From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.alien8.de (mail.alien8.de [65.109.113.108]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B4A534D991D for ; Wed, 13 May 2026 17:10:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=65.109.113.108 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778692204; cv=none; b=R8PT8pl7mj+7kKS1XhJZF1D4bcIELC34lPN2RgLEI+WBCcFttGez85UfnSV3qn8KllHxpHfdjqsxsw62cxAF1CDL+oaxRuF0Yx04yfqpFgCogOJ371SgKYzDRAzRbmSgJKi9oppsnhvzfCPLZEWfsoeighnV0d4D5WR3Y2tJFJo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778692204; c=relaxed/simple; bh=BLfUucJAa1p7eBwP2/g+ZYdIdt9wEIKlDqPMbxMhOHU=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=HKHtzaNijQ7XmVPyc65FdE/GyZfyQsf5cC9mFn6KOCLecMT0eC7vgceYqqUB05ThIsq0NY11Xw3E6F8QsUiRUxkrncZISkVNzbiWIKgbC6EWR6P23qV7JqIfcnE2jPKXlkUWz8Dk6a0X1plE5CcuBFEbOsR7FqOINi+By7X2b90= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=alien8.de; spf=pass smtp.mailfrom=alien8.de; dkim=pass (4096-bit key) header.d=alien8.de header.i=@alien8.de header.b=X8rNKAsJ; arc=none smtp.client-ip=65.109.113.108 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=alien8.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=alien8.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (4096-bit key) header.d=alien8.de header.i=@alien8.de header.b="X8rNKAsJ" Received: from localhost (localhost.localdomain [127.0.0.1]) by mail.alien8.de (SuperMail on ZX Spectrum 128k) with ESMTP id B0D1F40E01A1; Wed, 13 May 2026 17:09:58 +0000 (UTC) X-Virus-Scanned: Debian amavisd-new at mail.alien8.de Authentication-Results: mail.alien8.de (amavisd-new); dkim=pass (4096-bit key) header.d=alien8.de Received: from mail.alien8.de ([127.0.0.1]) by localhost (mail.alien8.de [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id idMGb2mrgx1e; Wed, 13 May 2026 17:09:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=alien8; t=1778692188; bh=eGNhxehJuvtYUstlvDzMF/lGpFYXMNdpZAa1DMzhi/k=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=X8rNKAsJ4L7cDqDMnBr/ZyIDYrP781PggOcVWjhcRXrPV4Xkoz1j9a683WlCP2/Km UkMV5xHBlWYDfgAyvqhch89T3RH/vJBI9GYZHEAXcwZKqa0NnuNooMJYIMuJukgviZ tLQr91Arql/XUtaqX7zUO4XaBvNxni7HATWLUJ1ZKakMjLQoiPwm8ZxW2t0vQd0iRY bKGEH4AeWqLWKA1/Usqzm6qEZcoOCy1zG3LC9bX0jIYqjzAELxSZmMzd4H15N+GF/t yjGS8Nkjgn0x3n5qs+tEPBwpGYm57JAa/twe3QVgO3vCuSFU4fDnM8ZhvVHwyVn1wZ wUEHSU/vi1ABReI45zHnz+udT+qns0fwF1ycF84vJQCkiHFXBh/PMF1alcbTnBF5WJ bq+IsfaE4xZHombYPMZCHczCJ50cFOe82hJdiAbnItmDH0URPBKT/ZQToyNxgIQCCA IprCZV/nXprrvcqEbDI2c4vcxOMp5Hbk3zgOkPwmI/98dstMqeTzgXRuxGmghslQQe tQJgLhmrvCHylbNPBTXMkgTDfV+R7nApqpsI2yrC1tqzTUp9rmYhK0o0An5B1+Qs3Q o8n0dViPVUKSlnmlAOyuHIuTGewYqtYheEs+dVR7Qu8nS9rqHnqaklnTcFtx2szPwU JwYHX2Jz58DKuLH6j+zmLByI= Received: from zn.tnic (pd953014d.dip0.t-ipconnect.de [217.83.1.77]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature ECDSA (P-256) server-digest SHA256) (No client certificate requested) by mail.alien8.de (SuperMail on ZX Spectrum 128k) with UTF8SMTPSA id 7DF8140E00BA; Wed, 13 May 2026 17:09:33 +0000 (UTC) Date: Wed, 13 May 2026 19:09:32 +0200 From: Borislav Petkov To: "Ahmed S. Darwish" Cc: Dave Hansen , Ingo Molnar , Thomas Gleixner , Andrew Cooper , "H. Peter Anvin" , Sean Christopherson , David Woodhouse , Peter Zijlstra , Christian Ludloff , Sohil Mehta , John Ogness , x86@kernel.org, x86-cpuid@lists.linux.dev, LKML Subject: Re: [PATCH v6 10/90] x86/cpu: Rescan CPUID table after disabling PSN Message-ID: <20260513170932.GIagSwTN4oawRCcEYw@fat_crate.local> References: <20260327021645.555257-1-darwi@linutronix.de> <20260327021645.555257-11-darwi@linutronix.de> <20260511200032.GAagI1YMP51EzCo7dn@fat_crate.local> <20260512143412.GDagM6ZLBpvt6X3jzq@fat_crate.local> <20260513152742.GDagSYbheCBWwNeVj-@fat_crate.local> <20260513165128.GFagSsEPFCogQu7n5t@fat_crate.local> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20260513165128.GFagSsEPFCogQu7n5t@fat_crate.local> On Wed, May 13, 2026 at 06:51:28PM +0200, Borislav Petkov wrote: > I guess we need to know which leaf changes when a MSR bit is toggled and > rescan only that leaf alone. And looking at the current code there: /* Disabling the serial number may affect the cpuid level */ c->cpuid_level = cpuid_eax(0); So why do you need to rescan leafs at all? We don't have to do them now... -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette