target/riscv: Add counter delegation/configuration support

The Smcdeleg/Ssccfg adds the support for counter delegation via
S*indcsr and Ssccfg.

It also adds a new shadow CSR scountinhibit and menvcfg enable bit (CDE)
to enable this extension and scountovf virtualization.

Signed-off-by: Kaiwen Xue <kaiwenx@rivosinc.com>
Co-developed-by: Atish Patra <atishp@rivosinc.com>
Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Atish Patra <atishp@rivosinc.com>
Message-ID: <20250110-counter_delegation-v5-8-e83d797ae294@rivosinc.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
This commit is contained in:
Kaiwen Xue 2025-01-10 00:21:36 -08:00 committed by Alistair Francis
parent b6504cd0d1
commit 6247dc2ef7

View File

@ -383,6 +383,21 @@ static RISCVException aia_smode32(CPURISCVState *env, int csrno)
return smode32(env, csrno);
}
static RISCVException scountinhibit_pred(CPURISCVState *env, int csrno)
{
RISCVCPU *cpu = env_archcpu(env);
if (!cpu->cfg.ext_ssccfg || !cpu->cfg.ext_smcdeleg) {
return RISCV_EXCP_ILLEGAL_INST;
}
if (env->virt_enabled) {
return RISCV_EXCP_VIRT_INSTRUCTION_FAULT;
}
return smode(env, csrno);
}
static bool csrind_extensions_present(CPURISCVState *env)
{
return riscv_cpu_cfg(env)->ext_smcsrind || riscv_cpu_cfg(env)->ext_sscsrind;
@ -1224,10 +1239,9 @@ done:
return result;
}
static RISCVException write_mhpmcounter(CPURISCVState *env, int csrno,
target_ulong val)
static RISCVException riscv_pmu_write_ctr(CPURISCVState *env, target_ulong val,
uint32_t ctr_idx)
{
int ctr_idx = csrno - CSR_MCYCLE;
PMUCTRState *counter = &env->pmu_ctrs[ctr_idx];
uint64_t mhpmctr_val = val;
@ -1252,10 +1266,9 @@ static RISCVException write_mhpmcounter(CPURISCVState *env, int csrno,
return RISCV_EXCP_NONE;
}
static RISCVException write_mhpmcounterh(CPURISCVState *env, int csrno,
target_ulong val)
static RISCVException riscv_pmu_write_ctrh(CPURISCVState *env, target_ulong val,
uint32_t ctr_idx)
{
int ctr_idx = csrno - CSR_MCYCLEH;
PMUCTRState *counter = &env->pmu_ctrs[ctr_idx];
uint64_t mhpmctr_val = counter->mhpmcounter_val;
uint64_t mhpmctrh_val = val;
@ -1277,6 +1290,20 @@ static RISCVException write_mhpmcounterh(CPURISCVState *env, int csrno,
return RISCV_EXCP_NONE;
}
static int write_mhpmcounter(CPURISCVState *env, int csrno, target_ulong val)
{
int ctr_idx = csrno - CSR_MCYCLE;
return riscv_pmu_write_ctr(env, val, ctr_idx);
}
static int write_mhpmcounterh(CPURISCVState *env, int csrno, target_ulong val)
{
int ctr_idx = csrno - CSR_MCYCLEH;
return riscv_pmu_write_ctrh(env, val, ctr_idx);
}
RISCVException riscv_pmu_read_ctr(CPURISCVState *env, target_ulong *val,
bool upper_half, uint32_t ctr_idx)
{
@ -1342,6 +1369,167 @@ static RISCVException read_hpmcounterh(CPURISCVState *env, int csrno,
return riscv_pmu_read_ctr(env, val, true, ctr_index);
}
static int rmw_cd_mhpmcounter(CPURISCVState *env, int ctr_idx,
target_ulong *val, target_ulong new_val,
target_ulong wr_mask)
{
if (wr_mask != 0 && wr_mask != -1) {
return -EINVAL;
}
if (!wr_mask && val) {
riscv_pmu_read_ctr(env, val, false, ctr_idx);
} else if (wr_mask) {
riscv_pmu_write_ctr(env, new_val, ctr_idx);
} else {
return -EINVAL;
}
return 0;
}
static int rmw_cd_mhpmcounterh(CPURISCVState *env, int ctr_idx,
target_ulong *val, target_ulong new_val,
target_ulong wr_mask)
{
if (wr_mask != 0 && wr_mask != -1) {
return -EINVAL;
}
if (!wr_mask && val) {
riscv_pmu_read_ctr(env, val, true, ctr_idx);
} else if (wr_mask) {
riscv_pmu_write_ctrh(env, new_val, ctr_idx);
} else {
return -EINVAL;
}
return 0;
}
static int rmw_cd_mhpmevent(CPURISCVState *env, int evt_index,
target_ulong *val, target_ulong new_val,
target_ulong wr_mask)
{
uint64_t mhpmevt_val = new_val;
if (wr_mask != 0 && wr_mask != -1) {
return -EINVAL;
}
if (!wr_mask && val) {
*val = env->mhpmevent_val[evt_index];
if (riscv_cpu_cfg(env)->ext_sscofpmf) {
*val &= ~MHPMEVENT_BIT_MINH;
}
} else if (wr_mask) {
wr_mask &= ~MHPMEVENT_BIT_MINH;
mhpmevt_val = (new_val & wr_mask) |
(env->mhpmevent_val[evt_index] & ~wr_mask);
if (riscv_cpu_mxl(env) == MXL_RV32) {
mhpmevt_val = mhpmevt_val |
((uint64_t)env->mhpmeventh_val[evt_index] << 32);
}
env->mhpmevent_val[evt_index] = mhpmevt_val;
riscv_pmu_update_event_map(env, mhpmevt_val, evt_index);
} else {
return -EINVAL;
}
return 0;
}
static int rmw_cd_mhpmeventh(CPURISCVState *env, int evt_index,
target_ulong *val, target_ulong new_val,
target_ulong wr_mask)
{
uint64_t mhpmevth_val;
uint64_t mhpmevt_val = env->mhpmevent_val[evt_index];
if (wr_mask != 0 && wr_mask != -1) {
return -EINVAL;
}
if (!wr_mask && val) {
*val = env->mhpmeventh_val[evt_index];
if (riscv_cpu_cfg(env)->ext_sscofpmf) {
*val &= ~MHPMEVENTH_BIT_MINH;
}
} else if (wr_mask) {
wr_mask &= ~MHPMEVENTH_BIT_MINH;
env->mhpmeventh_val[evt_index] =
(new_val & wr_mask) | (env->mhpmeventh_val[evt_index] & ~wr_mask);
mhpmevth_val = env->mhpmeventh_val[evt_index];
mhpmevt_val = mhpmevt_val | (mhpmevth_val << 32);
riscv_pmu_update_event_map(env, mhpmevt_val, evt_index);
} else {
return -EINVAL;
}
return 0;
}
static int rmw_cd_ctr_cfg(CPURISCVState *env, int cfg_index, target_ulong *val,
target_ulong new_val, target_ulong wr_mask)
{
switch (cfg_index) {
case 0: /* CYCLECFG */
if (wr_mask) {
wr_mask &= ~MCYCLECFG_BIT_MINH;
env->mcyclecfg = (new_val & wr_mask) | (env->mcyclecfg & ~wr_mask);
} else {
*val = env->mcyclecfg &= ~MHPMEVENTH_BIT_MINH;
}
break;
case 2: /* INSTRETCFG */
if (wr_mask) {
wr_mask &= ~MINSTRETCFG_BIT_MINH;
env->minstretcfg = (new_val & wr_mask) |
(env->minstretcfg & ~wr_mask);
} else {
*val = env->minstretcfg &= ~MHPMEVENTH_BIT_MINH;
}
break;
default:
return -EINVAL;
}
return 0;
}
static int rmw_cd_ctr_cfgh(CPURISCVState *env, int cfg_index, target_ulong *val,
target_ulong new_val, target_ulong wr_mask)
{
if (riscv_cpu_mxl(env) != MXL_RV32) {
return RISCV_EXCP_ILLEGAL_INST;
}
switch (cfg_index) {
case 0: /* CYCLECFGH */
if (wr_mask) {
wr_mask &= ~MCYCLECFGH_BIT_MINH;
env->mcyclecfgh = (new_val & wr_mask) |
(env->mcyclecfgh & ~wr_mask);
} else {
*val = env->mcyclecfgh;
}
break;
case 2: /* INSTRETCFGH */
if (wr_mask) {
wr_mask &= ~MINSTRETCFGH_BIT_MINH;
env->minstretcfgh = (new_val & wr_mask) |
(env->minstretcfgh & ~wr_mask);
} else {
*val = env->minstretcfgh;
}
break;
default:
return -EINVAL;
}
return 0;
}
static RISCVException read_scountovf(CPURISCVState *env, int csrno,
target_ulong *val)
{
@ -1351,6 +1539,14 @@ static RISCVException read_scountovf(CPURISCVState *env, int csrno,
target_ulong *mhpm_evt_val;
uint64_t of_bit_mask;
/* Virtualize scountovf for counter delegation */
if (riscv_cpu_cfg(env)->ext_sscofpmf &&
riscv_cpu_cfg(env)->ext_ssccfg &&
get_field(env->menvcfg, MENVCFG_CDE) &&
env->virt_enabled) {
return RISCV_EXCP_VIRT_INSTRUCTION_FAULT;
}
if (riscv_cpu_mxl(env) == MXL_RV32) {
mhpm_evt_val = env->mhpmeventh_val;
of_bit_mask = MHPMEVENTH_BIT_OF;
@ -2293,11 +2489,72 @@ static int rmw_xireg_cd(CPURISCVState *env, int csrno,
target_ulong isel, target_ulong *val,
target_ulong new_val, target_ulong wr_mask)
{
if (!riscv_cpu_cfg(env)->ext_smcdeleg) {
return RISCV_EXCP_ILLEGAL_INST;
int ret = -EINVAL;
int ctr_index = isel - ISELECT_CD_FIRST;
int isel_hpm_start = ISELECT_CD_FIRST + 3;
if (!riscv_cpu_cfg(env)->ext_smcdeleg || !riscv_cpu_cfg(env)->ext_ssccfg) {
ret = RISCV_EXCP_ILLEGAL_INST;
goto done;
}
/* TODO: Implement the functionality later */
return RISCV_EXCP_NONE;
/* Invalid siselect value for reserved */
if (ctr_index == 1) {
goto done;
}
/* sireg4 and sireg5 provides access RV32 only CSRs */
if (((csrno == CSR_SIREG5) || (csrno == CSR_SIREG4)) &&
(riscv_cpu_mxl(env) != MXL_RV32)) {
ret = RISCV_EXCP_ILLEGAL_INST;
goto done;
}
/* Check Sscofpmf dependancy */
if (!riscv_cpu_cfg(env)->ext_sscofpmf && csrno == CSR_SIREG5 &&
(isel_hpm_start <= isel && isel <= ISELECT_CD_LAST)) {
goto done;
}
/* Check smcntrpmf dependancy */
if (!riscv_cpu_cfg(env)->ext_smcntrpmf &&
(csrno == CSR_SIREG2 || csrno == CSR_SIREG5) &&
(ISELECT_CD_FIRST <= isel && isel < isel_hpm_start)) {
goto done;
}
if (!get_field(env->mcounteren, BIT(ctr_index)) ||
!get_field(env->menvcfg, MENVCFG_CDE)) {
goto done;
}
switch (csrno) {
case CSR_SIREG:
ret = rmw_cd_mhpmcounter(env, ctr_index, val, new_val, wr_mask);
break;
case CSR_SIREG4:
ret = rmw_cd_mhpmcounterh(env, ctr_index, val, new_val, wr_mask);
break;
case CSR_SIREG2:
if (ctr_index <= 2) {
ret = rmw_cd_ctr_cfg(env, ctr_index, val, new_val, wr_mask);
} else {
ret = rmw_cd_mhpmevent(env, ctr_index, val, new_val, wr_mask);
}
break;
case CSR_SIREG5:
if (ctr_index <= 2) {
ret = rmw_cd_ctr_cfgh(env, ctr_index, val, new_val, wr_mask);
} else {
ret = rmw_cd_mhpmeventh(env, ctr_index, val, new_val, wr_mask);
}
break;
default:
goto done;
}
done:
return ret;
}
/*
@ -2576,6 +2833,21 @@ static RISCVException write_mcountinhibit(CPURISCVState *env, int csrno,
return RISCV_EXCP_NONE;
}
static RISCVException read_scountinhibit(CPURISCVState *env, int csrno,
target_ulong *val)
{
/* S-mode can only access the bits delegated by M-mode */
*val = env->mcountinhibit & env->mcounteren;
return RISCV_EXCP_NONE;
}
static RISCVException write_scountinhibit(CPURISCVState *env, int csrno,
target_ulong val)
{
write_mcountinhibit(env, csrno, val & env->mcounteren);
return RISCV_EXCP_NONE;
}
static RISCVException read_mcounteren(CPURISCVState *env, int csrno,
target_ulong *val)
{
@ -2678,11 +2950,13 @@ static RISCVException write_menvcfg(CPURISCVState *env, int csrno,
target_ulong val)
{
const RISCVCPUConfig *cfg = riscv_cpu_cfg(env);
uint64_t mask = MENVCFG_FIOM | MENVCFG_CBIE | MENVCFG_CBCFE | MENVCFG_CBZE;
uint64_t mask = MENVCFG_FIOM | MENVCFG_CBIE | MENVCFG_CBCFE |
MENVCFG_CBZE | MENVCFG_CDE;
if (riscv_cpu_mxl(env) == MXL_RV64) {
mask |= (cfg->ext_svpbmt ? MENVCFG_PBMTE : 0) |
(cfg->ext_sstc ? MENVCFG_STCE : 0) |
(cfg->ext_smcdeleg ? MENVCFG_CDE : 0) |
(cfg->ext_svadu ? MENVCFG_ADUE : 0);
if (env_archcpu(env)->cfg.ext_zicfilp) {
@ -2717,7 +2991,8 @@ static RISCVException write_menvcfgh(CPURISCVState *env, int csrno,
const RISCVCPUConfig *cfg = riscv_cpu_cfg(env);
uint64_t mask = (cfg->ext_svpbmt ? MENVCFG_PBMTE : 0) |
(cfg->ext_sstc ? MENVCFG_STCE : 0) |
(cfg->ext_svadu ? MENVCFG_ADUE : 0);
(cfg->ext_svadu ? MENVCFG_ADUE : 0) |
(cfg->ext_smcdeleg ? MENVCFG_CDE : 0);
uint64_t valh = (uint64_t)val << 32;
env->menvcfg = (env->menvcfg & ~mask) | (valh & mask);
@ -5304,6 +5579,11 @@ riscv_csr_operations csr_ops[CSR_TABLE_SIZE] = {
[CSR_MNSTATUS] = { "mnstatus", rnmi, read_mnstatus, write_mnstatus,
.min_priv_ver = PRIV_VERSION_1_12_0 },
/* Supervisor Counter Delegation */
[CSR_SCOUNTINHIBIT] = {"scountinhibit", scountinhibit_pred,
read_scountinhibit, write_scountinhibit,
.min_priv_ver = PRIV_VERSION_1_12_0 },
/* Supervisor Trap Setup */
[CSR_SSTATUS] = { "sstatus", smode, read_sstatus, write_sstatus,
NULL, read_sstatus_i128 },