From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ot1-f51.google.com (mail-ot1-f51.google.com [209.85.210.51]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0D2EF376; Mon, 24 Jun 2024 07:06:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.51 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719212820; cv=none; b=Wpg2a0+yFJMikz+t5EJblQ/0OtEvwresobI1mpy50HIS9BgGhynJzYMCh4t0jleaTnq/OSZIMa7RFJPZ8KARlYp2BHSy9dMBQBv7rfBjCiac2hwOaHu5yqvl1rWHZO64hd4PdRGHVHpW9fF3HdRYaR8q+/fKi4iuWvmdzu+S9q4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719212820; c=relaxed/simple; bh=zm04avjiqQZBn5KYoGNw+kGHuCoJrS4M9EjVbFU044Q=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ScsW9Tm8SYAuMgpP8Pvo4+fU/G+722oG2RKL3Wxo+LIhTSYbcYKowCvECcv558JXelcSjZBp4Q/MyIQ1Gn/bBc2p+v7bhpE1WLD1JHUjvB36rQVWZQxoxJOg6NFEhP6zhggNDxcdzt36TMSBYYH/IhLaCd6l8Hs27PA7o2Aua6Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org; spf=pass smtp.mailfrom=gmail.com; arc=none smtp.client-ip=209.85.210.51 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Received: by mail-ot1-f51.google.com with SMTP id 46e09a7af769-6f9b4d69f53so2229152a34.0; Mon, 24 Jun 2024 00:06:58 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1719212818; x=1719817618; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=Gr4VGylpKfe5jMi8mL9RhC6vYgLNd3Lq3GNPGy76NUA=; b=VskuYmLRIFp24qvPSbBE9jMM2ThFZSDA40rMutUFuBXdLhyblS72tFSmgNJV7VR5Qz vgMLQhojtp5/3mRcNDCv8Wwn6ixsq0i/GV8LDXpqES/0PMld86nLEn9UTFU15oVMvUMr /ZIqcz0Uj6k9w1fgEbhhPsHKXdfAFdP8QDVn1t5iuvF3gNHFFKWvoJKR33x/+awOzi41 y39M5wg1w0LLVpPxKsQtrrkSVkY0Ebj+l00MOGjzcQJ5IUNZ4B//1Xwjnd+lVEYejzmC dIZ9ZbEEktew7V/PexX2+o3vRoKK9dpFFGE2eG334hzjVVgL1d6/mE04qdUj0s8A8rlV dZpg== X-Forwarded-Encrypted: i=1; AJvYcCX7Em0s2pqNmroWpJsJM97M3tDfR4yoRM04uQyvqYA987qDSK+E/umPpnSzK19VQuZR1c6Cu9kmb/JRaBqj2bjwIsEEWsGhXnIWPkev38JF7zr1NxYx4XjeANKw5/MhWszBP3x2rAAzgFDpbK3pQCe3FeDT0Xj7vCfknYEAscMX/zUP X-Gm-Message-State: AOJu0Yxqte62CYApTmcrYw+50bn1/PYq96lOJl2OYpTwUfd5vMT6SasU rJwHzxnhgNJ3iX3POnduAHeFwsbMamSMGnQAqZSOYPAs9TfqSXsq X-Google-Smtp-Source: AGHT+IFVgbLtqk9su7HvLOSkwZwXr3Asb6+QVGzFFmt6I+NRQOYit5CDFSpqlwRE6ZczWCj8iWBtig== X-Received: by 2002:a05:6359:5a8d:b0:19f:1e0c:e1a5 with SMTP id e5c5f4694b2df-1a23c1b1f97mr554831255d.20.1719212817982; Mon, 24 Jun 2024 00:06:57 -0700 (PDT) Received: from liuwe-devbox-debian-v2 ([20.69.120.36]) by smtp.gmail.com with ESMTPSA id 41be03b00d2f7-716ba5b5f7asm4774472a12.64.2024.06.24.00.06.57 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 24 Jun 2024 00:06:57 -0700 (PDT) Date: Mon, 24 Jun 2024 07:06:50 +0000 From: Wei Liu To: Dexuan Cui Cc: mhklinux@outlook.com, "K. Y. Srinivasan" , Haiyang Zhang , Wei Liu , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)" , "H. Peter Anvin" , Daniel Lezcano , "open list:Hyper-V/Azure CORE AND DRIVERS" , "open list:X86 ARCHITECTURE (32-BIT AND 64-BIT)" , stable@vger.kernel.org, Roman Kisel Subject: Re: [PATCH v2] clocksource: hyper-v: Use lapic timer in a TDX VM without paravisor Message-ID: References: <20240621061614.8339-1-decui@microsoft.com> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240621061614.8339-1-decui@microsoft.com> On Thu, Jun 20, 2024 at 11:16:14PM -0700, Dexuan Cui wrote: > In a TDX VM without paravisor, currently the default timer is the Hyper-V > timer, which depends on the slow VM Reference Counter MSR: the Hyper-V TSC > page is not enabled in such a VM because the VM uses Invariant TSC as a > better clocksource and it's challenging to mark the Hyper-V TSC page shared > in very early boot. > > Lower the rating of the Hyper-V timer so the local APIC timer becomes the > the default timer in such a VM, and print a warning in case Invariant TSC > is unavailable in such a VM. This change should cause no perceivable > performance difference. > > Cc: stable@vger.kernel.org # 6.6+ > Reviewed-by: Roman Kisel > Signed-off-by: Dexuan Cui Applied to hyperv-fixes. Thanks.