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=-2.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 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 F3F0AC433DF for ; Wed, 20 May 2020 09:14:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BD25A206C3 for ; Wed, 20 May 2020 09:14:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=alien8.de header.i=@alien8.de header.b="NAfDGZuY" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726844AbgETJOY (ORCPT ); Wed, 20 May 2020 05:14:24 -0400 Received: from mail.skyhub.de ([5.9.137.197]:43102 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726224AbgETJOX (ORCPT ); Wed, 20 May 2020 05:14:23 -0400 Received: from zn.tnic (p200300ec2f0bab00d907527c3c1e360d.dip0.t-ipconnect.de [IPv6:2003:ec:2f0b:ab00:d907:527c:3c1e:360d]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id 47C811EC032C; Wed, 20 May 2020 11:14:22 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1589966062; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:in-reply-to:in-reply-to: references:references; bh=LiDZJ/nDDOx6HNQyMN6etFUDBDZ4zUzKnqjvmtstft0=; b=NAfDGZuYM1NLD2lCZ1oQZIZ7UGOSHsSZ0Zu/lgomzdOS6sf36E9Rj79WbRNcWpl86KpX+L zvCKYyoH/HH8DbtCZKcEsv40un5TfHc0NyTxCuLOPjo0ovPggkKuqcLUUbHTcKokbQ/mS0 o0l9nWvwsPxoFmCz1B3jcXZp80MWqlM= Date: Wed, 20 May 2020 11:14:15 +0200 From: Borislav Petkov To: Joerg Roedel Cc: x86@kernel.org, hpa@zytor.com, Andy Lutomirski , Dave Hansen , Peter Zijlstra , Thomas Hellstrom , Jiri Slaby , Dan Williams , Tom Lendacky , Juergen Gross , Kees Cook , David Rientjes , Cfir Cohen , Erdem Aktas , Masami Hiramatsu , Mike Stunes , Joerg Roedel , linux-kernel@vger.kernel.org, kvm@vger.kernel.org, virtualization@lists.linux-foundation.org Subject: Re: [PATCH v3 40/75] x86/sev-es: Compile early handler code into kernel image Message-ID: <20200520091415.GC1457@zn.tnic> References: <20200428151725.31091-1-joro@8bytes.org> <20200428151725.31091-41-joro@8bytes.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20200428151725.31091-41-joro@8bytes.org> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Apr 28, 2020 at 05:16:50PM +0200, Joerg Roedel wrote: > +static inline u64 sev_es_rd_ghcb_msr(void) > +{ > + return native_read_msr(MSR_AMD64_SEV_ES_GHCB); > +} > + > +static inline void sev_es_wr_ghcb_msr(u64 val) > +{ > + u32 low, high; > + > + low = (u32)(val); > + high = (u32)(val >> 32); > + > + native_write_msr(MSR_AMD64_SEV_ES_GHCB, low, high); > +} Instead of duplicating those two, you can lift the ones in the compressed image into sev-es.h and use them here. I don't care one bit about the MSR tracepoints in native_*_msr(). > +static enum es_result vc_write_mem(struct es_em_ctxt *ctxt, > + char *dst, char *buf, size_t size) > +{ > + unsigned long error_code = X86_PF_PROT | X86_PF_WRITE; > + char __user *target = (char __user *)dst; > + u64 d8; > + u32 d4; > + u16 d2; > + u8 d1; > + > + switch (size) { > + case 1: > + memcpy(&d1, buf, 1); > + if (put_user(d1, target)) > + goto fault; > + break; > + case 2: > + memcpy(&d2, buf, 2); > + if (put_user(d2, target)) > + goto fault; > + break; > + case 4: > + memcpy(&d4, buf, 4); > + if (put_user(d4, target)) > + goto fault; > + break; > + case 8: > + memcpy(&d8, buf, 8); > + if (put_user(d8, target)) > + goto fault; Ok, those (and below) memcpys get nicely optimized to MOVs by the compiler here. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette