Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754569AbdG3T7o (ORCPT ); Sun, 30 Jul 2017 15:59:44 -0400 Received: from mail-wm0-f47.google.com ([74.125.82.47]:35959 "EHLO mail-wm0-f47.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754481AbdG3T7l (ORCPT ); Sun, 30 Jul 2017 15:59:41 -0400 Date: Sun, 30 Jul 2017 21:59:38 +0200 From: Christoffer Dall To: Jintack Lim Cc: kvmarm@lists.cs.columbia.edu, christoffer.dall@linaro.org, marc.zyngier@arm.com, corbet@lwn.net, pbonzini@redhat.com, rkrcmar@redhat.com, linux@armlinux.org.uk, catalin.marinas@arm.com, will.deacon@arm.com, akpm@linux-foundation.org, mchehab@kernel.org, cov@codeaurora.org, daniel.lezcano@linaro.org, david.daney@cavium.com, mark.rutland@arm.com, suzuki.poulose@arm.com, stefan@hello-penguin.com, andy.gross@linaro.org, wcohen@redhat.com, ard.biesheuvel@linaro.org, shankerd@codeaurora.org, vladimir.murzin@arm.com, james.morse@arm.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [RFC PATCH v2 04/38] KVM: arm/arm64: Check if nested virtualization is in use Message-ID: <20170730195938.GD5176@cbox> References: <1500397144-16232-1-git-send-email-jintack.lim@linaro.org> <1500397144-16232-5-git-send-email-jintack.lim@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1500397144-16232-5-git-send-email-jintack.lim@linaro.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2769 Lines: 97 On Tue, Jul 18, 2017 at 11:58:30AM -0500, Jintack Lim wrote: > Nested virtualizaion is in use only if all three conditions are met: > - The architecture supports nested virtualization. > - The kernel parameter is set. > - The userspace uses nested virtualiztion feature. > > Signed-off-by: Jintack Lim > --- > arch/arm/include/asm/kvm_host.h | 11 +++++++++++ > arch/arm64/include/asm/kvm_host.h | 2 ++ > arch/arm64/kvm/nested.c | 17 +++++++++++++++++ > virt/kvm/arm/arm.c | 4 ++++ > 4 files changed, 34 insertions(+) > > diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h > index 00b0f97..7e9e6c8 100644 > --- a/arch/arm/include/asm/kvm_host.h > +++ b/arch/arm/include/asm/kvm_host.h > @@ -303,4 +303,15 @@ static inline int __init kvmarm_nested_cfg(char *buf) > { > return 0; > } > + > +static inline int init_nested_virt(void) > +{ > + return 0; > +} > + > +static inline bool nested_virt_in_use(struct kvm_vcpu *vcpu) > +{ > + return false; > +} > + > #endif /* __ARM_KVM_HOST_H__ */ > diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h > index 6df0c7c..86d4b6c 100644 > --- a/arch/arm64/include/asm/kvm_host.h > +++ b/arch/arm64/include/asm/kvm_host.h > @@ -387,5 +387,7 @@ static inline void __cpu_init_stage2(void) > } > > int __init kvmarm_nested_cfg(char *buf); > +int init_nested_virt(void); > +bool nested_virt_in_use(struct kvm_vcpu *vcpu); > > #endif /* __ARM64_KVM_HOST_H__ */ > diff --git a/arch/arm64/kvm/nested.c b/arch/arm64/kvm/nested.c > index 79f38da..9a05c76 100644 > --- a/arch/arm64/kvm/nested.c > +++ b/arch/arm64/kvm/nested.c > @@ -24,3 +24,20 @@ int __init kvmarm_nested_cfg(char *buf) > { > return strtobool(buf, &nested_param); > } > + > +int init_nested_virt(void) > +{ > + if (nested_param && cpus_have_const_cap(ARM64_HAS_NESTED_VIRT)) > + kvm_info("Nested virtualization is supported\n"); > + > + return 0; > +} > + > +bool nested_virt_in_use(struct kvm_vcpu *vcpu) > +{ > + if (nested_param && cpus_have_const_cap(ARM64_HAS_NESTED_VIRT) > + && test_bit(KVM_ARM_VCPU_NESTED_VIRT, vcpu->arch.features)) > + return true; > + > + return false; > +} after reading through a lot of your patches, I feel like vm_has_el2() would be a more elegant name, but it's not a strict requirement to change it. > diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c > index 1c1c772..36aae3a 100644 > --- a/virt/kvm/arm/arm.c > +++ b/virt/kvm/arm/arm.c > @@ -1478,6 +1478,10 @@ int kvm_arch_init(void *opaque) > if (err) > goto out_err; > > + err = init_nested_virt(); > + if (err) > + return err; > + > err = init_subsystems(); > if (err) > goto out_hyp; > -- > 1.9.1 > Thanks, -Christoffer