From mboxrd@z Thu Jan 1 00:00:00 1970 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 4779CC25B47 for ; Fri, 27 Oct 2023 19:31:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:Reply-To:List-Subscribe:List-Help: List-Post:List-Archive:List-Unsubscribe:List-Id:Cc:To:From:Subject:Message-ID :References:Mime-Version:In-Reply-To:Date:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=88u608inW6TK/+pVEKCZrKRH3CDds7/kh7afwv442/Y=; b=FZK9sjrjn/hZzy JSwx4UTk1B6hG2/JVcoVuwFjlwmCJRR4VTD5sqLENW/ThMw1RfJeiugy0Xxfmokz89y9lnil0DAVY otMLU3y2jZjUwy0TgfVNwDNxua740osNhWM0cmR831/OFwSn0aWXPiSWN8NyaF0ha8bqGENAJcZIs QYz+6YH+6ucAVgw34JjN97e9TM4j+SEraXbCXCU9Qqz1veb/Z2UN9j8526q/MKrrto8oeFHvlBW1J NfOygQ9pH05U8UJmeAQ150HPmWRcHrjmmIs46VtX7gCVKfGLVotGnMrf0SG/yxxCya4swscNvH9d6 2cWEf+fHFYd49bWC1S5Q==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qwSYd-00H628-10; Fri, 27 Oct 2023 19:31:47 +0000 Received: from desiato.infradead.org ([2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qwRUS-00Gxds-1I for linux-arm-kernel@bombadil.infradead.org; Fri, 27 Oct 2023 18:23:24 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=Content-Type:Cc:To:From:Subject: Message-ID:References:Mime-Version:In-Reply-To:Date:Reply-To:Sender: Content-Transfer-Encoding:Content-ID:Content-Description; bh=vy9wKTn0fkDEcqGdy+Uw8qnM4ToO/Gfdy3c1eQgyq4E=; b=YZ2JCcD6q9HIVWQ/q80K8p/ews MNKZlyXs2LVaJ9lEW+lU5jQHsCkXECfFWq/l4PojZhEEEWrGp4eLrlzKHSNPJHYi+oUVf928gyfi/ 8aZsDC8XvS+JWH5Id0Tm+yXloMuerIvmm8XvRXJg95tVaPM78XR1TKyLEztlUGso0quHKLNpP2YdR bZTfv2WFOwPF6Zyp2v4rRPSFCrDYSyKoYupFPriyJeQ+sdDmIul2OthbYWh/O+oDKklvfqYf6W4us Un3g9tLyPfN2m/ZS8CtrCq+BbgY39oqpNqeHcdYYQU7ua6ZQ4SleRpMeumM12mg013J4CfSJOj+TL yZ6J6FBw==; Received: from mail-pg1-f201.google.com ([209.85.215.201]) by desiato.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qwRUJ-000ukN-0u for linux-arm-kernel@lists.infradead.org; Fri, 27 Oct 2023 18:23:22 +0000 Received: by mail-pg1-f201.google.com with SMTP id 41be03b00d2f7-5b87a3d4a31so2076745a12.2 for ; Fri, 27 Oct 2023 11:23:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1698430991; x=1699035791; darn=lists.infradead.org; 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=vy9wKTn0fkDEcqGdy+Uw8qnM4ToO/Gfdy3c1eQgyq4E=; b=YNV2GoxeVjAeSVMDUyObZtSLy0GE8bUSOWViGun9LR+o9w3lZCGGLvmxMwQQgxb1Hu e05xDr3Gbh5ZpRJYaYHlmdA+SUcNgypMMXqDU+efG+trb+qumtiWxXkDHkAUySUR+hwF oWAHLQBXgmvJ3q4QTpopTnNBz3KNtAg1vzT4alyPTvGADGYjmKqVh+WebqAH1IW5/st5 dW8eVyaDdfPQPVZsOKPomI5lhbBJUB+sPpXWoyuznoZUEpNUTDKvHJf3yJsZhaAeMMiG SKB7R5Q7o2fniUdnWTyFaZa0q+tfzBXIUzrUTPdiM9gD9qFyNZ5hTySGnk6Q5pazBuQ5 uvTg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1698430991; x=1699035791; 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=vy9wKTn0fkDEcqGdy+Uw8qnM4ToO/Gfdy3c1eQgyq4E=; b=AqeG9Dllbo4noiAliQzUEdL6vMoINYeFYMD1jJAaL52douW7LtWCfMZe5f4eF4o/7H 7JWyVVIwPQQ6nXCAX9/HnK030yCJ6KYASEom12BNWo3AZRVQpvJfKNtGGYp30ceRDa8W CUPSWWFbh/jx+2xiUVhKVD+zgDHfLiqrO6Sh1gWseqAae+hRRz6VhV6oeEq6prhB5Bc4 eFqISYRJW1BmmFitaPSryM5a8spusVahXxhdtYjICZ4t78e3jzzce8oGQ1u4BebtNfZN 9Wz7lmqy6SEadWeToT0jvvYROwuZPlp1Qy2w0lZZoah6sNFtkvIpTKxd5jPrWR8c6Dey KYpw== X-Gm-Message-State: AOJu0YytbPDabXHtz9RDVAG17aD4Fuyrt2geItRXoZN6j3DxKMSVxaud wwWx1GLnhRgSC+63rz2PDEvfLxphw0g= X-Google-Smtp-Source: AGHT+IHJ99M17cdlIrIz+y3E5dgMN6oBoPPflGRQ0snggMyySInUDtQaTlwdekdlvCWpXPVtetZE0SP3KDw= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a17:902:d4cc:b0:1cc:1900:28d7 with SMTP id o12-20020a170902d4cc00b001cc190028d7mr82411plg.12.1698430991116; Fri, 27 Oct 2023 11:23:11 -0700 (PDT) Date: Fri, 27 Oct 2023 11:22:05 -0700 In-Reply-To: <20231027182217.3615211-1-seanjc@google.com> Mime-Version: 1.0 References: <20231027182217.3615211-1-seanjc@google.com> X-Mailer: git-send-email 2.42.0.820.g83a721a137-goog Message-ID: <20231027182217.3615211-24-seanjc@google.com> Subject: [PATCH v13 23/35] 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 , Alexander Viro , Christian Brauner , "Matthew Wilcox (Oracle)" , Andrew Morton 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-kernel@vger.kernel.org, Xiaoyao Li , Xu Yilun , Chao Peng , Fuad Tabba , Jarkko Sakkinen , Anish Moorthy , David Matlack , Yu Zhang , Isaku Yamahata , "=?UTF-8?q?Micka=C3=ABl=20Sala=C3=BCn?=" , Vlastimil Babka , Vishal Annapurve , Ackerley Tng , Maciej Szmigiero , David Hildenbrand , Quentin Perret , Michael Roth , Wang , Liam Merwick , Isaku Yamahata , "Kirill A . Shutemov" X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20231027_192315_655327_8B92521F X-CRM114-Status: GOOD ( 24.32 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Sean Christopherson Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Add a new x86 VM type, KVM_X86_SW_PROTECTED_VM, to serve as a development and testing vehicle for Confidential (CoCo) VMs, and potentially to even become a "real" product in the distant future, e.g. a la pKVM. The private memory support in KVM x86 is aimed at AMD's SEV-SNP and Intel's TDX, but those technologies are extremely complex (understatement), difficult to debug, don't support running as nested guests, and require hardware that's isn't universally accessible. I.e. relying SEV-SNP or TDX for maintaining guest private memory isn't a realistic option. At the very least, KVM_X86_SW_PROTECTED_VM will enable a variety of selftests for guest_memfd and private memory support without requiring unique hardware. 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 38dc1fda4f45..00029436ac5b 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 @@ -8650,6 +8669,19 @@ block sizes is exposed in KVM_CAP_ARM_SUPPORTED_BLOCK_SIZES as a 64-bit bitmap (each bit describing a block size). The default value is 0, to disable the eager page splitting. +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 f9e8d5642069..dff10051e9b6 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1244,6 +1244,7 @@ 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; @@ -2077,6 +2078,12 @@ 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; @@ -2125,14 +2132,10 @@ 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 091b74599c22..8452ed0228cb 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 86c7cb692786..b66a7d47e0e4 100644 --- a/arch/x86/kvm/mmu/mmu_internal.h +++ b/arch/x86/kvm/mmu/mmu_internal.h @@ -297,6 +297,7 @@ 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 c4d17727b199..e3eb608b6692 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -4441,6 +4441,13 @@ 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; @@ -4632,6 +4639,11 @@ 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; } @@ -12314,9 +12326,11 @@ 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 29e9eb51dec9..5b5820d19e71 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -1218,6 +1218,7 @@ struct kvm_ppc_resize_hpt { #define KVM_CAP_MEMORY_FAULT_INFO 231 #define KVM_CAP_MEMORY_ATTRIBUTES 232 #define KVM_CAP_GUEST_MEMFD 233 +#define KVM_CAP_VM_TYPES 234 #ifdef KVM_CAP_IRQ_ROUTING diff --git a/virt/kvm/Kconfig b/virt/kvm/Kconfig index 08afef022db9..2c964586aa14 100644 --- a/virt/kvm/Kconfig +++ b/virt/kvm/Kconfig @@ -104,3 +104,8 @@ 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 -- 2.42.0.820.g83a721a137-goog _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel