From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 126C5FD7077 for ; Tue, 17 Mar 2026 10:45:28 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id C23E910E1ED; Tue, 17 Mar 2026 10:45:27 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="lcrdKgLX"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.13]) by gabe.freedesktop.org (Postfix) with ESMTPS id B929A10E1ED for ; Tue, 17 Mar 2026 10:45:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1773744327; x=1805280327; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=rchWW5a+2wWcJZRD+Xz4sWsrBBSKlG/inHusim50V38=; b=lcrdKgLXH7pOR9cgtPBAeGfRr1WdxtYBAglR2zKkDtC0U9HjxiFQgnr8 q9KBZhLoHX1Il2B7fPYjn6V7h+eRvue7StqxlbeXFm38NG8Boyc8B/7TQ Q1byn6QhCVNZzOd06PDhITLB6+kOBk651zbbJsQZHEy5Bq129GqIEVHsa UwqT6/L5BjeoqeIWkfdXjjV3xpJsLMa3Su6VJy6ySWXX4ycs0j73i44YS lQNzCPpYKCihrhzXxUYFldQUseyCY7zFVgKb4NuHhhbhRWYBVxZRGjJcb x04bWUOTJ5yTx/+DDKs+jQ/qZr+vJDEY08R1dVmvp8da62KFawpdLhM7s A==; X-CSE-ConnectionGUID: QrFo0zQTSaOmnMY2xaXCFA== X-CSE-MsgGUID: clBRXLYBSWuntlnVCcAf4g== X-IronPort-AV: E=McAfee;i="6800,10657,11731"; a="77382228" X-IronPort-AV: E=Sophos;i="6.23,124,1770624000"; d="scan'208";a="77382228" Received: from orviesa010.jf.intel.com ([10.64.159.150]) by fmvoesa107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Mar 2026 03:45:27 -0700 X-CSE-ConnectionGUID: WYVWxBfCSA6YeL3Kf3CIeg== X-CSE-MsgGUID: i/7bohZxQvGFo5MugMrFhQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.23,124,1770624000"; d="scan'208";a="221456845" Received: from egrumbac-mobl6.ger.corp.intel.com (HELO [10.245.245.147]) ([10.245.245.147]) by orviesa010-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Mar 2026 03:45:24 -0700 Message-ID: <80b5e2f3-88e4-44c6-84b2-1fae9444467e@intel.com> Date: Tue, 17 Mar 2026 10:45:22 +0000 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v6 2/2] drm/xe: Reject coh_none PAT index for CPU_ADDR_MIRROR To: Jia Yao , intel-xe@lists.freedesktop.org Cc: stable@vger.kernel.org, Shuicheng Lin , Mathew Alwin , Michal Mrozek , Matthew Brost References: <20260129000147.339361-1-jia.yao@intel.com> <20260316164253.262406-1-jia.yao@intel.com> <20260316164253.262406-3-jia.yao@intel.com> Content-Language: en-GB From: Matthew Auld In-Reply-To: <20260316164253.262406-3-jia.yao@intel.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-BeenThere: intel-xe@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel Xe graphics driver List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-xe-bounces@lists.freedesktop.org Sender: "Intel-xe" On 16/03/2026 16:42, Jia Yao wrote: > Add validation in xe_vm_bind_ioctl() to reject PAT indices with > XE_COH_NONE coherency mode when used with > DRM_XE_VM_BIND_FLAG_CPU_ADDR_MIRROR, consistent with the existing > validation for DRM_XE_VM_BIND_OP_MAP_USERPTR. > > CPU address mirror mappings use system memory which is CPU cached, > making them incompatible with COH_NONE PAT index. Using COH_NONE with > CPU cached buffers is a security issue: GPU can bypass CPU caches and > directly read stale sensitive data from DRAM, potentially leaking data > from previously freed pages. > > Although CPU_ADDR_MIRROR mappings don't create actual memory mappings > (the range is reserved for dynamic mapping on GPU page faults), the > underlying system memory is still CPU cached, so the same PAT coherency > restrictions as MAP_USERPTR should apply. > > v2: > - Correct fix tag > > Fixes: e1fbc4f18d5b ("drm/xe/uapi: support pat_index selection with vm_bind") I don't think addr_mirror existed yet? Maybe: Fixes: b43e864af0d4 ("drm/xe/uapi: Add DRM_XE_VM_BIND_FLAG_CPU_ADDR_MIRROR") Cc: # v6.15+ > Cc: stable@vger.kernel.org # v6.18 > Cc: Shuicheng Lin > Cc: Mathew Alwin > Cc: Michal Mrozek > Cc: Matthew Brost > Cc: Matthew Auld > Signed-off-by: Jia Yao > Reviewed-by: Matthew Auld > --- > drivers/gpu/drm/xe/xe_vm.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/xe/xe_vm.c b/drivers/gpu/drm/xe/xe_vm.c > index 5572e12c2a7e..1c4b4a5eeadb 100644 > --- a/drivers/gpu/drm/xe/xe_vm.c > +++ b/drivers/gpu/drm/xe/xe_vm.c > @@ -3491,7 +3491,7 @@ static int vm_bind_ioctl_check_args(struct xe_device *xe, struct xe_vm *vm, > XE_IOCTL_DBG(xe, obj && > op == DRM_XE_VM_BIND_OP_MAP_USERPTR) || > XE_IOCTL_DBG(xe, coh_mode == XE_COH_NONE && > - op == DRM_XE_VM_BIND_OP_MAP_USERPTR) || > + (op == DRM_XE_VM_BIND_OP_MAP_USERPTR || is_cpu_addr_mirror)) || > XE_IOCTL_DBG(xe, comp_en && > op == DRM_XE_VM_BIND_OP_MAP_USERPTR) || > XE_IOCTL_DBG(xe, op == DRM_XE_VM_BIND_OP_MAP_USERPTR &&