| Message ID | 20211201151734.654994-10-danielhb413@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | PMU-EBB support for PPC64 TCG | expand |
Hello, On 12/1/21 16:17, Daniel Henrique Barboza wrote: > From: Gustavo Romero <gromero@linux.ibm.com> > > Following up the rfebb implementation, this patch adds the EBB exception > support that are triggered by Performance Monitor alerts. This exception > occurs when an enabled PMU condition or event happens and both MMCR0_EBE > and BESCR_PME are set. > > The supported PM alerts will consist of counter negative conditions of > the PMU counters. This will be achieved by a timer mechanism that will > predict when a counter becomes negative. The PMU timer callback will set > the appropriate bits in MMCR0 and fire a PMC interrupt. The EBB > exception code will then set the appropriate BESCR bits, set the next > instruction pointer to the address pointed by the return register > (SPR_EBBRR), and redirect execution to the handler (pointed by > SPR_EBBHR). > > CC: Gustavo Romero <gustavo.romero@linaro.org> > Signed-off-by: Gustavo Romero <gromero@linux.ibm.com> > Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com> > --- > target/ppc/cpu.h | 5 ++++- > target/ppc/excp_helper.c | 29 +++++++++++++++++++++++++++++ > target/ppc/power8-pmu.c | 40 ++++++++++++++++++++++++++++++++++++++-- > 3 files changed, 71 insertions(+), 3 deletions(-) > > diff --git a/target/ppc/cpu.h b/target/ppc/cpu.h > index 741b8baf4c..8e0e6319ee 100644 > --- a/target/ppc/cpu.h > +++ b/target/ppc/cpu.h > @@ -129,8 +129,10 @@ enum { > /* ISA 3.00 additions */ > POWERPC_EXCP_HVIRT = 101, > POWERPC_EXCP_SYSCALL_VECTORED = 102, /* scv exception */ > + POWERPC_EXCP_EBB = 103, /* Event-based branch exception */ > + > /* EOL */ > - POWERPC_EXCP_NB = 103, > + POWERPC_EXCP_NB = 104, > /* QEMU exceptions: special cases we want to stop translation */ > POWERPC_EXCP_SYSCALL_USER = 0x203, /* System call in user mode only */ > }; > @@ -2452,6 +2454,7 @@ enum { > PPC_INTERRUPT_HMI, /* Hypervisor Maintenance interrupt */ > PPC_INTERRUPT_HDOORBELL, /* Hypervisor Doorbell interrupt */ > PPC_INTERRUPT_HVIRT, /* Hypervisor virtualization interrupt */ > + PPC_INTERRUPT_PMC, /* PMU interrupt */ This is referred as a Performance Monitor event-based exception in ISA. PPC_INTERRUPT_PM_EBB would be a better name I think. We also have : Load Monitored event-based exceptions External event-based exceptions > }; > > /* Processor Compatibility mask (PCR) */ > diff --git a/target/ppc/excp_helper.c b/target/ppc/excp_helper.c > index 7ead32279c..a26d266fe6 100644 > --- a/target/ppc/excp_helper.c > +++ b/target/ppc/excp_helper.c > @@ -799,6 +799,23 @@ static inline void powerpc_excp(PowerPCCPU *cpu, int excp_model, int excp) > cpu_abort(cs, "Non maskable external exception " > "is not implemented yet !\n"); > break; > + case POWERPC_EXCP_EBB: /* Event-based branch exception */ > + if ((env->spr[SPR_FSCR] & (1ull << FSCR_EBB)) && > + (env->spr[SPR_BESCR] & BESCR_GE) && > + (env->spr[SPR_BESCR] & BESCR_PME)) { Shouldn't we check these conditions to gate the EBB before sending it ? What about the HFSCR_EBB case ? > + target_ulong nip; > + > + env->spr[SPR_BESCR] &= ~BESCR_GE; /* Clear GE */ > + env->spr[SPR_BESCR] |= BESCR_PMEO; /* Set PMEO */ > + env->spr[SPR_EBBRR] = env->nip; /* Save NIP for rfebb insn */ > + nip = env->spr[SPR_EBBHR]; /* EBB handler */ > + powerpc_set_excp_state(cpu, nip, env->msr); > + } I am in favor of not adding anything more under the powerpc_excp() routine. Can we add a helper to isolate the EBB case ? I have the feeling it could become big. > + /* > + * This interrupt is handled by userspace. No need > + * to proceed. > + */ > + return; > default: > excp_invalid: > cpu_abort(cs, "Invalid PowerPC exception %d. Aborting\n", excp); > @@ -1046,6 +1063,18 @@ static void ppc_hw_interrupt(CPUPPCState *env) > powerpc_excp(cpu, env->excp_model, POWERPC_EXCP_THERM); > return; > } > + /* PMC -> Event-based branch exception */ > + if (env->pending_interrupts & (1 << PPC_INTERRUPT_PMC)) { > + /* > + * Performance Monitor event-based exception can only > + * occur in problem state. > + */ Yes. is the PM EBB exception gated by EE also ? Thanks, C. > + if (msr_pr == 1) { > + env->pending_interrupts &= ~(1 << PPC_INTERRUPT_PMC); > + powerpc_excp(cpu, env->excp_model, POWERPC_EXCP_EBB); > + return; > + } > + } > } > > if (env->resume_as_sreset) { > diff --git a/target/ppc/power8-pmu.c b/target/ppc/power8-pmu.c > index 08d1902cd5..279b824c3f 100644 > --- a/target/ppc/power8-pmu.c > +++ b/target/ppc/power8-pmu.c > @@ -297,6 +297,20 @@ void helper_store_pmc(CPUPPCState *env, uint32_t sprn, uint64_t value) > pmc_update_overflow_timer(env, sprn); > } > > +static void pmu_delete_timers(CPUPPCState *env) > +{ > + QEMUTimer *pmc_overflow_timer; > + int sprn; > + > + for (sprn = SPR_POWER_PMC1; sprn <= SPR_POWER_PMC6; sprn++) { > + pmc_overflow_timer = get_cyc_overflow_timer(env, sprn); > + > + if (pmc_overflow_timer) { > + timer_del(pmc_overflow_timer); > + } > + } > +} > + > static void fire_PMC_interrupt(PowerPCCPU *cpu) > { > CPUPPCState *env = &cpu->env; > @@ -305,8 +319,30 @@ static void fire_PMC_interrupt(PowerPCCPU *cpu) > return; > } > > - /* PMC interrupt not implemented yet */ > - return; > + pmu_update_cycles(env); > + > + if (env->spr[SPR_POWER_MMCR0] & MMCR0_FCECE) { > + env->spr[SPR_POWER_MMCR0] &= ~MMCR0_FCECE; > + env->spr[SPR_POWER_MMCR0] |= MMCR0_FC; > + > + /* Changing MMCR0_FC demands a new hflags compute */ > + hreg_compute_hflags(env); > + > + /* > + * Delete all pending timers if we need to freeze > + * the PMC. We'll restart them when the PMC starts > + * running again. > + */ > + pmu_delete_timers(env); > + } > + > + if (env->spr[SPR_POWER_MMCR0] & MMCR0_PMAE) { > + env->spr[SPR_POWER_MMCR0] &= ~MMCR0_PMAE; > + env->spr[SPR_POWER_MMCR0] |= MMCR0_PMAO; > + } > + > + /* Fire the PMC hardware exception */ > + ppc_set_irq(cpu, PPC_INTERRUPT_PMC, 1); > } > > /* This helper assumes that the PMC is running. */ >
On Wed, Dec 01, 2021 at 12:17:33PM -0300, Daniel Henrique Barboza wrote: > From: Gustavo Romero <gromero@linux.ibm.com> > > Following up the rfebb implementation, this patch adds the EBB exception > support that are triggered by Performance Monitor alerts. This exception > occurs when an enabled PMU condition or event happens and both MMCR0_EBE > and BESCR_PME are set. > > The supported PM alerts will consist of counter negative conditions of > the PMU counters. This will be achieved by a timer mechanism that will > predict when a counter becomes negative. The PMU timer callback will set > the appropriate bits in MMCR0 and fire a PMC interrupt. The EBB > exception code will then set the appropriate BESCR bits, set the next > instruction pointer to the address pointed by the return register > (SPR_EBBRR), and redirect execution to the handler (pointed by > SPR_EBBHR). > > CC: Gustavo Romero <gustavo.romero@linaro.org> > Signed-off-by: Gustavo Romero <gromero@linux.ibm.com> > Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com> > --- > target/ppc/cpu.h | 5 ++++- > target/ppc/excp_helper.c | 29 +++++++++++++++++++++++++++++ > target/ppc/power8-pmu.c | 40 ++++++++++++++++++++++++++++++++++++++-- > 3 files changed, 71 insertions(+), 3 deletions(-) > > diff --git a/target/ppc/cpu.h b/target/ppc/cpu.h > index 741b8baf4c..8e0e6319ee 100644 > --- a/target/ppc/cpu.h > +++ b/target/ppc/cpu.h > @@ -129,8 +129,10 @@ enum { > /* ISA 3.00 additions */ > POWERPC_EXCP_HVIRT = 101, > POWERPC_EXCP_SYSCALL_VECTORED = 102, /* scv exception */ > + POWERPC_EXCP_EBB = 103, /* Event-based branch exception */ > + > /* EOL */ > - POWERPC_EXCP_NB = 103, > + POWERPC_EXCP_NB = 104, > /* QEMU exceptions: special cases we want to stop translation */ > POWERPC_EXCP_SYSCALL_USER = 0x203, /* System call in user mode only */ > }; > @@ -2452,6 +2454,7 @@ enum { > PPC_INTERRUPT_HMI, /* Hypervisor Maintenance interrupt */ > PPC_INTERRUPT_HDOORBELL, /* Hypervisor Doorbell interrupt */ > PPC_INTERRUPT_HVIRT, /* Hypervisor virtualization interrupt */ > + PPC_INTERRUPT_PMC, /* PMU interrupt */ > }; All this low-level exception stuff is very clunky, but addressing that is not reasonably in scope for this series. So, Reviewed-by: David Gibson <david@gibson.dropbear.id.au> > > /* Processor Compatibility mask (PCR) */ > diff --git a/target/ppc/excp_helper.c b/target/ppc/excp_helper.c > index 7ead32279c..a26d266fe6 100644 > --- a/target/ppc/excp_helper.c > +++ b/target/ppc/excp_helper.c > @@ -799,6 +799,23 @@ static inline void powerpc_excp(PowerPCCPU *cpu, int excp_model, int excp) > cpu_abort(cs, "Non maskable external exception " > "is not implemented yet !\n"); > break; > + case POWERPC_EXCP_EBB: /* Event-based branch exception */ > + if ((env->spr[SPR_FSCR] & (1ull << FSCR_EBB)) && > + (env->spr[SPR_BESCR] & BESCR_GE) && > + (env->spr[SPR_BESCR] & BESCR_PME)) { > + target_ulong nip; > + > + env->spr[SPR_BESCR] &= ~BESCR_GE; /* Clear GE */ > + env->spr[SPR_BESCR] |= BESCR_PMEO; /* Set PMEO */ > + env->spr[SPR_EBBRR] = env->nip; /* Save NIP for rfebb insn */ > + nip = env->spr[SPR_EBBHR]; /* EBB handler */ > + powerpc_set_excp_state(cpu, nip, env->msr); > + } > + /* > + * This interrupt is handled by userspace. No need > + * to proceed. > + */ > + return; > default: > excp_invalid: > cpu_abort(cs, "Invalid PowerPC exception %d. Aborting\n", excp); > @@ -1046,6 +1063,18 @@ static void ppc_hw_interrupt(CPUPPCState *env) > powerpc_excp(cpu, env->excp_model, POWERPC_EXCP_THERM); > return; > } > + /* PMC -> Event-based branch exception */ > + if (env->pending_interrupts & (1 << PPC_INTERRUPT_PMC)) { > + /* > + * Performance Monitor event-based exception can only > + * occur in problem state. > + */ > + if (msr_pr == 1) { > + env->pending_interrupts &= ~(1 << PPC_INTERRUPT_PMC); > + powerpc_excp(cpu, env->excp_model, POWERPC_EXCP_EBB); > + return; > + } > + } > } > > if (env->resume_as_sreset) { > diff --git a/target/ppc/power8-pmu.c b/target/ppc/power8-pmu.c > index 08d1902cd5..279b824c3f 100644 > --- a/target/ppc/power8-pmu.c > +++ b/target/ppc/power8-pmu.c > @@ -297,6 +297,20 @@ void helper_store_pmc(CPUPPCState *env, uint32_t sprn, uint64_t value) > pmc_update_overflow_timer(env, sprn); > } > > +static void pmu_delete_timers(CPUPPCState *env) > +{ > + QEMUTimer *pmc_overflow_timer; > + int sprn; > + > + for (sprn = SPR_POWER_PMC1; sprn <= SPR_POWER_PMC6; sprn++) { > + pmc_overflow_timer = get_cyc_overflow_timer(env, sprn); > + > + if (pmc_overflow_timer) { > + timer_del(pmc_overflow_timer); > + } > + } > +} > + > static void fire_PMC_interrupt(PowerPCCPU *cpu) > { > CPUPPCState *env = &cpu->env; > @@ -305,8 +319,30 @@ static void fire_PMC_interrupt(PowerPCCPU *cpu) > return; > } > > - /* PMC interrupt not implemented yet */ > - return; > + pmu_update_cycles(env); > + > + if (env->spr[SPR_POWER_MMCR0] & MMCR0_FCECE) { > + env->spr[SPR_POWER_MMCR0] &= ~MMCR0_FCECE; > + env->spr[SPR_POWER_MMCR0] |= MMCR0_FC; > + > + /* Changing MMCR0_FC demands a new hflags compute */ > + hreg_compute_hflags(env); > + > + /* > + * Delete all pending timers if we need to freeze > + * the PMC. We'll restart them when the PMC starts > + * running again. > + */ > + pmu_delete_timers(env); > + } > + > + if (env->spr[SPR_POWER_MMCR0] & MMCR0_PMAE) { > + env->spr[SPR_POWER_MMCR0] &= ~MMCR0_PMAE; > + env->spr[SPR_POWER_MMCR0] |= MMCR0_PMAO; > + } > + > + /* Fire the PMC hardware exception */ > + ppc_set_irq(cpu, PPC_INTERRUPT_PMC, 1); > } > > /* This helper assumes that the PMC is running. */
diff --git a/target/ppc/cpu.h b/target/ppc/cpu.h index 741b8baf4c..8e0e6319ee 100644 --- a/target/ppc/cpu.h +++ b/target/ppc/cpu.h @@ -129,8 +129,10 @@ enum { /* ISA 3.00 additions */ POWERPC_EXCP_HVIRT = 101, POWERPC_EXCP_SYSCALL_VECTORED = 102, /* scv exception */ + POWERPC_EXCP_EBB = 103, /* Event-based branch exception */ + /* EOL */ - POWERPC_EXCP_NB = 103, + POWERPC_EXCP_NB = 104, /* QEMU exceptions: special cases we want to stop translation */ POWERPC_EXCP_SYSCALL_USER = 0x203, /* System call in user mode only */ }; @@ -2452,6 +2454,7 @@ enum { PPC_INTERRUPT_HMI, /* Hypervisor Maintenance interrupt */ PPC_INTERRUPT_HDOORBELL, /* Hypervisor Doorbell interrupt */ PPC_INTERRUPT_HVIRT, /* Hypervisor virtualization interrupt */ + PPC_INTERRUPT_PMC, /* PMU interrupt */ }; /* Processor Compatibility mask (PCR) */ diff --git a/target/ppc/excp_helper.c b/target/ppc/excp_helper.c index 7ead32279c..a26d266fe6 100644 --- a/target/ppc/excp_helper.c +++ b/target/ppc/excp_helper.c @@ -799,6 +799,23 @@ static inline void powerpc_excp(PowerPCCPU *cpu, int excp_model, int excp) cpu_abort(cs, "Non maskable external exception " "is not implemented yet !\n"); break; + case POWERPC_EXCP_EBB: /* Event-based branch exception */ + if ((env->spr[SPR_FSCR] & (1ull << FSCR_EBB)) && + (env->spr[SPR_BESCR] & BESCR_GE) && + (env->spr[SPR_BESCR] & BESCR_PME)) { + target_ulong nip; + + env->spr[SPR_BESCR] &= ~BESCR_GE; /* Clear GE */ + env->spr[SPR_BESCR] |= BESCR_PMEO; /* Set PMEO */ + env->spr[SPR_EBBRR] = env->nip; /* Save NIP for rfebb insn */ + nip = env->spr[SPR_EBBHR]; /* EBB handler */ + powerpc_set_excp_state(cpu, nip, env->msr); + } + /* + * This interrupt is handled by userspace. No need + * to proceed. + */ + return; default: excp_invalid: cpu_abort(cs, "Invalid PowerPC exception %d. Aborting\n", excp); @@ -1046,6 +1063,18 @@ static void ppc_hw_interrupt(CPUPPCState *env) powerpc_excp(cpu, env->excp_model, POWERPC_EXCP_THERM); return; } + /* PMC -> Event-based branch exception */ + if (env->pending_interrupts & (1 << PPC_INTERRUPT_PMC)) { + /* + * Performance Monitor event-based exception can only + * occur in problem state. + */ + if (msr_pr == 1) { + env->pending_interrupts &= ~(1 << PPC_INTERRUPT_PMC); + powerpc_excp(cpu, env->excp_model, POWERPC_EXCP_EBB); + return; + } + } } if (env->resume_as_sreset) { diff --git a/target/ppc/power8-pmu.c b/target/ppc/power8-pmu.c index 08d1902cd5..279b824c3f 100644 --- a/target/ppc/power8-pmu.c +++ b/target/ppc/power8-pmu.c @@ -297,6 +297,20 @@ void helper_store_pmc(CPUPPCState *env, uint32_t sprn, uint64_t value) pmc_update_overflow_timer(env, sprn); } +static void pmu_delete_timers(CPUPPCState *env) +{ + QEMUTimer *pmc_overflow_timer; + int sprn; + + for (sprn = SPR_POWER_PMC1; sprn <= SPR_POWER_PMC6; sprn++) { + pmc_overflow_timer = get_cyc_overflow_timer(env, sprn); + + if (pmc_overflow_timer) { + timer_del(pmc_overflow_timer); + } + } +} + static void fire_PMC_interrupt(PowerPCCPU *cpu) { CPUPPCState *env = &cpu->env; @@ -305,8 +319,30 @@ static void fire_PMC_interrupt(PowerPCCPU *cpu) return; } - /* PMC interrupt not implemented yet */ - return; + pmu_update_cycles(env); + + if (env->spr[SPR_POWER_MMCR0] & MMCR0_FCECE) { + env->spr[SPR_POWER_MMCR0] &= ~MMCR0_FCECE; + env->spr[SPR_POWER_MMCR0] |= MMCR0_FC; + + /* Changing MMCR0_FC demands a new hflags compute */ + hreg_compute_hflags(env); + + /* + * Delete all pending timers if we need to freeze + * the PMC. We'll restart them when the PMC starts + * running again. + */ + pmu_delete_timers(env); + } + + if (env->spr[SPR_POWER_MMCR0] & MMCR0_PMAE) { + env->spr[SPR_POWER_MMCR0] &= ~MMCR0_PMAE; + env->spr[SPR_POWER_MMCR0] |= MMCR0_PMAO; + } + + /* Fire the PMC hardware exception */ + ppc_set_irq(cpu, PPC_INTERRUPT_PMC, 1); } /* This helper assumes that the PMC is running. */