From ab348b09823cb2d50271dcb039350bfb25d86aad Mon Sep 17 00:00:00 2001 From: "Fea.Wang" Date: Tue, 3 Dec 2024 11:49:30 +0800 Subject: [PATCH] target/riscv: Check memory access to meet svukte rule 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 execute 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 Signed-off-by: Fea.Wang Signed-off-by: Daniel Henrique Barboza Reviewed-by: Jim Shu Reviewed-by: Daniel Henrique Barboza Reviewed-by: Alistair Francis Message-ID: <20241203034932.25185-5-fea.wang@sifive.com> Signed-off-by: Alistair Francis --- 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 45806f5ab0..750c0537ca 100644 --- a/target/riscv/cpu_helper.c +++ b/target/riscv/cpu_helper.c @@ -857,6 +857,55 @@ static int get_physical_address_pmp(CPURISCVState *env, int *prot, hwaddr addr, return TRANSLATE_SUCCESS; } +/* Returns 'true' if a svukte address check is needed */ +static bool do_svukte_check(CPURISCVState *env, bool first_stage, + int mode, bool virt) +{ + /* Svukte extension depends on Sv39. */ + if (!(env_archcpu(env)->cfg.ext_svukte || + !first_stage || + VM_1_10_SV39 != get_field(env->satp, SATP64_MODE))) { + return false; + } + + /* + * 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. + */ + if (env->priv == PRV_U && !env->virt_enabled && virt) { + if (!get_field(env->hstatus, HSTATUS_HUKTE)) { + return false; + } + } else if (!get_field(env->senvcfg, SENVCFG_UKTE)) { + return false; + } + + /* + * 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 false; + } + + return true; +} + +static bool check_svukte_addr(CPURISCVState *env, vaddr addr) +{ + /* svukte extension excludes RV32 */ + uint32_t sxlen = 32 * riscv_cpu_sxl(env); + uint64_t high_bit = addr & (1UL << (sxlen - 1)); + return !high_bit; +} + /* * get_physical_address - get the physical address for this virtual address * @@ -894,6 +943,7 @@ 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; @@ -901,6 +951,11 @@ static int get_physical_address(CPURISCVState *env, hwaddr *physical, bool is_sstack_idx = ((mmu_idx & MMU_IDX_SS_WRITE) == MMU_IDX_SS_WRITE); bool sstack_page = false; + if (do_svukte_check(env, first_stage, mode, virt) && + !check_svukte_addr(env, addr)) { + return TRANSLATE_FAIL; + } + /* * Check if we should use the background registers for the two * stage translation. We don't need to check if we actually need -- 2.30.2