From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (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 D386F1947A for ; Mon, 30 Oct 2023 17:18:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="GdH8gq5M" Received: from mgamail.intel.com (mgamail.intel.com [134.134.136.65]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E9BCEC4; Mon, 30 Oct 2023 10:18:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1698686314; x=1730222314; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=hDTPK0YUHt+pocd+0mVi0nC1xAxpzlBeSTE52VF45wI=; b=GdH8gq5MRmD4sY1oSKdZtiLBpJHY6ZSZEsG/ohTcsm0rRSodxOLwkOm2 EyY5luwtGFZcnAq88y8fmeOmucSyPGYPXruSJtRXTwP6ch3ewhnrs6/Fb 11++pM9+dN9z/orNHT4F5trZe8a6UiuL4GXegY8OhTMtdcVyyWwPn1OUx i9rt/FPHfMzPwWoEaZy+qg+LzQpklRjhoyvL89xHZJQR4HunQPDTgqe+K 1tgHMgLDmdryDoehXjUD3K1x7rDnF42mvBzj+hnvk3j0ur1QXpjFXhWw+ LY8WmEuxY+7i2ZEFiCf190L44odjj/IV4UWPT1VXn69+LHJ2A8XA1aOwu w==; X-IronPort-AV: E=McAfee;i="6600,9927,10879"; a="391983159" X-IronPort-AV: E=Sophos;i="6.03,263,1694761200"; d="scan'208";a="391983159" Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Oct 2023 10:18:23 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10879"; a="830743997" X-IronPort-AV: E=Sophos;i="6.03,263,1694761200"; d="scan'208";a="830743997" Received: from rgibson-mobl.amr.corp.intel.com (HELO [10.251.7.5]) ([10.251.7.5]) by fmsmga004-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Oct 2023 10:18:22 -0700 Message-ID: <57d63309-51cd-4138-889d-43fbdf5ec790@intel.com> Date: Mon, 30 Oct 2023 10:18:21 -0700 Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v5 13/14] x86/tsc: Mark Secure TSC as reliable clocksource Content-Language: en-US To: Nikunj A Dadhania , linux-kernel@vger.kernel.org, thomas.lendacky@amd.com, x86@kernel.org, kvm@vger.kernel.org Cc: bp@alien8.de, mingo@redhat.com, tglx@linutronix.de, dave.hansen@linux.intel.com, dionnaglaze@google.com, pgonda@google.com, seanjc@google.com, pbonzini@redhat.com References: <20231030063652.68675-1-nikunj@amd.com> <20231030063652.68675-14-nikunj@amd.com> From: Dave Hansen Autocrypt: addr=dave.hansen@intel.com; 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charset=UTF-8 Content-Transfer-Encoding: 7bit On 10/29/23 23:36, Nikunj A Dadhania wrote: ... > diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c > index 15f97c0abc9d..b0a8546d3703 100644 > --- a/arch/x86/kernel/tsc.c > +++ b/arch/x86/kernel/tsc.c > @@ -1241,7 +1241,7 @@ static void __init check_system_tsc_reliable(void) > tsc_clocksource_reliable = 1; > } > #endif > - if (boot_cpu_has(X86_FEATURE_TSC_RELIABLE)) > + if (boot_cpu_has(X86_FEATURE_TSC_RELIABLE) || cc_platform_has(CC_ATTR_GUEST_SECURE_TSC)) > tsc_clocksource_reliable = 1; Why can't you just set X86_FEATURE_TSC_RELIABLE?