From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave Martin Subject: [PATCH v4 20/25] KVM: arm/arm64: Add hook to finalize the vcpu configuration Date: Thu, 17 Jan 2019 20:33:34 +0000 Message-ID: <1547757219-19439-21-git-send-email-Dave.Martin@arm.com> References: <1547757219-19439-1-git-send-email-Dave.Martin@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id A570B4A214 for ; Thu, 17 Jan 2019 15:35:12 -0500 (EST) Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id YZtLM20zzvMt for ; Thu, 17 Jan 2019 15:35:11 -0500 (EST) Received: from foss.arm.com (usa-sjc-mx-foss1.foss.arm.com [217.140.101.70]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 7FD3A4A36C for ; Thu, 17 Jan 2019 15:35:11 -0500 (EST) In-Reply-To: <1547757219-19439-1-git-send-email-Dave.Martin@arm.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu To: kvmarm@lists.cs.columbia.edu Cc: Okamoto Takayuki , Christoffer Dall , Ard Biesheuvel , Marc Zyngier , Catalin Marinas , Will Deacon , linux-arm-kernel@lists.infradead.org List-Id: kvmarm@lists.cs.columbia.edu Some aspects of vcpu configuration can't be completed inside KVM_VCPU_INIT, but still change API behaviour visible to userspace. Where such configuration choices affect the register list visible to userspace, we will need to track whether we have made a commitment to userspace regarding the list of vcpu registers. This patch adds a new hook kvm_arm_vcpu_finalize() to capture this commitment, along with a corresponding check kvm_arm_vcpu_finalized(). We commit to the register list when userspace reads it via KVM_GET_REG_LIST, or when the vcpu is fired up via KVM_RUN. kvm_arm_vcpu_finalize() is currently a no-op, but future patches will amend this to handle SVE on arm64. Signed-off-by: Dave Martin --- arch/arm/include/asm/kvm_host.h | 4 ++++ arch/arm64/include/asm/kvm_host.h | 4 ++++ virt/kvm/arm/arm.c | 8 ++++++++ 3 files changed, 16 insertions(+) diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h index ca56537..ab7c76b 100644 --- a/arch/arm/include/asm/kvm_host.h +++ b/arch/arm/include/asm/kvm_host.h @@ -360,4 +360,8 @@ static inline int kvm_arm_setup_stage2(struct kvm *kvm, unsigned long type) return 0; } +/* Commit to the set of vcpu registers currently configured: */ +static inline int kvm_arm_vcpu_finalize(struct kvm_vcpu *vcpu) { return 0; } +#define kvm_arm_vcpu_finalized(vcpu) true + #endif /* __ARM_KVM_HOST_H__ */ diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 77b6f3e..55bf9d0 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -539,4 +539,8 @@ void kvm_arch_free_vm(struct kvm *kvm); int kvm_arm_setup_stage2(struct kvm *kvm, unsigned long type); +/* Commit to the set of vcpu registers currently configured: */ +static inline int kvm_arm_vcpu_finalize(struct kvm_vcpu *vcpu) { return 0; } +#define kvm_arm_vcpu_finalized(vcpu) true + #endif /* __ARM64_KVM_HOST_H__ */ diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c index 9e350fd3..12f9dc2 100644 --- a/virt/kvm/arm/arm.c +++ b/virt/kvm/arm/arm.c @@ -560,6 +560,10 @@ static int kvm_vcpu_first_run_init(struct kvm_vcpu *vcpu) if (likely(vcpu->arch.has_run_once)) return 0; + ret = kvm_arm_vcpu_finalize(vcpu); + if (ret) + return ret; + vcpu->arch.has_run_once = true; if (likely(irqchip_in_kernel(kvm))) { @@ -1121,6 +1125,10 @@ long kvm_arch_vcpu_ioctl(struct file *filp, if (unlikely(!kvm_vcpu_initialized(vcpu))) break; + r = kvm_arm_vcpu_finalize(vcpu); + if (r) + break; + r = -EFAULT; if (copy_from_user(®_list, user_list, sizeof(reg_list))) break; -- 2.1.4