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 00271C3DA63 for ; Tue, 23 Jul 2024 04:59:42 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1sW7cE-0003sq-08; Tue, 23 Jul 2024 00:59:10 -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 1sW7cB-0003rO-BI; Tue, 23 Jul 2024 00:59:07 -0400 Received: from mail-pf1-x433.google.com ([2607:f8b0:4864:20::433]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1sW7c8-0004ce-N4; Tue, 23 Jul 2024 00:59:07 -0400 Received: by mail-pf1-x433.google.com with SMTP id d2e1a72fcca58-70d316f0060so809333b3a.1; Mon, 22 Jul 2024 21:59:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1721710742; x=1722315542; darn=nongnu.org; h=in-reply-to:references:content-transfer-encoding:cc:to:from:subject :message-id:date:mime-version:from:to:cc:subject:date:message-id :reply-to; bh=FgpFYmOgkh+3Nuy6wkK/bugSyVYsw4Ol+/5eGQtZWP8=; b=PAt/bWRjIDY1q03uDNviQ6yZd1WJwCdFt1eiCLEXW9B/gPC/JHrBMCk4g8HJ/MPXzq TcaEyKvximwDg9BZz9lPqshVbtCbvn8Dz47sgad2beoDOIhWgQZjLeNao7lio9yRaFeU otskCewbIwtDqdMckJXD1voVmB22OLAYGP1zWmEyizGjjOVMQ4F5HptvIEC1tUFYvPkw edtkserkLfKCquUYxYlneCMppzlVjn7EBzO2Z1nBNP5Q61jBdwLS9fWd93kyjgcQgKqM 8Bjww6pzPRdr/CHFMZ4zbErhGSdUJoULN5Gj/RV2qfIh87y6gX03JWus1TqwKIMHYROq U2Iw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1721710742; x=1722315542; h=in-reply-to:references:content-transfer-encoding:cc:to:from:subject :message-id:date:mime-version:x-gm-message-state:from:to:cc:subject :date:message-id:reply-to; bh=FgpFYmOgkh+3Nuy6wkK/bugSyVYsw4Ol+/5eGQtZWP8=; b=Fk9kiEvemijeipEXMMhlZHD2tX0O21+OOmbKpmDtmb7CEKGZfkV220pWkVqg8dOhg0 xxIdP3frPin5/F62egbm/TXefUs1sbSLW6tSFJYa3ySVMg/EIFgiu25q/U8DPDx3eNOY 4O7mWUSIRaSxNtaHzD1682yrb6TMOgKYtTLVcTrDupYbg3l6HmeqRfp2U1RO69wpoXBU PwMPSyD0iJJ1QsY66PCHotlyWQOufLl0Mgj4YOCXz+Fm7MNLpmbwKOw/Rnui3BaY5F38 xvf6RdyKnGW4OrtHnMT2/S8c35f219F1jezBK1i38M+0V1z1mYZDDIW8hlmJtJqymV0/ Y02w== X-Forwarded-Encrypted: i=1; AJvYcCVaBMK13BWrh4VHTCrpCq2iZiIfIqKF8mj5ZreZ1swH4VmGN3Lu0nd1naF+Av4qgLpab3qE3r1SQtYPlsetqqSvdc/P X-Gm-Message-State: AOJu0Yxi/+x68atpD4rwYEj1ngyCjJMxl34nr9KKnH6TCL4GsaxebyPE Jy3QKaXRqZ75kN1tKEznPEY9oETl0r5cjLY7gKSZQ8D7AbJfLwI0 X-Google-Smtp-Source: AGHT+IGNdzFvzQjFI7aAqRL08NErMHDXpIMccWscVdTALtiUphwRs6QP3XPXMhTNYKae84aI+hmQwg== X-Received: by 2002:a05:6a20:4f22:b0:1c0:e8f9:5ac0 with SMTP id adf61e73a8af0-1c4522d5e86mr1160520637.27.1721710742405; Mon, 22 Jul 2024 21:59:02 -0700 (PDT) Received: from localhost ([203.220.44.216]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-70d13c2b588sm4247450b3a.3.2024.07.22.21.58.59 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 22 Jul 2024 21:59:02 -0700 (PDT) Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Date: Tue, 23 Jul 2024 14:58:57 +1000 Message-Id: Subject: Re: [PATCH v5 5/5] target/ppc: Fix regression due to Power10 and Power11 having same PCR From: "Nicholas Piggin" To: "Aditya Gupta" , "Mahesh J Salgaonkar" , "Madhavan Srinivasan" , =?utf-8?q?C=C3=A9dric_Le_Goater?= , "Harsh Prateek Bora" Cc: , , "Daniel Henrique Barboza" Content-Transfer-Encoding: quoted-printable X-Mailer: aerc 0.18.0 References: <20240606121657.254308-1-adityag@linux.ibm.com> <20240606121657.254308-6-adityag@linux.ibm.com> In-Reply-To: <20240606121657.254308-6-adityag@linux.ibm.com> Received-SPF: pass client-ip=2607:f8b0:4864:20::433; envelope-from=npiggin@gmail.com; helo=mail-pf1-x433.google.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 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 Thu Jun 6, 2024 at 10:16 PM AEST, Aditya Gupta wrote: > Power11 has the same PCR (Processor Compatibility Register) value, as > Power10. > > Due to this, QEMU considers Power11 as a valid compat-mode for Power10, > ie. earlier it was possible to run QEMU with '-M pseries,max-compat-mode= =3Dpower11 --cpu power10' Isn't this expected to work, or no? > > Same PCR also introduced a regression where `-M pseries --cpu power10` > boots as Power11 (ie. logical PVR is of Power11, even though PVR is Power= 10). > The regression was due to 'do_client_architecture_support' checking for > valid compat modes and finding Power11 to be a valid compat mode for > Power10 (it happens even without passing 'max-compat-mode' explicitly). > > Fix compat-mode issue and regression, by ensuring a future Power > processor (with a higher logical_pvr value, eg. P11) cannot be valid > compat-mode for an older Power processor (eg. P10) This should be done before introducing the Power11 CPU so there's no regression inside the series. > > Cc: C=C3=A9dric Le Goater > Cc: Daniel Henrique Barboza > Cc: Harsh Prateek Bora > Cc: Mahesh J Salgaonkar > Cc: Madhavan Srinivasan > Cc: Nicholas Piggin > Signed-off-by: Aditya Gupta > --- > target/ppc/compat.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/target/ppc/compat.c b/target/ppc/compat.c > index 12dd8ae290ca..168a3c06316f 100644 > --- a/target/ppc/compat.c > +++ b/target/ppc/compat.c > @@ -139,6 +139,10 @@ static bool pcc_compat(PowerPCCPUClass *pcc, uint32_= t compat_pvr, > /* Outside specified range */ > return false; > } > + if (compat->pvr > pcc->logical_pvr) { > + /* Older CPU cannot support a newer processor's compat mode */ > + return false; > + } Hmm. I suppose this is the right way to fix it. Reviewed-by: Nicholas Piggin > if (!(pcc->pcr_supported & compat->pcr_level)) { > /* Not supported by this CPU */ > return false;