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 X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 ECC29C3B186 for ; Tue, 11 Feb 2020 13:53:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B7DBB2467A for ; Tue, 11 Feb 2020 13:53:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729656AbgBKNxf (ORCPT ); Tue, 11 Feb 2020 08:53:35 -0500 Received: from 8bytes.org ([81.169.241.247]:52306 "EHLO theia.8bytes.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729551AbgBKNx0 (ORCPT ); Tue, 11 Feb 2020 08:53:26 -0500 Received: by theia.8bytes.org (Postfix, from userid 1000) id 5E10CE85; Tue, 11 Feb 2020 14:53:14 +0100 (CET) From: Joerg Roedel To: x86@kernel.org Cc: hpa@zytor.com, Andy Lutomirski , Dave Hansen , Peter Zijlstra , Thomas Hellstrom , Jiri Slaby , Dan Williams , Tom Lendacky , Juergen Gross , Kees Cook , linux-kernel@vger.kernel.org, kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, Joerg Roedel , Joerg Roedel Subject: [PATCH 40/62] x86/sev-es: Filter exceptions not supported from user-space Date: Tue, 11 Feb 2020 14:52:34 +0100 Message-Id: <20200211135256.24617-41-joro@8bytes.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200211135256.24617-1-joro@8bytes.org> References: <20200211135256.24617-1-joro@8bytes.org> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Joerg Roedel Currently only CPUID caused #VC exceptions are supported from user-space. Filter the others out early. Signed-off-by: Joerg Roedel --- arch/x86/kernel/sev-es.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) diff --git a/arch/x86/kernel/sev-es.c b/arch/x86/kernel/sev-es.c index d128a9397639..84b5b8f7897a 100644 --- a/arch/x86/kernel/sev-es.c +++ b/arch/x86/kernel/sev-es.c @@ -209,6 +209,26 @@ static enum es_result handle_vc_exception(struct es_em_ctxt *ctxt, return result; } +static enum es_result context_filter(struct pt_regs *regs, long exit_code) +{ + enum es_result r = ES_OK; + + if (user_mode(regs)) { + switch (exit_code) { + /* List of #VC exit-codes we support in user-space */ + case SVM_EXIT_EXCP_BASE ... SVM_EXIT_LAST_EXCP: + case SVM_EXIT_CPUID: + r = ES_OK; + break; + default: + r = ES_UNSUPPORTED; + break; + } + } + + return r; +} + static void forward_exception(struct es_em_ctxt *ctxt) { long error_code = ctxt->fi.error_code; @@ -245,6 +265,10 @@ dotraplinkage void do_vmm_communication(struct pt_regs *regs, unsigned long exit ghcb_invalidate(ghcb); result = init_em_ctxt(&ctxt, regs, exit_code); + /* Check if the exception is supported in the context we came from. */ + if (result == ES_OK) + result = context_filter(regs, exit_code); + if (result == ES_OK) result = handle_vc_exception(&ctxt, ghcb, exit_code); -- 2.17.1