RISC-V: Check for the effective memory privilege mode during PMP checks

The current PMP check function checks for env->priv which is not the effective
memory privilege mode.

For example, mstatus.MPRV could be set while executing in M-Mode, and in that
case the privilege mode for the PMP check should be S-Mode rather than M-Mode
(in env->priv) if mstatus.MPP == PRV_S.

This patch passes the effective memory privilege mode to the PMP check.
Functions that call the PMP check should pass the correct memory privilege mode
after reading mstatus' MPRV/MPP or hstatus.SPRV (if Hypervisor mode exists).

Suggested-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Hesham Almatary <Hesham.Almatary@cl.cam.ac.uk>
Reviewed-by: Palmer Dabbelt <palmer@sifive.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>

1 files changed, 9 insertions, 1 deletions

diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
index ffbfaf4332..71b8123b10 100644
--- a/target/riscv/cpu_helper.c
+++ b/target/riscv/cpu_helper.c
@@ -427,19 +427,27 @@ bool riscv_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
     int prot;
     bool pmp_violation = false;
     int ret = TRANSLATE_FAIL;
+    int mode = mmu_idx;
 
     qemu_log_mask(CPU_LOG_MMU, "%s ad %" VADDR_PRIx " rw %d mmu_idx %d\n",
                   __func__, address, access_type, mmu_idx);
 
     ret = get_physical_address(env, &pa, &prot, address, access_type, mmu_idx);
 
+    if (mode == PRV_M && access_type != MMU_INST_FETCH) {
+        if (get_field(env->mstatus, MSTATUS_MPRV)) {
+            mode = get_field(env->mstatus, MSTATUS_MPP);
+        }
+    }
+
     qemu_log_mask(CPU_LOG_MMU,
                   "%s address=%" VADDR_PRIx " ret %d physical " TARGET_FMT_plx
                   " prot %d\n", __func__, address, ret, pa, prot);
 
     if (riscv_feature(env, RISCV_FEATURE_PMP) &&
         (ret == TRANSLATE_SUCCESS) &&
-        !pmp_hart_has_privs(env, pa, TARGET_PAGE_SIZE, 1 << access_type)) {
+        !pmp_hart_has_privs(env, pa, TARGET_PAGE_SIZE, 1 << access_type,
+        mode)) {
         pmp_violation = true;
         ret = TRANSLATE_FAIL;
     }