From nobody Fri Dec 19 04:52:21 2025 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E4446CA0EEB for ; Tue, 12 Sep 2023 15:32:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236524AbjILPcj (ORCPT ); Tue, 12 Sep 2023 11:32:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49850 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236416AbjILPcK (ORCPT ); Tue, 12 Sep 2023 11:32:10 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 14B6810E5; Tue, 12 Sep 2023 08:32:07 -0700 (PDT) Date: Tue, 12 Sep 2023 15:32:04 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1694532725; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=MdHqwe5s0tlMo1gtm11NLrpTwCjp+Y3BpZCJRKfsNFI=; b=wHWH4jjFNd/SIYHZWftOBWpeS4f7NiXxPR/O+tyCYLXUP1+j5hCLKgkDKPeD1AC5gWbqLJ s0XltDnX1NlGBoBjF+i8Qy8v/J9IpwV5BMPuQEl3vteGTrI90C3dNaiq98L9QIuprIuynj HMgugUPCqPUe2KS4mYGRLOK/rpENiXevCwGOMB3mciAMzNsdaoxEFjV0X1xoX25q4wm1e2 RH7LwsXkqw7stHBnBOzhh1/VHjNNt0zG+TsQ1lDFwzJhx66x2IlcbuTj4jItM+nvwPPk9V A0YLWK9iA7yWa+GllTwTG8NyfDtmqxcjFMFSwkFcJT8shZv2X1Dq4CZmYNc3Tg== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1694532725; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=MdHqwe5s0tlMo1gtm11NLrpTwCjp+Y3BpZCJRKfsNFI=; b=WfIV75LOYRMl/I7eZl5pBI4jtxoyhLyF1MRqsc8mpkY/llw9+t1vj2Dnf9UFsCNgk1FVcc VDPBo/36DbDHb3AQ== From: "tip-bot2 for Kai Huang" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: x86/tdx] x86/tdx: Zero out the missing RSI in TDX_HYPERCALL macro Cc: Kai Huang , Dave Hansen , Kuppuswamy Sathyanarayanan , "Kirill A. Shutemov" , "Peter Zijlstra (Intel)" , x86@kernel.org, linux-kernel@vger.kernel.org MIME-Version: 1.0 Message-ID: <169453272495.27769.4055377041051736661.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The following commit has been merged into the x86/tdx branch of tip: Commit-ID: 5d092b66119d774853cc9308522620299048a662 Gitweb: https://git.kernel.org/tip/5d092b66119d774853cc9308522620299= 048a662 Author: Kai Huang AuthorDate: Tue, 15 Aug 2023 23:01:55 +12:00 Committer: Dave Hansen CommitterDate: Mon, 11 Sep 2023 16:31:52 -07:00 x86/tdx: Zero out the missing RSI in TDX_HYPERCALL macro In the TDX_HYPERCALL asm, after the TDCALL instruction returns from the untrusted VMM, the registers that the TDX guest shares to the VMM need to be cleared to avoid speculative execution of VMM-provided values. RSI is specified in the bitmap of those registers, but it is missing when zeroing out those registers in the current TDX_HYPERCALL. It was there when it was originally added in commit 752d13305c78 ("x86/tdx: Expand __tdx_hypercall() to handle more arguments"), but was later removed in commit 1e70c680375a ("x86/tdx: Do not corrupt frame-pointer in __tdx_hypercall()"), which was correct because %rsi is later restored in the "pop %rsi". However a later commit 7a3a401874be ("x86/tdx: Drop flags from __tdx_hypercall()") removed that "pop %rsi" but forgot to add the "xor %rsi, %rsi" back. Fix by adding it back. Fixes: 7a3a401874be ("x86/tdx: Drop flags from __tdx_hypercall()") Signed-off-by: Kai Huang Signed-off-by: Dave Hansen Reviewed-by: Kuppuswamy Sathyanarayanan Reviewed-by: Kirill A. Shutemov Acked-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/all/e7d1157074a0b45d34564d5f17f3e0ffee8115e9.= 1692096753.git.kai.huang%40intel.com --- arch/x86/coco/tdx/tdcall.S | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/x86/coco/tdx/tdcall.S b/arch/x86/coco/tdx/tdcall.S index b193c0a..2eca5f4 100644 --- a/arch/x86/coco/tdx/tdcall.S +++ b/arch/x86/coco/tdx/tdcall.S @@ -195,6 +195,7 @@ SYM_FUNC_END(__tdx_module_call) xor %r10d, %r10d xor %r11d, %r11d xor %rdi, %rdi + xor %rsi, %rsi xor %rdx, %rdx =20 /* Restore callee-saved GPRs as mandated by the x86_64 ABI */