Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751806AbdHAN4p (ORCPT ); Tue, 1 Aug 2017 09:56:45 -0400 Received: from mail-oi0-f53.google.com ([209.85.218.53]:35339 "EHLO mail-oi0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751677AbdHAN4m (ORCPT ); Tue, 1 Aug 2017 09:56:42 -0400 MIME-Version: 1.0 In-Reply-To: <20170730195944.GE5176@cbox> References: <1500397144-16232-1-git-send-email-jintack.lim@linaro.org> <1500397144-16232-3-git-send-email-jintack.lim@linaro.org> <20170730195944.GE5176@cbox> From: Jintack Lim Date: Tue, 1 Aug 2017 09:56:39 -0400 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [RFC PATCH v2 02/38] KVM: arm/arm64: Enable nested virtualization via command-line To: Christoffer Dall Cc: kvmarm@lists.cs.columbia.edu, Christoffer Dall , Marc Zyngier , Jonathan Corbet , Paolo Bonzini , =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= , linux@armlinux.org.uk, Catalin Marinas , Will Deacon , akpm@linux-foundation.org, mchehab@kernel.org, cov@codeaurora.org, Daniel Lezcano , david.daney@cavium.com, mark.rutland@arm.com, Suzuki K Poulose , stefan@hello-penguin.com, Andy Gross , wcohen@redhat.com, Ard Biesheuvel , shankerd@codeaurora.org, vladimir.murzin@arm.com, james.morse@arm.com, linux-doc@vger.kernel.org, lkml - Kernel Mailing List , KVM General , arm-mail-list Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4953 Lines: 125 On Sun, Jul 30, 2017 at 3:59 PM, Christoffer Dall wrote: > 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. > Sounds good! Thanks. >> + >> 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 >>