On Wed, Feb 28, 2024 at 05:01:25PM -0800, Atish Patra wrote: > The SBI v2.0 introduced a fw_read_hi function to read 64 bit firmware > counters for RV32 based systems. > > Add infrastructure to support that. > > Reviewed-by: Anup Patel <anup@xxxxxxxxxxxxxx> > Signed-off-by: Atish Patra <atishp@xxxxxxxxxxxx> > --- > arch/riscv/include/asm/kvm_vcpu_pmu.h | 4 ++- > arch/riscv/kvm/vcpu_pmu.c | 37 ++++++++++++++++++++++++++- > arch/riscv/kvm/vcpu_sbi_pmu.c | 6 +++++ > 3 files changed, 45 insertions(+), 2 deletions(-) > > diff --git a/arch/riscv/include/asm/kvm_vcpu_pmu.h b/arch/riscv/include/asm/kvm_vcpu_pmu.h > index 8cb21a4f862c..e0ad27dea46c 100644 > --- a/arch/riscv/include/asm/kvm_vcpu_pmu.h > +++ b/arch/riscv/include/asm/kvm_vcpu_pmu.h > @@ -20,7 +20,7 @@ static_assert(RISCV_KVM_MAX_COUNTERS <= 64); > > struct kvm_fw_event { > /* Current value of the event */ > - unsigned long value; > + u64 value; > > /* Event monitoring status */ > bool started; > @@ -91,6 +91,8 @@ int kvm_riscv_vcpu_pmu_ctr_cfg_match(struct kvm_vcpu *vcpu, unsigned long ctr_ba > struct kvm_vcpu_sbi_return *retdata); > int kvm_riscv_vcpu_pmu_ctr_read(struct kvm_vcpu *vcpu, unsigned long cidx, > struct kvm_vcpu_sbi_return *retdata); > +int kvm_riscv_vcpu_pmu_fw_ctr_read_hi(struct kvm_vcpu *vcpu, unsigned long cidx, > + struct kvm_vcpu_sbi_return *retdata); > void kvm_riscv_vcpu_pmu_init(struct kvm_vcpu *vcpu); > int kvm_riscv_vcpu_pmu_setup_snapshot(struct kvm_vcpu *vcpu, unsigned long saddr_low, > unsigned long saddr_high, unsigned long flags, > diff --git a/arch/riscv/kvm/vcpu_pmu.c b/arch/riscv/kvm/vcpu_pmu.c > index a02f7b981005..469bb430cf97 100644 > --- a/arch/riscv/kvm/vcpu_pmu.c > +++ b/arch/riscv/kvm/vcpu_pmu.c > @@ -196,6 +196,29 @@ static int pmu_get_pmc_index(struct kvm_pmu *pmu, unsigned long eidx, > return kvm_pmu_get_programmable_pmc_index(pmu, eidx, cbase, cmask); > } > > +static int pmu_fw_ctr_read_hi(struct kvm_vcpu *vcpu, unsigned long cidx, > + unsigned long *out_val) > +{ > + struct kvm_pmu *kvpmu = vcpu_to_pmu(vcpu); > + struct kvm_pmc *pmc; > + int fevent_code; > + > + if (!IS_ENABLED(CONFIG_32BIT)) Let's remove the CONFIG_32BIT check in kvm_sbi_ext_pmu_handler() and then set *out_val to zero here and return success. Either that, or we should WARN or something here since it's a KVM bug to get here with !CONFIG_32BIT. > + return -EINVAL; > + > + pmc = &kvpmu->pmc[cidx]; Uh oh! We're missing range validation of cidx! And I see we're missing it in pmu_ctr_read() too. We need the same check we have in kvm_riscv_vcpu_pmu_ctr_info(). I think the other SBI functions are OK, but it's worth a triple check. > + > + if (pmc->cinfo.type != SBI_PMU_CTR_TYPE_FW) > + return -EINVAL; > + > + fevent_code = get_event_code(pmc->event_idx); > + pmc->counter_val = kvpmu->fw_event[fevent_code].value; > + > + *out_val = pmc->counter_val >> 32; > + > + return 0; > +} > + > static int pmu_ctr_read(struct kvm_vcpu *vcpu, unsigned long cidx, > unsigned long *out_val) > { > @@ -702,6 +725,18 @@ int kvm_riscv_vcpu_pmu_ctr_cfg_match(struct kvm_vcpu *vcpu, unsigned long ctr_ba > return 0; > } > > +int kvm_riscv_vcpu_pmu_fw_ctr_read_hi(struct kvm_vcpu *vcpu, unsigned long cidx, > + struct kvm_vcpu_sbi_return *retdata) > +{ > + int ret; > + > + ret = pmu_fw_ctr_read_hi(vcpu, cidx, &retdata->out_val); > + if (ret == -EINVAL) > + retdata->err_val = SBI_ERR_INVALID_PARAM; > + > + return 0; I see this follows the pattern we have with kvm_riscv_vcpu_pmu_ctr_read and pmu_ctr_read, but I wonder if we really need the kvm_riscv_vcpu_pmu_ctr_read() and kvm_riscv_vcpu_pmu_fw_ctr_read_hi() wrapper functions? > +} > + > int kvm_riscv_vcpu_pmu_ctr_read(struct kvm_vcpu *vcpu, unsigned long cidx, > struct kvm_vcpu_sbi_return *retdata) > { > @@ -775,7 +810,7 @@ void kvm_riscv_vcpu_pmu_init(struct kvm_vcpu *vcpu) > pmc->cinfo.csr = CSR_CYCLE + i; > } else { > pmc->cinfo.type = SBI_PMU_CTR_TYPE_FW; > - pmc->cinfo.width = BITS_PER_LONG - 1; > + pmc->cinfo.width = 63; > } > } > > diff --git a/arch/riscv/kvm/vcpu_sbi_pmu.c b/arch/riscv/kvm/vcpu_sbi_pmu.c > index 9f61136e4bb1..58a0e5587e2a 100644 > --- a/arch/riscv/kvm/vcpu_sbi_pmu.c > +++ b/arch/riscv/kvm/vcpu_sbi_pmu.c > @@ -64,6 +64,12 @@ static int kvm_sbi_ext_pmu_handler(struct kvm_vcpu *vcpu, struct kvm_run *run, > case SBI_EXT_PMU_COUNTER_FW_READ: > ret = kvm_riscv_vcpu_pmu_ctr_read(vcpu, cp->a0, retdata); > break; > + case SBI_EXT_PMU_COUNTER_FW_READ_HI: > + if (IS_ENABLED(CONFIG_32BIT)) > + ret = kvm_riscv_vcpu_pmu_fw_ctr_read_hi(vcpu, cp->a0, retdata); > + else > + retdata->out_val = 0; > + break; > case SBI_EXT_PMU_SNAPSHOT_SET_SHMEM: > ret = kvm_riscv_vcpu_pmu_setup_snapshot(vcpu, cp->a0, cp->a1, cp->a2, retdata); > break; > -- > 2.34.1 > Thanks, drew