From nobody Mon Oct 6 13:35:27 2025 Received: from mail-wr1-f74.google.com (mail-wr1-f74.google.com [209.85.221.74]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BC2462C15B3 for ; Tue, 22 Jul 2025 07:29:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.221.74 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753169395; cv=none; b=E8CGjOJrp0CFOjVkSEkfZ5GIyreZ+7w8V1vp3zV3ME8MxHUF3qxutjK1vJSyPXcuFtL98UsdSwtp1S6yXqItLURFJLZgHFg+xfF9KIJfTyATomVl1Wif3BLTNyuDiJMD57UV8FNUuxZSIcb4KN9YRJA2OF/1g8QbcX+hWj0zwnw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753169395; c=relaxed/simple; bh=JUHAkipg3EAWRigg95o0oDZv/aTDkXQTohagQF+Jgqw=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=EH11eB5uiyyGVOs5ZBYhZw1LlPnwj31Sr7prOisqUHFXpFQPVM2btD7baMWP5cvi5q4+q3MrrKLNPsiIH3CRcHn/E8b2EvWjaJIhQfOeVN3zlOjp5K5bFJgkLbARuzK3Y+XItT6SEETte3uoozgyLDc1rrXfGON6V4BNhTLVMTM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--ardb.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=CxxPdHVr; arc=none smtp.client-ip=209.85.221.74 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--ardb.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="CxxPdHVr" Received: by mail-wr1-f74.google.com with SMTP id ffacd0b85a97d-3a4eeed54c2so3313261f8f.3 for ; Tue, 22 Jul 2025 00:29:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1753169392; x=1753774192; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=Z3StoCFGTVKHcmu3it2Teel6mdHgsbdfG3fJy5aNQEI=; b=CxxPdHVrrqxBk9L2KutKAFrv6poY818kv4s0/pG9FYMo7bhbd/up62tk2tR8fKIoIl G+G81Eza+eLMUJRdbZcaOywLSI4Snp0JE/wvnCBBsvzjY+HM+QtbUntEN+ep/i7QCziD 4ULY9CFWMilV3A3fEYkjYuAeO+N5vqRT4ixytUcEwCNSmJv21UYm1P4C9/LwepUPE099 I7auX07tbZY4hrTruTV6oroVrODDZddPF64lVNHvXbJH54ntGoTgC2GuDESz8ZEBeKDe j9M08DRjR6x1PPIpdfWbrO5pMDQdY4tl895WpO3QUmqRaWH12QSx8gBR9JaSnSpiZFcO PzqQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1753169392; x=1753774192; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=Z3StoCFGTVKHcmu3it2Teel6mdHgsbdfG3fJy5aNQEI=; b=cnwTsCM2wEkvBV2akt/wa4wDDfpjmf74Q2wMxGBqyhaSydhDrlOa0B8ZePZ67QGoJO M+qPBZu6ctQ7CUMZCU0AxcfX1HpoDFWKXRr7hlVDjYG9M+Poj/aGwhGpsyiPdNlFdism xK43r8vH4MOnYnRLtDccT7BiGgSPckgEEfj7WVeMhghGItSyeEESzYiRn7C42EE7PPtC XNfnCeQRRgcv7NrE1bgfwz6YIO8HpOyzSNiYpd06424NXY8g02W7Mg94Aa/zxjF9RYoP rervEJQBW76L5k0ItEGQPt6/9ItYE7y945kYTJj2RjUUPA9ZlFgwL5yjrQyy+kXIfEIM wtzw== X-Gm-Message-State: AOJu0YyN6tEu0vcWbKug9gSaJO2VlOgqC3fadGIXW30Epv2JusWgoo/F t9YpXXMH2ZluPFYZqDQGm+Ve+RfYMI5zLnHvWoTkI8v+7jbLFFENqfODRYQpotpGyXVicw+fOa4 aSD/M2ymOAZMdt5bZKUYmpkvebks+tmrqago8HN/j/g8TkpMpQ0r0Zw2Hh1olj38kuYwsO0zibV aD2TmhRStWnbZhxTSKIZfa5UPtWrMAK1Q2Zg== X-Google-Smtp-Source: AGHT+IEA8ROGNkNmSHtQT4zFRMHm9eM6qEUhvSlk0z+MCALyHBYlA2/EZonoCvsLaHf3lJAKRK7RcgfX X-Received: from wrnl8.prod.google.com ([2002:adf:e9c8:0:b0:3a5:75f:1fb7]) (user=ardb job=prod-delivery.src-stubby-dispatcher) by 2002:a5d:5d0c:0:b0:3b6:463:d886 with SMTP id ffacd0b85a97d-3b60e4ccea6mr20386959f8f.20.1753169391932; Tue, 22 Jul 2025 00:29:51 -0700 (PDT) Date: Tue, 22 Jul 2025 09:27:11 +0200 In-Reply-To: <20250722072708.2079165-24-ardb+git@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20250722072708.2079165-24-ardb+git@google.com> X-Developer-Key: i=ardb@kernel.org; a=openpgp; fpr=F43D03328115A198C90016883D200E9CA6329909 X-Developer-Signature: v=1; a=openpgp-sha256; l=2215; i=ardb@kernel.org; h=from:subject; bh=cO87Xko990PxM0uCuqTN+gjd/OGjzTrbKtnIRx9uufk=; b=kA0DAAoWMG4JVi59LVwByyZiAGh/PVmhjv/xfnUVNnQmz3R4nT1oRIf0snLyTiTfh9k8oGqx4 Yh1BAAWCgAdFiEEEJv97rnLkRp9Q5odMG4JVi59LVwFAmh/PVkACgkQMG4JVi59LVzEggEAxPdz v4I5KJTZA1I8yjO2+ZZHz07pRMqeDB7XZCcFJM0A/0qLymr+h8gmCBl/Ei3vA7pZ3aAhdS0XQ2X DPTO9RSkF X-Mailer: git-send-email 2.50.0.727.gbf7dc18ff4-goog Message-ID: <20250722072708.2079165-26-ardb+git@google.com> Subject: [PATCH v6 02/22] x86/sev: Use MSR protocol for remapping SVSM calling area From: Ard Biesheuvel To: linux-kernel@vger.kernel.org Cc: linux-efi@vger.kernel.org, x86@kernel.org, Ard Biesheuvel , Borislav Petkov , Ingo Molnar , Kevin Loughlin , Tom Lendacky , Josh Poimboeuf , Peter Zijlstra , Nikunj A Dadhania Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Ard Biesheuvel As the preceding code comment already indicates, remapping the SVSM calling area occurs long before the GHCB page is configured, and so calling svsm_perform_call_protocol() is guaranteed to result in a call to svsm_perform_msr_protocol(). So just call the latter directly. This allows most of the GHCB based API infrastructure to be moved out of the startup code in a subsequent patch. Signed-off-by: Ard Biesheuvel Reviewed-by: Borislav Petkov (AMD) Reviewed-by: Tom Lendacky --- arch/x86/boot/startup/sev-shared.c | 11 +++++++++++ arch/x86/boot/startup/sev-startup.c | 5 ++--- 2 files changed, 13 insertions(+), 3 deletions(-) diff --git a/arch/x86/boot/startup/sev-shared.c b/arch/x86/boot/startup/sev= -shared.c index a1e211e0000c..4b958d03834b 100644 --- a/arch/x86/boot/startup/sev-shared.c +++ b/arch/x86/boot/startup/sev-shared.c @@ -724,6 +724,17 @@ static void __head setup_cpuid_table(const struct cc_b= lob_sev_info *cc_info) } } =20 +static int __head svsm_call_msr_protocol(struct svsm_call *call) +{ + int ret; + + do { + ret =3D svsm_perform_msr_protocol(call); + } while (ret =3D=3D -EAGAIN); + + return ret; +} + static void __head svsm_pval_4k_page(unsigned long paddr, bool validate) { struct svsm_pvalidate_call *pc; diff --git a/arch/x86/boot/startup/sev-startup.c b/arch/x86/boot/startup/se= v-startup.c index 0b7e3b950183..8412807a865c 100644 --- a/arch/x86/boot/startup/sev-startup.c +++ b/arch/x86/boot/startup/sev-startup.c @@ -295,7 +295,6 @@ static __head struct cc_blob_sev_info *find_cc_blob(str= uct boot_params *bp) static __head void svsm_setup(struct cc_blob_sev_info *cc_info) { struct svsm_call call =3D {}; - int ret; u64 pa; =20 /* @@ -325,8 +324,8 @@ static __head void svsm_setup(struct cc_blob_sev_info *= cc_info) call.caa =3D svsm_get_caa(); call.rax =3D SVSM_CORE_CALL(SVSM_CORE_REMAP_CA); call.rcx =3D pa; - ret =3D svsm_perform_call_protocol(&call); - if (ret) + + if (svsm_call_msr_protocol(&call)) sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_SVSM_CA_REMAP_FAIL); =20 boot_svsm_caa =3D (struct svsm_ca *)pa; --=20 2.50.0.727.gbf7dc18ff4-goog