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=-3.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no 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 534ABC433DF for ; Tue, 26 May 2020 21:56:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3264F208DB for ; Tue, 26 May 2020 21:56:35 +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="Rdj07d1E" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389618AbgEZV40 (ORCPT ); Tue, 26 May 2020 17:56:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60292 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389582AbgEZV4Y (ORCPT ); Tue, 26 May 2020 17:56:24 -0400 Received: from mail-lj1-x242.google.com (mail-lj1-x242.google.com [IPv6:2a00:1450:4864:20::242]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 625E3C061A0F for ; Tue, 26 May 2020 14:56:24 -0700 (PDT) Received: by mail-lj1-x242.google.com with SMTP id b6so26478015ljj.1 for ; Tue, 26 May 2020 14:56:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=shutemov-name.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=KxA9UmGJJnl7Bb+4Hp5hGEl722cKfUNLx8ou3ZEhvTQ=; b=Rdj07d1EbBsd4yaGts4o+yqzcD6soXFmwEnvmWnKKkkMxr4IzXZCRjUTJqQ0b010v3 QCViqtYyatK+6gpTvUUspFrQ+zruGqU7KH44vMYy2OZ3Zz/zaly4trhle/tcrtMgZMnm LnEITkjaw/mB9K1DttC+YgzADHQ/izR/asILurcN7rLch/r/ZUjle2DQa17WJYFuL7H9 yfWZ+EOFZPbQkSb/D/+GXzEViwlKYd4HKr0NRPce3hroQ0JffQtCKP79tgSShlUSHbm7 UkQQ0zKl4bK/mvTBH0UJYqgNftgHENuCLJzhnIk6dqfK20eYm7k60qJVlizWE2dv5ebi QR6Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=KxA9UmGJJnl7Bb+4Hp5hGEl722cKfUNLx8ou3ZEhvTQ=; b=J+yC9mhbbs9pJRbt1tsr4m6i6C6kCI1mpbkszqLgiUGWd17QsqzmWgGA16OwEi9LCR QVtlLJdCCE+NkN3GMZAAwsYc/4MT2MImnn1xL7nv9ozobrr3tHi5/BqyfaKChfeRMd8d akMjkhawLMwk6V1lVM2TMWS1OYGY716IQll/WX3WiLhILlhNIJUVlOBfQYyr1aOKDgqH QsBQlEz+XaDRaf8UQ53tV5f2/1lTDb13fBuC5ydbU0A8KcDzeMbRaOVvYhtlshmHGzPX sUFbj2eNw0xO7gFEx9HBzZzijwVeHgcDZKTzXx3qK9fRCVQNX1c8X2Mc8Ne9lwl8xg4g 63Sg== X-Gm-Message-State: AOAM533F4CBdpHS8PMXeO3SeMphsYQLAhJWrfb7pZlLc0oOIlxnQSyz2 mcYy2dhm0vPd85GOTRocq2Rtng== X-Google-Smtp-Source: ABdhPJyBJffVuN8Gxouh7odL35w4h73NN8hmaj17eT0JxNv7QR2g36h9/tqS3jaVBhyIz8dNFQkR1g== X-Received: by 2002:a2e:8091:: with SMTP id i17mr1625888ljg.141.1590530182839; Tue, 26 May 2020 14:56:22 -0700 (PDT) Received: from box.localdomain ([86.57.175.117]) by smtp.gmail.com with ESMTPSA id w24sm218345ljo.136.2020.05.26.14.56.21 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 26 May 2020 14:56:22 -0700 (PDT) Received: by box.localdomain (Postfix, from userid 1000) id 850B710230F; Wed, 27 May 2020 00:56:22 +0300 (+03) Date: Wed, 27 May 2020 00:56:22 +0300 From: "Kirill A. Shutemov" To: Mike Rapoport Cc: Dave Hansen , Andy Lutomirski , Peter Zijlstra , Paolo Bonzini , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , David Rientjes , Andrea Arcangeli , Kees Cook , Will Drewry , "Edgecombe, Rick P" , "Kleen, Andi" , x86@kernel.org, kvm@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, "Kirill A. Shutemov" Subject: Re: [RFC 06/16] KVM: Use GUP instead of copy_from/to_user() to access guest memory Message-ID: <20200526215622.r455gfohtufr45vj@box> References: <20200522125214.31348-1-kirill.shutemov@linux.intel.com> <20200522125214.31348-7-kirill.shutemov@linux.intel.com> <20200526061459.GC13247@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200526061459.GC13247@kernel.org> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Tue, May 26, 2020 at 09:14:59AM +0300, Mike Rapoport wrote: > On Fri, May 22, 2020 at 03:52:04PM +0300, Kirill A. Shutemov wrote: > > 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 | 78 ++++++++++++++++++++++++++++++++++------ > > 2 files changed, 72 insertions(+), 10 deletions(-) > > > > 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; > > @@ -2257,7 +2297,10 @@ static int __kvm_read_guest_page(struct kvm_memory_slot *slot, gfn_t gfn, > > 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 (protected) > > + r = copy_from_guest(data, addr + offset, len); > > + else > > + r = __copy_from_user(data, (void __user *)addr + offset, len); > > Maybe always use copy_{from,to}_guest() and move the 'if (protected)' > there? > If kvm is added to memory slot, it cab be the passed to copy_{to,from}_guest. Right, Vitaly has pointed me to this already. -- Kirill A. Shutemov