From nobody Wed Dec 17 21:27:30 2025 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 4AB35C41513 for ; Wed, 16 Aug 2023 08:27:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242890AbjHPI0o (ORCPT ); Wed, 16 Aug 2023 04:26:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52668 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242585AbjHPI02 (ORCPT ); Wed, 16 Aug 2023 04:26:28 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8858D1990; Wed, 16 Aug 2023 01:26:27 -0700 (PDT) Date: Wed, 16 Aug 2023 08:26:25 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1692174386; 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=D5Uo85dlChXiK1e7VOp+AQdIs8SHZzORk/Gf/7Po0gY=; b=vvzkT8cZIWvKKpoafhrHBB0EvECJqCy3HOtNKtHHGa5gtwOofoBYVJHrDjs+G2aQJWA5cs crX7U0GbrrKCtzflf2hYwqaR/VdK6jDHF7P1oLEoZUSD+l3IlSv6MReEOdwuYC4VXKZY8v Q//9heXPlibT9N5Mlhx9aqNHVL47QSjyMtofRDObBu5tCPwnVTvymDZg2zFvptlSIZkq4Q qlbBCBfpFXZo+EIvkjSzTIbgJTCv/RH19OOVS7dCfHeuCDjVm0RhfExIZoUkrWCod3JgFt Vx9eEXSrzn2d9pm/vyjYXHBfoAhMM0hlNx/ATRR3zbvi+GsNKt0QlWUAuEj6jQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1692174386; 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=D5Uo85dlChXiK1e7VOp+AQdIs8SHZzORk/Gf/7Po0gY=; b=KQeEmaEtXMLBxbkGf+kVuX1J/ONMEeazGLNhs+5NRyY1nUdZI0Ve9IjXibDf7VcgLM/PZi rkXM9RNBPrArUnCg== From: "tip-bot2 for Alexey Kardashevskiy" 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: Do not handle #VC for DR7 read/write Cc: Alexey Kardashevskiy , "Borislav Petkov (AMD)" , Carlos Bilbao , Tom Lendacky , Pankaj Gupta , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20230816022122.981998-1-aik@amd.com> References: <20230816022122.981998-1-aik@amd.com> MIME-Version: 1.0 Message-ID: <169217438542.27769.5398729789133595994.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: quoted-printable 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: e221804dad4e6fe3a0cf192ba3c42cd2f328bdac Gitweb: https://git.kernel.org/tip/e221804dad4e6fe3a0cf192ba3c42cd2f= 328bdac Author: Alexey Kardashevskiy AuthorDate: Wed, 16 Aug 2023 12:21:22 +10:00 Committer: Borislav Petkov (AMD) CommitterDate: Wed, 16 Aug 2023 10:13:42 +02:00 x86/sev: Do not handle #VC for DR7 read/write With MSR_AMD64_SEV_DEBUG_SWAP enabled, the guest is not expected to receive a #VC for reads or writes of DR7. Update the SNP_FEATURES_PRESENT mask with MSR_AMD64_SNP_DEBUG_SWAP so an SNP guest doesn't gracefully terminate during SNP feature negotiation if MSR_AMD64_SEV_DEBUG_SWAP is enabled. Since a guest is not expected to receive a #VC on DR7 accesses when MSR_AMD64_SEV_DEBUG_SWAP is enabled, return an error from the #VC handler in this situation. Signed-off-by: Alexey Kardashevskiy Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Carlos Bilbao Reviewed-by: Tom Lendacky Reviewed-by: Pankaj Gupta Link: https://lore.kernel.org/r/20230816022122.981998-1-aik@amd.com --- arch/x86/boot/compressed/sev.c | 2 +- arch/x86/kernel/sev.c | 6 ++++++ 2 files changed, 7 insertions(+), 1 deletion(-) diff --git a/arch/x86/boot/compressed/sev.c b/arch/x86/boot/compressed/sev.c index c3e343b..e83e710 100644 --- a/arch/x86/boot/compressed/sev.c +++ b/arch/x86/boot/compressed/sev.c @@ -365,7 +365,7 @@ static void enforce_vmpl0(void) * by the guest kernel. As and when a new feature is implemented in the * guest kernel, a corresponding bit should be added to the mask. */ -#define SNP_FEATURES_PRESENT (0) +#define SNP_FEATURES_PRESENT MSR_AMD64_SNP_DEBUG_SWAP =20 void snp_check_features(void) { diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c index 1ee7bed..d380c93 100644 --- a/arch/x86/kernel/sev.c +++ b/arch/x86/kernel/sev.c @@ -1575,6 +1575,9 @@ static enum es_result vc_handle_dr7_write(struct ghcb= *ghcb, long val, *reg =3D vc_insn_get_rm(ctxt); enum es_result ret; =20 + if (sev_status & MSR_AMD64_SNP_DEBUG_SWAP) + return ES_VMM_ERROR; + if (!reg) return ES_DECODE_FAILED; =20 @@ -1612,6 +1615,9 @@ static enum es_result vc_handle_dr7_read(struct ghcb = *ghcb, struct sev_es_runtime_data *data =3D this_cpu_read(runtime_data); long *reg =3D vc_insn_get_rm(ctxt); =20 + if (sev_status & MSR_AMD64_SNP_DEBUG_SWAP) + return ES_VMM_ERROR; + if (!reg) return ES_DECODE_FAILED;