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 Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 85F69C02181 for ; Wed, 22 Jan 2025 10:24:22 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.875862.1286275 (Exim 4.92) (envelope-from ) id 1taXtw-0000A6-6f; Wed, 22 Jan 2025 10:24:00 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 875862.1286275; Wed, 22 Jan 2025 10:24:00 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1taXtw-00009x-3t; Wed, 22 Jan 2025 10:24:00 +0000 Received: by outflank-mailman (input) for mailman id 875862; Wed, 22 Jan 2025 10:23:58 +0000 Received: from se1-gles-flk1-in.inumbo.com ([94.247.172.50] helo=se1-gles-flk1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1taXtu-00009o-N5 for xen-devel@lists.xenproject.org; Wed, 22 Jan 2025 10:23:58 +0000 Received: from mail-wm1-x332.google.com (mail-wm1-x332.google.com [2a00:1450:4864:20::332]) by se1-gles-flk1.inumbo.com (Halon) with ESMTPS id fc7faff4-d8aa-11ef-99a4-01e77a169b0f; Wed, 22 Jan 2025 11:23:56 +0100 (CET) Received: by mail-wm1-x332.google.com with SMTP id 5b1f17b1804b1-437a92d7b96so66206925e9.2 for ; Wed, 22 Jan 2025 02:23:56 -0800 (PST) Received: from localhost ([84.78.159.3]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-438b318c059sm19606175e9.8.2025.01.22.02.23.55 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 22 Jan 2025 02:23:55 -0800 (PST) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: fc7faff4-d8aa-11ef-99a4-01e77a169b0f DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=citrix.com; s=google; t=1737541436; x=1738146236; darn=lists.xenproject.org; h=in-reply-to:content-transfer-encoding:content-disposition :mime-version:references:message-id:subject:cc:to:from:date:from:to :cc:subject:date:message-id:reply-to; bh=FLcwpP7Zz4xxiGaVQcgn7KerB+Yi5fPr3kurnqDBUq8=; b=Nw1dtYylIdLr/HBSHIS52POr8lnAqFFAnx7eFeof+PHH/W1HSJT4JWi42rqNW77UdI 2dY2dIus28JAbsy83vhI8VeGUK/oe4iP84o5f8WHXO3kKznk3oSKen5aY1Us/X5whmLL yj/RC7DiEY+YIX7aenbDpjTIWg1IVF52c+be8= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1737541436; x=1738146236; h=in-reply-to:content-transfer-encoding:content-disposition :mime-version:references:message-id:subject:cc:to:from:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=FLcwpP7Zz4xxiGaVQcgn7KerB+Yi5fPr3kurnqDBUq8=; b=HOy7hhtDChQIVg+uvzV6WJ0i3ReJcZYBUeKpGiLT4DInumY926PV7jxsMe8n04W9jn bKvFrUBybFCfjKQ+GVSlUk8UfLBCjyuNDGmVshkE0MAk4eXkZiHVgGNY8nsf6Aa+uCwd 5d3k0hPlfH6q8qJQE+vDmgs4hnmu4CZuHkm+Yb7BKKzFdUXATsuFKNGmmGxnVYp+fsFa 2Gs6QPx9trAN21TdIE6Er0xqBJ7sNIkXPULFI7bMvnS48Dg015kzQg/71FZ3YkBWSphV Q1sUfzdXcFSgLLIxSmK9yVD2INN4F+hGm9xwJLF7IyoWizAqDjSLChaee3zQ07fqJqo1 EN/w== X-Gm-Message-State: AOJu0YwqMhW5+/oppE6jvH3518ldY7YSJuQBOXIGhzVq8/vA13msYpCZ Mqk5AbUWHIhlwmA9wvOxWpMu3p4vZhNI+5OT78ry9HyZQrSnoYbMCTEnplWOl0A= X-Gm-Gg: ASbGncvTbEoILXL5m3bmQdHi9/TN3iYozu9ahnVL0SA/aA+1tj2/C7xjx3LZYs53QNG B2fOjHF5yeKIg+e97s5t/sVyLt9U3SuSTMvt9tCwbWOa16rV3OWbw/gFpTjHV8yvye6vXozOqSW dcpsA8fkcPjSFRwpgkEXNWLxpN/qC9APSHJeb7EH+RLp85tkLV8puc0Vop8NZnM8iEorMNuNLB4 +MBikW6Jp3JkF4AgDeklCHDjnPbgIvo1VhCr9xagB6S/bMZpfzeKdsxjsk4jJ7hWDugvfZncuA= X-Google-Smtp-Source: AGHT+IE98PFtbN2cemTu0C8JTlVwZnRETr+CNiItbJ830J/cDg5kGb2/ApLZ/TLbwh/qDPthQ+IP0g== X-Received: by 2002:a7b:cd0a:0:b0:438:a1f5:3e38 with SMTP id 5b1f17b1804b1-438a1f53e8fmr165716365e9.30.1737541436004; Wed, 22 Jan 2025 02:23:56 -0800 (PST) Date: Wed, 22 Jan 2025 11:23:54 +0100 From: Roger Pau =?utf-8?B?TW9ubsOp?= To: Jan Beulich Cc: "xen-devel@lists.xenproject.org" , Andrew Cooper , Wei Liu Subject: Re: [PATCH v3] x86emul: further correct 64-bit mode zero count repeated string insn handling Message-ID: References: <2e81cf29-65fd-74fc-db4f-95c453acc327@suse.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <2e81cf29-65fd-74fc-db4f-95c453acc327@suse.com> On Fri, Aug 04, 2023 at 07:58:21AM +0200, Jan Beulich wrote: > In an entirely different context I came across Linux commit 428e3d08574b > ("KVM: x86: Fix zero iterations REP-string"), which points out that > we're still doing things wrong: For one, there's no zero-extension at > all on AMD. And then while RCX is zero-extended from 32 bits uniformly > for all string instructions on newer hardware, RSI/RDI are only for MOVS > and STOS on the systems I have access to. (On an old family 0xf system > I've further found that for REP LODS even RCX is not zero-extended.) > > Fixes: 79e996a89f69 ("x86emul: correct 64-bit mode repeated string insn handling with zero count") > Signed-off-by: Jan Beulich Acked-by: Roger Pau Monné > --- > Partly RFC for none of this being documented anywhere (and it partly > being model specific); inquiry pending. Did you get any reply on this? Thanks, Roger.