SBI PMU extension allows KVM guests to configure/start/stop/query about the PMU counters in virtualized enviornment as well. In order to allow that, KVM implements the entire SBI PMU extension. Signed-off-by: Atish Patra <atishp@xxxxxxxxxxxx> --- arch/riscv/kvm/vcpu_sbi.c | 11 +++++ arch/riscv/kvm/vcpu_sbi_pmu.c | 81 +++++++++++++++++++++++++++++++++++ 2 files changed, 92 insertions(+) create mode 100644 arch/riscv/kvm/vcpu_sbi_pmu.c diff --git a/arch/riscv/kvm/vcpu_sbi.c b/arch/riscv/kvm/vcpu_sbi.c index d45e7da3f0d3..da9f7959340e 100644 --- a/arch/riscv/kvm/vcpu_sbi.c +++ b/arch/riscv/kvm/vcpu_sbi.c @@ -50,6 +50,16 @@ extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_hsm; extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_experimental; extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_vendor; +#ifdef CONFIG_RISCV_PMU_SBI +extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_pmu; +#else +static const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_pmu = { + .extid_start = -1UL, + .extid_end = -1UL, + .handler = NULL, +}; +#endif + static const struct kvm_vcpu_sbi_extension *sbi_ext[] = { &vcpu_sbi_ext_v01, &vcpu_sbi_ext_base, @@ -58,6 +68,7 @@ static const struct kvm_vcpu_sbi_extension *sbi_ext[] = { &vcpu_sbi_ext_rfence, &vcpu_sbi_ext_srst, &vcpu_sbi_ext_hsm, + &vcpu_sbi_ext_pmu, &vcpu_sbi_ext_experimental, &vcpu_sbi_ext_vendor, }; diff --git a/arch/riscv/kvm/vcpu_sbi_pmu.c b/arch/riscv/kvm/vcpu_sbi_pmu.c new file mode 100644 index 000000000000..90c51a95d4f4 --- /dev/null +++ b/arch/riscv/kvm/vcpu_sbi_pmu.c @@ -0,0 +1,81 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2022 Rivos Inc + * + * Authors: + * Atish Patra <atishp@xxxxxxxxxxxx> + */ + +#include <linux/errno.h> +#include <linux/err.h> +#include <linux/kvm_host.h> +#include <asm/csr.h> +#include <asm/sbi.h> +#include <asm/kvm_vcpu_sbi.h> + +static int kvm_sbi_ext_pmu_handler(struct kvm_vcpu *vcpu, struct kvm_run *run, + unsigned long *out_val, + struct kvm_cpu_trap *utrap, + bool *exit) +{ + int ret = -EOPNOTSUPP; + struct kvm_cpu_context *cp = &vcpu->arch.guest_context; + unsigned long funcid = cp->a6; + uint64_t temp; + + switch (funcid) { + case SBI_EXT_PMU_NUM_COUNTERS: + ret = kvm_riscv_vcpu_pmu_num_ctrs(vcpu, out_val); + break; + case SBI_EXT_PMU_COUNTER_GET_INFO: + ret = kvm_riscv_vcpu_pmu_ctr_info(vcpu, cp->a0, out_val); + break; + case SBI_EXT_PMU_COUNTER_CFG_MATCH: +#if defined(CONFIG_32BIT) + temp = ((uint64_t)cp->a5 << 32) | cp->a4; +#else + temp = cp->a4; +#endif + ret = kvm_riscv_vcpu_pmu_ctr_cfg_match(vcpu, cp->a0, cp->a1, cp->a2, cp->a3, temp); + if (ret >= 0) { + *out_val = ret; + ret = 0; + } + break; + case SBI_EXT_PMU_COUNTER_START: +#if defined(CONFIG_32BIT) + temp = ((uint64_t)cp->a4 << 32) | cp->a3; +#else + temp = cp->a3; +#endif + ret = kvm_riscv_vcpu_pmu_ctr_start(vcpu, cp->a0, cp->a1, cp->a2, temp); + break; + case SBI_EXT_PMU_COUNTER_STOP: + ret = kvm_riscv_vcpu_pmu_ctr_stop(vcpu, cp->a0, cp->a1, cp->a2); + break; + case SBI_EXT_PMU_COUNTER_FW_READ: + ret = kvm_riscv_vcpu_pmu_ctr_read(vcpu, cp->a0, out_val); + break; + default: + ret = -EOPNOTSUPP; + } + + return ret; +} + +unsigned long kvm_sbi_ext_pmu_probe(unsigned long extid) +{ + /* + * PMU Extension is only available to guests if privilege mode filtering + * is available. Otherwise, guest will always count events while the + * execution is in hypervisor mode. + */ + return riscv_isa_extension_available(NULL, SSCOFPMF); +} + +const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_pmu = { + .extid_start = SBI_EXT_PMU, + .extid_end = SBI_EXT_PMU, + .handler = kvm_sbi_ext_pmu_handler, + .probe = kvm_sbi_ext_pmu_probe, +}; -- 2.25.1