From patchwork Tue Jul 18 23:45:00 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sean Christopherson X-Patchwork-Id: 13317946 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id EA848C001DE for ; Tue, 18 Jul 2023 23:52:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230406AbjGRXwP (ORCPT ); Tue, 18 Jul 2023 19:52:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49624 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230368AbjGRXv0 (ORCPT ); Tue, 18 Jul 2023 19:51:26 -0400 Received: from mail-yb1-xb4a.google.com (mail-yb1-xb4a.google.com [IPv6:2607:f8b0:4864:20::b4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BF95D1BD9 for ; Tue, 18 Jul 2023 16:49:37 -0700 (PDT) Received: by mail-yb1-xb4a.google.com with SMTP id 3f1490d57ef6-cb8263615d7so4003646276.1 for ; Tue, 18 Jul 2023 16:49:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1689724144; x=1692316144; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:reply-to:from:to:cc:subject:date:message-id:reply-to; bh=8TdJ1H9vY0vZ6d4Ib+S5mGLNRUVvHsylOvOW0QhRfnk=; b=u+28WdzeWc40Gm+Je1x1UFfDLSLxds49kd/6cqkzLMXf4jy+V6QtZTuGEoBKa71Rcu xg+sLXnFWp3IWF94fBSqPSjOmJbnWdsevA1ZXgY7o9A/h+kuNZYLpmc2HukjMPatPza4 bxbe/VVib5gL1I9HqShDRV4bFhCvQBMgcqIy1VFhBxpcya3h6Q52dV75EjdhVIAPxjjN wxT87kXK0wL48yMvGVPc/XWafV0cS0EPf90K+wFMc3WuKEWI3FatqxiQl8K69yyJ40KH xIklmB6W3R2L80L6WyYqIQwJ5fMxk7Q+kqHJKmDnyACB3D7Hucmc3LR/fm+aquGvOS2x x9lQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1689724144; x=1692316144; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:reply-to:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=8TdJ1H9vY0vZ6d4Ib+S5mGLNRUVvHsylOvOW0QhRfnk=; b=aXkUQjQFb18mg3VBnWtq41CM4WBz6sK7rzaakHC48BhSEM6v0qxntw7yklENojnq3K oNlhiEn4TzpGQMmCTV6RAaCVXOA4hE1hXK2zYQb3P8Cn1WMrDPMLv0fdvexf63fNdSC8 y9QkR83+VTM/eowOq4VXTYynv2168/poM6XfOzEObFcpXPmwaDyxmR6mrizdCEa7nVdg PgdtzlLpbY2IaZrM4BoThnCwP6K5UgjMbC1vkZAlPQ9RaqVds9w67K0ApAuXB/SPBjuo YjYjdcdrI6108ttUou95NDpMCvKu1me6BOLgFAlFez2HVdmByguAQ5iZWtL7+nRvSJc0 yffg== X-Gm-Message-State: ABy/qLZHPyRLXP6HG/9O16qGmLrYOOejvJIbDN8zAy0Bc/cC0BnN9Z63 PSt3Q2lq66SF+UhMM32iyIlthsblKJQ= X-Google-Smtp-Source: APBJJlG8VHtP5R3fLmhww44xOijLMkdC3Pr9yKhyucdlmfeXwSJcZ8t7uie3AFyIq7NSw15x1EhqscyHcLI= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a25:d78b:0:b0:c4c:b107:65f9 with SMTP id o133-20020a25d78b000000b00c4cb10765f9mr12571ybg.10.1689724144344; Tue, 18 Jul 2023 16:49:04 -0700 (PDT) Reply-To: Sean Christopherson Date: Tue, 18 Jul 2023 16:45:00 -0700 In-Reply-To: <20230718234512.1690985-1-seanjc@google.com> Mime-Version: 1.0 References: <20230718234512.1690985-1-seanjc@google.com> X-Mailer: git-send-email 2.41.0.255.g8b1d071c50-goog Message-ID: <20230718234512.1690985-18-seanjc@google.com> Subject: [RFC PATCH v11 17/29] KVM: x86: Add support for "protected VMs" that can utilize private memory From: Sean Christopherson To: Paolo Bonzini , Marc Zyngier , Oliver Upton , Huacai Chen , Michael Ellerman , Anup Patel , Paul Walmsley , Palmer Dabbelt , Albert Ou , Sean Christopherson , "Matthew Wilcox (Oracle)" , Andrew Morton , Paul Moore , James Morris , "Serge E. Hallyn" Cc: kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-mips@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, kvm-riscv@lists.infradead.org, linux-riscv@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, Chao Peng , Fuad Tabba , Jarkko Sakkinen , Yu Zhang , Vishal Annapurve , Ackerley Tng , Maciej Szmigiero , Vlastimil Babka , David Hildenbrand , Quentin Perret , Michael Roth , Wang , Liam Merwick , Isaku Yamahata , "Kirill A . Shutemov" Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Signed-off-by: Sean Christopherson --- Documentation/virt/kvm/api.rst | 32 ++++++++++++++++++++++++++++++++ arch/x86/include/asm/kvm_host.h | 15 +++++++++------ arch/x86/include/uapi/asm/kvm.h | 3 +++ arch/x86/kvm/Kconfig | 12 ++++++++++++ arch/x86/kvm/mmu/mmu_internal.h | 1 + arch/x86/kvm/x86.c | 16 +++++++++++++++- include/uapi/linux/kvm.h | 1 + virt/kvm/Kconfig | 5 +++++ 8 files changed, 78 insertions(+), 7 deletions(-) diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst index 0ca8561775ac..9f7b95327c2a 100644 --- a/Documentation/virt/kvm/api.rst +++ b/Documentation/virt/kvm/api.rst @@ -147,10 +147,29 @@ described as 'basic' will be available. The new VM has no virtual cpus and no memory. You probably want to use 0 as machine type. +X86: +^^^^ + +Supported X86 VM types can be queried via KVM_CAP_VM_TYPES. + +S390: +^^^^^ + In order to create user controlled virtual machines on S390, check KVM_CAP_S390_UCONTROL and use the flag KVM_VM_S390_UCONTROL as privileged user (CAP_SYS_ADMIN). +MIPS: +^^^^^ + +To use hardware assisted virtualization on MIPS (VZ ASE) rather than +the default trap & emulate implementation (which changes the virtual +memory layout to fit in user mode), check KVM_CAP_MIPS_VZ and use the +flag KVM_VM_MIPS_VZ. + +ARM64: +^^^^^^ + On arm64, the physical address size for a VM (IPA Size limit) is limited to 40bits by default. The limit can be configured if the host supports the extension KVM_CAP_ARM_VM_IPA_SIZE. When supported, use @@ -8554,6 +8573,19 @@ block sizes is exposed in KVM_CAP_ARM_SUPPORTED_BLOCK_SIZES as a This capability indicates KVM supports per-page memory attributes and ioctls KVM_GET_SUPPORTED_MEMORY_ATTRIBUTES/KVM_SET_MEMORY_ATTRIBUTES are available. +8.41 KVM_CAP_VM_TYPES +--------------------- + +:Capability: KVM_CAP_MEMORY_ATTRIBUTES +:Architectures: x86 +:Type: system ioctl + +This capability returns a bitmap of support VM types. The 1-setting of bit @n +means the VM type with value @n is supported. Possible values of @n are:: + + #define KVM_X86_DEFAULT_VM 0 + #define KVM_X86_SW_PROTECTED_VM 1 + 9. Known KVM API problems ========================= diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 08b44544a330..bbefd79b7950 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1227,6 +1227,7 @@ enum kvm_apicv_inhibit { }; struct kvm_arch { + unsigned long vm_type; unsigned long n_used_mmu_pages; unsigned long n_requested_mmu_pages; unsigned long n_max_mmu_pages; @@ -2058,6 +2059,12 @@ void kvm_mmu_new_pgd(struct kvm_vcpu *vcpu, gpa_t new_pgd); void kvm_configure_mmu(bool enable_tdp, int tdp_forced_root_level, int tdp_max_root_level, int tdp_huge_page_level); +#ifdef CONFIG_KVM_PRIVATE_MEM +#define kvm_arch_has_private_mem(kvm) ((kvm)->arch.vm_type != KVM_X86_DEFAULT_VM) +#else +#define kvm_arch_has_private_mem(kvm) false +#endif + static inline u16 kvm_read_ldt(void) { u16 ldt; @@ -2106,14 +2113,10 @@ enum { #define HF_SMM_INSIDE_NMI_MASK (1 << 2) # define KVM_MAX_NR_ADDRESS_SPACES 2 +/* SMM is currently unsupported for guests with private memory. */ +# define kvm_arch_nr_memslot_as_ids(kvm) (kvm_arch_has_private_mem(kvm) ? 1 : 2) # define kvm_arch_vcpu_memslots_id(vcpu) ((vcpu)->arch.hflags & HF_SMM_MASK ? 1 : 0) # define kvm_memslots_for_spte_role(kvm, role) __kvm_memslots(kvm, (role).smm) - -static inline int kvm_arch_nr_memslot_as_ids(struct kvm *kvm) -{ - return KVM_MAX_NR_ADDRESS_SPACES; -} - #else # define kvm_memslots_for_spte_role(kvm, role) __kvm_memslots(kvm, 0) #endif diff --git a/arch/x86/include/uapi/asm/kvm.h b/arch/x86/include/uapi/asm/kvm.h index 1a6a1f987949..a448d0964fc0 100644 --- a/arch/x86/include/uapi/asm/kvm.h +++ b/arch/x86/include/uapi/asm/kvm.h @@ -562,4 +562,7 @@ struct kvm_pmu_event_filter { /* x86-specific KVM_EXIT_HYPERCALL flags. */ #define KVM_EXIT_HYPERCALL_LONG_MODE BIT(0) +#define KVM_X86_DEFAULT_VM 0 +#define KVM_X86_SW_PROTECTED_VM 1 + #endif /* _ASM_X86_KVM_H */ diff --git a/arch/x86/kvm/Kconfig b/arch/x86/kvm/Kconfig index a7eb2bdbfb18..029c76bcd1a5 100644 --- a/arch/x86/kvm/Kconfig +++ b/arch/x86/kvm/Kconfig @@ -77,6 +77,18 @@ config KVM_WERROR If in doubt, say "N". +config KVM_SW_PROTECTED_VM + bool "Enable support for KVM software-protected VMs" + depends on EXPERT + depends on X86_64 + select KVM_GENERIC_PRIVATE_MEM + help + Enable support for KVM software-protected VMs. Currently "protected" + means the VM can be backed with memory provided by + KVM_CREATE_GUEST_MEMFD. + + If unsure, say "N". + config KVM_INTEL tristate "KVM for Intel (and compatible) processors support" depends on KVM && IA32_FEAT_CTL diff --git a/arch/x86/kvm/mmu/mmu_internal.h b/arch/x86/kvm/mmu/mmu_internal.h index 268b517e88cb..f1786698ae00 100644 --- a/arch/x86/kvm/mmu/mmu_internal.h +++ b/arch/x86/kvm/mmu/mmu_internal.h @@ -301,6 +301,7 @@ static inline int kvm_mmu_do_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, .max_level = KVM_MAX_HUGEPAGE_LEVEL, .req_level = PG_LEVEL_4K, .goal_level = PG_LEVEL_4K, + .is_private = kvm_mem_is_private(vcpu->kvm, cr2_or_gpa >> PAGE_SHIFT), }; int r; diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 463ecf70cec0..de195ad83ec0 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -4427,6 +4427,13 @@ static int kvm_ioctl_get_supported_hv_cpuid(struct kvm_vcpu *vcpu, return 0; } +static bool kvm_is_vm_type_supported(unsigned long type) +{ + return type == KVM_X86_DEFAULT_VM || + (type == KVM_X86_SW_PROTECTED_VM && + IS_ENABLED(CONFIG_KVM_SW_PROTECTED_VM) && tdp_enabled); +} + int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) { int r = 0; @@ -4617,6 +4624,11 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) case KVM_CAP_X86_NOTIFY_VMEXIT: r = kvm_caps.has_notify_vmexit; break; + case KVM_CAP_VM_TYPES: + r = BIT(KVM_X86_DEFAULT_VM); + if (kvm_is_vm_type_supported(KVM_X86_SW_PROTECTED_VM)) + r |= BIT(KVM_X86_SW_PROTECTED_VM); + break; default: break; } @@ -12274,9 +12286,11 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type) int ret; unsigned long flags; - if (type) + if (!kvm_is_vm_type_supported(type)) return -EINVAL; + kvm->arch.vm_type = type; + ret = kvm_page_track_init(kvm); if (ret) goto out; diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 17b12ee8b70e..eb900344a054 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -1216,6 +1216,7 @@ struct kvm_ppc_resize_hpt { #define KVM_CAP_ARM_SUPPORTED_BLOCK_SIZES 229 #define KVM_CAP_USER_MEMORY2 230 #define KVM_CAP_MEMORY_ATTRIBUTES 231 +#define KVM_CAP_VM_TYPES 232 #ifdef KVM_CAP_IRQ_ROUTING diff --git a/virt/kvm/Kconfig b/virt/kvm/Kconfig index 3ee3205e0b39..1a48cb530092 100644 --- a/virt/kvm/Kconfig +++ b/virt/kvm/Kconfig @@ -107,3 +107,8 @@ config KVM_GENERIC_MEMORY_ATTRIBUTES config KVM_PRIVATE_MEM select XARRAY_MULTI bool + +config KVM_GENERIC_PRIVATE_MEM + select KVM_GENERIC_MEMORY_ATTRIBUTES + select KVM_PRIVATE_MEM + bool