From patchwork Wed May 19 13:52:51 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Joerg Roedel X-Patchwork-Id: 12267393 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 72F97C433B4 for ; Wed, 19 May 2021 13:53:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 568D06100C for ; Wed, 19 May 2021 13:53:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1353829AbhESNyj (ORCPT ); Wed, 19 May 2021 09:54:39 -0400 Received: from 8bytes.org ([81.169.241.247]:40240 "EHLO theia.8bytes.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1353786AbhESNye (ORCPT ); Wed, 19 May 2021 09:54:34 -0400 Received: from cap.home.8bytes.org (p549ad305.dip0.t-ipconnect.de [84.154.211.5]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (No client certificate requested) by theia.8bytes.org (Postfix) with ESMTPSA id 7FCAC50F; Wed, 19 May 2021 15:53:12 +0200 (CEST) From: Joerg Roedel To: x86@kernel.org, Hyunwook Baek Cc: Joerg Roedel , Joerg Roedel , hpa@zytor.com, Andy Lutomirski , Dave Hansen , Peter Zijlstra , Jiri Slaby , Dan Williams , Tom Lendacky , Juergen Gross , Kees Cook , David Rientjes , Cfir Cohen , Erdem Aktas , Masami Hiramatsu , Mike Stunes , Sean Christopherson , Martin Radev , Arvind Sankar , linux-coco@lists.linux.dev, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, virtualization@lists.linux-foundation.org Subject: [PATCH v2 8/8] x86/sev-es: Propagate #GP if getting linear instruction address failed Date: Wed, 19 May 2021 15:52:51 +0200 Message-Id: <20210519135251.30093-9-joro@8bytes.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210519135251.30093-1-joro@8bytes.org> References: <20210519135251.30093-1-joro@8bytes.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: Joerg Roedel When an instruction is fetched from user-space, segmentation needs to be taken into account. This means that getting the linear address of an instruction can fail. Hardware would raise a #GP exception in that case, but the #VC exception handler would emulate it as a page-fault. The insn_fetch_from_user*() functions now provide the relevant information in case of an failure. Use that and propagate a #GP when the linear address of an instruction to fetch could not be calculated. Signed-off-by: Joerg Roedel --- arch/x86/kernel/sev.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c index 1edb6cd5e308..4736290361e4 100644 --- a/arch/x86/kernel/sev.c +++ b/arch/x86/kernel/sev.c @@ -261,11 +261,16 @@ static enum es_result __vc_decode_user_insn(struct es_em_ctxt *ctxt) int insn_bytes = 0, res; res = insn_fetch_from_user_inatomic(ctxt->regs, buffer, &insn_bytes); - if (res) { + if (res == -EFAULT) { ctxt->fi.vector = X86_TRAP_PF; ctxt->fi.error_code = X86_PF_INSTR | X86_PF_USER; ctxt->fi.cr2 = ctxt->regs->ip; return ES_EXCEPTION; + } else if (res == -EINVAL) { + ctxt->fi.vector = X86_TRAP_GP; + ctxt->fi.error_code = 0; + ctxt->fi.cr2 = 0; + return ES_EXCEPTION; } if (!insn_decode_from_regs(&ctxt->insn, ctxt->regs, buffer, insn_bytes))