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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 6395AC07E9D for ; Mon, 5 Jul 2021 08:26:24 +0000 (UTC) Received: from smtp1.osuosl.org (smtp1.osuosl.org [140.211.166.138]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 23BF6613F6 for ; Mon, 5 Jul 2021 08:26:24 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 23BF6613F6 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=8bytes.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=virtualization-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by smtp1.osuosl.org (Postfix) with ESMTP id F0B0783A7A; Mon, 5 Jul 2021 08:26:23 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp1.osuosl.org ([127.0.0.1]) by localhost (smtp1.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id zPHXIBU7asgN; Mon, 5 Jul 2021 08:26:23 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by smtp1.osuosl.org (Postfix) with ESMTPS id 74A1983A75; Mon, 5 Jul 2021 08:26:22 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 52F96C0029; Mon, 5 Jul 2021 08:26:22 +0000 (UTC) Received: from smtp1.osuosl.org (smtp1.osuosl.org [140.211.166.138]) by lists.linuxfoundation.org (Postfix) with ESMTP id 9082FC002E for ; Mon, 5 Jul 2021 08:26:20 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp1.osuosl.org (Postfix) with ESMTP id 80CEC83A4D for ; Mon, 5 Jul 2021 08:26:20 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp1.osuosl.org ([127.0.0.1]) by localhost (smtp1.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id tu4_uztyA0RM for ; Mon, 5 Jul 2021 08:26:20 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.8.0 Received: from theia.8bytes.org (8bytes.org [IPv6:2a01:238:4383:600:38bc:a715:4b6d:a889]) by smtp1.osuosl.org (Postfix) with ESMTPS id A807383A53 for ; Mon, 5 Jul 2021 08:26:19 +0000 (UTC) Received: from cap.home.8bytes.org (p5b006775.dip0.t-ipconnect.de [91.0.103.117]) (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 324D5694; Mon, 5 Jul 2021 10:26:15 +0200 (CEST) From: Joerg Roedel To: x86@kernel.org Subject: [RFC PATCH 05/12] x86/sev: Use GHCB protocol version 2 if supported Date: Mon, 5 Jul 2021 10:24:36 +0200 Message-Id: <20210705082443.14721-6-joro@8bytes.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210705082443.14721-1-joro@8bytes.org> References: <20210705082443.14721-1-joro@8bytes.org> MIME-Version: 1.0 Cc: kvm@vger.kernel.org, Peter Zijlstra , Dave Hansen , virtualization@lists.linux-foundation.org, Arvind Sankar , hpa@zytor.com, Jiri Slaby , Joerg Roedel , David Rientjes , Martin Radev , Tom Lendacky , Joerg Roedel , Kees Cook , Cfir Cohen , linux-coco@lists.linux.dev, Andy Lutomirski , Dan Williams , Juergen Gross , Mike Stunes , Sean Christopherson , linux-kernel@vger.kernel.org, Masami Hiramatsu , Erdem Aktas X-BeenThere: virtualization@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Linux virtualization List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: virtualization-bounces@lists.linux-foundation.org Sender: "Virtualization" From: Joerg Roedel Check whether the hypervisor supports GHCB version 2 and use it if available. Signed-off-by: Joerg Roedel --- arch/x86/boot/compressed/sev.c | 10 ++++++++-- arch/x86/include/asm/sev.h | 4 ++-- arch/x86/kernel/sev-shared.c | 17 ++++++++++++++--- 3 files changed, 24 insertions(+), 7 deletions(-) diff --git a/arch/x86/boot/compressed/sev.c b/arch/x86/boot/compressed/sev.c index 101e08c67296..7f8416f76be7 100644 --- a/arch/x86/boot/compressed/sev.c +++ b/arch/x86/boot/compressed/sev.c @@ -119,16 +119,22 @@ static enum es_result vc_read_mem(struct es_em_ctxt *ctxt, /* Include code for early handlers */ #include "../../kernel/sev-shared.c" +static unsigned int ghcb_protocol; + static u64 sev_get_ghcb_proto_ver(void) { - return GHCB_PROTOCOL_MAX; + return ghcb_protocol; } static bool early_setup_sev_es(void) { - if (!sev_es_negotiate_protocol(NULL)) + struct sev_ghcb_protocol_info info; + + if (!sev_es_negotiate_protocol(&info)) sev_es_terminate(GHCB_SEV_ES_REASON_PROTOCOL_UNSUPPORTED); + ghcb_protocol = info.vm_proto; + if (set_page_decrypted((unsigned long)&boot_ghcb_page)) return false; diff --git a/arch/x86/include/asm/sev.h b/arch/x86/include/asm/sev.h index fa5cd05d3b5b..134a7c9d91b6 100644 --- a/arch/x86/include/asm/sev.h +++ b/arch/x86/include/asm/sev.h @@ -12,8 +12,8 @@ #include #include -#define GHCB_PROTO_OUR 0x0001UL -#define GHCB_PROTOCOL_MAX 1ULL +#define GHCB_PROTOCOL_MIN 1ULL +#define GHCB_PROTOCOL_MAX 2ULL #define GHCB_DEFAULT_USAGE 0ULL #define VMGEXIT() { asm volatile("rep; vmmcall\n\r"); } diff --git a/arch/x86/kernel/sev-shared.c b/arch/x86/kernel/sev-shared.c index 36eaac2773ed..40a1ca81bdb8 100644 --- a/arch/x86/kernel/sev-shared.c +++ b/arch/x86/kernel/sev-shared.c @@ -61,6 +61,7 @@ static void __noreturn sev_es_terminate(unsigned int reason) static bool sev_es_negotiate_protocol(struct sev_ghcb_protocol_info *info) { + unsigned int protocol; u64 val; /* Do the GHCB protocol version negotiation */ @@ -71,14 +72,24 @@ static bool sev_es_negotiate_protocol(struct sev_ghcb_protocol_info *info) if (GHCB_MSR_INFO(val) != GHCB_MSR_SEV_INFO_RESP) return false; - if (GHCB_MSR_PROTO_MAX(val) < GHCB_PROTO_OUR || - GHCB_MSR_PROTO_MIN(val) > GHCB_PROTO_OUR) + /* Sanity check untrusted input */ + if (GHCB_MSR_PROTO_MIN(val) > GHCB_MSR_PROTO_MAX(val)) + return false; + + /* Use maximum supported protocol version */ + protocol = min_t(unsigned int, GHCB_MSR_PROTO_MAX(val), GHCB_PROTOCOL_MAX); + + /* + * Hypervisor does not support any protocol version required for this + * kernel. + */ + if (protocol < GHCB_MSR_PROTO_MIN(val)) return false; if (info) { info->hv_proto_min = GHCB_MSR_PROTO_MIN(val); info->hv_proto_max = GHCB_MSR_PROTO_MAX(val); - info->vm_proto = GHCB_PROTO_OUR; + info->vm_proto = protocol; } return true; -- 2.31.1 _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization