From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoffer Dall Subject: Re: [RFC PATCH v2 02/38] KVM: arm/arm64: Enable nested virtualization via command-line Date: Sun, 30 Jul 2017 21:59:44 +0200 Message-ID: <20170730195944.GE5176@cbox> References: <1500397144-16232-1-git-send-email-jintack.lim@linaro.org> <1500397144-16232-3-git-send-email-jintack.lim@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org, david.daney@cavium.com, catalin.marinas@arm.com, will.deacon@arm.com, kvmarm@lists.cs.columbia.edu, stefan@hello-penguin.com, corbet@lwn.net, daniel.lezcano@linaro.org, linux@armlinux.org.uk, linux-arm-kernel@lists.infradead.org, andy.gross@linaro.org, marc.zyngier@arm.com, cov@codeaurora.org, wcohen@redhat.com, mchehab@kernel.org, ard.biesheuvel@linaro.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, pbonzini@redhat.com, akpm@linux-foundation.org To: Jintack Lim Return-path: Content-Disposition: inline In-Reply-To: <1500397144-16232-3-git-send-email-jintack.lim@linaro.org> 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 List-Id: kvm.vger.kernel.org On Tue, Jul 18, 2017 at 11:58:28AM -0500, Jintack Lim wrote: > Add a new kernel parameter(kvm-arm.nested) to enable KVM/ARM nested > virtualization support. This kernel parameter on arm architecture is > ignored since nested virtualization is not supported on arm. > > Note that this kernel parameter will not have any impact until nested > virtualization support is completed. Just add this parameter first to > use it when implementing nested virtualization support. > > Signed-off-by: Jintack Lim > --- > Documentation/admin-guide/kernel-parameters.txt | 4 ++++ > arch/arm/include/asm/kvm_host.h | 4 ++++ > arch/arm64/include/asm/kvm_host.h | 2 ++ > arch/arm64/kvm/Makefile | 2 ++ > arch/arm64/kvm/nested.c | 26 +++++++++++++++++++++++++ > virt/kvm/arm/arm.c | 2 ++ > 6 files changed, 40 insertions(+) > create mode 100644 arch/arm64/kvm/nested.c > > diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt > index aa8341e..8fb152d 100644 > --- a/Documentation/admin-guide/kernel-parameters.txt > +++ b/Documentation/admin-guide/kernel-parameters.txt > @@ -1841,6 +1841,10 @@ > [KVM,ARM] Trap guest accesses to GICv3 common > system registers > > + kvm-arm.nested= > + [KVM,ARM] Allow nested virtualization in KVM/ARM. > + Default is 0 (disabled) We may want to say "on systems that support it" or something like that here as well. > + > kvm-intel.ept= [KVM,Intel] Disable extended page tables > (virtualized MMU) support on capable Intel chips. > Default is 1 (enabled) > diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h > index 127e2dd..00b0f97 100644 > --- a/arch/arm/include/asm/kvm_host.h > +++ b/arch/arm/include/asm/kvm_host.h > @@ -299,4 +299,8 @@ int kvm_arm_vcpu_arch_get_attr(struct kvm_vcpu *vcpu, > int kvm_arm_vcpu_arch_has_attr(struct kvm_vcpu *vcpu, > struct kvm_device_attr *attr); > > +static inline int __init kvmarm_nested_cfg(char *buf) > +{ > + return 0; > +} > #endif /* __ARM_KVM_HOST_H__ */ > diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h > index 0c4fd1f..dcc4df8 100644 > --- a/arch/arm64/include/asm/kvm_host.h > +++ b/arch/arm64/include/asm/kvm_host.h > @@ -386,4 +386,6 @@ static inline void __cpu_init_stage2(void) > "PARange is %d bits, unsupported configuration!", parange); > } > > +int __init kvmarm_nested_cfg(char *buf); > + > #endif /* __ARM64_KVM_HOST_H__ */ > diff --git a/arch/arm64/kvm/Makefile b/arch/arm64/kvm/Makefile > index 5d98100..f513047 100644 > --- a/arch/arm64/kvm/Makefile > +++ b/arch/arm64/kvm/Makefile > @@ -35,3 +35,5 @@ kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic/vgic-debug.o > kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/irqchip.o > kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/arch_timer.o > kvm-$(CONFIG_KVM_ARM_PMU) += $(KVM)/arm/pmu.o > + > +kvm-$(CONFIG_KVM_ARM_HOST) += nested.o > diff --git a/arch/arm64/kvm/nested.c b/arch/arm64/kvm/nested.c > new file mode 100644 > index 0000000..79f38da > --- /dev/null > +++ b/arch/arm64/kvm/nested.c > @@ -0,0 +1,26 @@ > +/* > + * Copyright (C) 2017 - Columbia University and Linaro Ltd. > + * Author: Jintack Lim > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License version 2 as > + * published by the Free Software Foundation. > + * > + * This program is distributed in the hope that it will be useful, > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > + * GNU General Public License for more details. > + * > + * You should have received a copy of the GNU General Public License > + * along with this program. If not, see . > + */ > + > +#include > +#include > + > +static bool nested_param; > + > +int __init kvmarm_nested_cfg(char *buf) > +{ > + return strtobool(buf, &nested_param); > +} > diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c > index a39a1e1..1c1c772 100644 > --- a/virt/kvm/arm/arm.c > +++ b/virt/kvm/arm/arm.c > @@ -67,6 +67,8 @@ > > static DEFINE_PER_CPU(unsigned char, kvm_arm_hardware_enabled); > > +early_param("kvm-arm.nested", kvmarm_nested_cfg); > + > static void kvm_arm_set_running_vcpu(struct kvm_vcpu *vcpu) > { > BUG_ON(preemptible()); > -- > 1.9.1 >