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 X-Spam-Level: X-Spam-Status: No, score=-12.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7FA9FC433E7 for ; Tue, 20 Oct 2020 06:21:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 330B922282 for ; Tue, 20 Oct 2020 06:21:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=shutemov-name.20150623.gappssmtp.com header.i=@shutemov-name.20150623.gappssmtp.com header.b="Mx8Loju0" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404026AbgJTGVJ (ORCPT ); Tue, 20 Oct 2020 02:21:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48566 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2403858AbgJTGTL (ORCPT ); Tue, 20 Oct 2020 02:19:11 -0400 Received: from mail-lf1-x143.google.com (mail-lf1-x143.google.com [IPv6:2a00:1450:4864:20::143]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 06C39C0613D7 for ; Mon, 19 Oct 2020 23:19:10 -0700 (PDT) Received: by mail-lf1-x143.google.com with SMTP id l28so649746lfp.10 for ; Mon, 19 Oct 2020 23:19:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=shutemov-name.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=AaYRj6xxvmS8+RSQnvAq9Jrn29IaqjqNuI5uDDknTs8=; b=Mx8Loju0ToSqHftzzoqfzPESbc1/N5hRz2KdNGw6KMMpjbYco5/VUfE0YsDuD/OBDB JpJ/p+fJo/oJLR6hyaQ81Ij7sV1JyaGGX4cvNalQc+/Smhjx6MWeJvV+7MmRii4qI9lr iLtnSPtkcNN9ChtzzeCEBk/GWIthMl995KtwZndE+McBnOElURh1YWLGLm9290oiKyzQ gs85KEQcShl9Na88mBkbryY9v93NrKHgz3fPWpqALkn/h2k8+gSjUvqBxaO5z39uQ/p4 H2s7AwoLkEmDssTQesbwtQiJXlxCDVAw3vhvG35bXeapUXA2tBY8eSngavhDBqnymtbB Rmeg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=AaYRj6xxvmS8+RSQnvAq9Jrn29IaqjqNuI5uDDknTs8=; b=MDog2T3QSKLzPpNDofyAF+f+LI79Ult5npsKE0aCRl60+WmmpPd0XJnY6B6zWGr9kT SVzb7VSjNkkbFJ8A8hX+alI1rK2AwXLo0yJz5XvYqOiDx3I/xtA/1uofQZQ3jHktoK4S 7eWfClogOJEErB/YCi73G0SdNKaRHpbIgY93yCpEszE06dgG/qzdjYcD42vvVMtESQ4M p6UYuZlnW8plwb2GYHlmZaWBmOGDrGVvwZGWjFKJSLaf54CQfxpSOC9QcFgAvJmGK8WI IoBmfBVWjZ6EDw02C0K5An+kJwPvKee2F8fGUGZakQgr1DtuEqKEaaVYzVhc1KORN3Cs l6Ww== X-Gm-Message-State: AOAM532q2hq/gnpz5+gPenr8GqgNdR+2OjQ5Jtg65AKkJJymIQl0is3G 5hhj3bNDKoeJGY3hBKL6ZetVyI+HRJxAVw== X-Google-Smtp-Source: ABdhPJzbVM30/ELO/VgPUbztIkJyCxcT3aLv3ozPYXAT3IE2iadH3MCBuaGjih+qQs0NlZhBazcvPQ== X-Received: by 2002:a19:8988:: with SMTP id l130mr405110lfd.126.1603174748490; Mon, 19 Oct 2020 23:19:08 -0700 (PDT) Received: from box.localdomain ([86.57.175.117]) by smtp.gmail.com with ESMTPSA id s17sm135242lfp.292.2020.10.19.23.19.06 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 19 Oct 2020 23:19:07 -0700 (PDT) From: "Kirill A. Shutemov" X-Google-Original-From: "Kirill A. Shutemov" Received: by box.localdomain (Postfix, from userid 1000) id EF98B102F67; Tue, 20 Oct 2020 09:19:01 +0300 (+03) To: Dave Hansen , Andy Lutomirski , Peter Zijlstra , Paolo Bonzini , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel Cc: David Rientjes , Andrea Arcangeli , Kees Cook , Will Drewry , "Edgecombe, Rick P" , "Kleen, Andi" , Liran Alon , Mike Rapoport , x86@kernel.org, kvm@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, "Kirill A. Shutemov" Subject: [RFCv2 08/16] KVM: Use GUP instead of copy_from/to_user() to access guest memory Date: Tue, 20 Oct 2020 09:18:51 +0300 Message-Id: <20201020061859.18385-9-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20201020061859.18385-1-kirill.shutemov@linux.intel.com> References: <20201020061859.18385-1-kirill.shutemov@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org New helpers copy_from_guest()/copy_to_guest() to be used if KVM memory protection feature is enabled. Signed-off-by: Kirill A. Shutemov --- include/linux/kvm_host.h | 4 ++ virt/kvm/kvm_main.c | 90 +++++++++++++++++++++++++++++++--------- 2 files changed, 75 insertions(+), 19 deletions(-) diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 05e3c2fb3ef7..380a64613880 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -504,6 +504,7 @@ struct kvm { struct srcu_struct irq_srcu; pid_t userspace_pid; unsigned int max_halt_poll_ns; + bool mem_protected; }; #define kvm_err(fmt, ...) \ @@ -728,6 +729,9 @@ void kvm_set_pfn_dirty(kvm_pfn_t pfn); void kvm_set_pfn_accessed(kvm_pfn_t pfn); void kvm_get_pfn(kvm_pfn_t pfn); +int copy_from_guest(void *data, unsigned long hva, int len, bool protected); +int copy_to_guest(unsigned long hva, const void *data, int len, bool protected); + void kvm_release_pfn(kvm_pfn_t pfn, bool dirty, struct gfn_to_pfn_cache *cache); int kvm_read_guest_page(struct kvm *kvm, gfn_t gfn, void *data, int offset, int len); diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index cf88233b819a..a9884cb8c867 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -2313,19 +2313,70 @@ static int next_segment(unsigned long len, int offset) return len; } +int copy_from_guest(void *data, unsigned long hva, int len, bool protected) +{ + int offset = offset_in_page(hva); + struct page *page; + int npages, seg; + + if (!protected) + return __copy_from_user(data, (void __user *)hva, len); + + might_fault(); + kasan_check_write(data, len); + check_object_size(data, len, false); + + while ((seg = next_segment(len, offset)) != 0) { + npages = get_user_pages_unlocked(hva, 1, &page, 0); + if (npages != 1) + return -EFAULT; + memcpy(data, page_address(page) + offset, seg); + put_page(page); + len -= seg; + hva += seg; + offset = 0; + } + + return 0; +} + +int copy_to_guest(unsigned long hva, const void *data, int len, bool protected) +{ + int offset = offset_in_page(hva); + struct page *page; + int npages, seg; + + if (!protected) + return __copy_to_user((void __user *)hva, data, len); + + might_fault(); + kasan_check_read(data, len); + check_object_size(data, len, true); + + while ((seg = next_segment(len, offset)) != 0) { + npages = get_user_pages_unlocked(hva, 1, &page, FOLL_WRITE); + if (npages != 1) + return -EFAULT; + memcpy(page_address(page) + offset, data, seg); + put_page(page); + len -= seg; + hva += seg; + offset = 0; + } + + return 0; +} + static int __kvm_read_guest_page(struct kvm_memory_slot *slot, gfn_t gfn, - void *data, int offset, int len) + void *data, int offset, int len, + bool protected) { - int r; unsigned long addr; addr = gfn_to_hva_memslot_prot(slot, gfn, NULL); if (kvm_is_error_hva(addr)) return -EFAULT; - r = __copy_from_user(data, (void __user *)addr + offset, len); - if (r) - return -EFAULT; - return 0; + return copy_from_guest(data, addr + offset, len, protected); } int kvm_read_guest_page(struct kvm *kvm, gfn_t gfn, void *data, int offset, @@ -2333,7 +2384,8 @@ int kvm_read_guest_page(struct kvm *kvm, gfn_t gfn, void *data, int offset, { struct kvm_memory_slot *slot = gfn_to_memslot(kvm, gfn); - return __kvm_read_guest_page(slot, gfn, data, offset, len); + return __kvm_read_guest_page(slot, gfn, data, offset, len, + kvm->mem_protected); } EXPORT_SYMBOL_GPL(kvm_read_guest_page); @@ -2342,7 +2394,8 @@ int kvm_vcpu_read_guest_page(struct kvm_vcpu *vcpu, gfn_t gfn, void *data, { struct kvm_memory_slot *slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn); - return __kvm_read_guest_page(slot, gfn, data, offset, len); + return __kvm_read_guest_page(slot, gfn, data, offset, len, + vcpu->kvm->mem_protected); } EXPORT_SYMBOL_GPL(kvm_vcpu_read_guest_page); @@ -2415,7 +2468,8 @@ int kvm_vcpu_read_guest_atomic(struct kvm_vcpu *vcpu, gpa_t gpa, EXPORT_SYMBOL_GPL(kvm_vcpu_read_guest_atomic); static int __kvm_write_guest_page(struct kvm_memory_slot *memslot, gfn_t gfn, - const void *data, int offset, int len) + const void *data, int offset, int len, + bool protected) { int r; unsigned long addr; @@ -2423,7 +2477,8 @@ static int __kvm_write_guest_page(struct kvm_memory_slot *memslot, gfn_t gfn, addr = gfn_to_hva_memslot(memslot, gfn); if (kvm_is_error_hva(addr)) return -EFAULT; - r = __copy_to_user((void __user *)addr + offset, data, len); + + r = copy_to_guest(addr + offset, data, len, protected); if (r) return -EFAULT; mark_page_dirty_in_slot(memslot, gfn); @@ -2435,7 +2490,8 @@ int kvm_write_guest_page(struct kvm *kvm, gfn_t gfn, { struct kvm_memory_slot *slot = gfn_to_memslot(kvm, gfn); - return __kvm_write_guest_page(slot, gfn, data, offset, len); + return __kvm_write_guest_page(slot, gfn, data, offset, len, + kvm->mem_protected); } EXPORT_SYMBOL_GPL(kvm_write_guest_page); @@ -2444,7 +2500,8 @@ int kvm_vcpu_write_guest_page(struct kvm_vcpu *vcpu, gfn_t gfn, { struct kvm_memory_slot *slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn); - return __kvm_write_guest_page(slot, gfn, data, offset, len); + return __kvm_write_guest_page(slot, gfn, data, offset, len, + vcpu->kvm->mem_protected); } EXPORT_SYMBOL_GPL(kvm_vcpu_write_guest_page); @@ -2560,7 +2617,7 @@ int kvm_write_guest_offset_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc, if (unlikely(!ghc->memslot)) return kvm_write_guest(kvm, gpa, data, len); - r = __copy_to_user((void __user *)ghc->hva + offset, data, len); + r = copy_to_guest(ghc->hva + offset, data, len, kvm->mem_protected); if (r) return -EFAULT; mark_page_dirty_in_slot(ghc->memslot, gpa >> PAGE_SHIFT); @@ -2581,7 +2638,6 @@ int kvm_read_guest_offset_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc, unsigned long len) { struct kvm_memslots *slots = kvm_memslots(kvm); - int r; gpa_t gpa = ghc->gpa + offset; BUG_ON(len + offset > ghc->len); @@ -2597,11 +2653,7 @@ int kvm_read_guest_offset_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc, if (unlikely(!ghc->memslot)) return kvm_read_guest(kvm, gpa, data, len); - r = __copy_from_user(data, (void __user *)ghc->hva + offset, len); - if (r) - return -EFAULT; - - return 0; + return copy_from_guest(data, ghc->hva + offset, len, kvm->mem_protected); } EXPORT_SYMBOL_GPL(kvm_read_guest_offset_cached); -- 2.26.2