From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) (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 9EB62318ED6; Wed, 20 May 2026 18:59:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.50.34 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779303561; cv=none; b=O46KWJoxkSbSLbjrO0M9jf0nudJRgrk121eWTaugQ0KrUkvHNQ1DI61ruwp4jvYYwVWl5JK7Ebtm0aE9ZVbN1k1uWS9XieWSp9cte4Nhjxqmmq2nHwMm6ggiyfn6kft+/DVJ9wRHKYR0avyFKOy5lAWwVMrBaT/u6McRHpFjjco= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779303561; c=relaxed/simple; bh=Q62hcPFZc1NYqJLxUGdKsz2+hy0EqGUz86+v1ivJn+s=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=DmwEwtEXCXQYW/mmZikEakH9n5h9ZRY5eVO9ZayTjxaecB5ySNnV1xpWHQOIznKoR/pP1RoP33zOE/xOgNgLJvbyacqBZNUkX9Ykl3sbh+7ILjcjNoRVzdHzlNooD5nwjVXVnYy4bdR6sqw6xTPWJplnmANRtypchr2sn/Kid9w= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=casper.srs.infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=g5JoUbWJ; arc=none smtp.client-ip=90.155.50.34 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=casper.srs.infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="g5JoUbWJ" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=MIME-Version:Content-Type:References: In-Reply-To:Date:Cc:To:From:Subject:Message-ID:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=Q62hcPFZc1NYqJLxUGdKsz2+hy0EqGUz86+v1ivJn+s=; b=g5JoUbWJQdG7sePmt8GlN2Kgqm bsgtRyCbYF3vxM3/Nedaj8XxmrWzGATtvuAoTxGm5KPEf4EzzLf0v9/Hafh3vT9zK/rHx2DttmiKu pW8SpVX/0FYF8PsbiegIcabyU7BBcJaQnsD66lRZe9YS0baBlP9pULXnvjknCaSDfUjVGy0wCLtlT Qtqzt10CHymMbbqv2Ok+IgydIWN/ELCCTwz/1IKoddqkR4WFERL7cLKMVv2X7yhLMBw9v111BUt+n /qDNPW6NjTuKyF5mttga1f22yZprgTCfTqXjQkt3CUsKmuXOw/3+n57JgRGvbQxdhhOntA39VrO8m LWv7AbDg==; Received: from 54-240-197-235.amazon.com ([54.240.197.235] helo=freeip.amazon.com) by casper.infradead.org with esmtpsa (Exim 4.99.1 #2 (Red Hat Linux)) id 1wPm8N-00000007Ufj-3Rdt; Wed, 20 May 2026 18:59:11 +0000 Message-ID: <810a35d31c00daf48efae533134f68e23ef98de8.camel@infradead.org> Subject: Re: [PATCH v3 01/41] x86/tsc: Add a standalone helpers for getting TSC info from CPUID.0x15 From: David Woodhouse To: Sean Christopherson , Kiryl Shutsemau , Paolo Bonzini , "K. Y. Srinivasan" , Haiyang Zhang , Wei Liu , Dexuan Cui , Long Li , Ajay Kaher , Alexey Makhalov , Jan Kiszka , Dave Hansen , Andy Lutomirski , Peter Zijlstra , Juergen Gross , Daniel Lezcano , Thomas Gleixner , John Stultz Cc: Rick Edgecombe , Vitaly Kuznetsov , Broadcom internal kernel review list , Boris Ostrovsky , Stephen Boyd , x86@kernel.org, linux-coco@lists.linux.dev, kvm@vger.kernel.org, linux-hyperv@vger.kernel.org, virtualization@lists.linux.dev, linux-kernel@vger.kernel.org, xen-devel@lists.xenproject.org, Michael Kelley , Tom Lendacky , Nikunj A Dadhania , Thomas Gleixner Date: Wed, 20 May 2026 19:59:10 +0100 In-Reply-To: <20260515191942.1892718-2-seanjc@google.com> References: <20260515191942.1892718-1-seanjc@google.com> <20260515191942.1892718-2-seanjc@google.com> Content-Type: multipart/signed; micalg="sha-256"; protocol="application/pkcs7-signature"; boundary="=-AYSJ/gnlvUPwOtRc9eC8" User-Agent: Evolution 3.52.3-0ubuntu1.1 Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html --=-AYSJ/gnlvUPwOtRc9eC8 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Fri, 2026-05-15 at 12:19 -0700, Sean Christopherson wrote: > Extract retrieval of TSC frequency information from CPUID into standalone > helpers so that TDX guest support can reuse the logic.=C2=A0 Provide a ve= rsion > that includes the multiplier math as TDX does NOT want to use > native_calibrate_tsc()'s fallback logic that derives the TSC frequency > based on CPUID.0x16, when the core crystal frequency isn't known. >=20 > Opportunsitically drop native_calibrate_tsc()'s "=3D=3D 0" and "!=3D 0" c= hecks > in favor of the kernel's preferred style. "Opportunistically" ? Now that looks wrong too...=20 > No functional change intended. >=20 > Signed-off-by: Sean Christopherson Reviewed-by: David Woodhouse --=-AYSJ/gnlvUPwOtRc9eC8 Content-Type: application/pkcs7-signature; name="smime.p7s" Content-Disposition: attachment; filename="smime.p7s" Content-Transfer-Encoding: base64 MIAGCSqGSIb3DQEHAqCAMIACAQExDzANBglghkgBZQMEAgEFADCABgkqhkiG9w0BBwEAAKCCD9Aw ggSOMIIDdqADAgECAhAOmiw0ECVD4cWj5DqVrT9PMA0GCSqGSIb3DQEBCwUAMGUxCzAJBgNVBAYT AlVTMRUwEwYDVQQKEwxEaWdpQ2VydCBJbmMxGTAXBgNVBAsTEHd3dy5kaWdpY2VydC5jb20xJDAi BgNVBAMTG0RpZ2lDZXJ0IEFzc3VyZWQgSUQgUm9vdCBDQTAeFw0yNDAxMzAwMDAwMDBaFw0zMTEx MDkyMzU5NTlaMEExCzAJBgNVBAYTAkFVMRAwDgYDVQQKEwdWZXJva2V5MSAwHgYDVQQDExdWZXJv a2V5IFNlY3VyZSBFbWFpbCBHMjCCASIwDQYJKoZIhvcNAQEBBQADggEPADCCAQoCggEBAMjvgLKj jfhCFqxYyRiW8g3cNFAvltDbK5AzcOaR7yVzVGadr4YcCVxjKrEJOgi7WEOH8rUgCNB5cTD8N/Et GfZI+LGqSv0YtNa54T9D1AWJy08ZKkWvfGGIXN9UFAPMJ6OLLH/UUEgFa+7KlrEvMUupDFGnnR06 aDJAwtycb8yXtILj+TvfhLFhafxroXrflspavejQkEiHjNjtHnwbZ+o43g0/yxjwnarGI3kgcak7 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