[PATCH v4 5/5] target/riscv: Implement privilege mode filtering for cycle/instret

Atish Patra posted 5 patches 10 months, 3 weeks ago
Maintainers: Palmer Dabbelt <palmer@dabbelt.com>, Alistair Francis <alistair.francis@wdc.com>, Bin Meng <bin.meng@windriver.com>, Weiwei Li <liwei1518@gmail.com>, Daniel Henrique Barboza <dbarboza@ventanamicro.com>, Liu Zhiwei <zhiwei_liu@linux.alibaba.com>
There is a newer version of this series
[PATCH v4 5/5] target/riscv: Implement privilege mode filtering for cycle/instret
Posted by Atish Patra 10 months, 3 weeks ago
Privilege mode filtering can also be emulated for cycle/instret by
tracking host_ticks/icount during each privilege mode switch. This
patch implements that for both cycle/instret and mhpmcounters. The
first one requires Smcntrpmf while the other one requires Sscofpmf
to be enabled.

The cycle/instret are still computed using host ticks when icount
is not enabled. Otherwise, they are computed using raw icount which
is more accurate in icount mode.

Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Signed-off-by: Atish Patra <atishp@rivosinc.com>
---
 target/riscv/cpu.h        | 11 +++++
 target/riscv/cpu_helper.c |  9 +++-
 target/riscv/csr.c        | 95 ++++++++++++++++++++++++++++++---------
 target/riscv/pmu.c        | 43 ++++++++++++++++++
 target/riscv/pmu.h        |  2 +
 5 files changed, 136 insertions(+), 24 deletions(-)

diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index 34617c4c4bab..40d10726155b 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -136,6 +136,15 @@ typedef struct PMUCTRState {
     target_ulong irq_overflow_left;
 } PMUCTRState;
 
+typedef struct PMUFixedCtrState {
+        /* Track cycle and icount for each privilege mode */
+        uint64_t counter[4];
+        uint64_t counter_prev[4];
+        /* Track cycle and icount for each privilege mode when V = 1*/
+        uint64_t counter_virt[2];
+        uint64_t counter_virt_prev[2];
+} PMUFixedCtrState;
+
 struct CPUArchState {
     target_ulong gpr[32];
     target_ulong gprh[32]; /* 64 top bits of the 128-bit registers */
@@ -334,6 +343,8 @@ struct CPUArchState {
     /* PMU event selector configured values for RV32 */
     target_ulong mhpmeventh_val[RV_MAX_MHPMEVENTS];
 
+    PMUFixedCtrState pmu_fixed_ctrs[2];
+
     target_ulong sscratch;
     target_ulong mscratch;
 
diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
index e7e23b34f455..3dddb1b433e8 100644
--- a/target/riscv/cpu_helper.c
+++ b/target/riscv/cpu_helper.c
@@ -715,8 +715,13 @@ void riscv_cpu_set_mode(CPURISCVState *env, target_ulong newpriv)
 {
     g_assert(newpriv <= PRV_M && newpriv != PRV_RESERVED);
 
-    if (icount_enabled() && newpriv != env->priv) {
-        riscv_itrigger_update_priv(env);
+    if (newpriv != env->priv) {
+        if (icount_enabled()) {
+            riscv_itrigger_update_priv(env);
+            riscv_pmu_icount_update_priv(env, newpriv);
+        } else {
+            riscv_pmu_cycle_update_priv(env, newpriv);
+        }
     }
     /* tlb_flush is unnecessary as mode is contained in mmu_idx */
     env->priv = newpriv;
diff --git a/target/riscv/csr.c b/target/riscv/csr.c
index 3bd4aa22374f..307d052021c5 100644
--- a/target/riscv/csr.c
+++ b/target/riscv/csr.c
@@ -782,32 +782,16 @@ static int write_vcsr(CPURISCVState *env, int csrno, target_ulong val)
     return RISCV_EXCP_NONE;
 }
 
+#if defined(CONFIG_USER_ONLY)
 /* User Timers and Counters */
 static target_ulong get_ticks(bool shift)
 {
-    int64_t val;
-    target_ulong result;
-
-#if !defined(CONFIG_USER_ONLY)
-    if (icount_enabled()) {
-        val = icount_get();
-    } else {
-        val = cpu_get_host_ticks();
-    }
-#else
-    val = cpu_get_host_ticks();
-#endif
-
-    if (shift) {
-        result = val >> 32;
-    } else {
-        result = val;
-    }
+    int64_t val = cpu_get_host_ticks();
+    target_ulong result = shift ? val >> 32 : val;
 
     return result;
 }
 
-#if defined(CONFIG_USER_ONLY)
 static RISCVException read_time(CPURISCVState *env, int csrno,
                                 target_ulong *val)
 {
@@ -932,6 +916,70 @@ static int write_mhpmeventh(CPURISCVState *env, int csrno, target_ulong val)
     return RISCV_EXCP_NONE;
 }
 
+static target_ulong riscv_pmu_ctr_get_fixed_counters_val(CPURISCVState *env,
+                                                         int counter_idx,
+                                                         bool upper_half)
+{
+    uint64_t curr_val = 0;
+    target_ulong result = 0;
+    uint64_t *counter_arr = icount_enabled() ? env->pmu_fixed_ctrs[1].counter :
+                            env->pmu_fixed_ctrs[0].counter;
+    uint64_t *counter_arr_virt = icount_enabled() ?
+                                 env->pmu_fixed_ctrs[1].counter_virt :
+                                 env->pmu_fixed_ctrs[0].counter_virt;
+    uint64_t cfg_val = 0;
+
+    if (counter_idx == 0) {
+        cfg_val = upper_half ? ((uint64_t)env->mcyclecfgh << 32) :
+                  env->mcyclecfg;
+    } else if (counter_idx == 2) {
+        cfg_val = upper_half ? ((uint64_t)env->minstretcfgh << 32) :
+                  env->minstretcfg;
+    } else {
+        cfg_val = upper_half ?
+                  ((uint64_t)env->mhpmeventh_val[counter_idx] << 32) :
+                  env->mhpmevent_val[counter_idx];
+    }
+
+    if (!cfg_val) {
+        if (icount_enabled()) {
+            curr_val = icount_get_raw();
+        } else {
+            curr_val = cpu_get_host_ticks();
+        }
+        goto done;
+    }
+
+    if (!(cfg_val & MCYCLECFG_BIT_MINH)) {
+        curr_val += counter_arr[PRV_M];
+    }
+
+    if (!(cfg_val & MCYCLECFG_BIT_SINH)) {
+        curr_val += counter_arr[PRV_S];
+    }
+
+    if (!(cfg_val & MCYCLECFG_BIT_UINH)) {
+        curr_val += counter_arr[PRV_U];
+    }
+
+    if (!(cfg_val & MCYCLECFG_BIT_VSINH)) {
+        curr_val += counter_arr_virt[PRV_S];
+    }
+
+    if (!(cfg_val & MCYCLECFG_BIT_VUINH)) {
+        curr_val += counter_arr_virt[PRV_U];
+    }
+
+done:
+    if (riscv_cpu_mxl(env) == MXL_RV32) {
+        result = upper_half ? curr_val >> 32 : curr_val;
+    } else {
+        result = curr_val;
+    }
+
+    return result;
+}
+
 static int write_mhpmcounter(CPURISCVState *env, int csrno, target_ulong val)
 {
     int ctr_idx = csrno - CSR_MCYCLE;
@@ -941,7 +989,8 @@ static int write_mhpmcounter(CPURISCVState *env, int csrno, target_ulong val)
     counter->mhpmcounter_val = val;
     if (riscv_pmu_ctr_monitor_cycles(env, ctr_idx) ||
         riscv_pmu_ctr_monitor_instructions(env, ctr_idx)) {
-        counter->mhpmcounter_prev = get_ticks(false);
+        counter->mhpmcounter_prev = riscv_pmu_ctr_get_fixed_counters_val(env,
+                                                                ctr_idx, false);
         if (ctr_idx > 2) {
             if (riscv_cpu_mxl(env) == MXL_RV32) {
                 mhpmctr_val = mhpmctr_val |
@@ -968,7 +1017,8 @@ static int write_mhpmcounterh(CPURISCVState *env, int csrno, target_ulong val)
     mhpmctr_val = mhpmctr_val | (mhpmctrh_val << 32);
     if (riscv_pmu_ctr_monitor_cycles(env, ctr_idx) ||
         riscv_pmu_ctr_monitor_instructions(env, ctr_idx)) {
-        counter->mhpmcounterh_prev = get_ticks(true);
+        counter->mhpmcounterh_prev = riscv_pmu_ctr_get_fixed_counters_val(env,
+                                                                 ctr_idx, true);
         if (ctr_idx > 2) {
             riscv_pmu_setup_timer(env, mhpmctr_val, ctr_idx);
         }
@@ -1009,7 +1059,8 @@ static RISCVException riscv_pmu_read_ctr(CPURISCVState *env, target_ulong *val,
      */
     if (riscv_pmu_ctr_monitor_cycles(env, ctr_idx) ||
         riscv_pmu_ctr_monitor_instructions(env, ctr_idx)) {
-        *val = get_ticks(upper_half) - ctr_prev + ctr_val;
+        *val = riscv_pmu_ctr_get_fixed_counters_val(env, ctr_idx, upper_half) -
+                                                    ctr_prev + ctr_val;
     } else {
         *val = ctr_val;
     }
diff --git a/target/riscv/pmu.c b/target/riscv/pmu.c
index 0e7d58b8a5c2..8b6cc4c6bb4d 100644
--- a/target/riscv/pmu.c
+++ b/target/riscv/pmu.c
@@ -19,6 +19,7 @@
 #include "qemu/osdep.h"
 #include "qemu/log.h"
 #include "qemu/error-report.h"
+#include "qemu/timer.h"
 #include "cpu.h"
 #include "pmu.h"
 #include "sysemu/cpu-timers.h"
@@ -176,6 +177,48 @@ static int riscv_pmu_incr_ctr_rv64(RISCVCPU *cpu, uint32_t ctr_idx)
     return 0;
 }
 
+void riscv_pmu_icount_update_priv(CPURISCVState *env, target_ulong newpriv)
+{
+    uint64_t delta;
+    uint64_t *counter_arr;
+    uint64_t *counter_arr_prev;
+    uint64_t current_icount = icount_get_raw();
+
+    if (env->virt_enabled) {
+        counter_arr = env->pmu_fixed_ctrs[1].counter_virt;
+        counter_arr_prev = env->pmu_fixed_ctrs[1].counter_virt_prev;
+    } else {
+        counter_arr = env->pmu_fixed_ctrs[1].counter;
+        counter_arr_prev = env->pmu_fixed_ctrs[1].counter_prev;
+    }
+
+    counter_arr_prev[newpriv] = current_icount;
+    delta = current_icount - counter_arr_prev[env->priv];
+
+    counter_arr[env->priv] += delta;
+}
+
+void riscv_pmu_cycle_update_priv(CPURISCVState *env, target_ulong newpriv)
+{
+    uint64_t delta;
+    uint64_t *counter_arr;
+    uint64_t *counter_arr_prev;
+    uint64_t current_host_ticks = cpu_get_host_ticks();
+
+    if (env->virt_enabled) {
+        counter_arr = env->pmu_fixed_ctrs[0].counter_virt;
+        counter_arr_prev = env->pmu_fixed_ctrs[0].counter_virt_prev;
+    } else {
+        counter_arr = env->pmu_fixed_ctrs[0].counter;
+        counter_arr_prev = env->pmu_fixed_ctrs[0].counter_prev;
+    }
+
+    counter_arr_prev[newpriv] = current_host_ticks;
+    delta = current_host_ticks - counter_arr_prev[env->priv];
+
+    counter_arr[env->priv] += delta;
+}
+
 int riscv_pmu_incr_ctr(RISCVCPU *cpu, enum riscv_pmu_event_idx event_idx)
 {
     uint32_t ctr_idx;
diff --git a/target/riscv/pmu.h b/target/riscv/pmu.h
index 505fc850d38e..50de6031a730 100644
--- a/target/riscv/pmu.h
+++ b/target/riscv/pmu.h
@@ -31,3 +31,5 @@ int riscv_pmu_incr_ctr(RISCVCPU *cpu, enum riscv_pmu_event_idx event_idx);
 void riscv_pmu_generate_fdt_node(void *fdt, uint32_t cmask, char *pmu_name);
 int riscv_pmu_setup_timer(CPURISCVState *env, uint64_t value,
                           uint32_t ctr_idx);
+void riscv_pmu_icount_update_priv(CPURISCVState *env, target_ulong newpriv);
+void riscv_pmu_cycle_update_priv(CPURISCVState *env, target_ulong newpriv);
-- 
2.34.1
Re: [PATCH v4 5/5] target/riscv: Implement privilege mode filtering for cycle/instret
Posted by Alistair Francis 9 months, 2 weeks ago
On Tue, Jan 9, 2024 at 10:29 AM Atish Patra <atishp@rivosinc.com> wrote:
>
> Privilege mode filtering can also be emulated for cycle/instret by
> tracking host_ticks/icount during each privilege mode switch. This
> patch implements that for both cycle/instret and mhpmcounters. The
> first one requires Smcntrpmf while the other one requires Sscofpmf
> to be enabled.
>
> The cycle/instret are still computed using host ticks when icount
> is not enabled. Otherwise, they are computed using raw icount which
> is more accurate in icount mode.
>
> Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
> Signed-off-by: Atish Patra <atishp@rivosinc.com>
> ---
>  target/riscv/cpu.h        | 11 +++++
>  target/riscv/cpu_helper.c |  9 +++-
>  target/riscv/csr.c        | 95 ++++++++++++++++++++++++++++++---------
>  target/riscv/pmu.c        | 43 ++++++++++++++++++
>  target/riscv/pmu.h        |  2 +
>  5 files changed, 136 insertions(+), 24 deletions(-)
>
> diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
> index 34617c4c4bab..40d10726155b 100644
> --- a/target/riscv/cpu.h
> +++ b/target/riscv/cpu.h
> @@ -136,6 +136,15 @@ typedef struct PMUCTRState {
>      target_ulong irq_overflow_left;
>  } PMUCTRState;
>
> +typedef struct PMUFixedCtrState {
> +        /* Track cycle and icount for each privilege mode */
> +        uint64_t counter[4];
> +        uint64_t counter_prev[4];
> +        /* Track cycle and icount for each privilege mode when V = 1*/
> +        uint64_t counter_virt[2];
> +        uint64_t counter_virt_prev[2];
> +} PMUFixedCtrState;
> +
>  struct CPUArchState {
>      target_ulong gpr[32];
>      target_ulong gprh[32]; /* 64 top bits of the 128-bit registers */
> @@ -334,6 +343,8 @@ struct CPUArchState {
>      /* PMU event selector configured values for RV32 */
>      target_ulong mhpmeventh_val[RV_MAX_MHPMEVENTS];
>
> +    PMUFixedCtrState pmu_fixed_ctrs[2];
> +
>      target_ulong sscratch;
>      target_ulong mscratch;
>
> diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
> index e7e23b34f455..3dddb1b433e8 100644
> --- a/target/riscv/cpu_helper.c
> +++ b/target/riscv/cpu_helper.c
> @@ -715,8 +715,13 @@ void riscv_cpu_set_mode(CPURISCVState *env, target_ulong newpriv)
>  {
>      g_assert(newpriv <= PRV_M && newpriv != PRV_RESERVED);
>
> -    if (icount_enabled() && newpriv != env->priv) {
> -        riscv_itrigger_update_priv(env);
> +    if (newpriv != env->priv) {
> +        if (icount_enabled()) {
> +            riscv_itrigger_update_priv(env);
> +            riscv_pmu_icount_update_priv(env, newpriv);
> +        } else {
> +            riscv_pmu_cycle_update_priv(env, newpriv);
> +        }
>      }
>      /* tlb_flush is unnecessary as mode is contained in mmu_idx */
>      env->priv = newpriv;
> diff --git a/target/riscv/csr.c b/target/riscv/csr.c
> index 3bd4aa22374f..307d052021c5 100644
> --- a/target/riscv/csr.c
> +++ b/target/riscv/csr.c
> @@ -782,32 +782,16 @@ static int write_vcsr(CPURISCVState *env, int csrno, target_ulong val)
>      return RISCV_EXCP_NONE;
>  }
>
> +#if defined(CONFIG_USER_ONLY)
>  /* User Timers and Counters */
>  static target_ulong get_ticks(bool shift)
>  {
> -    int64_t val;
> -    target_ulong result;
> -
> -#if !defined(CONFIG_USER_ONLY)
> -    if (icount_enabled()) {
> -        val = icount_get();
> -    } else {
> -        val = cpu_get_host_ticks();
> -    }
> -#else
> -    val = cpu_get_host_ticks();
> -#endif
> -
> -    if (shift) {
> -        result = val >> 32;
> -    } else {
> -        result = val;
> -    }
> +    int64_t val = cpu_get_host_ticks();
> +    target_ulong result = shift ? val >> 32 : val;
>
>      return result;
>  }
>
> -#if defined(CONFIG_USER_ONLY)
>  static RISCVException read_time(CPURISCVState *env, int csrno,
>                                  target_ulong *val)
>  {
> @@ -932,6 +916,70 @@ static int write_mhpmeventh(CPURISCVState *env, int csrno, target_ulong val)
>      return RISCV_EXCP_NONE;
>  }
>
> +static target_ulong riscv_pmu_ctr_get_fixed_counters_val(CPURISCVState *env,
> +                                                         int counter_idx,
> +                                                         bool upper_half)
> +{
> +    uint64_t curr_val = 0;
> +    target_ulong result = 0;
> +    uint64_t *counter_arr = icount_enabled() ? env->pmu_fixed_ctrs[1].counter :
> +                            env->pmu_fixed_ctrs[0].counter;

I don't follow why we access different arrays depending if
icount_enabled(). Can we at least comment this?

Alistair

> +    uint64_t *counter_arr_virt = icount_enabled() ?
> +                                 env->pmu_fixed_ctrs[1].counter_virt :
> +                                 env->pmu_fixed_ctrs[0].counter_virt;
> +    uint64_t cfg_val = 0;
> +
> +    if (counter_idx == 0) {
> +        cfg_val = upper_half ? ((uint64_t)env->mcyclecfgh << 32) :
> +                  env->mcyclecfg;
> +    } else if (counter_idx == 2) {
> +        cfg_val = upper_half ? ((uint64_t)env->minstretcfgh << 32) :
> +                  env->minstretcfg;
> +    } else {
> +        cfg_val = upper_half ?
> +                  ((uint64_t)env->mhpmeventh_val[counter_idx] << 32) :
> +                  env->mhpmevent_val[counter_idx];
> +    }
> +
> +    if (!cfg_val) {
> +        if (icount_enabled()) {
> +            curr_val = icount_get_raw();
> +        } else {
> +            curr_val = cpu_get_host_ticks();
> +        }
> +        goto done;
> +    }
> +
> +    if (!(cfg_val & MCYCLECFG_BIT_MINH)) {
> +        curr_val += counter_arr[PRV_M];
> +    }
> +
> +    if (!(cfg_val & MCYCLECFG_BIT_SINH)) {
> +        curr_val += counter_arr[PRV_S];
> +    }
> +
> +    if (!(cfg_val & MCYCLECFG_BIT_UINH)) {
> +        curr_val += counter_arr[PRV_U];
> +    }
> +
> +    if (!(cfg_val & MCYCLECFG_BIT_VSINH)) {
> +        curr_val += counter_arr_virt[PRV_S];
> +    }
> +
> +    if (!(cfg_val & MCYCLECFG_BIT_VUINH)) {
> +        curr_val += counter_arr_virt[PRV_U];
> +    }
> +
> +done:
> +    if (riscv_cpu_mxl(env) == MXL_RV32) {
> +        result = upper_half ? curr_val >> 32 : curr_val;
> +    } else {
> +        result = curr_val;
> +    }
> +
> +    return result;
> +}
> +
>  static int write_mhpmcounter(CPURISCVState *env, int csrno, target_ulong val)
>  {
>      int ctr_idx = csrno - CSR_MCYCLE;
> @@ -941,7 +989,8 @@ static int write_mhpmcounter(CPURISCVState *env, int csrno, target_ulong val)
>      counter->mhpmcounter_val = val;
>      if (riscv_pmu_ctr_monitor_cycles(env, ctr_idx) ||
>          riscv_pmu_ctr_monitor_instructions(env, ctr_idx)) {
> -        counter->mhpmcounter_prev = get_ticks(false);
> +        counter->mhpmcounter_prev = riscv_pmu_ctr_get_fixed_counters_val(env,
> +                                                                ctr_idx, false);
>          if (ctr_idx > 2) {
>              if (riscv_cpu_mxl(env) == MXL_RV32) {
>                  mhpmctr_val = mhpmctr_val |
> @@ -968,7 +1017,8 @@ static int write_mhpmcounterh(CPURISCVState *env, int csrno, target_ulong val)
>      mhpmctr_val = mhpmctr_val | (mhpmctrh_val << 32);
>      if (riscv_pmu_ctr_monitor_cycles(env, ctr_idx) ||
>          riscv_pmu_ctr_monitor_instructions(env, ctr_idx)) {
> -        counter->mhpmcounterh_prev = get_ticks(true);
> +        counter->mhpmcounterh_prev = riscv_pmu_ctr_get_fixed_counters_val(env,
> +                                                                 ctr_idx, true);
>          if (ctr_idx > 2) {
>              riscv_pmu_setup_timer(env, mhpmctr_val, ctr_idx);
>          }
> @@ -1009,7 +1059,8 @@ static RISCVException riscv_pmu_read_ctr(CPURISCVState *env, target_ulong *val,
>       */
>      if (riscv_pmu_ctr_monitor_cycles(env, ctr_idx) ||
>          riscv_pmu_ctr_monitor_instructions(env, ctr_idx)) {
> -        *val = get_ticks(upper_half) - ctr_prev + ctr_val;
> +        *val = riscv_pmu_ctr_get_fixed_counters_val(env, ctr_idx, upper_half) -
> +                                                    ctr_prev + ctr_val;
>      } else {
>          *val = ctr_val;
>      }
> diff --git a/target/riscv/pmu.c b/target/riscv/pmu.c
> index 0e7d58b8a5c2..8b6cc4c6bb4d 100644
> --- a/target/riscv/pmu.c
> +++ b/target/riscv/pmu.c
> @@ -19,6 +19,7 @@
>  #include "qemu/osdep.h"
>  #include "qemu/log.h"
>  #include "qemu/error-report.h"
> +#include "qemu/timer.h"
>  #include "cpu.h"
>  #include "pmu.h"
>  #include "sysemu/cpu-timers.h"
> @@ -176,6 +177,48 @@ static int riscv_pmu_incr_ctr_rv64(RISCVCPU *cpu, uint32_t ctr_idx)
>      return 0;
>  }
>
> +void riscv_pmu_icount_update_priv(CPURISCVState *env, target_ulong newpriv)
> +{
> +    uint64_t delta;
> +    uint64_t *counter_arr;
> +    uint64_t *counter_arr_prev;
> +    uint64_t current_icount = icount_get_raw();
> +
> +    if (env->virt_enabled) {
> +        counter_arr = env->pmu_fixed_ctrs[1].counter_virt;
> +        counter_arr_prev = env->pmu_fixed_ctrs[1].counter_virt_prev;
> +    } else {
> +        counter_arr = env->pmu_fixed_ctrs[1].counter;
> +        counter_arr_prev = env->pmu_fixed_ctrs[1].counter_prev;
> +    }
> +
> +    counter_arr_prev[newpriv] = current_icount;
> +    delta = current_icount - counter_arr_prev[env->priv];
> +
> +    counter_arr[env->priv] += delta;
> +}
> +
> +void riscv_pmu_cycle_update_priv(CPURISCVState *env, target_ulong newpriv)
> +{
> +    uint64_t delta;
> +    uint64_t *counter_arr;
> +    uint64_t *counter_arr_prev;
> +    uint64_t current_host_ticks = cpu_get_host_ticks();
> +
> +    if (env->virt_enabled) {
> +        counter_arr = env->pmu_fixed_ctrs[0].counter_virt;
> +        counter_arr_prev = env->pmu_fixed_ctrs[0].counter_virt_prev;
> +    } else {
> +        counter_arr = env->pmu_fixed_ctrs[0].counter;
> +        counter_arr_prev = env->pmu_fixed_ctrs[0].counter_prev;
> +    }
> +
> +    counter_arr_prev[newpriv] = current_host_ticks;
> +    delta = current_host_ticks - counter_arr_prev[env->priv];
> +
> +    counter_arr[env->priv] += delta;
> +}
> +
>  int riscv_pmu_incr_ctr(RISCVCPU *cpu, enum riscv_pmu_event_idx event_idx)
>  {
>      uint32_t ctr_idx;
> diff --git a/target/riscv/pmu.h b/target/riscv/pmu.h
> index 505fc850d38e..50de6031a730 100644
> --- a/target/riscv/pmu.h
> +++ b/target/riscv/pmu.h
> @@ -31,3 +31,5 @@ int riscv_pmu_incr_ctr(RISCVCPU *cpu, enum riscv_pmu_event_idx event_idx);
>  void riscv_pmu_generate_fdt_node(void *fdt, uint32_t cmask, char *pmu_name);
>  int riscv_pmu_setup_timer(CPURISCVState *env, uint64_t value,
>                            uint32_t ctr_idx);
> +void riscv_pmu_icount_update_priv(CPURISCVState *env, target_ulong newpriv);
> +void riscv_pmu_cycle_update_priv(CPURISCVState *env, target_ulong newpriv);
> --
> 2.34.1
>
>
Re: [PATCH v4 5/5] target/riscv: Implement privilege mode filtering for cycle/instret
Posted by Alistair Francis 10 months, 1 week ago
On Tue, Jan 9, 2024 at 10:29 AM Atish Patra <atishp@rivosinc.com> wrote:
>
> Privilege mode filtering can also be emulated for cycle/instret by
> tracking host_ticks/icount during each privilege mode switch. This
> patch implements that for both cycle/instret and mhpmcounters. The
> first one requires Smcntrpmf while the other one requires Sscofpmf
> to be enabled.
>
> The cycle/instret are still computed using host ticks when icount
> is not enabled. Otherwise, they are computed using raw icount which
> is more accurate in icount mode.
>
> Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
> Signed-off-by: Atish Patra <atishp@rivosinc.com>
> ---
>  target/riscv/cpu.h        | 11 +++++
>  target/riscv/cpu_helper.c |  9 +++-
>  target/riscv/csr.c        | 95 ++++++++++++++++++++++++++++++---------
>  target/riscv/pmu.c        | 43 ++++++++++++++++++
>  target/riscv/pmu.h        |  2 +
>  5 files changed, 136 insertions(+), 24 deletions(-)
>
> diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
> index 34617c4c4bab..40d10726155b 100644
> --- a/target/riscv/cpu.h
> +++ b/target/riscv/cpu.h
> @@ -136,6 +136,15 @@ typedef struct PMUCTRState {
>      target_ulong irq_overflow_left;
>  } PMUCTRState;
>
> +typedef struct PMUFixedCtrState {
> +        /* Track cycle and icount for each privilege mode */
> +        uint64_t counter[4];
> +        uint64_t counter_prev[4];

Are these two used?

Alistair

> +        /* Track cycle and icount for each privilege mode when V = 1*/
> +        uint64_t counter_virt[2];
> +        uint64_t counter_virt_prev[2];
> +} PMUFixedCtrState;
> +
>  struct CPUArchState {
>      target_ulong gpr[32];
>      target_ulong gprh[32]; /* 64 top bits of the 128-bit registers */
> @@ -334,6 +343,8 @@ struct CPUArchState {
>      /* PMU event selector configured values for RV32 */
>      target_ulong mhpmeventh_val[RV_MAX_MHPMEVENTS];
>
> +    PMUFixedCtrState pmu_fixed_ctrs[2];
> +
>      target_ulong sscratch;
>      target_ulong mscratch;
>
> diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
> index e7e23b34f455..3dddb1b433e8 100644
> --- a/target/riscv/cpu_helper.c
> +++ b/target/riscv/cpu_helper.c
> @@ -715,8 +715,13 @@ void riscv_cpu_set_mode(CPURISCVState *env, target_ulong newpriv)
>  {
>      g_assert(newpriv <= PRV_M && newpriv != PRV_RESERVED);
>
> -    if (icount_enabled() && newpriv != env->priv) {
> -        riscv_itrigger_update_priv(env);
> +    if (newpriv != env->priv) {
> +        if (icount_enabled()) {
> +            riscv_itrigger_update_priv(env);
> +            riscv_pmu_icount_update_priv(env, newpriv);
> +        } else {
> +            riscv_pmu_cycle_update_priv(env, newpriv);
> +        }
>      }
>      /* tlb_flush is unnecessary as mode is contained in mmu_idx */
>      env->priv = newpriv;
> diff --git a/target/riscv/csr.c b/target/riscv/csr.c
> index 3bd4aa22374f..307d052021c5 100644
> --- a/target/riscv/csr.c
> +++ b/target/riscv/csr.c
> @@ -782,32 +782,16 @@ static int write_vcsr(CPURISCVState *env, int csrno, target_ulong val)
>      return RISCV_EXCP_NONE;
>  }
>
> +#if defined(CONFIG_USER_ONLY)
>  /* User Timers and Counters */
>  static target_ulong get_ticks(bool shift)
>  {
> -    int64_t val;
> -    target_ulong result;
> -
> -#if !defined(CONFIG_USER_ONLY)
> -    if (icount_enabled()) {
> -        val = icount_get();
> -    } else {
> -        val = cpu_get_host_ticks();
> -    }
> -#else
> -    val = cpu_get_host_ticks();
> -#endif
> -
> -    if (shift) {
> -        result = val >> 32;
> -    } else {
> -        result = val;
> -    }
> +    int64_t val = cpu_get_host_ticks();
> +    target_ulong result = shift ? val >> 32 : val;
>
>      return result;
>  }
>
> -#if defined(CONFIG_USER_ONLY)
>  static RISCVException read_time(CPURISCVState *env, int csrno,
>                                  target_ulong *val)
>  {
> @@ -932,6 +916,70 @@ static int write_mhpmeventh(CPURISCVState *env, int csrno, target_ulong val)
>      return RISCV_EXCP_NONE;
>  }
>
> +static target_ulong riscv_pmu_ctr_get_fixed_counters_val(CPURISCVState *env,
> +                                                         int counter_idx,
> +                                                         bool upper_half)
> +{
> +    uint64_t curr_val = 0;
> +    target_ulong result = 0;
> +    uint64_t *counter_arr = icount_enabled() ? env->pmu_fixed_ctrs[1].counter :
> +                            env->pmu_fixed_ctrs[0].counter;
> +    uint64_t *counter_arr_virt = icount_enabled() ?
> +                                 env->pmu_fixed_ctrs[1].counter_virt :
> +                                 env->pmu_fixed_ctrs[0].counter_virt;
> +    uint64_t cfg_val = 0;
> +
> +    if (counter_idx == 0) {
> +        cfg_val = upper_half ? ((uint64_t)env->mcyclecfgh << 32) :
> +                  env->mcyclecfg;
> +    } else if (counter_idx == 2) {
> +        cfg_val = upper_half ? ((uint64_t)env->minstretcfgh << 32) :
> +                  env->minstretcfg;
> +    } else {
> +        cfg_val = upper_half ?
> +                  ((uint64_t)env->mhpmeventh_val[counter_idx] << 32) :
> +                  env->mhpmevent_val[counter_idx];
> +    }
> +
> +    if (!cfg_val) {
> +        if (icount_enabled()) {
> +            curr_val = icount_get_raw();
> +        } else {
> +            curr_val = cpu_get_host_ticks();
> +        }
> +        goto done;
> +    }
> +
> +    if (!(cfg_val & MCYCLECFG_BIT_MINH)) {
> +        curr_val += counter_arr[PRV_M];
> +    }
> +
> +    if (!(cfg_val & MCYCLECFG_BIT_SINH)) {
> +        curr_val += counter_arr[PRV_S];
> +    }
> +
> +    if (!(cfg_val & MCYCLECFG_BIT_UINH)) {
> +        curr_val += counter_arr[PRV_U];
> +    }
> +
> +    if (!(cfg_val & MCYCLECFG_BIT_VSINH)) {
> +        curr_val += counter_arr_virt[PRV_S];
> +    }
> +
> +    if (!(cfg_val & MCYCLECFG_BIT_VUINH)) {
> +        curr_val += counter_arr_virt[PRV_U];
> +    }
> +
> +done:
> +    if (riscv_cpu_mxl(env) == MXL_RV32) {
> +        result = upper_half ? curr_val >> 32 : curr_val;
> +    } else {
> +        result = curr_val;
> +    }
> +
> +    return result;
> +}
> +
>  static int write_mhpmcounter(CPURISCVState *env, int csrno, target_ulong val)
>  {
>      int ctr_idx = csrno - CSR_MCYCLE;
> @@ -941,7 +989,8 @@ static int write_mhpmcounter(CPURISCVState *env, int csrno, target_ulong val)
>      counter->mhpmcounter_val = val;
>      if (riscv_pmu_ctr_monitor_cycles(env, ctr_idx) ||
>          riscv_pmu_ctr_monitor_instructions(env, ctr_idx)) {
> -        counter->mhpmcounter_prev = get_ticks(false);
> +        counter->mhpmcounter_prev = riscv_pmu_ctr_get_fixed_counters_val(env,
> +                                                                ctr_idx, false);
>          if (ctr_idx > 2) {
>              if (riscv_cpu_mxl(env) == MXL_RV32) {
>                  mhpmctr_val = mhpmctr_val |
> @@ -968,7 +1017,8 @@ static int write_mhpmcounterh(CPURISCVState *env, int csrno, target_ulong val)
>      mhpmctr_val = mhpmctr_val | (mhpmctrh_val << 32);
>      if (riscv_pmu_ctr_monitor_cycles(env, ctr_idx) ||
>          riscv_pmu_ctr_monitor_instructions(env, ctr_idx)) {
> -        counter->mhpmcounterh_prev = get_ticks(true);
> +        counter->mhpmcounterh_prev = riscv_pmu_ctr_get_fixed_counters_val(env,
> +                                                                 ctr_idx, true);
>          if (ctr_idx > 2) {
>              riscv_pmu_setup_timer(env, mhpmctr_val, ctr_idx);
>          }
> @@ -1009,7 +1059,8 @@ static RISCVException riscv_pmu_read_ctr(CPURISCVState *env, target_ulong *val,
>       */
>      if (riscv_pmu_ctr_monitor_cycles(env, ctr_idx) ||
>          riscv_pmu_ctr_monitor_instructions(env, ctr_idx)) {
> -        *val = get_ticks(upper_half) - ctr_prev + ctr_val;
> +        *val = riscv_pmu_ctr_get_fixed_counters_val(env, ctr_idx, upper_half) -
> +                                                    ctr_prev + ctr_val;
>      } else {
>          *val = ctr_val;
>      }
> diff --git a/target/riscv/pmu.c b/target/riscv/pmu.c
> index 0e7d58b8a5c2..8b6cc4c6bb4d 100644
> --- a/target/riscv/pmu.c
> +++ b/target/riscv/pmu.c
> @@ -19,6 +19,7 @@
>  #include "qemu/osdep.h"
>  #include "qemu/log.h"
>  #include "qemu/error-report.h"
> +#include "qemu/timer.h"
>  #include "cpu.h"
>  #include "pmu.h"
>  #include "sysemu/cpu-timers.h"
> @@ -176,6 +177,48 @@ static int riscv_pmu_incr_ctr_rv64(RISCVCPU *cpu, uint32_t ctr_idx)
>      return 0;
>  }
>
> +void riscv_pmu_icount_update_priv(CPURISCVState *env, target_ulong newpriv)
> +{
> +    uint64_t delta;
> +    uint64_t *counter_arr;
> +    uint64_t *counter_arr_prev;
> +    uint64_t current_icount = icount_get_raw();
> +
> +    if (env->virt_enabled) {
> +        counter_arr = env->pmu_fixed_ctrs[1].counter_virt;
> +        counter_arr_prev = env->pmu_fixed_ctrs[1].counter_virt_prev;
> +    } else {
> +        counter_arr = env->pmu_fixed_ctrs[1].counter;
> +        counter_arr_prev = env->pmu_fixed_ctrs[1].counter_prev;
> +    }
> +
> +    counter_arr_prev[newpriv] = current_icount;
> +    delta = current_icount - counter_arr_prev[env->priv];
> +
> +    counter_arr[env->priv] += delta;
> +}
> +
> +void riscv_pmu_cycle_update_priv(CPURISCVState *env, target_ulong newpriv)
> +{
> +    uint64_t delta;
> +    uint64_t *counter_arr;
> +    uint64_t *counter_arr_prev;
> +    uint64_t current_host_ticks = cpu_get_host_ticks();
> +
> +    if (env->virt_enabled) {
> +        counter_arr = env->pmu_fixed_ctrs[0].counter_virt;
> +        counter_arr_prev = env->pmu_fixed_ctrs[0].counter_virt_prev;
> +    } else {
> +        counter_arr = env->pmu_fixed_ctrs[0].counter;
> +        counter_arr_prev = env->pmu_fixed_ctrs[0].counter_prev;
> +    }
> +
> +    counter_arr_prev[newpriv] = current_host_ticks;
> +    delta = current_host_ticks - counter_arr_prev[env->priv];
> +
> +    counter_arr[env->priv] += delta;
> +}
> +
>  int riscv_pmu_incr_ctr(RISCVCPU *cpu, enum riscv_pmu_event_idx event_idx)
>  {
>      uint32_t ctr_idx;
> diff --git a/target/riscv/pmu.h b/target/riscv/pmu.h
> index 505fc850d38e..50de6031a730 100644
> --- a/target/riscv/pmu.h
> +++ b/target/riscv/pmu.h
> @@ -31,3 +31,5 @@ int riscv_pmu_incr_ctr(RISCVCPU *cpu, enum riscv_pmu_event_idx event_idx);
>  void riscv_pmu_generate_fdt_node(void *fdt, uint32_t cmask, char *pmu_name);
>  int riscv_pmu_setup_timer(CPURISCVState *env, uint64_t value,
>                            uint32_t ctr_idx);
> +void riscv_pmu_icount_update_priv(CPURISCVState *env, target_ulong newpriv);
> +void riscv_pmu_cycle_update_priv(CPURISCVState *env, target_ulong newpriv);
> --
> 2.34.1
>
>
Re: [PATCH v4 5/5] target/riscv: Implement privilege mode filtering for cycle/instret
Posted by Atish Kumar Patra 10 months, 1 week ago
On Sun, Jan 21, 2024 at 9:04 PM Alistair Francis <alistair23@gmail.com> wrote:
>
> On Tue, Jan 9, 2024 at 10:29 AM Atish Patra <atishp@rivosinc.com> wrote:
> >
> > Privilege mode filtering can also be emulated for cycle/instret by
> > tracking host_ticks/icount during each privilege mode switch. This
> > patch implements that for both cycle/instret and mhpmcounters. The
> > first one requires Smcntrpmf while the other one requires Sscofpmf
> > to be enabled.
> >
> > The cycle/instret are still computed using host ticks when icount
> > is not enabled. Otherwise, they are computed using raw icount which
> > is more accurate in icount mode.
> >
> > Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
> > Signed-off-by: Atish Patra <atishp@rivosinc.com>
> > ---
> >  target/riscv/cpu.h        | 11 +++++
> >  target/riscv/cpu_helper.c |  9 +++-
> >  target/riscv/csr.c        | 95 ++++++++++++++++++++++++++++++---------
> >  target/riscv/pmu.c        | 43 ++++++++++++++++++
> >  target/riscv/pmu.h        |  2 +
> >  5 files changed, 136 insertions(+), 24 deletions(-)
> >
> > diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
> > index 34617c4c4bab..40d10726155b 100644
> > --- a/target/riscv/cpu.h
> > +++ b/target/riscv/cpu.h
> > @@ -136,6 +136,15 @@ typedef struct PMUCTRState {
> >      target_ulong irq_overflow_left;
> >  } PMUCTRState;
> >
> > +typedef struct PMUFixedCtrState {
> > +        /* Track cycle and icount for each privilege mode */
> > +        uint64_t counter[4];
> > +        uint64_t counter_prev[4];
>
> Are these two used?
>

Yes. That's where it tracks the current/previous value cycle/instret.
riscv_pmu_icount_update_priv/riscv_pmu_cycle_update_priv

The priv mode based filtering is enabled in riscv_pmu_ctr_get_fixed_counters_val
using "counter" afterwards.

Did I misunderstand your question ?

> Alistair
>
> > +        /* Track cycle and icount for each privilege mode when V = 1*/
> > +        uint64_t counter_virt[2];
> > +        uint64_t counter_virt_prev[2];
> > +} PMUFixedCtrState;
> > +
> >  struct CPUArchState {
> >      target_ulong gpr[32];
> >      target_ulong gprh[32]; /* 64 top bits of the 128-bit registers */
> > @@ -334,6 +343,8 @@ struct CPUArchState {
> >      /* PMU event selector configured values for RV32 */
> >      target_ulong mhpmeventh_val[RV_MAX_MHPMEVENTS];
> >
> > +    PMUFixedCtrState pmu_fixed_ctrs[2];
> > +
> >      target_ulong sscratch;
> >      target_ulong mscratch;
> >
> > diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
> > index e7e23b34f455..3dddb1b433e8 100644
> > --- a/target/riscv/cpu_helper.c
> > +++ b/target/riscv/cpu_helper.c
> > @@ -715,8 +715,13 @@ void riscv_cpu_set_mode(CPURISCVState *env, target_ulong newpriv)
> >  {
> >      g_assert(newpriv <= PRV_M && newpriv != PRV_RESERVED);
> >
> > -    if (icount_enabled() && newpriv != env->priv) {
> > -        riscv_itrigger_update_priv(env);
> > +    if (newpriv != env->priv) {
> > +        if (icount_enabled()) {
> > +            riscv_itrigger_update_priv(env);
> > +            riscv_pmu_icount_update_priv(env, newpriv);
> > +        } else {
> > +            riscv_pmu_cycle_update_priv(env, newpriv);
> > +        }
> >      }
> >      /* tlb_flush is unnecessary as mode is contained in mmu_idx */
> >      env->priv = newpriv;
> > diff --git a/target/riscv/csr.c b/target/riscv/csr.c
> > index 3bd4aa22374f..307d052021c5 100644
> > --- a/target/riscv/csr.c
> > +++ b/target/riscv/csr.c
> > @@ -782,32 +782,16 @@ static int write_vcsr(CPURISCVState *env, int csrno, target_ulong val)
> >      return RISCV_EXCP_NONE;
> >  }
> >
> > +#if defined(CONFIG_USER_ONLY)
> >  /* User Timers and Counters */
> >  static target_ulong get_ticks(bool shift)
> >  {
> > -    int64_t val;
> > -    target_ulong result;
> > -
> > -#if !defined(CONFIG_USER_ONLY)
> > -    if (icount_enabled()) {
> > -        val = icount_get();
> > -    } else {
> > -        val = cpu_get_host_ticks();
> > -    }
> > -#else
> > -    val = cpu_get_host_ticks();
> > -#endif
> > -
> > -    if (shift) {
> > -        result = val >> 32;
> > -    } else {
> > -        result = val;
> > -    }
> > +    int64_t val = cpu_get_host_ticks();
> > +    target_ulong result = shift ? val >> 32 : val;
> >
> >      return result;
> >  }
> >
> > -#if defined(CONFIG_USER_ONLY)
> >  static RISCVException read_time(CPURISCVState *env, int csrno,
> >                                  target_ulong *val)
> >  {
> > @@ -932,6 +916,70 @@ static int write_mhpmeventh(CPURISCVState *env, int csrno, target_ulong val)
> >      return RISCV_EXCP_NONE;
> >  }
> >
> > +static target_ulong riscv_pmu_ctr_get_fixed_counters_val(CPURISCVState *env,
> > +                                                         int counter_idx,
> > +                                                         bool upper_half)
> > +{
> > +    uint64_t curr_val = 0;
> > +    target_ulong result = 0;
> > +    uint64_t *counter_arr = icount_enabled() ? env->pmu_fixed_ctrs[1].counter :
> > +                            env->pmu_fixed_ctrs[0].counter;
> > +    uint64_t *counter_arr_virt = icount_enabled() ?
> > +                                 env->pmu_fixed_ctrs[1].counter_virt :
> > +                                 env->pmu_fixed_ctrs[0].counter_virt;
> > +    uint64_t cfg_val = 0;
> > +
> > +    if (counter_idx == 0) {
> > +        cfg_val = upper_half ? ((uint64_t)env->mcyclecfgh << 32) :
> > +                  env->mcyclecfg;
> > +    } else if (counter_idx == 2) {
> > +        cfg_val = upper_half ? ((uint64_t)env->minstretcfgh << 32) :
> > +                  env->minstretcfg;
> > +    } else {
> > +        cfg_val = upper_half ?
> > +                  ((uint64_t)env->mhpmeventh_val[counter_idx] << 32) :
> > +                  env->mhpmevent_val[counter_idx];
> > +    }
> > +
> > +    if (!cfg_val) {
> > +        if (icount_enabled()) {
> > +            curr_val = icount_get_raw();
> > +        } else {
> > +            curr_val = cpu_get_host_ticks();
> > +        }
> > +        goto done;
> > +    }
> > +
> > +    if (!(cfg_val & MCYCLECFG_BIT_MINH)) {
> > +        curr_val += counter_arr[PRV_M];
> > +    }
> > +
> > +    if (!(cfg_val & MCYCLECFG_BIT_SINH)) {
> > +        curr_val += counter_arr[PRV_S];
> > +    }
> > +
> > +    if (!(cfg_val & MCYCLECFG_BIT_UINH)) {
> > +        curr_val += counter_arr[PRV_U];
> > +    }
> > +
> > +    if (!(cfg_val & MCYCLECFG_BIT_VSINH)) {
> > +        curr_val += counter_arr_virt[PRV_S];
> > +    }
> > +
> > +    if (!(cfg_val & MCYCLECFG_BIT_VUINH)) {
> > +        curr_val += counter_arr_virt[PRV_U];
> > +    }
> > +
> > +done:
> > +    if (riscv_cpu_mxl(env) == MXL_RV32) {
> > +        result = upper_half ? curr_val >> 32 : curr_val;
> > +    } else {
> > +        result = curr_val;
> > +    }
> > +
> > +    return result;
> > +}
> > +
> >  static int write_mhpmcounter(CPURISCVState *env, int csrno, target_ulong val)
> >  {
> >      int ctr_idx = csrno - CSR_MCYCLE;
> > @@ -941,7 +989,8 @@ static int write_mhpmcounter(CPURISCVState *env, int csrno, target_ulong val)
> >      counter->mhpmcounter_val = val;
> >      if (riscv_pmu_ctr_monitor_cycles(env, ctr_idx) ||
> >          riscv_pmu_ctr_monitor_instructions(env, ctr_idx)) {
> > -        counter->mhpmcounter_prev = get_ticks(false);
> > +        counter->mhpmcounter_prev = riscv_pmu_ctr_get_fixed_counters_val(env,
> > +                                                                ctr_idx, false);
> >          if (ctr_idx > 2) {
> >              if (riscv_cpu_mxl(env) == MXL_RV32) {
> >                  mhpmctr_val = mhpmctr_val |
> > @@ -968,7 +1017,8 @@ static int write_mhpmcounterh(CPURISCVState *env, int csrno, target_ulong val)
> >      mhpmctr_val = mhpmctr_val | (mhpmctrh_val << 32);
> >      if (riscv_pmu_ctr_monitor_cycles(env, ctr_idx) ||
> >          riscv_pmu_ctr_monitor_instructions(env, ctr_idx)) {
> > -        counter->mhpmcounterh_prev = get_ticks(true);
> > +        counter->mhpmcounterh_prev = riscv_pmu_ctr_get_fixed_counters_val(env,
> > +                                                                 ctr_idx, true);
> >          if (ctr_idx > 2) {
> >              riscv_pmu_setup_timer(env, mhpmctr_val, ctr_idx);
> >          }
> > @@ -1009,7 +1059,8 @@ static RISCVException riscv_pmu_read_ctr(CPURISCVState *env, target_ulong *val,
> >       */
> >      if (riscv_pmu_ctr_monitor_cycles(env, ctr_idx) ||
> >          riscv_pmu_ctr_monitor_instructions(env, ctr_idx)) {
> > -        *val = get_ticks(upper_half) - ctr_prev + ctr_val;
> > +        *val = riscv_pmu_ctr_get_fixed_counters_val(env, ctr_idx, upper_half) -
> > +                                                    ctr_prev + ctr_val;
> >      } else {
> >          *val = ctr_val;
> >      }
> > diff --git a/target/riscv/pmu.c b/target/riscv/pmu.c
> > index 0e7d58b8a5c2..8b6cc4c6bb4d 100644
> > --- a/target/riscv/pmu.c
> > +++ b/target/riscv/pmu.c
> > @@ -19,6 +19,7 @@
> >  #include "qemu/osdep.h"
> >  #include "qemu/log.h"
> >  #include "qemu/error-report.h"
> > +#include "qemu/timer.h"
> >  #include "cpu.h"
> >  #include "pmu.h"
> >  #include "sysemu/cpu-timers.h"
> > @@ -176,6 +177,48 @@ static int riscv_pmu_incr_ctr_rv64(RISCVCPU *cpu, uint32_t ctr_idx)
> >      return 0;
> >  }
> >
> > +void riscv_pmu_icount_update_priv(CPURISCVState *env, target_ulong newpriv)
> > +{
> > +    uint64_t delta;
> > +    uint64_t *counter_arr;
> > +    uint64_t *counter_arr_prev;
> > +    uint64_t current_icount = icount_get_raw();
> > +
> > +    if (env->virt_enabled) {
> > +        counter_arr = env->pmu_fixed_ctrs[1].counter_virt;
> > +        counter_arr_prev = env->pmu_fixed_ctrs[1].counter_virt_prev;
> > +    } else {
> > +        counter_arr = env->pmu_fixed_ctrs[1].counter;
> > +        counter_arr_prev = env->pmu_fixed_ctrs[1].counter_prev;
> > +    }
> > +
> > +    counter_arr_prev[newpriv] = current_icount;
> > +    delta = current_icount - counter_arr_prev[env->priv];
> > +
> > +    counter_arr[env->priv] += delta;
> > +}
> > +
> > +void riscv_pmu_cycle_update_priv(CPURISCVState *env, target_ulong newpriv)
> > +{
> > +    uint64_t delta;
> > +    uint64_t *counter_arr;
> > +    uint64_t *counter_arr_prev;
> > +    uint64_t current_host_ticks = cpu_get_host_ticks();
> > +
> > +    if (env->virt_enabled) {
> > +        counter_arr = env->pmu_fixed_ctrs[0].counter_virt;
> > +        counter_arr_prev = env->pmu_fixed_ctrs[0].counter_virt_prev;
> > +    } else {
> > +        counter_arr = env->pmu_fixed_ctrs[0].counter;
> > +        counter_arr_prev = env->pmu_fixed_ctrs[0].counter_prev;
> > +    }
> > +
> > +    counter_arr_prev[newpriv] = current_host_ticks;
> > +    delta = current_host_ticks - counter_arr_prev[env->priv];
> > +
> > +    counter_arr[env->priv] += delta;
> > +}
> > +
> >  int riscv_pmu_incr_ctr(RISCVCPU *cpu, enum riscv_pmu_event_idx event_idx)
> >  {
> >      uint32_t ctr_idx;
> > diff --git a/target/riscv/pmu.h b/target/riscv/pmu.h
> > index 505fc850d38e..50de6031a730 100644
> > --- a/target/riscv/pmu.h
> > +++ b/target/riscv/pmu.h
> > @@ -31,3 +31,5 @@ int riscv_pmu_incr_ctr(RISCVCPU *cpu, enum riscv_pmu_event_idx event_idx);
> >  void riscv_pmu_generate_fdt_node(void *fdt, uint32_t cmask, char *pmu_name);
> >  int riscv_pmu_setup_timer(CPURISCVState *env, uint64_t value,
> >                            uint32_t ctr_idx);
> > +void riscv_pmu_icount_update_priv(CPURISCVState *env, target_ulong newpriv);
> > +void riscv_pmu_cycle_update_priv(CPURISCVState *env, target_ulong newpriv);
> > --
> > 2.34.1
> >
> >
Re: [PATCH v4 5/5] target/riscv: Implement privilege mode filtering for cycle/instret
Posted by Alistair Francis 9 months, 2 weeks ago
On Wed, Jan 24, 2024 at 10:15 AM Atish Kumar Patra <atishp@rivosinc.com> wrote:
>
> On Sun, Jan 21, 2024 at 9:04 PM Alistair Francis <alistair23@gmail.com> wrote:
> >
> > On Tue, Jan 9, 2024 at 10:29 AM Atish Patra <atishp@rivosinc.com> wrote:
> > >
> > > Privilege mode filtering can also be emulated for cycle/instret by
> > > tracking host_ticks/icount during each privilege mode switch. This
> > > patch implements that for both cycle/instret and mhpmcounters. The
> > > first one requires Smcntrpmf while the other one requires Sscofpmf
> > > to be enabled.
> > >
> > > The cycle/instret are still computed using host ticks when icount
> > > is not enabled. Otherwise, they are computed using raw icount which
> > > is more accurate in icount mode.
> > >
> > > Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
> > > Signed-off-by: Atish Patra <atishp@rivosinc.com>
> > > ---
> > >  target/riscv/cpu.h        | 11 +++++
> > >  target/riscv/cpu_helper.c |  9 +++-
> > >  target/riscv/csr.c        | 95 ++++++++++++++++++++++++++++++---------
> > >  target/riscv/pmu.c        | 43 ++++++++++++++++++
> > >  target/riscv/pmu.h        |  2 +
> > >  5 files changed, 136 insertions(+), 24 deletions(-)
> > >
> > > diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
> > > index 34617c4c4bab..40d10726155b 100644
> > > --- a/target/riscv/cpu.h
> > > +++ b/target/riscv/cpu.h
> > > @@ -136,6 +136,15 @@ typedef struct PMUCTRState {
> > >      target_ulong irq_overflow_left;
> > >  } PMUCTRState;
> > >
> > > +typedef struct PMUFixedCtrState {
> > > +        /* Track cycle and icount for each privilege mode */
> > > +        uint64_t counter[4];
> > > +        uint64_t counter_prev[4];
> >
> > Are these two used?
> >
>
> Yes. That's where it tracks the current/previous value cycle/instret.
> riscv_pmu_icount_update_priv/riscv_pmu_cycle_update_priv
>
> The priv mode based filtering is enabled in riscv_pmu_ctr_get_fixed_counters_val
> using "counter" afterwards.

Ah! Yeah sorry was not reading this correctly

Alistair
Re: [PATCH v4 5/5] target/riscv: Implement privilege mode filtering for cycle/instret
Posted by Atish Kumar Patra 9 months, 3 weeks ago
On Tue, Jan 23, 2024 at 4:15 PM Atish Kumar Patra <atishp@rivosinc.com>
wrote:

> On Sun, Jan 21, 2024 at 9:04 PM Alistair Francis <alistair23@gmail.com>
> wrote:
> >
> > On Tue, Jan 9, 2024 at 10:29 AM Atish Patra <atishp@rivosinc.com> wrote:
> > >
> > > Privilege mode filtering can also be emulated for cycle/instret by
> > > tracking host_ticks/icount during each privilege mode switch. This
> > > patch implements that for both cycle/instret and mhpmcounters. The
> > > first one requires Smcntrpmf while the other one requires Sscofpmf
> > > to be enabled.
> > >
> > > The cycle/instret are still computed using host ticks when icount
> > > is not enabled. Otherwise, they are computed using raw icount which
> > > is more accurate in icount mode.
> > >
> > > Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
> > > Signed-off-by: Atish Patra <atishp@rivosinc.com>
> > > ---
> > >  target/riscv/cpu.h        | 11 +++++
> > >  target/riscv/cpu_helper.c |  9 +++-
> > >  target/riscv/csr.c        | 95 ++++++++++++++++++++++++++++++---------
> > >  target/riscv/pmu.c        | 43 ++++++++++++++++++
> > >  target/riscv/pmu.h        |  2 +
> > >  5 files changed, 136 insertions(+), 24 deletions(-)
> > >
> > > diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
> > > index 34617c4c4bab..40d10726155b 100644
> > > --- a/target/riscv/cpu.h
> > > +++ b/target/riscv/cpu.h
> > > @@ -136,6 +136,15 @@ typedef struct PMUCTRState {
> > >      target_ulong irq_overflow_left;
> > >  } PMUCTRState;
> > >
> > > +typedef struct PMUFixedCtrState {
> > > +        /* Track cycle and icount for each privilege mode */
> > > +        uint64_t counter[4];
> > > +        uint64_t counter_prev[4];
> >
> > Are these two used?
> >
>
> Yes. That's where it tracks the current/previous value cycle/instret.
> riscv_pmu_icount_update_priv/riscv_pmu_cycle_update_priv
>
> The priv mode based filtering is enabled in
> riscv_pmu_ctr_get_fixed_counters_val
> using "counter" afterwards.
>
> Did I misunderstand your question ?
>
>
ping ?


> > Alistair
> >
> > > +        /* Track cycle and icount for each privilege mode when V = 1*/
> > > +        uint64_t counter_virt[2];
> > > +        uint64_t counter_virt_prev[2];
> > > +} PMUFixedCtrState;
> > > +
> > >  struct CPUArchState {
> > >      target_ulong gpr[32];
> > >      target_ulong gprh[32]; /* 64 top bits of the 128-bit registers */
> > > @@ -334,6 +343,8 @@ struct CPUArchState {
> > >      /* PMU event selector configured values for RV32 */
> > >      target_ulong mhpmeventh_val[RV_MAX_MHPMEVENTS];
> > >
> > > +    PMUFixedCtrState pmu_fixed_ctrs[2];
> > > +
> > >      target_ulong sscratch;
> > >      target_ulong mscratch;
> > >
> > > diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
> > > index e7e23b34f455..3dddb1b433e8 100644
> > > --- a/target/riscv/cpu_helper.c
> > > +++ b/target/riscv/cpu_helper.c
> > > @@ -715,8 +715,13 @@ void riscv_cpu_set_mode(CPURISCVState *env,
> target_ulong newpriv)
> > >  {
> > >      g_assert(newpriv <= PRV_M && newpriv != PRV_RESERVED);
> > >
> > > -    if (icount_enabled() && newpriv != env->priv) {
> > > -        riscv_itrigger_update_priv(env);
> > > +    if (newpriv != env->priv) {
> > > +        if (icount_enabled()) {
> > > +            riscv_itrigger_update_priv(env);
> > > +            riscv_pmu_icount_update_priv(env, newpriv);
> > > +        } else {
> > > +            riscv_pmu_cycle_update_priv(env, newpriv);
> > > +        }
> > >      }
> > >      /* tlb_flush is unnecessary as mode is contained in mmu_idx */
> > >      env->priv = newpriv;
> > > diff --git a/target/riscv/csr.c b/target/riscv/csr.c
> > > index 3bd4aa22374f..307d052021c5 100644
> > > --- a/target/riscv/csr.c
> > > +++ b/target/riscv/csr.c
> > > @@ -782,32 +782,16 @@ static int write_vcsr(CPURISCVState *env, int
> csrno, target_ulong val)
> > >      return RISCV_EXCP_NONE;
> > >  }
> > >
> > > +#if defined(CONFIG_USER_ONLY)
> > >  /* User Timers and Counters */
> > >  static target_ulong get_ticks(bool shift)
> > >  {
> > > -    int64_t val;
> > > -    target_ulong result;
> > > -
> > > -#if !defined(CONFIG_USER_ONLY)
> > > -    if (icount_enabled()) {
> > > -        val = icount_get();
> > > -    } else {
> > > -        val = cpu_get_host_ticks();
> > > -    }
> > > -#else
> > > -    val = cpu_get_host_ticks();
> > > -#endif
> > > -
> > > -    if (shift) {
> > > -        result = val >> 32;
> > > -    } else {
> > > -        result = val;
> > > -    }
> > > +    int64_t val = cpu_get_host_ticks();
> > > +    target_ulong result = shift ? val >> 32 : val;
> > >
> > >      return result;
> > >  }
> > >
> > > -#if defined(CONFIG_USER_ONLY)
> > >  static RISCVException read_time(CPURISCVState *env, int csrno,
> > >                                  target_ulong *val)
> > >  {
> > > @@ -932,6 +916,70 @@ static int write_mhpmeventh(CPURISCVState *env,
> int csrno, target_ulong val)
> > >      return RISCV_EXCP_NONE;
> > >  }
> > >
> > > +static target_ulong
> riscv_pmu_ctr_get_fixed_counters_val(CPURISCVState *env,
> > > +                                                         int
> counter_idx,
> > > +                                                         bool
> upper_half)
> > > +{
> > > +    uint64_t curr_val = 0;
> > > +    target_ulong result = 0;
> > > +    uint64_t *counter_arr = icount_enabled() ?
> env->pmu_fixed_ctrs[1].counter :
> > > +                            env->pmu_fixed_ctrs[0].counter;
> > > +    uint64_t *counter_arr_virt = icount_enabled() ?
> > > +                                 env->pmu_fixed_ctrs[1].counter_virt :
> > > +                                 env->pmu_fixed_ctrs[0].counter_virt;
> > > +    uint64_t cfg_val = 0;
> > > +
> > > +    if (counter_idx == 0) {
> > > +        cfg_val = upper_half ? ((uint64_t)env->mcyclecfgh << 32) :
> > > +                  env->mcyclecfg;
> > > +    } else if (counter_idx == 2) {
> > > +        cfg_val = upper_half ? ((uint64_t)env->minstretcfgh << 32) :
> > > +                  env->minstretcfg;
> > > +    } else {
> > > +        cfg_val = upper_half ?
> > > +                  ((uint64_t)env->mhpmeventh_val[counter_idx] << 32) :
> > > +                  env->mhpmevent_val[counter_idx];
> > > +    }
> > > +
> > > +    if (!cfg_val) {
> > > +        if (icount_enabled()) {
> > > +            curr_val = icount_get_raw();
> > > +        } else {
> > > +            curr_val = cpu_get_host_ticks();
> > > +        }
> > > +        goto done;
> > > +    }
> > > +
> > > +    if (!(cfg_val & MCYCLECFG_BIT_MINH)) {
> > > +        curr_val += counter_arr[PRV_M];
> > > +    }
> > > +
> > > +    if (!(cfg_val & MCYCLECFG_BIT_SINH)) {
> > > +        curr_val += counter_arr[PRV_S];
> > > +    }
> > > +
> > > +    if (!(cfg_val & MCYCLECFG_BIT_UINH)) {
> > > +        curr_val += counter_arr[PRV_U];
> > > +    }
> > > +
> > > +    if (!(cfg_val & MCYCLECFG_BIT_VSINH)) {
> > > +        curr_val += counter_arr_virt[PRV_S];
> > > +    }
> > > +
> > > +    if (!(cfg_val & MCYCLECFG_BIT_VUINH)) {
> > > +        curr_val += counter_arr_virt[PRV_U];
> > > +    }
> > > +
> > > +done:
> > > +    if (riscv_cpu_mxl(env) == MXL_RV32) {
> > > +        result = upper_half ? curr_val >> 32 : curr_val;
> > > +    } else {
> > > +        result = curr_val;
> > > +    }
> > > +
> > > +    return result;
> > > +}
> > > +
> > >  static int write_mhpmcounter(CPURISCVState *env, int csrno,
> target_ulong val)
> > >  {
> > >      int ctr_idx = csrno - CSR_MCYCLE;
> > > @@ -941,7 +989,8 @@ static int write_mhpmcounter(CPURISCVState *env,
> int csrno, target_ulong val)
> > >      counter->mhpmcounter_val = val;
> > >      if (riscv_pmu_ctr_monitor_cycles(env, ctr_idx) ||
> > >          riscv_pmu_ctr_monitor_instructions(env, ctr_idx)) {
> > > -        counter->mhpmcounter_prev = get_ticks(false);
> > > +        counter->mhpmcounter_prev =
> riscv_pmu_ctr_get_fixed_counters_val(env,
> > > +
> ctr_idx, false);
> > >          if (ctr_idx > 2) {
> > >              if (riscv_cpu_mxl(env) == MXL_RV32) {
> > >                  mhpmctr_val = mhpmctr_val |
> > > @@ -968,7 +1017,8 @@ static int write_mhpmcounterh(CPURISCVState *env,
> int csrno, target_ulong val)
> > >      mhpmctr_val = mhpmctr_val | (mhpmctrh_val << 32);
> > >      if (riscv_pmu_ctr_monitor_cycles(env, ctr_idx) ||
> > >          riscv_pmu_ctr_monitor_instructions(env, ctr_idx)) {
> > > -        counter->mhpmcounterh_prev = get_ticks(true);
> > > +        counter->mhpmcounterh_prev =
> riscv_pmu_ctr_get_fixed_counters_val(env,
> > > +
>  ctr_idx, true);
> > >          if (ctr_idx > 2) {
> > >              riscv_pmu_setup_timer(env, mhpmctr_val, ctr_idx);
> > >          }
> > > @@ -1009,7 +1059,8 @@ static RISCVException
> riscv_pmu_read_ctr(CPURISCVState *env, target_ulong *val,
> > >       */
> > >      if (riscv_pmu_ctr_monitor_cycles(env, ctr_idx) ||
> > >          riscv_pmu_ctr_monitor_instructions(env, ctr_idx)) {
> > > -        *val = get_ticks(upper_half) - ctr_prev + ctr_val;
> > > +        *val = riscv_pmu_ctr_get_fixed_counters_val(env, ctr_idx,
> upper_half) -
> > > +                                                    ctr_prev +
> ctr_val;
> > >      } else {
> > >          *val = ctr_val;
> > >      }
> > > diff --git a/target/riscv/pmu.c b/target/riscv/pmu.c
> > > index 0e7d58b8a5c2..8b6cc4c6bb4d 100644
> > > --- a/target/riscv/pmu.c
> > > +++ b/target/riscv/pmu.c
> > > @@ -19,6 +19,7 @@
> > >  #include "qemu/osdep.h"
> > >  #include "qemu/log.h"
> > >  #include "qemu/error-report.h"
> > > +#include "qemu/timer.h"
> > >  #include "cpu.h"
> > >  #include "pmu.h"
> > >  #include "sysemu/cpu-timers.h"
> > > @@ -176,6 +177,48 @@ static int riscv_pmu_incr_ctr_rv64(RISCVCPU *cpu,
> uint32_t ctr_idx)
> > >      return 0;
> > >  }
> > >
> > > +void riscv_pmu_icount_update_priv(CPURISCVState *env, target_ulong
> newpriv)
> > > +{
> > > +    uint64_t delta;
> > > +    uint64_t *counter_arr;
> > > +    uint64_t *counter_arr_prev;
> > > +    uint64_t current_icount = icount_get_raw();
> > > +
> > > +    if (env->virt_enabled) {
> > > +        counter_arr = env->pmu_fixed_ctrs[1].counter_virt;
> > > +        counter_arr_prev = env->pmu_fixed_ctrs[1].counter_virt_prev;
> > > +    } else {
> > > +        counter_arr = env->pmu_fixed_ctrs[1].counter;
> > > +        counter_arr_prev = env->pmu_fixed_ctrs[1].counter_prev;
> > > +    }
> > > +
> > > +    counter_arr_prev[newpriv] = current_icount;
> > > +    delta = current_icount - counter_arr_prev[env->priv];
> > > +
> > > +    counter_arr[env->priv] += delta;
> > > +}
> > > +
> > > +void riscv_pmu_cycle_update_priv(CPURISCVState *env, target_ulong
> newpriv)
> > > +{
> > > +    uint64_t delta;
> > > +    uint64_t *counter_arr;
> > > +    uint64_t *counter_arr_prev;
> > > +    uint64_t current_host_ticks = cpu_get_host_ticks();
> > > +
> > > +    if (env->virt_enabled) {
> > > +        counter_arr = env->pmu_fixed_ctrs[0].counter_virt;
> > > +        counter_arr_prev = env->pmu_fixed_ctrs[0].counter_virt_prev;
> > > +    } else {
> > > +        counter_arr = env->pmu_fixed_ctrs[0].counter;
> > > +        counter_arr_prev = env->pmu_fixed_ctrs[0].counter_prev;
> > > +    }
> > > +
> > > +    counter_arr_prev[newpriv] = current_host_ticks;
> > > +    delta = current_host_ticks - counter_arr_prev[env->priv];
> > > +
> > > +    counter_arr[env->priv] += delta;
> > > +}
> > > +
> > >  int riscv_pmu_incr_ctr(RISCVCPU *cpu, enum riscv_pmu_event_idx
> event_idx)
> > >  {
> > >      uint32_t ctr_idx;
> > > diff --git a/target/riscv/pmu.h b/target/riscv/pmu.h
> > > index 505fc850d38e..50de6031a730 100644
> > > --- a/target/riscv/pmu.h
> > > +++ b/target/riscv/pmu.h
> > > @@ -31,3 +31,5 @@ int riscv_pmu_incr_ctr(RISCVCPU *cpu, enum
> riscv_pmu_event_idx event_idx);
> > >  void riscv_pmu_generate_fdt_node(void *fdt, uint32_t cmask, char
> *pmu_name);
> > >  int riscv_pmu_setup_timer(CPURISCVState *env, uint64_t value,
> > >                            uint32_t ctr_idx);
> > > +void riscv_pmu_icount_update_priv(CPURISCVState *env, target_ulong
> newpriv);
> > > +void riscv_pmu_cycle_update_priv(CPURISCVState *env, target_ulong
> newpriv);
> > > --
> > > 2.34.1
> > >
> > >
>