From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.zytor.com (terminus.zytor.com [198.137.202.136]) (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 562553624DD; Thu, 22 Jan 2026 18:01:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.136 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769104881; cv=none; b=VZd6w/1+3QDHlgRxCg2IA7Xn3UMN4yzCIc8oEp0bAGe9I6OY1KL6xKWtquCQnWissuUf2bbCLYNyPHS92TS89Kxwy5RsuWzKjZxKeWvigyKgOTGQIYfZHppxj2YJeq4yqKfvemvYu7MRauwId2IZXKHVYRVPn8Sot4xLd7iXc8s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769104881; c=relaxed/simple; bh=bHqoE0YcdoZpbvR6YrAEbo499n+yiKtZFm2WglH44L8=; h=Content-Type:Mime-Version:Subject:From:In-Reply-To:Date:Cc: Message-Id:References:To; b=gnpvt5BPsBoDirZynwggwDf79fj0ajOqVIR028BKXcDImlFA3mtKLsSXV1lCfhABY10MkfrhKBGM5wVTRP5wVLcNvrX4tz2s7qNdGGR/C4HtMedYTrx+cmfqoT/YoHbuFtiNoNvEF4FATrST6ooFR56egddLZ/xnmITyT0b15Jc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zytor.com; spf=pass smtp.mailfrom=zytor.com; dkim=pass (2048-bit key) header.d=zytor.com header.i=@zytor.com header.b=BZ6uwuH5; arc=none smtp.client-ip=198.137.202.136 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zytor.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=zytor.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=zytor.com header.i=@zytor.com header.b="BZ6uwuH5" Received: from smtpclient.apple (c-24-130-165-117.hsd1.ca.comcast.net [24.130.165.117]) (authenticated bits=0) by mail.zytor.com (8.18.1/8.17.1) with ESMTPSA id 60MHvs0Y3527047 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Thu, 22 Jan 2026 09:57:55 -0800 DKIM-Filter: OpenDKIM Filter v2.11.0 mail.zytor.com 60MHvs0Y3527047 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zytor.com; s=2025122301; t=1769104676; bh=seLKPBdrljPR4UDaZaQOYumoRFOXXF/nQYSI9x8QdZI=; h=Subject:From:In-Reply-To:Date:Cc:References:To:From; b=BZ6uwuH5/US/mhnsa3WtQSYZ8DyxW7YBCQKKzFIiNyr7JQh+nb30nOtWnOYbU7mWG eGdoR2/YNiXtDfZVFue2AQ+vzfZ8sF0Eazspc//rfF7SujmaIzGNe4T2zC7nMQz7lM Z9DGT3pO3ip60eae1ZhijQ/IxvFtQ0oT1WBw10hy0k8zGuj7hIQ+ahRyQDop84IFmE +TbUcuCQF76pxbugu1dYw3FglenbuZrn6xqwO8IJlEjSaYhYzOaVVCDAWF/bGTfUWh sg0uvRc1MVKPmHN6FIYBLPlEw6kRcbh+KonWsNbyFXXYhB44CkJEQMwg1OK7WcVMGN I+wSZIGH6wasQ== Content-Type: text/plain; charset=utf-8 Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 (Mac OS X Mail 16.0 \(3864.300.41.1.7\)) Subject: Re: [PATCH v9 02/22] KVM: VMX: Initialize VM entry/exit FRED controls in vmcs_config From: Xin Li In-Reply-To: <81bb8149-45c7-472a-a240-46d43bd33b5d@linux.intel.com> Date: Thu, 22 Jan 2026 09:57:44 -0800 Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, linux-doc@vger.kernel.org, pbonzini@redhat.com, seanjc@google.com, corbet@lwn.net, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com, luto@kernel.org, peterz@infradead.org, andrew.cooper3@citrix.com, chao.gao@intel.com, hch@infradead.org, sohil.mehta@intel.com Content-Transfer-Encoding: quoted-printable Message-Id: <4FCC46DA-37E6-4C0A-ABDF-D1278502732C@zytor.com> References: <20251026201911.505204-1-xin@zytor.com> <20251026201911.505204-3-xin@zytor.com> <81bb8149-45c7-472a-a240-46d43bd33b5d@linux.intel.com> To: Binbin Wu X-Mailer: Apple Mail (2.3864.300.41.1.7) > On Jan 20, 2026, at 1:24=E2=80=AFAM, Binbin Wu = wrote: >=20 >>=20 >> Setup VM entry/exit FRED controls in the global vmcs_config for = proper >> FRED VMCS fields management: >> 1) load guest FRED state upon VM entry. >> 2) save guest FRED state during VM exit. >> 3) load host FRED state during VM exit. >>=20 >=20 > Nit: > I think it's worth noting that IA32_FRED_RSP0 and IA32_FRED_SSP0 are = treated > differently. The change log might need more context on which MSRs are > atomically switched in order to describe that though. I deliberately omitted this point, as I felt that mentioning special = cases would be a distraction within a patch intended for the common framework. In the overall patch series, this particular patch is like initially = claiming FRED simplifies virtualization state management, only to introduce = complexities in subsequent patches.=