From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.10]) (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 E1742466B73; Fri, 5 Jun 2026 07:08:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.10 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780643334; cv=none; b=UOGrDOxUbDFn4js85qA4Wv6xbO+zKRTstepenriws/O+dGPZlzu6VFbwzd8/KF+A87ydngBx2rGVrmNoaF7+ESfbC3K/i99I63rXdb4Zqu6VsItUlLze4Q7slR5iShyiub8L4qSItf2PAixnhZ66OLIC5Zo0MvOpaXLamBNW9Cs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780643334; c=relaxed/simple; bh=QLYgE3faB0Y4ODsuMCvTJ5m9OPKO6/YajYcQVTdZyvc=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=LubZnyFNVSFm0WKvmBNgLAYy358RuiSsRXpzo6jJPiTPjwRulooDlALCIGNZKr+M9nVZiGoVdzCtUjkxZKr0W7TuuzvQyzuoJFN74wmKIFDkk6BhFRtrA+tahIwXiEoaMLuvlf0Pz1cpIz0joVKAncWSPwGK5OenbBjrZJhjeP0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=pass smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=XAYxB+ba; arc=none smtp.client-ip=192.198.163.10 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="XAYxB+ba" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1780643332; x=1812179332; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=QLYgE3faB0Y4ODsuMCvTJ5m9OPKO6/YajYcQVTdZyvc=; b=XAYxB+ba01yS/bRteA3g4WUmi1Sn2OHivwNEXko3Q4M0Hbf7RRl7+Kg2 fYsc0toIDGY1Cseux1lsirchyyQbAqGoKndDruzE+rn3XkWLk9dLtsmm+ /DRPDLpFkWokK1l9rlyh5POXtCy3ShUXEFvukEcaA6sGFA8GP2O3O6Xex JnUNRDkF9KSvfz0IlG1UpiSuBa9dZ83EhnX7s+BZSDDf/8BXgbtCLADJl jNlcOyY2XafzR20ruzGy0tXsZNKQJhWuLbTInAZOmHypcaVxQ4Albj2FO PSAEyTYm2pZeA+zSTZXF6DyCQwxKSdosZqoPYmfQXLnc/cqm6usrfd+0e A==; X-CSE-ConnectionGUID: Of5pXinwTzG4tIoG1Wtacw== X-CSE-MsgGUID: Qrkby6PuSaSSil/Lwf6UhQ== X-IronPort-AV: E=McAfee;i="6800,10657,11807"; a="92850545" X-IronPort-AV: E=Sophos;i="6.24,188,1774335600"; d="scan'208";a="92850545" Received: from fmviesa001.fm.intel.com ([10.60.135.141]) by fmvoesa104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Jun 2026 00:08:51 -0700 X-CSE-ConnectionGUID: a8p7PPSQRjyJvTMi1Hb8lw== X-CSE-MsgGUID: 2HkUb3ZhR06wlAk7DXrOzQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.24,188,1774335600"; d="scan'208";a="268701891" Received: from binbinwu-mobl.ccr.corp.intel.com (HELO [10.124.241.59]) ([10.124.241.59]) by smtpauth.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Jun 2026 00:08:46 -0700 Message-ID: Date: Fri, 5 Jun 2026 15:08:44 +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 v4 1/3] x86/tdx: Fix off-by-one in port I/O handling To: "Kiryl Shutsemau (Meta)" Cc: tglx@kernel.org, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, seanjc@google.com, pbonzini@redhat.com, sathyanarayanan.kuppuswamy@linux.intel.com, kai.huang@intel.com, xiaoyao.li@intel.com, rick.p.edgecombe@intel.com, david.laight.linux@gmail.com, ak@linux.intel.com, djbw@kernel.org, tsyrulnikov.borys@gmail.com, x86@kernel.org, kvm@vger.kernel.org, linux-coco@lists.linux.dev, linux-kernel@vger.kernel.org, stable@vger.kernel.org References: Content-Language: en-US From: Binbin Wu In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 6/4/2026 10:46 PM, Kiryl Shutsemau (Meta) wrote: > handle_in() and handle_out() in arch/x86/coco/tdx/tdx.c use: > > u64 mask = GENMASK(BITS_PER_BYTE * size, 0); > > GENMASK(h, l) includes bit h. For size=1 (INB), this produces > GENMASK(8, 0) = 0x1FF (9 bits) instead of GENMASK(7, 0) = 0xFF (8 > bits). The mask is one bit too wide for all I/O sizes. > > Fix the mask calculation. > > Fixes: 03149948832a ("x86/tdx: Port I/O: Add runtime hypercalls") > Reported-by: Borys Tsyrulnikov > Link: https://lore.kernel.org/all/CAKw_Dz96rfSQc6Rn+9QBcUFHhmkK+9zu+P=bxowfZwxrATCBRg@mail.gmail.com/ > Signed-off-by: Kiryl Shutsemau (Meta) > Reviewed-by: Kai Huang > Reviewed-by: Kuppuswamy Sathyanarayanan > Cc: stable@vger.kernel.org Reviewed-by: Binbin Wu > --- > arch/x86/coco/tdx/tdx.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/arch/x86/coco/tdx/tdx.c b/arch/x86/coco/tdx/tdx.c > index 186915a17c50..65119362f9a2 100644 > --- a/arch/x86/coco/tdx/tdx.c > +++ b/arch/x86/coco/tdx/tdx.c > @@ -693,7 +693,7 @@ static bool handle_in(struct pt_regs *regs, int size, int port) > .r13 = PORT_READ, > .r14 = port, > }; > - u64 mask = GENMASK(BITS_PER_BYTE * size, 0); > + u64 mask = GENMASK(BITS_PER_BYTE * size - 1, 0); > bool success; > > /* > @@ -713,7 +713,7 @@ static bool handle_in(struct pt_regs *regs, int size, int port) > > static bool handle_out(struct pt_regs *regs, int size, int port) > { > - u64 mask = GENMASK(BITS_PER_BYTE * size, 0); > + u64 mask = GENMASK(BITS_PER_BYTE * size - 1, 0); > > /* > * Emulate the I/O write via hypercall. More info about ABI can be found