On Tue, Nov 12, 2024 at 7:13 PM Fea.Wang <fea.w...@sifive.com> 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 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 <frank.ch...@sifive.com>
> Signed-off-by: Fea.Wang <fea.w...@sifive.com>
> Signed-off-by: Daniel Henrique Barboza <dbarb...@ventanamicro.com>
> Reviewed-by: Jim Shu <jim....@sifive.com>
> ---
> target/riscv/cpu_helper.c | 61 +++++++++++++++++++++++++++++++++++++++
> 1 file changed, 61 insertions(+)
>
> diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
> index 0a3ead69ea..5b29344c4f 100644
> --- a/target/riscv/cpu_helper.c
> +++ b/target/riscv/cpu_helper.c
> @@ -857,6 +857,61 @@ 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)
> +{
> + bool ukte;
> +
> + /* 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) {
> + ukte = !!(env->hstatus & HSTATUS_HUKTE);
You should just be able to use get_field() here
> + } else {
> + ukte = !!(env->senvcfg & SENVCFG_UKTE);
> + }
> +
> + if (!ukte) {
> + return false;
and it's probably simpler to remove the ukte variable and just return
based on the result of get_field()
> + }
> +
> + /*
> + * 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)
> +{
> + uint32_t sxl = riscv_cpu_sxl(env);
> + sxl = (sxl == 0) ? MXL_RV32 : sxl;
I don't think riscv_cpu_sxl() can return 0, do we actually need this check?
Also this extension isn't defined for RV32
Alistair
> + 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
> *
> @@ -894,6 +949,7 @@ 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 +957,11 @@ 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
> --
> 2.34.1
>
>
