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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B2CEFC433F5 for ; Fri, 8 Apr 2022 09:15:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232685AbiDHJRC (ORCPT ); Fri, 8 Apr 2022 05:17:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42676 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233099AbiDHJMG (ORCPT ); Fri, 8 Apr 2022 05:12:06 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D47371252B6; Fri, 8 Apr 2022 02:09:12 -0700 (PDT) Date: Fri, 08 Apr 2022 09:09:09 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1649408950; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=VL6W8xBiAHENLUziclyBl/sRfCmbPUlf8MEowg+MPJM=; b=nYfny0ToDDymeUnREkvUVKXoHwdXvLiHmnD/fhJT2Vm4rNagYxC32woSrbcq21nSgkFTuR s0rY2SNnw7oeVcHl92QFEyALVdc3tIsJvkizKFB0r55t7nFZdsIUtQ4DoEV3vny46TjGLC RUpA4Y6W3hvipOZ6bbJA83CfUiigsHE5ZEnktuMCjXca+lEVUNC5ubgFSW+PHA9Qdz8gU/ YhPZiE65hRWzRWmGUjqp+EKLCrMJpwhnOKUjNnWvBhDeDu3bIdYGi6vrEwIEDh1l+6j17C xwfVdU9lb6PiiTuEf0iifIV2MbQr1sePLJTIDtvaIBzhFjhBmEdirPYPhJsc5g== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1649408950; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=VL6W8xBiAHENLUziclyBl/sRfCmbPUlf8MEowg+MPJM=; b=htfL/VAQiV+Lp2+9pX4M264J9X0iIyIAdGY078wpIiMHJ1rELY2qtkWKT+Twybk2F+8e77 j7bHrs81/j5knDDw== From: "tip-bot2 for Brijesh Singh" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: x86/sev] x86/sev: Save the negotiated GHCB version Cc: Brijesh Singh , Borislav Petkov , Venu Busireddy , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20220307213356.2797205-12-brijesh.singh@amd.com> References: <20220307213356.2797205-12-brijesh.singh@amd.com> MIME-Version: 1.0 Message-ID: <164940894981.389.4710155959955476545.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The following commit has been merged into the x86/sev branch of tip: Commit-ID: 2ea29c5abbc27147c2d9e2ab5e05436aca706b65 Gitweb: https://git.kernel.org/tip/2ea29c5abbc27147c2d9e2ab5e05436aca706b65 Author: Brijesh Singh AuthorDate: Wed, 09 Feb 2022 12:10:05 -06:00 Committer: Borislav Petkov CommitterDate: Wed, 06 Apr 2022 13:10:18 +02:00 x86/sev: Save the negotiated GHCB version The SEV-ES guest calls sev_es_negotiate_protocol() to negotiate the GHCB protocol version before establishing the GHCB. Cache the negotiated GHCB version so that it can be used later. Signed-off-by: Brijesh Singh Signed-off-by: Borislav Petkov Reviewed-by: Venu Busireddy Link: https://lore.kernel.org/r/20220307213356.2797205-12-brijesh.singh@amd.com --- arch/x86/include/asm/sev.h | 2 +- arch/x86/kernel/sev-shared.c | 17 ++++++++++++++--- 2 files changed, 15 insertions(+), 4 deletions(-) diff --git a/arch/x86/include/asm/sev.h b/arch/x86/include/asm/sev.h index ec060c4..9b9c190 100644 --- a/arch/x86/include/asm/sev.h +++ b/arch/x86/include/asm/sev.h @@ -12,7 +12,7 @@ #include #include -#define GHCB_PROTO_OUR 0x0001UL +#define GHCB_PROTOCOL_MIN 1ULL #define GHCB_PROTOCOL_MAX 1ULL #define GHCB_DEFAULT_USAGE 0ULL diff --git a/arch/x86/kernel/sev-shared.c b/arch/x86/kernel/sev-shared.c index 2abf8a7..91105f5 100644 --- a/arch/x86/kernel/sev-shared.c +++ b/arch/x86/kernel/sev-shared.c @@ -14,6 +14,15 @@ #define has_cpuflag(f) boot_cpu_has(f) #endif +/* + * Since feature negotiation related variables are set early in the boot + * process they must reside in the .data section so as not to be zeroed + * out when the .bss section is later cleared. + * + * GHCB protocol version negotiated with the hypervisor. + */ +static u16 ghcb_version __ro_after_init; + static bool __init sev_es_check_cpu_features(void) { if (!has_cpuflag(X86_FEATURE_RDRAND)) { @@ -51,10 +60,12 @@ static bool sev_es_negotiate_protocol(void) 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) + if (GHCB_MSR_PROTO_MAX(val) < GHCB_PROTOCOL_MIN || + GHCB_MSR_PROTO_MIN(val) > GHCB_PROTOCOL_MAX) return false; + ghcb_version = min_t(size_t, GHCB_MSR_PROTO_MAX(val), GHCB_PROTOCOL_MAX); + return true; } @@ -127,7 +138,7 @@ enum es_result sev_es_ghcb_hv_call(struct ghcb *ghcb, bool set_ghcb_msr, u64 exit_info_1, u64 exit_info_2) { /* Fill in protocol and format specifiers */ - ghcb->protocol_version = GHCB_PROTOCOL_MAX; + ghcb->protocol_version = ghcb_version; ghcb->ghcb_usage = GHCB_DEFAULT_USAGE; ghcb_set_sw_exit_code(ghcb, exit_code);