From patchwork Tue Apr 28 15:17:13 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Joerg Roedel X-Patchwork-Id: 11514873 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 1D1B51575 for ; Tue, 28 Apr 2020 15:19:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 01CE4218AC for ; Tue, 28 Apr 2020 15:19:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728445AbgD1PST (ORCPT ); Tue, 28 Apr 2020 11:18:19 -0400 Received: from 8bytes.org ([81.169.241.247]:37910 "EHLO theia.8bytes.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728413AbgD1PSS (ORCPT ); Tue, 28 Apr 2020 11:18:18 -0400 Received: by theia.8bytes.org (Postfix, from userid 1000) id 6BC3EF42; Tue, 28 Apr 2020 17:17:54 +0200 (CEST) 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 , David Rientjes , Cfir Cohen , Erdem Aktas , Masami Hiramatsu , Mike Stunes , Joerg Roedel , Joerg Roedel , linux-kernel@vger.kernel.org, kvm@vger.kernel.org, virtualization@lists.linux-foundation.org Subject: [PATCH v3 63/75] x86/sev-es: Handle #DB Events Date: Tue, 28 Apr 2020 17:17:13 +0200 Message-Id: <20200428151725.31091-64-joro@8bytes.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200428151725.31091-1-joro@8bytes.org> References: <20200428151725.31091-1-joro@8bytes.org> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: Joerg Roedel Handle #VC exceptions caused by #DB exceptions in the guest. Do not forward them to the hypervisor and handle them with do_debug() instead. Signed-off-by: Joerg Roedel --- arch/x86/kernel/sev-es.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/arch/x86/kernel/sev-es.c b/arch/x86/kernel/sev-es.c index 050a15da9ae5..03095bc7b563 100644 --- a/arch/x86/kernel/sev-es.c +++ b/arch/x86/kernel/sev-es.c @@ -882,6 +882,19 @@ static enum es_result vc_handle_trap_ac(struct ghcb *ghcb, return ES_EXCEPTION; } +static enum es_result vc_handle_trap_db(struct ghcb *ghcb, + struct es_em_ctxt *ctxt) +{ + /* + * Calling do_debug() directly does not work, because it might enable + * IRQs and the GHCB is active. Forward the exception and call it later + * from vc_forward_exception(). + */ + ctxt->fi.vector = X86_TRAP_DB; + ctxt->fi.error_code = 0; + return ES_EXCEPTION; +} + static enum es_result vc_handle_exitcode(struct es_em_ctxt *ctxt, struct ghcb *ghcb, unsigned long exit_code) @@ -895,6 +908,9 @@ static enum es_result vc_handle_exitcode(struct es_em_ctxt *ctxt, case SVM_EXIT_WRITE_DR7: result = vc_handle_dr7_write(ghcb, ctxt); break; + case SVM_EXIT_EXCP_BASE + X86_TRAP_DB: + result = vc_handle_trap_db(ghcb, ctxt); + break; case SVM_EXIT_EXCP_BASE + X86_TRAP_AC: result = vc_handle_trap_ac(ghcb, ctxt); break; @@ -960,6 +976,9 @@ static void vc_forward_exception(struct es_em_ctxt *ctxt) case X86_TRAP_AC: do_alignment_check(ctxt->regs, error_code); break; + case X86_TRAP_DB: + do_debug(ctxt->regs, error_code); + break; default: pr_emerg("Unsupported exception in #VC instruction emulation - can't continue\n"); BUG();