From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.15]) (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 4A88F3FCC; Sat, 13 Jun 2026 03:03:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.15 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781319805; cv=none; b=PUqS0sw7IYgF76WK0LFnrcsIfl2EVOYdOhMx21w5iqTcg47aZEb0mZfAwcSWCkkQO/6G6oaR1+hzVthuXcou7DW/MZRmRG0yMOkVv7a9abYOcsu6HlxIl8S5wYwcY3CjlbfM5YVnfJIMrwim4lk7iweR0uSkREWGRJn2E2mwhhU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781319805; c=relaxed/simple; bh=4xt+4xk0Hc3YMw1aNHlRBQaT0gBOUbECiVq0tCcnseI=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=Ls86r+aG7AahJVms5Vyj6MjBQLmH0kB6BQj7L/BzSrlPaOwLJEjaCiInNrgh4EgpnvF3RMacyFjaPL/MXpY7TX97COCDe1QGfQXNjoYWzu/BFCl4tYCwVQ+yr82HSgbRruTdo/3CA+EfKZIGlfXpq4LxH2GewlMykYre61stFY8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=kVJkxMm8; arc=none smtp.client-ip=192.198.163.15 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="kVJkxMm8" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1781319803; x=1812855803; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=4xt+4xk0Hc3YMw1aNHlRBQaT0gBOUbECiVq0tCcnseI=; b=kVJkxMm83OKP4W6cpMoXdp8kJV2lI4IggB6GKb7mMoW2r4jGkejbVDRZ Kfhu+ZtbRjl5YvqutmreC/BqLa8nOicOg3608t/Tnbz8Uk6E+Xk6Ve7qz AtGXM3QqX696HbBox0OJsty2XVLE40a2B5VB4VsZbVnA83lGDhzYN3zYN 1De3Qc81R+4fXe/R9AAo/OMgAFpFid4yE0ZaBv9PzKTprbOR5swE+8srT oxGxgdGZCLiCLJMNd2vjM0n7xFhHuIebsjLgwYWf7OysdBlm1QhdRIm9A rgHxvedalvR+0K8i/OL3GReeVKZGVWk4KradMyGnwxqQUJQntiHOpJGNJ A==; X-CSE-ConnectionGUID: PUw2tFT1QB6cBj+lIP431w== X-CSE-MsgGUID: fwlYRGhKR22RWB8haoptXg== X-IronPort-AV: E=McAfee;i="6800,10657,11815"; a="82261892" X-IronPort-AV: E=Sophos;i="6.24,201,1774335600"; d="scan'208";a="82261892" Received: from orviesa007.jf.intel.com ([10.64.159.147]) by fmvoesa109.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Jun 2026 20:03:23 -0700 X-CSE-ConnectionGUID: vxHDOxuNQyOXrSIrb6P1Zw== X-CSE-MsgGUID: l8eRTb/IQP+iDLA2PysOHw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.24,201,1774335600"; d="scan'208";a="247044250" Received: from unknown (HELO [10.238.0.202]) ([10.238.0.202]) by orviesa007-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Jun 2026 20:03:19 -0700 Message-ID: <141a4dff-adb8-4af0-b25c-f87b2189cbae@intel.com> Date: Sat, 13 Jun 2026 11:03:16 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: VMX Preemption Timer appears to be buggy on SKX, CLX, and ICX To: Jim Mattson , Chao Gao Cc: Sean Christopherson , Reinette Chatre , isaku.yamahata@intel.com, pbonzini@redhat.com, erdemaktas@google.com, vkuznets@redhat.com, vannapurve@google.com, mlevitsk@redhat.com, rick.p.edgecombe@intel.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, chenyi.qiang@intel.com, Yosry Ahmed References: <2fccf35715b5ba8aec5e5708d86ad7015b8d74e6.1718214999.git.reinette.chatre@intel.com> Content-Language: en-US From: Xiaoyao Li In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit On 6/13/2026 6:51 AM, Jim Mattson wrote: > On Thu, Jun 4, 2026 at 10:56 PM Chao Gao wrote: >> >> On Thu, Jun 04, 2026 at 10:34:40PM -0700, Jim Mattson wrote: > ... >>> With respect to EMR, you wrote previously, "A mitigation for this >>> erratum is for software to program the VMX preemption timer for values >>> below 2^25 * CPUID.15H:EBX[31:0] / CPUID.15H:EAX[31:0]." >>> >>> My question is whether the exponent, 25, is a fixed value for all >>> CPUs, regardless of their IA32_VMX_MISC[4:0]. It sounds like you are >>> saying that the exponent may depend on IA32_VMX_MISC[4:0]. >> >> Let me double-check this with the internal team and get back to you. > > Have you discovered anything? Chao is on vacation, let's wait one more week.