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AJvYcCXrkvLuXjyYbKXkk34Ek211GIqpJVLixVS+A14quQ2TyO4dI5tuUSrLcEyFR5knUCj9c/lAuwTm4GDxiMo=@vger.kernel.org X-Gm-Message-State: AOJu0Yx9e/SgZA8GsLKpxqN79HLsrF/pKHZlJi7C0y5WB0aqJ2xSIyW0 M0ZpBVxzvb+wbG7XhyJH2NvVSItFFoprFy3TgHkMQ7vLO4x8Y7d5Tw531yxuCwQhQIxp2+eoVWQ 50PPye1FIAcppXvckFGtpTHryzA== X-Google-Smtp-Source: AGHT+IFQs2Wwdg/fSES5A58gFSJxMknzSDLNOp4k85bx8hXhl1wyXlz+jCSjhcviMYqna778nTCFvIvjB3UkqOM8qQ== X-Received: from ilbbm19.prod.google.com ([2002:a05:6e02:3313:b0:3df:3a5e:9ba8]) (user=coltonlewis job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6e02:2589:b0:3df:460a:ec3c with SMTP id e9e14a558f8ab-3df4acc520fmr11509085ab.22.1750968369104; Thu, 26 Jun 2025 13:06:09 -0700 (PDT) Date: Thu, 26 Jun 2025 20:04:53 +0000 In-Reply-To: <20250626200459.1153955-1-coltonlewis@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20250626200459.1153955-1-coltonlewis@google.com> X-Mailer: git-send-email 2.50.0.727.gbf7dc18ff4-goog Message-ID: <20250626200459.1153955-18-coltonlewis@google.com> Subject: [PATCH v3 17/22] KVM: arm64: Context swap Partitioned PMU guest registers From: Colton Lewis To: kvm@vger.kernel.org Cc: Paolo Bonzini , Jonathan Corbet , Russell King , Catalin Marinas , Will Deacon , Marc Zyngier , Oliver Upton , Mingwei Zhang , Joey Gouly , Suzuki K Poulose , Zenghui Yu , Mark Rutland , Shuah Khan , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-perf-users@vger.kernel.org, linux-kselftest@vger.kernel.org, Colton Lewis Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Save and restore newly untrapped registers that can be directly accessed by the guest when the PMU is partitioned. * PMEVCNTRn_EL0 * PMCCNTR_EL0 * PMICNTR_EL0 * PMUSERENR_EL0 * PMSELR_EL0 * PMCR_EL0 * PMCNTEN_EL0 * PMINTEN_EL1 If the PMU is not partitioned or MDCR_EL2.TPM is set, all PMU registers are trapped so return immediately. Signed-off-by: Colton Lewis --- arch/arm64/include/asm/kvm_pmu.h | 4 ++ arch/arm64/kvm/arm.c | 2 + arch/arm64/kvm/pmu-part.c | 101 +++++++++++++++++++++++++++++++ 3 files changed, 107 insertions(+) diff --git a/arch/arm64/include/asm/kvm_pmu.h b/arch/arm64/include/asm/kvm_= pmu.h index 35674879aae0..4f0741bf6779 100644 --- a/arch/arm64/include/asm/kvm_pmu.h +++ b/arch/arm64/include/asm/kvm_pmu.h @@ -98,6 +98,8 @@ void kvm_pmu_host_counters_disable(void); =20 u8 kvm_pmu_guest_num_counters(struct kvm_vcpu *vcpu); u8 kvm_pmu_hpmn(struct kvm_vcpu *vcpu); +void kvm_pmu_load(struct kvm_vcpu *vcpu); +void kvm_pmu_put(struct kvm_vcpu *vcpu); =20 #if !defined(__KVM_NVHE_HYPERVISOR__) bool kvm_vcpu_pmu_is_partitioned(struct kvm_vcpu *vcpu); @@ -169,6 +171,8 @@ static inline u8 kvm_pmu_hpmn(struct kvm_vcpu *vcpu) { return 0; } +static inline void kvm_pmu_load(struct kvm_vcpu *vcpu) {} +static inline void kvm_pmu_put(struct kvm_vcpu *vcpu) {} static inline void kvm_pmu_set_counter_value(struct kvm_vcpu *vcpu, u64 select_idx, u64 val) {} static inline void kvm_pmu_set_counter_value_user(struct kvm_vcpu *vcpu, diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index e452aba1a3b2..7c007ee44ecb 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -616,6 +616,7 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu) kvm_vcpu_load_vhe(vcpu); kvm_arch_vcpu_load_fp(vcpu); kvm_vcpu_pmu_restore_guest(vcpu); + kvm_pmu_load(vcpu); if (kvm_arm_is_pvtime_enabled(&vcpu->arch)) kvm_make_request(KVM_REQ_RECORD_STEAL, vcpu); =20 @@ -658,6 +659,7 @@ void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu) kvm_timer_vcpu_put(vcpu); kvm_vgic_put(vcpu); kvm_vcpu_pmu_restore_host(vcpu); + kvm_pmu_put(vcpu); if (vcpu_has_nv(vcpu)) kvm_vcpu_put_hw_mmu(vcpu); kvm_arm_vmid_clear_active(); diff --git a/arch/arm64/kvm/pmu-part.c b/arch/arm64/kvm/pmu-part.c index f954d2d29314..5eb53c6409e7 100644 --- a/arch/arm64/kvm/pmu-part.c +++ b/arch/arm64/kvm/pmu-part.c @@ -9,6 +9,7 @@ #include =20 #include +#include #include =20 /** @@ -194,3 +195,103 @@ u8 kvm_pmu_hpmn(struct kvm_vcpu *vcpu) =20 return hpmn; } + +/** + * kvm_pmu_load() - Load untrapped PMU registers + * @vcpu: Pointer to struct kvm_vcpu + * + * Load all untrapped PMU registers from the VCPU into the PCPU. Mask + * to only bits belonging to guest-reserved counters and leave + * host-reserved counters alone in bitmask registers. + */ +void kvm_pmu_load(struct kvm_vcpu *vcpu) +{ + struct arm_pmu *pmu =3D vcpu->kvm->arch.arm_pmu; + u64 mask =3D kvm_pmu_guest_counter_mask(pmu); + u8 i; + u64 val; + + /* + * If the PMU is not partitioned or we have MDCR_EL2_TPM, + * every PMU access is trapped so don't bother with the swap. + */ + if (!kvm_pmu_is_partitioned(pmu) || (vcpu->arch.mdcr_el2 & MDCR_EL2_TPM)) + return; + + for (i =3D 0; i < pmu->hpmn_max; i++) { + val =3D __vcpu_sys_reg(vcpu, PMEVCNTR0_EL0 + i); + write_pmevcntrn(i, val); + } + + val =3D __vcpu_sys_reg(vcpu, PMCCNTR_EL0); + write_pmccntr(val); + + val =3D __vcpu_sys_reg(vcpu, PMUSERENR_EL0); + write_pmuserenr(val); + + val =3D __vcpu_sys_reg(vcpu, PMSELR_EL0); + write_pmselr(val); + + val =3D __vcpu_sys_reg(vcpu, PMCR_EL0); + write_pmcr(val); + + /* + * Loading these registers is tricky because of + * 1. Applying only the bits for guest counters (indicated by mask) + * 2. Setting and clearing are different registers + */ + val =3D __vcpu_sys_reg(vcpu, PMCNTENSET_EL0); + write_pmcntenset(val & mask); + write_pmcntenclr(~val & mask); + + val =3D __vcpu_sys_reg(vcpu, PMINTENSET_EL1); + write_pmintenset(val & mask); + write_pmintenclr(~val & mask); +} + +/** + * kvm_pmu_put() - Put untrapped PMU registers + * @vcpu: Pointer to struct kvm_vcpu + * + * Put all untrapped PMU registers from the VCPU into the PCPU. Mask + * to only bits belonging to guest-reserved counters and leave + * host-reserved counters alone in bitmask registers. + */ +void kvm_pmu_put(struct kvm_vcpu *vcpu) +{ + struct arm_pmu *pmu =3D vcpu->kvm->arch.arm_pmu; + u64 mask =3D kvm_pmu_guest_counter_mask(pmu); + u8 i; + u64 val; + + /* + * If the PMU is not partitioned or we have MDCR_EL2_TPM, + * every PMU access is trapped so don't bother with the swap. + */ + if (!kvm_pmu_is_partitioned(pmu) || (vcpu->arch.mdcr_el2 & MDCR_EL2_TPM)) + return; + + for (i =3D 0; i < pmu->hpmn_max; i++) { + val =3D read_pmevcntrn(i); + __vcpu_assign_sys_reg(vcpu, PMEVCNTR0_EL0 + i, val); + } + + val =3D read_pmccntr(); + __vcpu_assign_sys_reg(vcpu, PMCCNTR_EL0, val); + + val =3D read_pmuserenr(); + __vcpu_assign_sys_reg(vcpu, PMUSERENR_EL0, val); + + val =3D read_pmselr(); + __vcpu_assign_sys_reg(vcpu, PMSELR_EL0, val); + + val =3D read_pmcr(); + __vcpu_assign_sys_reg(vcpu, PMCR_EL0, val); + + /* Mask these to only save the guest relevant bits. */ + val =3D read_pmcntenset(); + __vcpu_assign_sys_reg(vcpu, PMCNTENSET_EL0, val & mask); + + val =3D read_pmintenset(); + __vcpu_assign_sys_reg(vcpu, PMINTENSET_EL1, val & mask); +} --=20 2.50.0.727.gbf7dc18ff4-goog