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 0DEF2215075; Thu, 5 Mar 2026 17:10:03 +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=1772730605; cv=none; b=dhMHDiplVXLQpbXOwO5o2QN2KS6Vb+hY20HeY4RnA4JzwzAj5E5AxOszxUTeZO74hWi8juxSLT8NZx4NK5Zp/YvRI7sCyWavA8Dh/UFG+oOmghnTaZLc6c68dHwBLyCC9asg7z9GnzBImLK5AMWN2BSyao4iRGpG+pAUy4q9u/A= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772730605; c=relaxed/simple; bh=RfT0f7vWA2mrexhTtUJsQeiXxCqLubDPU4wLv5jwW1M=; h=Content-Type:Mime-Version:Subject:From:In-Reply-To:Date:Cc: Message-Id:References:To; b=joOnADr4SIH/BjDiMB3IMGP4u8pXxRQIjXZggHxO5yJtYiDmQBvJosFCoktghCHJN7BTXudeuNIKjSO0l2Jpm53KzH2pLDiJi3mVAELwQCEJ4zST3lER0+jPjz/LkpZFksgNgejk1KjgkShOGlEptLoPElM9aqHd9G0NMkFUDR0= 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=aM7XMe3Y; 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="aM7XMe3Y" 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 625H9J2E3494905 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Thu, 5 Mar 2026 09:09:19 -0800 DKIM-Filter: OpenDKIM Filter v2.11.0 mail.zytor.com 625H9J2E3494905 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zytor.com; s=2026022301; t=1772730560; bh=+1y5MvbjQL4jaYiB+MHx6KKMMG1bQpE5wCYGmarD9Uw=; h=Subject:From:In-Reply-To:Date:Cc:References:To:From; b=aM7XMe3Y1sDknDpx0TJimpHX98NwEYNxWVd4j87Ona8HCjHxe7L1Y4b6XVAX38GG8 dzFjxQGPCM+CAU9lUIfO+46rErEm9n62AdC5z6Sy0c+eLgSlI7tUzMcRTF9wylya58 xeMtJ5iDNklEFF+iYkqP4qsc0gUWS9qVLvAbjYGoGtVCgMHVVwIeOuGgH3PCUuYXvh vdyXB75RCZ9CxLEEJvVq5UWV9aWA7Nu7tc29yBrjvArTZcI7MI9Rhp9QVTnu5P/zs8 gcWZua364pcUWcFdjvl5f/K9NEWyinOsouZquUlXAEa8Td449AmNuKgE/7WqmO/YOh 0mdE1R0cqFDxA== 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 \(3864.400.21\)) Subject: Re: [PATCH v9 15/22] KVM: x86: Mark CR4.FRED as not reserved From: Xin Li In-Reply-To: Date: Thu, 5 Mar 2026 09:09:08 -0800 Cc: Chao Gao , linux-kernel@vger.kernel.org, kvm@vger.kernel.org, linux-doc@vger.kernel.org, pbonzini@redhat.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, hch@infradead.org, sohil.mehta@intel.com Content-Transfer-Encoding: quoted-printable Message-Id: References: <20251026201911.505204-1-xin@zytor.com> <20251026201911.505204-16-xin@zytor.com> <263F364B-D516-40B3-B065-A5369BFB1A7F@zytor.com> To: Sean Christopherson X-Mailer: Apple Mail (2.3864.400.21) >> I planned to send out these new kvm unit tests (not just FRED tests) = after >> KVM FRED patch series gets merged. >=20 > Definitely send them before. Even if no one outside of Intel can run = them (I > forget when FRED hardware is coming), people like me can at least see = what you're > testing, which makes it more likely that we'll spot bugs. E.g. in = this case, the > lack of negative tests for CR4.FRED is a big red flag. No excuse, sadly mk_cr_64() completely escaped my notice. And I didn=E2=80=99t even think about adding a CR4 test for FRED. And as you expected, the happy path doesn=E2=80=99t expose it at all.