From nobody Fri Dec 19 14:14:04 2025 Received: from mail.zytor.com (terminus.zytor.com [198.137.202.136]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3777119D8A4 for ; Tue, 9 Jul 2024 15:41:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.136 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720539695; cv=none; b=hNXTdBi9WNZa6F53CPu3kiVh2I3zSqrLJK7F5lJ3JQq6/cD03wCe2sQrRzQpENGjUZZGkcvI+suqpNnDRh3ZudH2JiXlEt7+mep12swvuFmBcypdzdlp7Sw5NfTgMgVYRUbs20s5u47IepNmvZwPpdnjBqiEu3KggerKYYgvqi4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720539695; c=relaxed/simple; bh=O8ek/YwTIjQFtI7v9g9Gq5ZPtEmuNrIJkMOoJPqId2E=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=S3rprksukCXY9jzURbcSlB1lkJEAwhvsHQ4dvXrZiimT/Pjdz9y1Xvhps3zwOfn8wz7MgpaLGJS8dRkweEu78yIGcyg84MdAaJ08ftze2pZRqxkvQtAeJ9GoGzF9t4G+Gr1msEjCaQyx2FLPh3XF2N32154zajfi0SZdAwuzqDc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zytor.com; spf=pass smtp.mailfrom=zytor.com; dkim=pass (2048-bit key) header.d=zytor.com header.i=@zytor.com header.b=TKKM5aCs; arc=none smtp.client-ip=198.137.202.136 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zytor.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=zytor.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=zytor.com header.i=@zytor.com header.b="TKKM5aCs" Received: from terminus.zytor.com (terminus.zytor.com [IPv6:2607:7c80:54:3:0:0:0:136]) (authenticated bits=0) by mail.zytor.com (8.17.2/8.17.1) with ESMTPSA id 469FemH33543378 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NO); Tue, 9 Jul 2024 08:41:02 -0700 DKIM-Filter: OpenDKIM Filter v2.11.0 mail.zytor.com 469FemH33543378 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zytor.com; s=2024061501; t=1720539663; bh=qfun97Jg+BIQEJ3LYgyV2vxqbqRdLnKMxvQ2b7HT42I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TKKM5aCs0rovstLABu+Hh7Y4R9pFBlfuWr7lfH4ZYBDA8YESDYVjdPXO89ne0bMP6 koyDpyIbjmDsYyHxOAJHJv886LbfK4QWcrnL7ezBSZ1QzbWrOxTlfd76mu1jzLvbsY C/qUIhdxjPjIjZA+pLqsv9c+eAc04xWY5V2GN/J1gNDLuIvzlpZq6Kx5N/DQaXAqDi sIGdlnBL5ZA5OF9d9slUqH6xqObxaMXsdyJCsnQlZj5YFEhwVqQcubn422zhWG9Osy gUk5G0UF5+oGgMndoAXAKbJBR9k6rRG/r9GuUn2foMnN2qlC92nkd/EEoxawJU9+r9 gu3uUdHe21rGg== From: "Xin Li (Intel)" To: linux-kernel@vger.kernel.org Cc: hpa@zytor.com, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, peterz@infradead.org, andrew.cooper3@citrix.com, nik.borisov@suse.com, houwenlong.hwl@antgroup.com Subject: [PATCH v2 3/3] x86/fred: Enable FRED right after init_mem_mapping() Date: Tue, 9 Jul 2024 08:40:48 -0700 Message-ID: <20240709154048.3543361-4-xin@zytor.com> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240709154048.3543361-1-xin@zytor.com> References: <20240709154048.3543361-1-xin@zytor.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Enable FRED right after init_mem_mapping() to avoid #PF handler, exc_page_fault(), fetching its faulting address from the stack before FRED is enabled. Fixes: 14619d912b65 ("x86/fred: FRED entry/exit and dispatch code") Reported-by: Hou Wenlong Suggested-by: Thomas Gleixner Signed-off-by: Xin Li (Intel) --- arch/x86/kernel/cpu/common.c | 6 +----- arch/x86/kernel/setup.c | 11 ++++++++++- arch/x86/kernel/smpboot.c | 6 ++++++ arch/x86/kernel/traps.c | 4 ++++ 4 files changed, 21 insertions(+), 6 deletions(-) diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 6de12b3c1b04..42d4136ed6ac 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -2195,12 +2195,8 @@ void cpu_init_exception_handling(void) /* GHCB needs to be setup to handle #VC. */ setup_ghcb(); =20 - if (cpu_feature_enabled(X86_FEATURE_FRED)) { - cpu_init_fred_exceptions(); - cpu_init_fred_rsps(); - } else { + if (!cpu_feature_enabled(X86_FEATURE_FRED)) load_current_idt(); - } } =20 /* diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index 728927e4ba51..36403b901eb2 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -39,6 +39,7 @@ #include #include #include +#include #include #include #include @@ -1040,7 +1041,15 @@ void __init setup_arch(char **cmdline_p) =20 init_mem_mapping(); =20 - idt_setup_early_pf(); + /* + * init_mem_mapping() uses early IDT to setup memory mappings, thus FRED + * can't be enabled earlier than that, unless FRED adds support to setup + * memory mappings. + */ + if (cpu_feature_enabled(X86_FEATURE_FRED)) + cpu_init_fred_exceptions(); + else + idt_setup_early_pf(); =20 /* * Update mmu_cr4_features (and, indirectly, trampoline_cr4_features) diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index 0c35207320cb..0d83377f9dcd 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -64,6 +64,7 @@ #include #include #include +#include #include #include #include @@ -248,6 +249,11 @@ static void notrace start_secondary(void *unused) =20 cpu_init_exception_handling(); =20 + if (cpu_feature_enabled(X86_FEATURE_FRED)) { + cpu_init_fred_exceptions(); + cpu_init_fred_rsps(); + } + /* * Load the microcode before reaching the AP alive synchronization * point below so it is not part of the full per CPU serialized diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index 6afb41e6cbbb..81648bd07576 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -1407,6 +1407,10 @@ void __init trap_init(void) /* Init cpu_entry_area before IST entries are set up */ setup_cpu_entry_areas(); =20 + /* FRED RSPs pointing to memory from CPU entry areas */ + if (cpu_feature_enabled(X86_FEATURE_FRED)) + cpu_init_fred_rsps(); + /* Init GHCB memory pages when running as an SEV-ES guest */ sev_es_init_vc_handling(); =20 --=20 2.45.2