to RISCV privileged spec sect. 9.4.4: When a guest
page-fault is taken into M-mode, mtval2 is written with either zero or guest
physical address that faulted, shifted by 2 bits. *For other traps, mtval2
is set to zero...*

Signed-off-by: Alexei Filippov <[email protected]>
Reviewed-by: Daniel Henrique Barboza <[email protected]>
Reviewed-by: Alistair Francis <[email protected]>
Message-ID: <[email protected]>
Cc: qemu-stable <[email protected]>
Signed-off-by: Alistair Francis <[email protected]>
(cherry picked from commit 6c9a344)
Signed-off-by: Michael Tokarev <[email protected]>

Author: Alexei Filippov

target/riscv/cpu_helper.c

@@ -1375,17 +1375,17 @@ bool riscv_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
                               __func__, pa, ret, prot_pmp, tlb_size);
 
                 prot &= prot_pmp;
-            }
-
-            if (ret != TRANSLATE_SUCCESS) {
+            } else {
                 /*
                  * Guest physical address translation failed, this is a HS
                  * level exception
                  */
                 first_stage_error = false;
-                env->guest_phys_fault_addr = (im_address |
-                                              (address &
-                                               (TARGET_PAGE_SIZE - 1))) >> 2;
+                if (ret != TRANSLATE_PMP_FAIL) {
+                    env->guest_phys_fault_addr = (im_address |
+                                                  (address &
+                                                   (TARGET_PAGE_SIZE - 1))) >> 2;
+                }
             }
         }
     } else {