From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.18]) (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 1A72232A3C3; Fri, 9 Jan 2026 14:09:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767967747; cv=none; b=GO6kW+SVxNNyk+GqnYqYMLtc09x79CksEclBSXlXiN/PiPFnQXycysiaovGqPhrK2NlbidinoYoC5j9+yoT8x6r6vFX5EciRsRivW9eYq7nlr7skcniJrw2OF9W6JNZbUQWa2TpyBeaglsC/24IiNSow0MhSE55y0Dwv5IYdJ8o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767967747; c=relaxed/simple; bh=b4wYY2R1JdGLlCq3kKGQld+574kqUBIfu6hg1mYSiBk=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=XFnjoRxAuwKpmqoQ+w2m45SKs6pgXWfpTHi6/DikL9Z3aUHevto75HBOrqA/3+TKGrMIqCBZprlf4LTrwt+WZalahkhn/c9YPQaLfXhGNW78CoqH0li6Vjm/2Xj4Kf2YjDzJCYCvy7fJj6cWBqnoexLX7XAekriHdFOx8ZzrCGk= 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=PasC6ArL; arc=none smtp.client-ip=198.175.65.18 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="PasC6ArL" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1767967745; x=1799503745; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=b4wYY2R1JdGLlCq3kKGQld+574kqUBIfu6hg1mYSiBk=; b=PasC6ArLtw2pNDvz9GXasyAv3mcBN8+6UqB7hOrQcqWMHW51ftMVEIXr EN+HvR6lxVI8UdPaw3HktxeQtRcjjtC9PyBFdWkHPiP74PyTyjqzJSJOA smSYAUPKDA1Uo25sYIX31ePAwFYm3z1xmonSJ62Kdlq0qYUTSuxQ+Ow0k lWDI2mdh6lnKjO0/m1EPsbhsBu+AlAglL/FCU0I5bG6zs/1HolHMGMPWa EpBtoRq4+fJdA6Zo7HJk4Qs8k+MCUfJlOwgFTOazwnYlJT5wupypTQ2Jm yE+pl2NxA+eCc5rRFRyrHB0xzRyZ6mhUMxZZO7UnVvF6+aKsgItZ9SU/6 g==; X-CSE-ConnectionGUID: J78KUbdTS0exo8VpSn37qg== X-CSE-MsgGUID: hG8UKUy+TVOj9iaMUyPofw== X-IronPort-AV: E=McAfee;i="6800,10657,11666"; a="69397843" X-IronPort-AV: E=Sophos;i="6.21,214,1763452800"; d="scan'208";a="69397843" Received: from orviesa001.jf.intel.com ([10.64.159.141]) by orvoesa110.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Jan 2026 06:09:05 -0800 X-CSE-ConnectionGUID: zUIYz8nPQZitrwQ/tr/n7A== X-CSE-MsgGUID: bwl7xQKPRguNw/TBzR7N5A== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.21,214,1763452800"; d="scan'208";a="240988683" Received: from xiaoyaol-hp-g830.ccr.corp.intel.com (HELO [10.124.240.173]) ([10.124.240.173]) by smtpauth.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Jan 2026 06:09:02 -0800 Message-ID: <288eaa68-7d4d-4c1b-ae70-419554d1d8f2@intel.com> Date: Fri, 9 Jan 2026 22:08:59 +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: [PATCH v3 3/4] KVM: nVMX: Disallow access to vmcs12 fields that aren't supported by "hardware" To: Sean Christopherson , Paolo Bonzini Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Chao Gao , Xin Li , Yosry Ahmed References: <20260109041523.1027323-1-seanjc@google.com> <20260109041523.1027323-4-seanjc@google.com> Content-Language: en-US From: Xiaoyao Li In-Reply-To: <20260109041523.1027323-4-seanjc@google.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 1/9/2026 12:15 PM, Sean Christopherson wrote: > diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c > index 61113ead3d7b..ac7a17560c8f 100644 > --- a/arch/x86/kvm/vmx/nested.c > +++ b/arch/x86/kvm/vmx/nested.c > @@ -111,6 +111,9 @@ static void init_vmcs_shadow_fields(void) > field <= GUEST_TR_AR_BYTES, > "Update vmcs12_write_any() to drop reserved bits from AR_BYTES"); > > + if (get_vmcs12_field_offset(field) < 0) > + continue; > + why shadow_read_only_fields[] doesn't need such guard? IIUC, copy_vmcs12_to_shadow() will VMWRITE shadowed readonly field even if it doesn't exist on the hardware?