From patchwork Thu Oct 4 11:56:09 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paul Mackerras X-Patchwork-Id: 978779 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=kvm-ppc-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=ozlabs.org Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; secure) header.d=ozlabs.org header.i=@ozlabs.org header.b="AQG+pw4D"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 42Qrvv1TXJzB4Nf for ; Thu, 4 Oct 2018 21:56:43 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727696AbeJDSti (ORCPT ); Thu, 4 Oct 2018 14:49:38 -0400 Received: from ozlabs.org ([203.11.71.1]:45859 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727690AbeJDSth (ORCPT ); Thu, 4 Oct 2018 14:49:37 -0400 Received: from authenticated.ozlabs.org (localhost [127.0.0.1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPSA id 42Qrvq0y44zB4NP; Thu, 4 Oct 2018 21:56:39 +1000 (AEST) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=ozlabs.org DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ozlabs.org; s=201707; t=1538654199; bh=35YwwPY6coOsarA0fTW69h1UXBxucZzDyAX9W/vVgKc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=AQG+pw4D7KFdIlfB0ywdLAHQT/FX8LjtcJqWpdEkTIfhE88oq37EYbuV5p1PTfW7m U31S6QQPZdTql6iZr7ksDCfJxOGFh/dOQtHfNVrz+3zd2moZIbWKRV5OtpnKFAvdGy 7JqscuZcEv50L3vcqfZifyVtkLQUjxQFz2JDSHxMTGDVPeBU00HRvZTCDhBgTGR2Kb j8ILwevWFhDeRpb0f7/Z3+FRjv8PnSVX6tR17RT33PqT9U4TJD6bQg3EpLL13gjfN4 u6YKy+CpfTSLCk48xxUKuZwA+L0UNW7QV8yNKz+pZKA7ZTsHdSl6o3womak+/XRfEi jMCWAHoFcmK9g== From: Paul Mackerras To: kvm@vger.kernel.org, kvm-ppc@vger.kernel.org Cc: linuxppc-dev@ozlabs.org, David Gibson Subject: [PATCH v4 32/32] KVM: PPC: Book3S HV: Add a VM capability to enable nested virtualization Date: Thu, 4 Oct 2018 21:56:09 +1000 Message-Id: <1538654169-15602-33-git-send-email-paulus@ozlabs.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1538654169-15602-1-git-send-email-paulus@ozlabs.org> References: <1538654169-15602-1-git-send-email-paulus@ozlabs.org> Sender: kvm-ppc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm-ppc@vger.kernel.org With this, userspace can enable a KVM-HV guest to run nested guests under it. The administrator can control whether any nested guests can be run; setting the "nested" module parameter to false prevents any guests becoming nested hypervisors (that is, any attempt to enable the nested capability on a guest will fail). Guests which are already nested hypervisors will continue to be so. Signed-off-by: Paul Mackerras Reviewed-by: David Gibson --- Documentation/virtual/kvm/api.txt | 14 ++++++++++++++ arch/powerpc/include/asm/kvm_ppc.h | 1 + arch/powerpc/kvm/book3s_hv.c | 19 +++++++++++++++++++ arch/powerpc/kvm/powerpc.c | 12 ++++++++++++ include/uapi/linux/kvm.h | 1 + 5 files changed, 47 insertions(+) diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index 017d851..a2d4832 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -4522,6 +4522,20 @@ hpage module parameter is not set to 1, -EINVAL is returned. While it is generally possible to create a huge page backed VM without this capability, the VM will not be able to run. +7.15 KVM_CAP_PPC_NESTED_HV + +Architectures: ppc +Parameters: enable flag (0 to disable, non-zero to enable) +Returns: 0 on success, -EINVAL when the implementation doesn't support +nested-HV virtualization. + +HV-KVM on POWER9 and later systems allows for "nested-HV" +virtualization, which provides a way for a guest VM to run guests that +can run using the CPU's supervisor mode (privileged non-hypervisor +state). Enabling this capability on a VM depends on the CPU having +the necessary functionality and on the facility being enabled with a +kvm-hv module parameter. + 8. Other capabilities. ---------------------- diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h index 245e564..80f0091 100644 --- a/arch/powerpc/include/asm/kvm_ppc.h +++ b/arch/powerpc/include/asm/kvm_ppc.h @@ -327,6 +327,7 @@ struct kvmppc_ops { int (*set_smt_mode)(struct kvm *kvm, unsigned long mode, unsigned long flags); void (*giveup_ext)(struct kvm_vcpu *vcpu, ulong msr); + int (*enable_nested)(struct kvm *kvm, bool enable); }; extern struct kvmppc_ops *kvmppc_hv_ops; diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index 7f89b22..d3cc013 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -118,6 +118,11 @@ module_param_cb(h_ipi_redirect, &module_param_ops, &h_ipi_redirect, 0644); MODULE_PARM_DESC(h_ipi_redirect, "Redirect H_IPI wakeup to a free host core"); #endif +/* If set, guests are allowed to create and control nested guests */ +static bool nested = true; +module_param(nested, bool, S_IRUGO | S_IWUSR); +MODULE_PARM_DESC(nested, "Enable nested virtualization (only on POWER9)"); + /* If set, the threads on each CPU core have to be in the same MMU mode */ static bool no_mixing_hpt_and_radix; @@ -5165,6 +5170,19 @@ static int kvmhv_configure_mmu(struct kvm *kvm, struct kvm_ppc_mmuv3_cfg *cfg) return err; } +static int kvmhv_enable_nested(struct kvm *kvm, bool enable) +{ + if (!nested) + return -EPERM; + if (!cpu_has_feature(CPU_FTR_ARCH_300)) + return -ENODEV; + + /* kvm == NULL means the caller is testing if the capability exists */ + if (kvm) + kvm->arch.nested_enable = enable; + return 0; +} + static struct kvmppc_ops kvm_ops_hv = { .get_sregs = kvm_arch_vcpu_ioctl_get_sregs_hv, .set_sregs = kvm_arch_vcpu_ioctl_set_sregs_hv, @@ -5204,6 +5222,7 @@ static struct kvmppc_ops kvm_ops_hv = { .configure_mmu = kvmhv_configure_mmu, .get_rmmu_info = kvmhv_get_rmmu_info, .set_smt_mode = kvmhv_set_smt_mode, + .enable_nested = kvmhv_enable_nested, }; static int kvm_init_subcore_bitmap(void) diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c index eba5756..449ae1d 100644 --- a/arch/powerpc/kvm/powerpc.c +++ b/arch/powerpc/kvm/powerpc.c @@ -596,6 +596,10 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) case KVM_CAP_PPC_MMU_HASH_V3: r = !!(hv_enabled && cpu_has_feature(CPU_FTR_ARCH_300)); break; + case KVM_CAP_PPC_NESTED_HV: + r = !!(hv_enabled && kvmppc_hv_ops->enable_nested && + !kvmppc_hv_ops->enable_nested(NULL, false)); + break; #endif case KVM_CAP_SYNC_MMU: #ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE @@ -2114,6 +2118,14 @@ static int kvm_vm_ioctl_enable_cap(struct kvm *kvm, r = kvm->arch.kvm_ops->set_smt_mode(kvm, mode, flags); break; } + + case KVM_CAP_PPC_NESTED_HV: + r = -EINVAL; + if (!is_kvmppc_hv_enabled(kvm) || + !kvm->arch.kvm_ops->enable_nested) + break; + r = kvm->arch.kvm_ops->enable_nested(kvm, !!cap->args[0]); + break; #endif default: r = -EINVAL; diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 07548de..a6d5a46 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -952,6 +952,7 @@ struct kvm_ppc_resize_hpt { #define KVM_CAP_S390_HPAGE_1M 156 #define KVM_CAP_NESTED_STATE 157 #define KVM_CAP_ARM_INJECT_SERROR_ESR 158 +#define KVM_CAP_PPC_NESTED_HV 160 #ifdef KVM_CAP_IRQ_ROUTING