From: Reiji Watanabe <reijiw@google.com> To: Marc Zyngier <maz@kernel.org>, Oliver Upton <oliver.upton@linux.dev>, kvmarm@lists.linux.dev Cc: kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, James Morse <james.morse@arm.com>, Alexandru Elisei <alexandru.elisei@arm.com>, Zenghui Yu <yuzenghui@huawei.com>, Suzuki K Poulose <suzuki.poulose@arm.com>, Paolo Bonzini <pbonzini@redhat.com>, Ricardo Koller <ricarkol@google.com>, Jing Zhang <jingzhangos@google.com>, Raghavendra Rao Anata <rananta@google.com>, Will Deacon <will@kernel.org>, Reiji Watanabe <reijiw@google.com> Subject: [PATCH 0/4] KVM: arm64: PMU: Fix PMUVer handling on heterogeneous PMU systems Date: Fri, 26 May 2023 21:02:32 -0700 [thread overview] Message-ID: <20230527040236.1875860-1-reijiw@google.com> (raw) This series fixes issues with PMUVer handling for a guest with PMU configured on heterogeneous PMU systems. Specifically, it addresses the following two issues. [A] The default value of ID_AA64DFR0_EL1.PMUVer of the vCPU is set to its sanitized value. This could be inappropriate on heterogeneous PMU systems, as arm64_ftr_bits for PMUVer is defined as FTR_EXACT with safe_val == 0 (when ID_AA64DFR0_EL1.PMUVer of all PEs on the host is not uniform, the sanitized value will be 0). [B] KVM uses PMUVer of the PMU hardware that is associated to the guest (kvm->arch.arm_pmu->pmuver) for the guest in some cases, even though userspace might have changed the guest's ID_AA64DFR0_EL1.PMUVer (kvm->arch.dfr0_pmuver.imp). To fix [A], KVM will set the default value of the guest's ID_AA64DFR0_EL1.PMUVer to the PMUVer of the guest's PMU (kvm->arch.arm_pmu->pmuver). To fix [B], KVM will stop using kvm->arch.arm_pmu->pmuver (except for some special cases) and use ID_AA64DFR0_EL1.PMUVer for the guest instead. Patch 1 adds a helper to set a PMU for the guest. This helper will make it easier for the following patches to modify the relevant code. Patch 2 make the default PMU for the guest set on the first vCPU reset. As userspace can get the value of ID_AA64DFR0_EL1 after the initial vCPU reset, this change is to make the default PMUVer value based on the guest's PMU available on the initial vCPU reset. Patch 3 and 4 fix the issue [A] and [B] respectively. The series is based on v6.4-rc3. The patches in this series were originally included as part of [1]. [1] https://lore.kernel.org/all/20230211031506.4159098-1-reijiw@google.com/ Reiji Watanabe (4): KVM: arm64: PMU: Introduce a helper to set the guest's PMU KVM: arm64: PMU: Set the default PMU for the guest on vCPU reset KVM: arm64: PMU: Use PMUVer of the guest's PMU for ID_AA64DFR0.PMUVer KVM: arm64: PMU: Don't use the PMUVer of the PMU set for guest arch/arm64/include/asm/kvm_host.h | 2 + arch/arm64/kvm/arm.c | 6 --- arch/arm64/kvm/pmu-emul.c | 73 +++++++++++++++++++++---------- arch/arm64/kvm/reset.c | 20 ++++++--- arch/arm64/kvm/sys_regs.c | 48 +++++++++++++------- include/kvm/arm_pmu.h | 10 ++++- 6 files changed, 106 insertions(+), 53 deletions(-) base-commit: 44c026a73be8038f03dbdeef028b642880cf1511 -- 2.41.0.rc0.172.g3f132b7071-goog
WARNING: multiple messages have this Message-ID (diff)
From: Reiji Watanabe <reijiw@google.com> To: Marc Zyngier <maz@kernel.org>, Oliver Upton <oliver.upton@linux.dev>, kvmarm@lists.linux.dev Cc: kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, James Morse <james.morse@arm.com>, Alexandru Elisei <alexandru.elisei@arm.com>, Zenghui Yu <yuzenghui@huawei.com>, Suzuki K Poulose <suzuki.poulose@arm.com>, Paolo Bonzini <pbonzini@redhat.com>, Ricardo Koller <ricarkol@google.com>, Jing Zhang <jingzhangos@google.com>, Raghavendra Rao Anata <rananta@google.com>, Will Deacon <will@kernel.org>, Reiji Watanabe <reijiw@google.com> Subject: [PATCH 0/4] KVM: arm64: PMU: Fix PMUVer handling on heterogeneous PMU systems Date: Fri, 26 May 2023 21:02:32 -0700 [thread overview] Message-ID: <20230527040236.1875860-1-reijiw@google.com> (raw) This series fixes issues with PMUVer handling for a guest with PMU configured on heterogeneous PMU systems. Specifically, it addresses the following two issues. [A] The default value of ID_AA64DFR0_EL1.PMUVer of the vCPU is set to its sanitized value. This could be inappropriate on heterogeneous PMU systems, as arm64_ftr_bits for PMUVer is defined as FTR_EXACT with safe_val == 0 (when ID_AA64DFR0_EL1.PMUVer of all PEs on the host is not uniform, the sanitized value will be 0). [B] KVM uses PMUVer of the PMU hardware that is associated to the guest (kvm->arch.arm_pmu->pmuver) for the guest in some cases, even though userspace might have changed the guest's ID_AA64DFR0_EL1.PMUVer (kvm->arch.dfr0_pmuver.imp). To fix [A], KVM will set the default value of the guest's ID_AA64DFR0_EL1.PMUVer to the PMUVer of the guest's PMU (kvm->arch.arm_pmu->pmuver). To fix [B], KVM will stop using kvm->arch.arm_pmu->pmuver (except for some special cases) and use ID_AA64DFR0_EL1.PMUVer for the guest instead. Patch 1 adds a helper to set a PMU for the guest. This helper will make it easier for the following patches to modify the relevant code. Patch 2 make the default PMU for the guest set on the first vCPU reset. As userspace can get the value of ID_AA64DFR0_EL1 after the initial vCPU reset, this change is to make the default PMUVer value based on the guest's PMU available on the initial vCPU reset. Patch 3 and 4 fix the issue [A] and [B] respectively. The series is based on v6.4-rc3. The patches in this series were originally included as part of [1]. [1] https://lore.kernel.org/all/20230211031506.4159098-1-reijiw@google.com/ Reiji Watanabe (4): KVM: arm64: PMU: Introduce a helper to set the guest's PMU KVM: arm64: PMU: Set the default PMU for the guest on vCPU reset KVM: arm64: PMU: Use PMUVer of the guest's PMU for ID_AA64DFR0.PMUVer KVM: arm64: PMU: Don't use the PMUVer of the PMU set for guest arch/arm64/include/asm/kvm_host.h | 2 + arch/arm64/kvm/arm.c | 6 --- arch/arm64/kvm/pmu-emul.c | 73 +++++++++++++++++++++---------- arch/arm64/kvm/reset.c | 20 ++++++--- arch/arm64/kvm/sys_regs.c | 48 +++++++++++++------- include/kvm/arm_pmu.h | 10 ++++- 6 files changed, 106 insertions(+), 53 deletions(-) base-commit: 44c026a73be8038f03dbdeef028b642880cf1511 -- 2.41.0.rc0.172.g3f132b7071-goog _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next reply other threads:[~2023-05-27 4:04 UTC|newest] Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top 2023-05-27 4:02 Reiji Watanabe [this message] 2023-05-27 4:02 ` [PATCH 0/4] KVM: arm64: PMU: Fix PMUVer handling on heterogeneous PMU systems Reiji Watanabe 2023-05-27 4:02 ` [PATCH 1/4] KVM: arm64: PMU: Introduce a helper to set the guest's PMU Reiji Watanabe 2023-05-27 4:02 ` Reiji Watanabe 2023-05-27 4:02 ` [PATCH 2/4] KVM: arm64: PMU: Set the default PMU for the guest on vCPU reset Reiji Watanabe 2023-05-27 4:02 ` Reiji Watanabe 2023-05-27 17:35 ` kernel test robot 2023-05-27 17:35 ` kernel test robot 2023-05-27 4:02 ` [PATCH 3/4] KVM: arm64: PMU: Use PMUVer of the guest's PMU for ID_AA64DFR0.PMUVer Reiji Watanabe 2023-05-27 4:02 ` Reiji Watanabe 2023-05-27 4:02 ` [PATCH 4/4] KVM: arm64: PMU: Don't use the PMUVer of the PMU set for guest Reiji Watanabe 2023-05-27 4:02 ` Reiji Watanabe 2023-05-29 13:39 ` [PATCH 0/4] KVM: arm64: PMU: Fix PMUVer handling on heterogeneous PMU systems Marc Zyngier 2023-05-29 13:39 ` Marc Zyngier 2023-05-30 12:53 ` Reiji Watanabe 2023-05-30 12:53 ` Reiji Watanabe 2023-06-01 5:02 ` Marc Zyngier 2023-06-01 5:02 ` Marc Zyngier 2023-06-02 5:23 ` Reiji Watanabe 2023-06-02 5:23 ` Reiji Watanabe 2023-06-02 9:05 ` Marc Zyngier 2023-06-02 9:05 ` Marc Zyngier 2023-06-02 16:07 ` Reiji Watanabe 2023-06-02 16:07 ` Reiji Watanabe
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