On Thu, Mar 31, 2022 at 10:19 AM Atish Patra <ati...@rivosinc.com> wrote:
>
> The Sscofpmf ('Ss' for Privileged arch and Supervisor-level extensions,
> and 'cofpmf' for Count OverFlow and Privilege Mode Filtering)
> extension allows the perf to handle overflow interrupts and filtering
> support. This patch provides a framework for programmable
> counters to leverage the extension. As the extension doesn't have any
> provision for the overflow bit for fixed counters, the fixed events
> can also be monitoring using programmable counters. The underlying
> counters for cycle and instruction counters are always running. Thus,
> a separate timer device is programmed to handle the overflow.
>
> Signed-off-by: Atish Patra <atish.pa...@wdc.com>
> Signed-off-by: Atish Patra <ati...@rivosinc.com>
> ---
> target/riscv/cpu.c | 11 ++
> target/riscv/cpu.h | 25 +++
> target/riscv/cpu_bits.h | 55 +++++++
> target/riscv/csr.c | 156 ++++++++++++++++--
> target/riscv/pmu.c | 347 +++++++++++++++++++++++++++++++++++++++-
> target/riscv/pmu.h | 7 +
> 6 files changed, 590 insertions(+), 11 deletions(-)
>
> diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
> index f63602828680..9715eed2fc4e 100644
> --- a/target/riscv/cpu.c
> +++ b/target/riscv/cpu.c
> @@ -22,6 +22,7 @@
> #include "qemu/ctype.h"
> #include "qemu/log.h"
> #include "cpu.h"
> +#include "pmu.h"
> #include "internals.h"
> #include "exec/exec-all.h"
> #include "qapi/error.h"
> @@ -696,6 +697,15 @@ static void riscv_cpu_realize(DeviceState *dev, Error
> **errp)
> set_misa(env, env->misa_mxl, ext);
> }
>
> +#ifndef CONFIG_USER_ONLY
> + if (cpu->cfg.pmu_num) {
> + if (!riscv_pmu_init(cpu, cpu->cfg.pmu_num) && cpu->cfg.ext_sscofpmf)
> {
> + cpu->pmu_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL,
> + riscv_pmu_timer_cb, cpu);
> + }
> + }
> +#endif
> +
> riscv_cpu_register_gdb_regs_for_features(cs);
>
> qemu_init_vcpu(cs);
> @@ -795,6 +805,7 @@ static Property riscv_cpu_properties[] = {
> DEFINE_PROP_BOOL("v", RISCVCPU, cfg.ext_v, false),
> DEFINE_PROP_BOOL("h", RISCVCPU, cfg.ext_h, true),
> DEFINE_PROP_UINT8("pmu-num", RISCVCPU, cfg.pmu_num, 16),
> + DEFINE_PROP_BOOL("sscofpmf", RISCVCPU, cfg.ext_sscofpmf, false),
> DEFINE_PROP_BOOL("Zifencei", RISCVCPU, cfg.ext_ifencei, true),
> DEFINE_PROP_BOOL("Zicsr", RISCVCPU, cfg.ext_icsr, true),
> DEFINE_PROP_BOOL("Zfh", RISCVCPU, cfg.ext_zfh, false),
> diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
> index 0fa15595fb37..a0e2279ea5e6 100644
> --- a/target/riscv/cpu.h
> +++ b/target/riscv/cpu.h
> @@ -131,6 +131,8 @@ typedef struct PMUCTRState {
> /* Snapshort value of a counter in RV32 */
> target_ulong mhpmcounterh_prev;
> bool started;
> + /* Value beyond UINT32_MAX/UINT64_MAX before overflow interrupt trigger
> */
> + target_ulong irq_overflow_left;
> } PMUCTRState;
>
> struct CPUArchState {
> @@ -291,6 +293,9 @@ struct CPUArchState {
> /* PMU event selector configured values. First three are unused*/
> target_ulong mhpmevent_val[RV_MAX_MHPMEVENTS];
>
> + /* PMU event selector configured values for RV32*/
> + target_ulong mhpmeventh_val[RV_MAX_MHPMEVENTS];
> +
> target_ulong sscratch;
> target_ulong mscratch;
>
> @@ -413,6 +418,7 @@ struct RISCVCPUConfig {
> bool ext_zhinxmin;
> bool ext_zve32f;
> bool ext_zve64f;
> + bool ext_sscofpmf;
>
> /* Vendor-specific custom extensions */
> bool ext_XVentanaCondOps;
> @@ -452,6 +458,12 @@ struct ArchCPU {
>
> /* Configuration Settings */
> RISCVCPUConfig cfg;
> +
> + QEMUTimer *pmu_timer;
> + /* A bitmask of Available programmable counters */
> + uint32_t pmu_avail_ctrs;
> + /* Mapping of events to counters */
> + GHashTable *pmu_event_ctr_map;
> };
>
> static inline int riscv_has_ext(CPURISCVState *env, target_ulong ext)
> @@ -709,6 +721,19 @@ enum {
> CSR_TABLE_SIZE = 0x1000
> };
>
> +/**
> + * The event id are encoded based on the encoding specified in the
> + * SBI specification v0.3
> + */
> +
> +enum riscv_pmu_event_idx {
> + RISCV_PMU_EVENT_HW_CPU_CYCLES = 0x01,
> + RISCV_PMU_EVENT_HW_INSTRUCTIONS = 0x02,
> + RISCV_PMU_EVENT_CACHE_DTLB_READ_MISS = 0x10019,
> + RISCV_PMU_EVENT_CACHE_DTLB_WRITE_MISS = 0x1001B,
> + RISCV_PMU_EVENT_CACHE_ITLB_PREFETCH_MISS = 0x10021,
> +};
> +
> /* CSR function table */
> extern riscv_csr_operations csr_ops[CSR_TABLE_SIZE];
>
> diff --git a/target/riscv/cpu_bits.h b/target/riscv/cpu_bits.h
> index 48b39e6d52a7..d0b53e5ea072 100644
> --- a/target/riscv/cpu_bits.h
> +++ b/target/riscv/cpu_bits.h
> @@ -400,6 +400,37 @@
> #define CSR_MHPMEVENT29 0x33d
> #define CSR_MHPMEVENT30 0x33e
> #define CSR_MHPMEVENT31 0x33f
> +
> +#define CSR_MHPMEVENT3H 0x723
> +#define CSR_MHPMEVENT4H 0x724
> +#define CSR_MHPMEVENT5H 0x725
> +#define CSR_MHPMEVENT6H 0x726
> +#define CSR_MHPMEVENT7H 0x727
> +#define CSR_MHPMEVENT8H 0x728
> +#define CSR_MHPMEVENT9H 0x729
> +#define CSR_MHPMEVENT10H 0x72a
> +#define CSR_MHPMEVENT11H 0x72b
> +#define CSR_MHPMEVENT12H 0x72c
> +#define CSR_MHPMEVENT13H 0x72d
> +#define CSR_MHPMEVENT14H 0x72e
> +#define CSR_MHPMEVENT15H 0x72f
> +#define CSR_MHPMEVENT16H 0x730
> +#define CSR_MHPMEVENT17H 0x731
> +#define CSR_MHPMEVENT18H 0x732
> +#define CSR_MHPMEVENT19H 0x733
> +#define CSR_MHPMEVENT20H 0x734
> +#define CSR_MHPMEVENT21H 0x735
> +#define CSR_MHPMEVENT22H 0x736
> +#define CSR_MHPMEVENT23H 0x737
> +#define CSR_MHPMEVENT24H 0x738
> +#define CSR_MHPMEVENT25H 0x739
> +#define CSR_MHPMEVENT26H 0x73a
> +#define CSR_MHPMEVENT27H 0x73b
> +#define CSR_MHPMEVENT28H 0x73c
> +#define CSR_MHPMEVENT29H 0x73d
> +#define CSR_MHPMEVENT30H 0x73e
> +#define CSR_MHPMEVENT31H 0x73f
> +
> #define CSR_MHPMCOUNTER3H 0xb83
> #define CSR_MHPMCOUNTER4H 0xb84
> #define CSR_MHPMCOUNTER5H 0xb85
> @@ -461,6 +492,7 @@
> #define CSR_VSMTE 0x2c0
> #define CSR_VSPMMASK 0x2c1
> #define CSR_VSPMBASE 0x2c2
> +#define CSR_SCOUNTOVF 0xda0
>
> /* mstatus CSR bits */
> #define MSTATUS_UIE 0x00000001
> @@ -635,6 +667,7 @@ typedef enum RISCVException {
> #define IRQ_VS_EXT 10
> #define IRQ_M_EXT 11
> #define IRQ_S_GEXT 12
> +#define IRQ_PMU_OVF 13
> #define IRQ_LOCAL_MAX 16
> #define IRQ_LOCAL_GUEST_MAX (TARGET_LONG_BITS - 1)
>
> @@ -652,11 +685,13 @@ typedef enum RISCVException {
> #define MIP_VSEIP (1 << IRQ_VS_EXT)
> #define MIP_MEIP (1 << IRQ_M_EXT)
> #define MIP_SGEIP (1 << IRQ_S_GEXT)
> +#define MIP_LCOFIP (1 << IRQ_PMU_OVF)
>
> /* sip masks */
> #define SIP_SSIP MIP_SSIP
> #define SIP_STIP MIP_STIP
> #define SIP_SEIP MIP_SEIP
> +#define SIP_LCOFIP MIP_LCOFIP
>
> /* MIE masks */
> #define MIE_SEIE (1 << IRQ_S_EXT)
> @@ -804,4 +839,24 @@ typedef enum RISCVException {
> #define HVICTL_VALID_MASK \
> (HVICTL_VTI | HVICTL_IID | HVICTL_IPRIOM | HVICTL_IPRIO)
>
> +/* PMU related bits */
> +#define MIE_LCOFIE (1 << IRQ_PMU_OVF)
> +
> +#define MHPMEVENT_BIT_OF BIT_ULL(63)
> +#define MHPMEVENTH_BIT_OF BIT(31)
> +#define MHPMEVENT_BIT_MINH BIT_ULL(62)
> +#define MHPMEVENTH_BIT_MINH BIT(30)
> +#define MHPMEVENT_BIT_SINH BIT_ULL(61)
> +#define MHPMEVENTH_BIT_SINH BIT(29)
> +#define MHPMEVENT_BIT_UINH BIT_ULL(60)
> +#define MHPMEVENTH_BIT_UINH BIT(28)
> +#define MHPMEVENT_BIT_VSINH BIT_ULL(59)
> +#define MHPMEVENTH_BIT_VSINH BIT(27)
> +#define MHPMEVENT_BIT_VUINH BIT_ULL(58)
> +#define MHPMEVENTH_BIT_VUINH BIT(26)
> +
> +#define MHPMEVENT_SSCOF_MASK _ULL(0xFFFF000000000000)
> +#define MHPMEVENT_IDX_MASK 0xFFFFF
> +#define MHPMEVENT_SSCOF_RESVD 16
> +
> #endif
> diff --git a/target/riscv/csr.c b/target/riscv/csr.c
> index 04796b99d0fe..519d6377fd9f 100644
> --- a/target/riscv/csr.c
> +++ b/target/riscv/csr.c
> @@ -72,7 +72,7 @@ static RISCVException ctr(CPURISCVState *env, int csrno)
> CPUState *cs = env_cpu(env);
> RISCVCPU *cpu = RISCV_CPU(cs);
> int ctr_index;
> - int base_csrno = CSR_HPMCOUNTER3;
> + int base_csrno = CSR_CYCLE;
> bool rv32 = riscv_cpu_mxl(env) == MXL_RV32 ? true : false;
>
> if (rv32 && csrno >= CSR_CYCLEH) {
> @@ -81,11 +81,18 @@ static RISCVException ctr(CPURISCVState *env, int csrno)
> }
> ctr_index = csrno - base_csrno;
>
> - if (!cpu->cfg.pmu_num || ctr_index >= (cpu->cfg.pmu_num)) {
> + if ((csrno >= CSR_CYCLE && csrno <= CSR_INSTRET) ||
> + (csrno >= CSR_CYCLEH && csrno <= CSR_INSTRETH)) {
> + goto skip_ext_pmu_check;
> + }
> +
> + if ((!cpu->cfg.pmu_num || !(cpu->pmu_avail_ctrs & BIT(ctr_index)))) {
> /* No counter is enabled in PMU or the counter is out of range */
> return RISCV_EXCP_ILLEGAL_INST;
> }
>
> +skip_ext_pmu_check:
> +
> if (env->priv == PRV_S) {
> switch (csrno) {
> case CSR_CYCLE:
> @@ -104,7 +111,6 @@ static RISCVException ctr(CPURISCVState *env, int csrno)
> }
> break;
> case CSR_HPMCOUNTER3...CSR_HPMCOUNTER31:
> - ctr_index = csrno - CSR_CYCLE;
> if (!get_field(env->mcounteren, 1 << ctr_index)) {
> return RISCV_EXCP_ILLEGAL_INST;
> }
> @@ -128,7 +134,6 @@ static RISCVException ctr(CPURISCVState *env, int csrno)
> }
> break;
> case CSR_HPMCOUNTER3H...CSR_HPMCOUNTER31H:
> - ctr_index = csrno - CSR_CYCLEH;
> if (!get_field(env->mcounteren, 1 << ctr_index)) {
> return RISCV_EXCP_ILLEGAL_INST;
> }
> @@ -158,7 +163,6 @@ static RISCVException ctr(CPURISCVState *env, int csrno)
> }
> break;
> case CSR_HPMCOUNTER3...CSR_HPMCOUNTER31:
> - ctr_index = csrno - CSR_CYCLE;
> if (!get_field(env->hcounteren, 1 << ctr_index) &&
> get_field(env->mcounteren, 1 << ctr_index)) {
> return RISCV_EXCP_VIRT_INSTRUCTION_FAULT;
> @@ -186,7 +190,6 @@ static RISCVException ctr(CPURISCVState *env, int csrno)
> }
> break;
> case CSR_HPMCOUNTER3H...CSR_HPMCOUNTER31H:
> - ctr_index = csrno - CSR_CYCLEH;
> if (!get_field(env->hcounteren, 1 << ctr_index) &&
> get_field(env->mcounteren, 1 << ctr_index)) {
> return RISCV_EXCP_VIRT_INSTRUCTION_FAULT;
> @@ -238,6 +241,18 @@ static RISCVException mctr32(CPURISCVState *env, int
> csrno)
> return mctr(env, csrno);
> }
>
> +static RISCVException sscofpmf(CPURISCVState *env, int csrno)
> +{
> + CPUState *cs = env_cpu(env);
> + RISCVCPU *cpu = RISCV_CPU(cs);
> +
> + if (!cpu->cfg.ext_sscofpmf) {
> + return RISCV_EXCP_ILLEGAL_INST;
> + }
> +
> + return RISCV_EXCP_NONE;
> +}
> +
> static RISCVException any(CPURISCVState *env, int csrno)
> {
> return RISCV_EXCP_NONE;
> @@ -622,11 +637,36 @@ static int write_mhpmevent(CPURISCVState *env, int
> csrno, target_ulong val)
> {
> int evt_index = csrno - CSR_MCOUNTINHIBIT;
>
> + if (riscv_cpu_mxl(env) != MXL_RV32) {
Is this right? What if the guest writes the high bytes first?
Alistair
