On 9/3/24 3:17 AM, Fea.Wang wrote:
Follow the Svukte spec, do the memory access address checking
1. Include instruction fetches or explicit memory accesses
2. System run in effective privilege U or VU
3. Check senvcfg[UKTE] being set, or hstatus[HUKTE] being set if
instruction is HLV, HLVX, HSV and excute from U mode to VU mode
4. Depend on Sv39 and check virtual addresses bit[SXLEN-1]
5. Raises a page-fault exception corresponding to the original access
type.
Ref: https://github.com/riscv/riscv-isa-manual/pull/1564/files
Signed-off-by: Frank Chang <frank.ch...@sifive.com>
Signed-off-by: Fea.Wang <fea.w...@sifive.com>
Reviewed-by: Jim Shu <jim....@sifive.com>
---
target/riscv/cpu_helper.c | 55 +++++++++++++++++++++++++++++++++++++++
1 file changed, 55 insertions(+)
diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
index 395a1d9140..db65ed14b9 100644
--- a/target/riscv/cpu_helper.c
+++ b/target/riscv/cpu_helper.c
@@ -777,6 +777,54 @@ static int get_physical_address_pmp(CPURISCVState *env,
int *prot, hwaddr addr,
return TRANSLATE_SUCCESS;
}
+/*
+ * Return 'true' means no need to do svukte check, or need to do svukte and the
+ * address is valid. Return 'false' means need to do svukte check but address
+ * is invalid.
+ */
+static bool check_svukte_valid(CPURISCVState *env, vaddr addr,
+ int mode, bool virt)
+{
+ if (VM_1_10_SV39 != get_field(env->satp, SATP64_MODE)) {
+ /* Svukte extension depends on Sv39. */
+ return true;
+ }
+
+ /*
+ * Svukte extension is qualified only in U or VU-mode.
+ *
+ * Effective mode can be switched to U or VU-mode by:
+ * - M-mode + mstatus.MPRV=1 + mstatus.MPP=U-mode.
+ * - Execute HLV/HLVX/HSV from HS-mode + hstatus.SPVP=0.
+ * - U-mode.
+ * - VU-mode.
+ * - Execute HLV/HLVX/HSV from U-mode + hstatus.HU=1.
+ */
+ if (mode != PRV_U) {
+ return true;
+ }
+
+ /*
+ * Check hstatus.HUKTE if the effective mode is switched to VU-mode by
+ * executing HLV/HLVX/HSV in U-mode.
+ * For other cases, check senvcfg.UKTE.
+ */
+ bool ukte = (env->priv == PRV_U && !env->virt_enabled && virt) ?
+ !!(env->hstatus & HSTATUS_HUKTE) :
+ !!(env->senvcfg & SENVCFG_UKTE);
I would move the 'bool ukte' to the start of the function, and would avoid the
ternary to make the code a bit more readable:
if (env->priv == PRV_U && !env->virt_enabled && virt) {
ukte = !!(env->hstatus & HSTATUS_HUKTE);
} else {
ukte = !!(env->senvcfg & SENVCFG_UKTE);
}
+
+ if (!ukte) {
+ return true;
+ }
+
+ uint32_t sxl = riscv_cpu_sxl(env);
+ sxl = (sxl == 0) ? MXL_RV32 : sxl;
+ uint32_t sxlen = 32 * sxl;
+ uint64_t high_bit = addr & (1UL << (sxlen - 1));
+
+ return !high_bit;
+}
+
/*
* get_physical_address - get the physical address for this virtual address
*
@@ -814,11 +862,18 @@ static int get_physical_address(CPURISCVState *env,
hwaddr *physical,
MemTxResult res;
MemTxAttrs attrs = MEMTXATTRS_UNSPECIFIED;
int mode = mmuidx_priv(mmu_idx);
+ bool virt = mmuidx_2stage(mmu_idx);
bool use_background = false;
hwaddr ppn;
int napot_bits = 0;
target_ulong napot_mask;
+ if (first_stage) {
+ if (!check_svukte_valid(env, addr, mode, virt)) {
+ return TRANSLATE_FAIL;
+ }
+ }
+
We can avoid the nested 'if':
+ if (first_stage && !check_svukte_valid(env, addr, mode, virt)) {
+ return TRANSLATE_FAIL;
+ }
I would also add a check for ext_svukte before doing any checks. If we don't
have
the ext enabled we can skip everything:
+ if (env_archcpu(env)->cfg.ext_svukte && first_stage &&
+ !check_svukte_valid(env, addr, mode, virt)) {
+ return TRANSLATE_FAIL;
+ }
Thanks,
Daniel
/*
* Check if we should use the background registers for the two
* stage translation. We don't need to check if we actually need
