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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 448BDC433F5 for ; Fri, 12 Nov 2021 15:39:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2B80460F5B for ; Fri, 12 Nov 2021 15:39:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235511AbhKLPmp (ORCPT ); Fri, 12 Nov 2021 10:42:45 -0500 Received: from mga03.intel.com ([134.134.136.65]:34487 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234508AbhKLPmc (ORCPT ); Fri, 12 Nov 2021 10:42:32 -0500 X-IronPort-AV: E=McAfee;i="6200,9189,10165"; a="233093246" X-IronPort-AV: E=Sophos;i="5.87,229,1631602800"; d="scan'208";a="233093246" Received: from orsmga006.jf.intel.com ([10.7.209.51]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Nov 2021 07:38:17 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.87,229,1631602800"; d="scan'208";a="453182164" Received: from lxy-dell.sh.intel.com ([10.239.159.55]) by orsmga006.jf.intel.com with ESMTP; 12 Nov 2021 07:38:13 -0800 From: Xiaoyao Li To: Paolo Bonzini , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel Cc: xiaoyao.li@intel.com, erdemaktas@google.com, Connor Kuehl , x86@kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, isaku.yamahata@intel.com, Kai Huang Subject: [PATCH 10/11] KVM: Disallow read-only memory for x86 TDX Date: Fri, 12 Nov 2021 23:37:32 +0800 Message-Id: <20211112153733.2767561-11-xiaoyao.li@intel.com> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20211112153733.2767561-1-xiaoyao.li@intel.com> References: <20211112153733.2767561-1-xiaoyao.li@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Isaku Yamahata TDX doesn't expose permission bits to the VMM in the SEPT tables, i.e., doesn't support read-only private memory. Introduce kvm_arch_support_readonly_mem(), which returns true except for x86. x86 has its own implementation based on vm_type that returns faluse for TDX VM. Propagate it to KVM_CAP_READONLY_MEM to allow reporting on a per-VM basis. Co-developed-by: Sean Christopherson Signed-off-by: Sean Christopherson Signed-off-by: Isaku Yamahata Signed-off-by: Xiaoyao Li --- arch/x86/kvm/x86.c | 9 ++++++++- include/linux/kvm_host.h | 1 + virt/kvm/kvm_main.c | 19 ++++++++++++++----- 3 files changed, 23 insertions(+), 6 deletions(-) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index d06ee07bd486..f091a4d3c8f2 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -4079,7 +4079,6 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) case KVM_CAP_ASYNC_PF_INT: case KVM_CAP_GET_TSC_KHZ: case KVM_CAP_KVMCLOCK_CTRL: - case KVM_CAP_READONLY_MEM: case KVM_CAP_HYPERV_TIME: case KVM_CAP_IOAPIC_POLARITY_IGNORED: case KVM_CAP_TSC_DEADLINE_TIMER: @@ -4202,6 +4201,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) if (static_call(kvm_x86_is_vm_type_supported)(KVM_X86_TDX_VM)) r |= BIT(KVM_X86_TDX_VM); break; + case KVM_CAP_READONLY_MEM: + r = kvm && !kvm_arch_support_readonly_mem(kvm) ? 0 : 1; + break; default: break; } @@ -12609,6 +12611,11 @@ int kvm_sev_es_string_io(struct kvm_vcpu *vcpu, unsigned int size, } EXPORT_SYMBOL_GPL(kvm_sev_es_string_io); +bool kvm_arch_support_readonly_mem(struct kvm *kvm) +{ + return kvm->arch.vm_type != KVM_X86_TDX_VM; +} + EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_entry); EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_exit); EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_fast_mmio); diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 60a35d9fe259..1dbabf199c13 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -1071,6 +1071,7 @@ 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_support_readonly_mem(struct kvm *kvm); #ifndef __KVM_HAVE_ARCH_VM_ALLOC /* diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 3f6d450355f0..c288c92a9c82 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1421,13 +1421,22 @@ static void update_memslots(struct kvm_memslots *slots, } } -static int check_memory_region_flags(const struct kvm_userspace_memory_region *mem) +bool __weak kvm_arch_support_readonly_mem(struct kvm *kvm) { - u32 valid_flags = KVM_MEM_LOG_DIRTY_PAGES; - #ifdef __KVM_HAVE_READONLY_MEM - valid_flags |= KVM_MEM_READONLY; + return true; +#else + return false; #endif +} + +static int check_memory_region_flags(struct kvm *kvm, + const struct kvm_userspace_memory_region *mem) +{ + u32 valid_flags = KVM_MEM_LOG_DIRTY_PAGES; + + if (kvm_arch_support_readonly_mem(kvm)) + valid_flags |= KVM_MEM_READONLY; if (mem->flags & ~valid_flags) return -EINVAL; @@ -1664,7 +1673,7 @@ int __kvm_set_memory_region(struct kvm *kvm, int as_id, id; int r; - r = check_memory_region_flags(mem); + r = check_memory_region_flags(kvm, mem); if (r) return r; -- 2.27.0