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=-12.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,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 06767C433DF for ; Mon, 24 Aug 2020 09:06:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DE3C5207D3 for ; Mon, 24 Aug 2020 09:06:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728387AbgHXJGR (ORCPT ); Mon, 24 Aug 2020 05:06:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37574 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730550AbgHXI4a (ORCPT ); Mon, 24 Aug 2020 04:56:30 -0400 Received: from theia.8bytes.org (8bytes.org [IPv6:2a01:238:4383:600:38bc:a715:4b6d:a889]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B2B4FC061573; Mon, 24 Aug 2020 01:56:29 -0700 (PDT) Received: from cap.home.8bytes.org (p4ff2bb8d.dip0.t-ipconnect.de [79.242.187.141]) (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 DCC6F1007; Mon, 24 Aug 2020 10:56:21 +0200 (CEST) From: Joerg Roedel To: x86@kernel.org Cc: Joerg Roedel , Joerg Roedel , Tom Lendacky , hpa@zytor.com, Andy Lutomirski , Dave Hansen , Peter Zijlstra , Jiri Slaby , Dan Williams , Juergen Gross , Kees Cook , David Rientjes , Cfir Cohen , Erdem Aktas , Masami Hiramatsu , Mike Stunes , Sean Christopherson , Martin Radev , linux-kernel@vger.kernel.org, kvm@vger.kernel.org, virtualization@lists.linux-foundation.org Subject: [PATCH v6 57/76] x86/sev-es: Handle RDTSC(P) Events Date: Mon, 24 Aug 2020 10:54:52 +0200 Message-Id: <20200824085511.7553-58-joro@8bytes.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200824085511.7553-1-joro@8bytes.org> References: <20200824085511.7553-1-joro@8bytes.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Tom Lendacky Implement a handler for #VC exceptions caused by RDTSC and RDTSCP instructions. Also make it available in the pre-decompression stage because the KASLR code used RDTSC/RDTSCP to gather entropy and some hypervisors intercept these instructions. Signed-off-by: Tom Lendacky [ jroedel@suse.de: - Adapt to #VC handling infrastructure - Make it available early ] Co-developed-by: Joerg Roedel Signed-off-by: Joerg Roedel Link: https://lore.kernel.org/r/20200724160336.5435-57-joro@8bytes.org --- arch/x86/boot/compressed/sev-es.c | 4 ++++ arch/x86/kernel/sev-es-shared.c | 23 +++++++++++++++++++++++ arch/x86/kernel/sev-es.c | 4 ++++ 3 files changed, 31 insertions(+) diff --git a/arch/x86/boot/compressed/sev-es.c b/arch/x86/boot/compressed/sev-es.c index 851d7af29d79..1ce144e0ddc3 100644 --- a/arch/x86/boot/compressed/sev-es.c +++ b/arch/x86/boot/compressed/sev-es.c @@ -181,6 +181,10 @@ void do_boot_stage2_vc(struct pt_regs *regs, unsigned long exit_code) goto finish; switch (exit_code) { + case SVM_EXIT_RDTSC: + case SVM_EXIT_RDTSCP: + result = vc_handle_rdtsc(boot_ghcb, &ctxt, exit_code); + break; case SVM_EXIT_IOIO: result = vc_handle_ioio(boot_ghcb, &ctxt); break; diff --git a/arch/x86/kernel/sev-es-shared.c b/arch/x86/kernel/sev-es-shared.c index a6b41910b8ab..92d77b725ccb 100644 --- a/arch/x86/kernel/sev-es-shared.c +++ b/arch/x86/kernel/sev-es-shared.c @@ -467,3 +467,26 @@ static enum es_result vc_handle_cpuid(struct ghcb *ghcb, return ES_OK; } + +static enum es_result vc_handle_rdtsc(struct ghcb *ghcb, + struct es_em_ctxt *ctxt, + unsigned long exit_code) +{ + bool rdtscp = (exit_code == SVM_EXIT_RDTSCP); + enum es_result ret; + + ret = sev_es_ghcb_hv_call(ghcb, ctxt, exit_code, 0, 0); + if (ret != ES_OK) + return ret; + + if (!(ghcb_rax_is_valid(ghcb) && ghcb_rdx_is_valid(ghcb) && + (!rdtscp || ghcb_rcx_is_valid(ghcb)))) + return ES_VMM_ERROR; + + ctxt->regs->ax = ghcb->save.rax; + ctxt->regs->dx = ghcb->save.rdx; + if (rdtscp) + ctxt->regs->cx = ghcb->save.rcx; + + return ES_OK; +} diff --git a/arch/x86/kernel/sev-es.c b/arch/x86/kernel/sev-es.c index 2e83bbc330c9..0d8103a87ff1 100644 --- a/arch/x86/kernel/sev-es.c +++ b/arch/x86/kernel/sev-es.c @@ -866,6 +866,10 @@ 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_RDTSC: + case SVM_EXIT_RDTSCP: + result = vc_handle_rdtsc(ghcb, ctxt, exit_code); + break; case SVM_EXIT_CPUID: result = vc_handle_cpuid(ghcb, ctxt); break; -- 2.28.0