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 E6C9533C9; Mon, 30 Dec 2024 17:05:19 +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=1735578322; cv=none; b=PLaFAVVAgnIXtcMot1y0j6Lu95tYrlea7pZw85AglkfX/WnS+amoIUxxDiSzArrkTN09+b3Hu0Wc+yIf8qzMtFH3g3+k3j4X3Nb0Sq3gApv86dPAGc0liPgg7sHqHRFQBGZNtTerbrbiqg9izdfGqA4F+xH0LjTdav7PXjw7cC8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1735578322; c=relaxed/simple; bh=YFXlJ8TPHvpk7Wpcpd2POrH7any0wx+iPgUzOMNZgfo=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=mrCrGxgVIDp8gjVr7Jb5e2QihvVt05oXMXmaSQm444T8Q09goyWyLHe6JHqqWTd8Ueik4U/tY+9CtGxrHPVj4QPqNG64hO8m+ZYCrFuoNS/SCSTJ8C43/JtlpiYxlApZGQSkZUE04HErzvpOFAyRR55UmzInB11DgiOfWGRR2FU= 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=cE2BrNWm; 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="cE2BrNWm" Received: from localhost (localhost.localdomain [127.0.0.1]) by mail.alien8.de (SuperMail on ZX Spectrum 128k) with ESMTP id A9D6240E0266; Mon, 30 Dec 2024 17:05:17 +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 W6SVJr85_Uuh; Mon, 30 Dec 2024 17:05:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=alien8; t=1735578313; bh=xv6cXaOYuLb9VTHT6jtpP6pWUGRVRwxk3B4YsspGCCA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=cE2BrNWmJdqb5YT/V1EAnvosos0IsY/1TCujEtCebfcOkdQKPn2fgYA5nHZAPxnF5 dip7hI9xquQFxWrUlAsFTWTfRmpJjtuktk6We0VQzuT4ngowcXKwPD3EGoc6v2CSAB ln8kvHPVSQ7xIwGTlQpK26deuI+LItE5TBSYJ3M8rD+fD5wb0kO2BKH1PM5nucLNwW 9q1Tajf88ICd/+wXsn2sYe5TLDNxeoq67WU2VQuQ42O5TfXG2wLDx5Edohp6KppIEl QRwKOXaY0cphwYVroFVoG9gIFLSq4breKRIs2oHPRW3eG6M+ItMZQ5ky6NVBTaGYbp CR9wOd87tTIKztEBlckpUL2n62LOwf3mgLErG+kyTL5/Mii6AhisnNQPLqyvcazpxp HB/d3lATqeAIi9syDjQlsRanf+t0D2tDtH3Cai6TDKqC7mW9lUnejiJBD5YlkWaCFb EhwEixMj3pZRzfp4Q1Qc/a1qQ3dkhnbt3/F1fcXoPDV9fuF5gyTchxRPD6XoUDGLOS 2l6zQ+fYzRsPwEm48m1c0UEhqABfICSJHkOWoFo5ByNUN3PED1a4m5MygH15DBETYY lUwcA8DcXPRH1NP6kdn1skEqG1hpuXNX518h3t6D0XkdREyVmWf+PA5ka67X1NRKYb j4jkppoxgCPFK8lPNtietI6E= Received: from zn.tnic (pd953008e.dip0.t-ipconnect.de [217.83.0.142]) (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 ESMTPSA id CBA6F40E02C0; Mon, 30 Dec 2024 17:05:01 +0000 (UTC) Date: Mon, 30 Dec 2024 18:04:53 +0100 From: Borislav Petkov To: Nikunj A Dadhania Cc: linux-kernel@vger.kernel.org, thomas.lendacky@amd.com, x86@kernel.org, kvm@vger.kernel.org, mingo@redhat.com, tglx@linutronix.de, dave.hansen@linux.intel.com, pgonda@google.com, seanjc@google.com, pbonzini@redhat.com Subject: Re: [PATCH v15 12/13] x86/kvmclock: Abort SecureTSC enabled guest when kvmclock is selected Message-ID: <20241230170453.GLZ3LStTw_bXGeiLnR@fat_crate.local> References: <20241203090045.942078-1-nikunj@amd.com> <20241203090045.942078-13-nikunj@amd.com> 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: <20241203090045.942078-13-nikunj@amd.com> On Tue, Dec 03, 2024 at 02:30:44PM +0530, Nikunj A Dadhania wrote: > SecureTSC enabled guests should use TSC as the only clock source, terminate > the guest with appropriate code when clock source switches to hypervisor > controlled kvmclock. This looks silly. Why not prevent kvm_register_clock() from succeeding simply on a secure-TSC guest? -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette