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[PATCH v5 5/5] target/riscv: Implement privilege mode filtering for cycl
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From: |
Atish Patra |
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Subject: |
[PATCH v5 5/5] target/riscv: Implement privilege mode filtering for cycle/instret |
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Date: |
Wed, 28 Feb 2024 10:51:16 -0800 |
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_bits.h | 5 ++
target/riscv/cpu_helper.c | 17 ++++++-
target/riscv/csr.c | 96 ++++++++++++++++++++++++++++++---------
target/riscv/pmu.c | 64 ++++++++++++++++++++++++++
target/riscv/pmu.h | 2 +
6 files changed, 171 insertions(+), 24 deletions(-)
diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index 174e8ba8e847..9e21d7f7d635 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -157,6 +157,15 @@ 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 */
@@ -353,6 +362,8 @@ 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_bits.h b/target/riscv/cpu_bits.h
index e866c60a400c..5fe349e313dc 100644
--- a/target/riscv/cpu_bits.h
+++ b/target/riscv/cpu_bits.h
@@ -920,6 +920,11 @@ typedef enum RISCVException {
#define MHPMEVENT_BIT_VUINH BIT_ULL(58)
#define MHPMEVENTH_BIT_VUINH BIT(26)
+#define MHPMEVENT_FILTER_MASK (MHPMEVENT_BIT_MINH | \
+ MHPMEVENT_BIT_SINH | \
+ MHPMEVENT_BIT_UINH | \
+ MHPMEVENT_BIT_VSINH | \
+ MHPMEVENT_BIT_VUINH)
#define MHPMEVENT_SSCOF_MASK _ULL(0xFFFF000000000000)
#define MHPMEVENT_IDX_MASK 0xFFFFF
#define MHPMEVENT_SSCOF_RESVD 16
diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
index d462d95ee165..33965d843d46 100644
--- a/target/riscv/cpu_helper.c
+++ b/target/riscv/cpu_helper.c
@@ -718,8 +718,21 @@ 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);
+ /*
+ * Invoke cycle/instret update between priv mode changes or
+ * VS->HS mode transition is SPV bit must be set
+ * HS->VS mode transition where virt_enabled must be set
+ * In both cases, priv will S mode only.
+ */
+ if (newpriv != env->priv ||
+ (env->priv == PRV_S && newpriv == PRV_S &&
+ (env->virt_enabled || get_field(env->hstatus, HSTATUS_SPV)))) {
+ 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 ff9bac537593..482e212c5f74 100644
--- a/target/riscv/csr.c
+++ b/target/riscv/csr.c
@@ -788,32 +788,16 @@ static RISCVException write_vcsr(CPURISCVState *env, int
csrno,
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)
{
@@ -952,6 +936,71 @@ static RISCVException write_mhpmeventh(CPURISCVState *env,
int csrno,
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];
+ cfg_val &= MHPMEVENT_FILTER_MASK;
+ }
+
+ 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 RISCVException write_mhpmcounter(CPURISCVState *env, int csrno,
target_ulong val)
{
@@ -962,7 +1011,8 @@ static RISCVException write_mhpmcounter(CPURISCVState
*env, int csrno,
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 |
@@ -990,7 +1040,8 @@ static RISCVException write_mhpmcounterh(CPURISCVState
*env, int csrno,
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);
}
@@ -1031,7 +1082,8 @@ 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..37309ff64cb6 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 +177,69 @@ 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;
+ }
+
+ if (newpriv != env->priv) {
+ delta = current_icount - counter_arr_prev[env->priv];
+ counter_arr_prev[newpriv] = current_icount;
+ } else {
+ delta = current_icount - counter_arr_prev[env->priv];
+ if (env->virt_enabled) {
+ /* HS->VS transition.The previous value should correspond to HS. */
+ env->pmu_fixed_ctrs[1].counter_prev[PRV_S] = current_icount;
+ } else if (get_field(env->hstatus, HSTATUS_SPV)) {
+ /* VS->HS transition.The previous value should correspond to VS. */
+ env->pmu_fixed_ctrs[1].counter_virt_prev[PRV_S] = current_icount;
+ }
+ }
+
+ 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;
+ }
+
+ if (newpriv != env->priv) {
+ delta = current_host_ticks - counter_arr_prev[env->priv];
+ counter_arr_prev[newpriv] = current_host_ticks;
+ } else {
+ delta = current_host_ticks - counter_arr_prev[env->priv];
+ if (env->virt_enabled) {
+ env->pmu_fixed_ctrs[0].counter_prev[PRV_S] = current_host_ticks;
+ } else if (get_field(env->hstatus, HSTATUS_SPV)) {
+ env->pmu_fixed_ctrs[0].counter_virt_prev[PRV_S] =
+ current_host_ticks;
+ }
+ }
+
+ 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