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.gnu.org (lists.gnu.org [209.51.188.17]) (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 6CFE6C27C53 for ; Wed, 12 Jun 2024 13:40:25 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1sHOCZ-0003ZE-Bz; Wed, 12 Jun 2024 09:39:47 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1sHOCX-0003Yv-OB for qemu-devel@nongnu.org; Wed, 12 Jun 2024 09:39:45 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1sHOCW-0007iN-10 for qemu-devel@nongnu.org; Wed, 12 Jun 2024 09:39:45 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1718199582; 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:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=QekPl/+SJDAqOkSOuUlcgF2vIe5Agb0K/30Ij11Y9HI=; b=asQq7xw+e6KAGST8cosqHtaZhadehU592KNtRght2zZZMDtUE4qrl9WsXuYdYB2QmftnNq XUbXA7Hmg99li4W8ngekVeLiJVOzDldbJckzfFmiPPAH/Y79qMn2N50EvGp9PBkY4EFA4i j4J8KbQhgjkMY+wlAtpwFM3slGcva3o= Received: from mail-wr1-f71.google.com (mail-wr1-f71.google.com [209.85.221.71]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-50-gyFDPiISMnaE1TqBuIzIVQ-1; Wed, 12 Jun 2024 09:39:41 -0400 X-MC-Unique: gyFDPiISMnaE1TqBuIzIVQ-1 Received: by mail-wr1-f71.google.com with SMTP id ffacd0b85a97d-35f06558bc3so1709152f8f.1 for ; Wed, 12 Jun 2024 06:39:41 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1718199580; x=1718804380; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=QekPl/+SJDAqOkSOuUlcgF2vIe5Agb0K/30Ij11Y9HI=; b=rGsY8zTsOth3MJmBPG1GPmpeCIwkPv+lYiky00WbhV3+Aqe7WIv8nNWGhIfURifHrm ow5rhxt/yfM4fbXunmGClP4uFufJM7qm2QSlt9FfB8AZ0ZZfEQBI+QW6Q4dQf63fewy9 Fd/BFHOK4HvSkeeJIROnC3TwAk5HVNw/VdQa7E478TpzooeBPbQ9z1D83KjZ+oOvAmBS klu7cL1Sf4IIrM+zWkdvLUOPlcipDUgFxhGA9t6qHMpqTVibnk/FIlzaUtnaP0TS1vcW nFRCAIsU1mdx+7CN0hmGcbBOotCeFMXIrKD+xJJd4CdEAM3Q9Y62Xk6qy1gxOu362zyG /zBA== X-Forwarded-Encrypted: i=1; AJvYcCUTauRCsw/Kn77rOj8M6s+OELoFD0o2R2vVZG/VM8t+JIXCo+16FZy5uSLXIRJ2d+gvc94JqKpvb6MiwkqVX2vRb1386h8= X-Gm-Message-State: AOJu0Yxm8WkPFjyT/r6fgEwMxudBcDRivvBTRqr9MS1YNV/q/MrLA9rD nFkZ/Vxpkl6KUMHMJylZR8F2JvUbEDYZLy3mZ4gNWHdh3mvJksRuasapzGv8uBDRJpYjoi7pAUC BmCT0dFpCCb1YFjf2tEBpmG2XyPHlDcmAouTE71M/jgc5d/dPWAKq+3b0AMwJZSZ4oejCrsUqo3 t9dwnDJH607f0FRBEG9nr8ECiRaIA= X-Received: by 2002:adf:e645:0:b0:360:6ffa:9803 with SMTP id ffacd0b85a97d-3606ffa98cbmr624438f8f.56.1718199580541; Wed, 12 Jun 2024 06:39:40 -0700 (PDT) X-Google-Smtp-Source: AGHT+IGBQ5ZcEbocLMw2CEB/I6OAGJRnGt3DmYLMT81vjeitZvtwMWDdjkbz5We1ZFIda+k5J4KY6rgClYRvqyo/ZDo= X-Received: by 2002:adf:e645:0:b0:360:6ffa:9803 with SMTP id ffacd0b85a97d-3606ffa98cbmr624419f8f.56.1718199580172; Wed, 12 Jun 2024 06:39:40 -0700 (PDT) MIME-Version: 1.0 References: <20240612105525.8795-1-amonakov@ispras.ru> In-Reply-To: From: Paolo Bonzini Date: Wed, 12 Jun 2024 15:39:28 +0200 Message-ID: Subject: Re: [PATCH 0/5] Reinstate ability to use Qemu on pre-SSE4.1 x86 hosts To: Alexander Monakov Cc: =?UTF-8?Q?Daniel_P=2E_Berrang=C3=A9?= , qemu-devel@nongnu.org, Richard Henderson Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Received-SPF: pass client-ip=170.10.133.124; envelope-from=pbonzini@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -22 X-Spam_score: -2.3 X-Spam_bar: -- X-Spam_report: (-2.3 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.143, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Wed, Jun 12, 2024 at 3:34=E2=80=AFPM Alexander Monakov wrote: > On Wed, 12 Jun 2024, Paolo Bonzini wrote: > > > I found out from the mailing list. My Core2-based desktop would be af= fected. > > > > Do you run QEMU on it? With KVM or TCG? > > Excuse me? Are you going to ask for SSH access to ensure my computer real= ly > exists and is in working order? Come on. The thing is, I'm not debating the existence of computers that don't have x86_64-v2, but I *am* debating the usefulness of making QEMU run on them and any extra information can be interesting. > Can you tell me why you never commented on buffer_is_zero improvements, w= here > v1 was sent in October? Just trying to understand how you care for 2% of= L1D > use but could be ok with those kinds of speedups be dropped on the floor. I'm not sure if there is any overlap in the scenarios where buffer_is_zero performance matters, and x86 emulation. People can care about thing A but not thing B. If there's anything that you think I can help reviewing, feel free to let me know offlist. Paolo