From patchwork Thu Nov 11 14:13:44 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chao Peng X-Patchwork-Id: 12614909 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 117F7C433F5 for ; Thu, 11 Nov 2021 14:15:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F278F6117A for ; Thu, 11 Nov 2021 14:15:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233801AbhKKOSg (ORCPT ); Thu, 11 Nov 2021 09:18:36 -0500 Received: from mga01.intel.com ([192.55.52.88]:20974 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233796AbhKKOSc (ORCPT ); Thu, 11 Nov 2021 09:18:32 -0500 X-IronPort-AV: E=McAfee;i="6200,9189,10164"; a="256621684" X-IronPort-AV: E=Sophos;i="5.87,226,1631602800"; d="scan'208";a="256621684" Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Nov 2021 06:15:43 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.87,226,1631602800"; d="scan'208";a="492555758" Received: from chaop.bj.intel.com ([10.240.192.101]) by orsmga007.jf.intel.com with ESMTP; 11 Nov 2021 06:15:32 -0800 From: Chao Peng To: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, qemu-devel@nongnu.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 , Yu Zhang , Chao Peng , "Kirill A . Shutemov" , luto@kernel.org, john.ji@intel.com, susie.li@intel.com, jun.nakajima@intel.com, dave.hansen@intel.com, ak@linux.intel.com, david@redhat.com Subject: [RFC PATCH 5/6] kvm: x86: add KVM_EXIT_MEMORY_ERROR exit Date: Thu, 11 Nov 2021 22:13:44 +0800 Message-Id: <20211111141352.26311-6-chao.p.peng@linux.intel.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20211111141352.26311-1-chao.p.peng@linux.intel.com> References: <20211111141352.26311-1-chao.p.peng@linux.intel.com> Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Currently support to exit to userspace for private/shared memory conversion. Signed-off-by: Sean Christopherson Signed-off-by: Yu Zhang Signed-off-by: Chao Peng --- arch/x86/kvm/mmu/mmu.c | 20 ++++++++++++++++++++ include/uapi/linux/kvm.h | 15 +++++++++++++++ 2 files changed, 35 insertions(+) diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index af5ecf4ef62a..780868888aa8 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -3950,6 +3950,17 @@ static bool try_async_pf(struct kvm_vcpu *vcpu, bool prefault, gfn_t gfn, slot = __kvm_vcpu_gfn_to_memslot(vcpu, gfn, private); + /* + * Exit to userspace to map the requested private/shared memory region + * if there is no memslot and (a) the access is private or (b) there is + * an existing private memslot. Emulated MMIO must be accessed through + * shared GPAs, thus a memslot miss on a private GPA is always handled + * as an implicit conversion "request". + */ + if (!slot && + (private || __kvm_vcpu_gfn_to_memslot(vcpu, gfn, true))) + goto out_convert; + /* Don't expose aliases for no slot GFNs or private memslots */ if ((cr2_or_gpa & vcpu_gpa_stolen_mask(vcpu)) && !kvm_is_visible_memslot(slot)) { @@ -3994,6 +4005,15 @@ static bool try_async_pf(struct kvm_vcpu *vcpu, bool prefault, gfn_t gfn, *pfn = __gfn_to_pfn_memslot(slot, gfn, false, NULL, write, writable, hva); return false; + +out_convert: + vcpu->run->exit_reason = KVM_EXIT_MEMORY_ERROR; + vcpu->run->mem.type = private ? KVM_EXIT_MEM_MAP_PRIVATE + : KVM_EXIT_MEM_MAP_SHARE; + vcpu->run->mem.u.map.gpa = cr2_or_gpa; + vcpu->run->mem.u.map.size = PAGE_SIZE; + return true; + } static int direct_page_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code, diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 8d20caae9180..470c472a9451 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -233,6 +233,18 @@ struct kvm_xen_exit { } u; }; +struct kvm_memory_exit { +#define KVM_EXIT_MEM_MAP_SHARE 1 +#define KVM_EXIT_MEM_MAP_PRIVATE 2 + __u32 type; + union { + struct { + __u64 gpa; + __u64 size; + } map; + } u; +}; + #define KVM_S390_GET_SKEYS_NONE 1 #define KVM_S390_SKEYS_MAX 1048576 @@ -272,6 +284,7 @@ struct kvm_xen_exit { #define KVM_EXIT_X86_BUS_LOCK 33 #define KVM_EXIT_XEN 34 #define KVM_EXIT_TDVMCALL 35 +#define KVM_EXIT_MEMORY_ERROR 36 /* For KVM_EXIT_INTERNAL_ERROR */ /* Emulate instruction failed. */ @@ -455,6 +468,8 @@ struct kvm_run { __u64 subfunc; __u64 param[4]; } tdvmcall; + /* KVM_EXIT_MEMORY_ERROR */ + struct kvm_memory_exit mem; /* Fix the size of the union. */ char padding[256]; };