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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0EBE9C433EF for ; Wed, 6 Jul 2022 08:25:54 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 8FE828E0006; Wed, 6 Jul 2022 04:25:54 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 8AE746B0075; Wed, 6 Jul 2022 04:25:54 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 74E268E0006; Wed, 6 Jul 2022 04:25:54 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 662946B0074 for ; Wed, 6 Jul 2022 04:25:54 -0400 (EDT) Received: from smtpin13.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id 251A434BA4 for ; Wed, 6 Jul 2022 08:25:54 +0000 (UTC) X-FDA: 79655991828.13.C53E6BD Received: from mga07.intel.com (mga07.intel.com [134.134.136.100]) by imf08.hostedemail.com (Postfix) with ESMTP id 3AC7E160011 for ; Wed, 6 Jul 2022 08:25:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1657095953; x=1688631953; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=E5etUVyGAjbLnFNE6o2Ik8Z3TK8BR2wbeWe9rjh6p1w=; b=cVdIwKEpxzamaRkEqMGaOi9NfpABi0RkWA9lWJUSN4LdZOPZ1Kjoqvsi ZNPp/wiBBoCop4865keh0TdoaEcWVH1izYXQkvMZkFAhtrJkvFKwAgurW X6TGmwYIjIVGZgQBtaIN+47BnirBzdXugK5gsWFNwTcuvTUCkCKHq8o5c wdho5uD+2z/BAbKiBUaVJemDcEL8xvJTmjhl8ANTcVhTg7Wbgzeaz+Pc/ AtcgC2i9bTdDVip5VXoTvgwokTI38iIMPK5fAsvhLG1ATdN+tok3iDp4j WZr9mJ6V6pY4Tj9XMuXcE5JfhKN1oaPaIgl4+wlGJkWiwckmnouSztGbV Q==; X-IronPort-AV: E=McAfee;i="6400,9594,10399"; a="347666085" X-IronPort-AV: E=Sophos;i="5.92,249,1650956400"; d="scan'208";a="347666085" Received: from orsmga006.jf.intel.com ([10.7.209.51]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 06 Jul 2022 01:25:51 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.92,249,1650956400"; d="scan'208";a="567968229" Received: from chaop.bj.intel.com ([10.240.192.101]) by orsmga006.jf.intel.com with ESMTP; 06 Jul 2022 01:25:40 -0700 From: Chao Peng To: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-api@vger.kernel.org, linux-doc@vger.kernel.org, qemu-devel@nongnu.org, linux-kselftest@vger.kernel.org Cc: Paolo Bonzini , Jonathan Corbet , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , Thomas Gleixner , Ingo Molnar , Borislav Petkov , x86@kernel.org, "H . Peter Anvin" , Hugh Dickins , Jeff Layton , "J . Bruce Fields" , Andrew Morton , Shuah Khan , Mike Rapoport , Steven Price , "Maciej S . Szmigiero" , Vlastimil Babka , Vishal Annapurve , Yu Zhang , Chao Peng , "Kirill A . Shutemov" , luto@kernel.org, jun.nakajima@intel.com, dave.hansen@intel.com, ak@linux.intel.com, david@redhat.com, aarcange@redhat.com, ddutile@redhat.com, dhildenb@redhat.com, Quentin Perret , Michael Roth , mhocko@suse.com, Muchun Song Subject: [PATCH v7 11/14] KVM: Register/unregister the guest private memory regions Date: Wed, 6 Jul 2022 16:20:13 +0800 Message-Id: <20220706082016.2603916-12-chao.p.peng@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220706082016.2603916-1-chao.p.peng@linux.intel.com> References: <20220706082016.2603916-1-chao.p.peng@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1657095953; a=rsa-sha256; cv=none; b=UwPMlY2r2dgHntUdT79O6GJ2u2CfUNON2okGkuAB809sggrADtxo6c7PxoTHB/NYc/iK7G 1FlY4vHo8xBPLzAi9K31uGxccTlYBqHjK/McFtSoF6jSggHcRkY2AbHYDcwv+Lgj8X0QWo P+S7OhpUGI42hWZLuq64taF+CKqcYlM= ARC-Authentication-Results: i=1; imf08.hostedemail.com; dkim=pass header.d=intel.com header.s=Intel header.b=cVdIwKEp; spf=none (imf08.hostedemail.com: domain of chao.p.peng@linux.intel.com has no SPF policy when checking 134.134.136.100) smtp.mailfrom=chao.p.peng@linux.intel.com; dmarc=pass (policy=none) header.from=intel.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1657095953; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=xTpFtw/pIILQBIdSU1DN/iGPpnIGCfpsYynjv+z+msI=; b=ztaMK4CstEmjZXbEAqIN6kJG0gambr4QqkqCn57IRbEh+Ci87zxb0OGpKKoUlyKUT8AE6A 9tYq42hB2Vkha24ztSWADKs1F6eQe4Eca2xyBEeTfugiq3UrllnOtQMX8epkMucRH53/2v 8ygtw6h/MIrlgmZzflbwK1bOtUN24mA= Authentication-Results: imf08.hostedemail.com; dkim=pass header.d=intel.com header.s=Intel header.b=cVdIwKEp; spf=none (imf08.hostedemail.com: domain of chao.p.peng@linux.intel.com has no SPF policy when checking 134.134.136.100) smtp.mailfrom=chao.p.peng@linux.intel.com; dmarc=pass (policy=none) header.from=intel.com X-Rspam-User: X-Rspamd-Server: rspam03 X-Stat-Signature: mjxo1g5xxd9i7nnb4mtaf9wkz4seokxm X-Rspamd-Queue-Id: 3AC7E160011 X-HE-Tag: 1657095952-966791 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: If CONFIG_HAVE_KVM_PRIVATE_MEM=y, userspace can register/unregister the guest private memory regions through KVM_MEMORY_ENCRYPT_{UN,}REG_REGION ioctls. The patch reuses existing SEV ioctl but differs that the address in the region for private memory is gpa while SEV case it's hva. The private memory region is stored as xarray in KVM for memory efficiency in normal usages and zapping existing memory mappings is also a side effect of these two ioctls. Signed-off-by: Chao Peng --- Documentation/virt/kvm/api.rst | 17 +++++++--- arch/x86/include/asm/kvm_host.h | 1 + arch/x86/kvm/Kconfig | 1 + arch/x86/kvm/mmu.h | 2 -- include/linux/kvm_host.h | 8 +++++ virt/kvm/kvm_main.c | 57 +++++++++++++++++++++++++++++++++ 6 files changed, 80 insertions(+), 6 deletions(-) diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst index 5ecfc7fbe0ee..dfb4caecab73 100644 --- a/Documentation/virt/kvm/api.rst +++ b/Documentation/virt/kvm/api.rst @@ -4715,10 +4715,19 @@ Documentation/virt/kvm/amd-memory-encryption.rst. This ioctl can be used to register a guest memory region which may contain encrypted data (e.g. guest RAM, SMRAM etc). -It is used in the SEV-enabled guest. When encryption is enabled, a guest -memory region may contain encrypted data. The SEV memory encryption -engine uses a tweak such that two identical plaintext pages, each at -different locations will have differing ciphertexts. So swapping or +Currently this ioctl supports registering memory regions for two usages: +private memory and SEV-encrypted memory. + +When private memory is enabled, this ioctl is used to register guest private +memory region and the addr/size of kvm_enc_region represents guest physical +address (GPA). In this usage, this ioctl zaps the existing guest memory +mappings in KVM that fallen into the region. + +When SEV-encrypted memory is enabled, this ioctl is used to register guest +memory region which may contain encrypted data for a SEV-enabled guest. The +addr/size of kvm_enc_region represents userspace address (HVA). The SEV +memory encryption engine uses a tweak such that two identical plaintext pages, +each at different locations will have differing ciphertexts. So swapping or moving ciphertext of those pages will not result in plaintext being swapped. So relocating (or migrating) physical backing pages for the SEV guest will require some additional steps. diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index dae190e19fce..92120e3a224e 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -37,6 +37,7 @@ #include #define __KVM_HAVE_ARCH_VCPU_DEBUGFS +#define __KVM_HAVE_ZAP_GFN_RANGE #define KVM_MAX_VCPUS 1024 diff --git a/arch/x86/kvm/Kconfig b/arch/x86/kvm/Kconfig index 1f160801e2a7..05861b9656a4 100644 --- a/arch/x86/kvm/Kconfig +++ b/arch/x86/kvm/Kconfig @@ -50,6 +50,7 @@ config KVM select HAVE_KVM_PM_NOTIFIER if PM select HAVE_KVM_PRIVATE_MEM if X86_64 select MEMFILE_NOTIFIER if HAVE_KVM_PRIVATE_MEM + select XARRAY_MULTI if HAVE_KVM_PRIVATE_MEM help Support hosting fully virtualized guest machines using hardware virtualization extensions. You will need a fairly recent diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h index a99acec925eb..428cd2e88cbd 100644 --- a/arch/x86/kvm/mmu.h +++ b/arch/x86/kvm/mmu.h @@ -209,8 +209,6 @@ static inline u8 permission_fault(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, return -(u32)fault & errcode; } -void kvm_zap_gfn_range(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end); - int kvm_arch_write_log_dirty(struct kvm_vcpu *vcpu); int kvm_mmu_post_init_vm(struct kvm *kvm); diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 1b203c8aa696..da33f8828456 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -260,6 +260,10 @@ bool kvm_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range); bool kvm_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range); #endif +#ifdef __KVM_HAVE_ZAP_GFN_RANGE +void kvm_zap_gfn_range(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end); +#endif + enum { OUTSIDE_GUEST_MODE, IN_GUEST_MODE, @@ -795,6 +799,9 @@ struct kvm { struct notifier_block pm_notifier; #endif char stats_id[KVM_STATS_NAME_SIZE]; +#ifdef CONFIG_HAVE_KVM_PRIVATE_MEM + struct xarray mem_attr_array; +#endif }; #define kvm_err(fmt, ...) \ @@ -1459,6 +1466,7 @@ bool kvm_arch_dy_has_pending_interrupt(struct kvm_vcpu *vcpu); int kvm_arch_post_init_vm(struct kvm *kvm); void kvm_arch_pre_destroy_vm(struct kvm *kvm); int kvm_arch_create_vm_debugfs(struct kvm *kvm); +bool kvm_arch_private_mem_supported(struct kvm *kvm); #ifndef __KVM_HAVE_ARCH_VM_ALLOC /* diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 230c8ff9659c..bb714c2a4b06 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -914,6 +914,35 @@ static int kvm_init_mmu_notifier(struct kvm *kvm) #endif /* CONFIG_MMU_NOTIFIER && KVM_ARCH_WANT_MMU_NOTIFIER */ +#ifdef CONFIG_HAVE_KVM_PRIVATE_MEM +#define KVM_MEM_ATTR_PRIVATE 0x0001 +static int kvm_vm_ioctl_set_encrypted_region(struct kvm *kvm, unsigned int ioctl, + struct kvm_enc_region *region) +{ + unsigned long start, end; + void *entry; + int r; + + if (region->size == 0 || region->addr + region->size < region->addr) + return -EINVAL; + if (region->addr & (PAGE_SIZE - 1) || region->size & (PAGE_SIZE - 1)) + return -EINVAL; + + start = region->addr >> PAGE_SHIFT; + end = (region->addr + region->size - 1) >> PAGE_SHIFT; + + entry = ioctl == KVM_MEMORY_ENCRYPT_REG_REGION ? + xa_mk_value(KVM_MEM_ATTR_PRIVATE) : NULL; + + r = xa_err(xa_store_range(&kvm->mem_attr_array, start, end, + entry, GFP_KERNEL_ACCOUNT)); + + kvm_zap_gfn_range(kvm, start, end + 1); + + return r; +} +#endif /* CONFIG_HAVE_KVM_PRIVATE_MEM */ + #ifdef CONFIG_HAVE_KVM_PM_NOTIFIER static int kvm_pm_notifier_call(struct notifier_block *bl, unsigned long state, @@ -1138,6 +1167,9 @@ static struct kvm *kvm_create_vm(unsigned long type) spin_lock_init(&kvm->mn_invalidate_lock); rcuwait_init(&kvm->mn_memslots_update_rcuwait); xa_init(&kvm->vcpu_array); +#ifdef CONFIG_HAVE_KVM_PRIVATE_MEM + xa_init(&kvm->mem_attr_array); +#endif INIT_LIST_HEAD(&kvm->gpc_list); spin_lock_init(&kvm->gpc_lock); @@ -1305,6 +1337,9 @@ static void kvm_destroy_vm(struct kvm *kvm) kvm_free_memslots(kvm, &kvm->__memslots[i][0]); kvm_free_memslots(kvm, &kvm->__memslots[i][1]); } +#ifdef CONFIG_HAVE_KVM_PRIVATE_MEM + xa_destroy(&kvm->mem_attr_array); +#endif cleanup_srcu_struct(&kvm->irq_srcu); cleanup_srcu_struct(&kvm->srcu); kvm_arch_free_vm(kvm); @@ -1508,6 +1543,11 @@ static void kvm_replace_memslot(struct kvm *kvm, } } +bool __weak kvm_arch_private_mem_supported(struct kvm *kvm) +{ + return false; +} + static int check_memory_region_flags(const struct kvm_user_mem_region *mem) { u32 valid_flags = KVM_MEM_LOG_DIRTY_PAGES; @@ -4689,6 +4729,22 @@ static long kvm_vm_ioctl(struct file *filp, r = kvm_vm_ioctl_set_memory_region(kvm, &mem); break; } +#ifdef CONFIG_HAVE_KVM_PRIVATE_MEM + case KVM_MEMORY_ENCRYPT_REG_REGION: + case KVM_MEMORY_ENCRYPT_UNREG_REGION: { + struct kvm_enc_region region; + + if (!kvm_arch_private_mem_supported(kvm)) + goto arch_vm_ioctl; + + r = -EFAULT; + if (copy_from_user(®ion, argp, sizeof(region))) + goto out; + + r = kvm_vm_ioctl_set_encrypted_region(kvm, ioctl, ®ion); + break; + } +#endif case KVM_GET_DIRTY_LOG: { struct kvm_dirty_log log; @@ -4842,6 +4898,7 @@ static long kvm_vm_ioctl(struct file *filp, r = kvm_vm_ioctl_get_stats_fd(kvm); break; default: +arch_vm_ioctl: r = kvm_arch_vm_ioctl(filp, ioctl, arg); } out: -- 2.25.1