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=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 6829CC07E98 for ; Mon, 5 Jul 2021 08:28:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3C373613F6 for ; Mon, 5 Jul 2021 08:28:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230226AbhGEI3G (ORCPT ); Mon, 5 Jul 2021 04:29:06 -0400 Received: from 8bytes.org ([81.169.241.247]:58948 "EHLO theia.8bytes.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230063AbhGEI2x (ORCPT ); Mon, 5 Jul 2021 04:28:53 -0400 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 EB77253F; Mon, 5 Jul 2021 10:26:13 +0200 (CEST) From: Joerg Roedel To: x86@kernel.org 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: [RFC PATCH 03/12] x86/sev: Save and print negotiated GHCB protocol version Date: Mon, 5 Jul 2021 10:24:34 +0200 Message-Id: <20210705082443.14721-4-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 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Joerg Roedel Save the results of the GHCB protocol negotiation into a data structure and print information about versions supported and used to the kernel log. Signed-off-by: Joerg Roedel --- arch/x86/boot/compressed/sev.c | 2 +- arch/x86/kernel/sev-shared.c | 22 +++++++++++++++++++++- arch/x86/kernel/sev.c | 13 ++++++++++++- 3 files changed, 34 insertions(+), 3 deletions(-) diff --git a/arch/x86/boot/compressed/sev.c b/arch/x86/boot/compressed/sev.c index 670e998fe930..1a2e49730f8b 100644 --- a/arch/x86/boot/compressed/sev.c +++ b/arch/x86/boot/compressed/sev.c @@ -121,7 +121,7 @@ static enum es_result vc_read_mem(struct es_em_ctxt *ctxt, static bool early_setup_sev_es(void) { - if (!sev_es_negotiate_protocol()) + if (!sev_es_negotiate_protocol(NULL)) sev_es_terminate(GHCB_SEV_ES_REASON_PROTOCOL_UNSUPPORTED); if (set_page_decrypted((unsigned long)&boot_ghcb_page)) diff --git a/arch/x86/kernel/sev-shared.c b/arch/x86/kernel/sev-shared.c index 9f90f460a28c..73eeb5897d16 100644 --- a/arch/x86/kernel/sev-shared.c +++ b/arch/x86/kernel/sev-shared.c @@ -14,6 +14,20 @@ #define has_cpuflag(f) boot_cpu_has(f) #endif +/* + * struct sev_ghcb_protocol_info - Used to return GHCB protocol + * negotiation details. + * + * @hv_proto_min: Minimum GHCB protocol version supported by Hypervisor + * @hv_proto_max: Maximum GHCB protocol version supported by Hypervisor + * @vm_proto: Protocol version the VM (this kernel) will use + */ +struct sev_ghcb_protocol_info { + unsigned int hv_proto_min; + unsigned int hv_proto_max; + unsigned int vm_proto; +}; + static bool __init sev_es_check_cpu_features(void) { if (!has_cpuflag(X86_FEATURE_RDRAND)) { @@ -42,7 +56,7 @@ static void __noreturn sev_es_terminate(unsigned int reason) asm volatile("hlt\n" : : : "memory"); } -static bool sev_es_negotiate_protocol(void) +static bool sev_es_negotiate_protocol(struct sev_ghcb_protocol_info *info) { u64 val; @@ -58,6 +72,12 @@ static bool sev_es_negotiate_protocol(void) GHCB_MSR_PROTO_MIN(val) > GHCB_PROTO_OUR) 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; + } + return true; } diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c index a6895e440bc3..8084bfd7cce1 100644 --- a/arch/x86/kernel/sev.c +++ b/arch/x86/kernel/sev.c @@ -495,6 +495,9 @@ static enum es_result vc_slow_virt_to_phys(struct ghcb *ghcb, struct es_em_ctxt /* Include code shared with pre-decompression boot stage */ #include "sev-shared.c" +/* Negotiated GHCB protocol version */ +static struct sev_ghcb_protocol_info ghcb_protocol_info __ro_after_init; + static noinstr void __sev_put_ghcb(struct ghcb_state *state) { struct sev_es_runtime_data *data; @@ -665,7 +668,7 @@ static enum es_result vc_handle_msr(struct ghcb *ghcb, struct es_em_ctxt *ctxt) static bool __init sev_es_setup_ghcb(void) { /* First make sure the hypervisor talks a supported protocol. */ - if (!sev_es_negotiate_protocol()) + if (!sev_es_negotiate_protocol(&ghcb_protocol_info)) return false; /* @@ -794,6 +797,14 @@ void __init sev_es_init_vc_handling(void) /* Secondary CPUs use the runtime #VC handler */ initial_vc_handler = (unsigned long)kernel_exc_vmm_communication; + + /* + * Print information about supported and negotiated GHCB protocol + * versions. + */ + pr_info("Hypervisor GHCB protocol version support: min=%u max=%u\n", + ghcb_protocol_info.hv_proto_min, ghcb_protocol_info.hv_proto_max); + pr_info("Using GHCB protocol version %u\n", ghcb_protocol_info.vm_proto); } static void __init vc_early_forward_exception(struct es_em_ctxt *ctxt) -- 2.31.1