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=-4.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 0B3BDC433E1 for ; Tue, 26 May 2020 06:15:12 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id C0DF0208DB for ; Tue, 26 May 2020 06:15:11 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="x53IR6Jd" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C0DF0208DB Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 5AD6C8007C; Tue, 26 May 2020 02:15:11 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 55E2D80061; Tue, 26 May 2020 02:15:11 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 44D698007C; Tue, 26 May 2020 02:15:11 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0182.hostedemail.com [216.40.44.182]) by kanga.kvack.org (Postfix) with ESMTP id 2B54F80061 for ; Tue, 26 May 2020 02:15:11 -0400 (EDT) Received: from smtpin01.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id DB84D181AC9BF for ; Tue, 26 May 2020 06:15:10 +0000 (UTC) X-FDA: 76857857580.01.vest59_67622f0e6540c X-HE-Tag: vest59_67622f0e6540c X-Filterd-Recvd-Size: 4292 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf15.hostedemail.com (Postfix) with ESMTP for ; Tue, 26 May 2020 06:15:10 +0000 (UTC) Received: from kernel.org (unknown [87.70.212.59]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 486852087D; Tue, 26 May 2020 06:15:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1590473709; bh=Ur2xk8PlFAdp1SqkrrLV/Z2pOfVx2LArPwI0PTzFmSM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=x53IR6Jdx8v+FrtVJ0pEbhAPnAPzTg32Pwto6iDx+Ywedcvs89VietzhFi20djMuN ej5tZ8gwm15PMi3B93btNoJ557MZ0g0SkVLmdgW4rddWFSquUFwjDQixRHA4VIeQJm UePksupJX9ie1uyLj4nEt1GIV8f1CBnRdXwGjwUw= Date: Tue, 26 May 2020 09:14:59 +0300 From: Mike Rapoport To: "Kirill A. Shutemov" 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: <20200526061459.GC13247@kernel.org> References: <20200522125214.31348-1-kirill.shutemov@linux.intel.com> <20200522125214.31348-7-kirill.shutemov@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200522125214.31348-7-kirill.shutemov@linux.intel.com> 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: 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. > if (r) > return -EFAULT; > return 0; > @@ -2268,7 +2311,8 @@ 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); > > @@ -2277,7 +2321,8 @@ 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); > -- Sincerely yours, Mike.