From nobody Fri Dec 19 14:15:49 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 B9FD213B5A1 for ; Wed, 3 Jul 2024 08:55:10 +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=1719996913; cv=none; b=uhR7a6HrfpQdajI+Fn2C7ZZvLToJNMiSYx9wwWiJsUudfgBTEAgL1HVVAYzYEEKFKO4cK1OmDuAwtsSwY7HdvJ+LugMJ7fOIUiD6818Fnd17pfTL98XSkDpBe5DxW0D2aNqIkyhpguggzwe4tKHMm9w+kn2+oMQ9bgA+vJyFzjQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719996913; c=relaxed/simple; bh=kdikNib9x+eTgS5GaTuz0ap4G90ilWCwk8wef1VJOOQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=I/fjJ0QgKexqk1p1HqiYALIHMMcaH/crzC9wD6wugOY3a++Wlzg7ynAS7q8Hn+QVPHLY2bGrEigPl9nTP8M500gM71nAprFN/T7k6is22gtqGfE1140yMBlYb13KznlOU7pjIwkmfq23FUHOfSHep0guD3VlRZ07si/jqykjlnk= 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=RtTNXEpB; 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="RtTNXEpB" 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 4638sQ1A274819 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NO); Wed, 3 Jul 2024 01:54:34 -0700 DKIM-Filter: OpenDKIM Filter v2.11.0 mail.zytor.com 4638sQ1A274819 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zytor.com; s=2024061501; t=1719996874; bh=Ko+FE7nG9WBnR7O9m6WOO/3Vh122gx7NsoMXFF+ciuI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=RtTNXEpBkHFfKjaLaqu7V8zjxdM8U+AwvSJ12KTjjGK2DSCiYsKg/IiiGGfz2/hNf b4IUHgoRAMu65YQBkKdRjn7oOtgeO35pb9NuZ/XQCVbzJ+61YNi9rRl4G4Vi8b2mcc f3e6x2k0b/paIvlnlqbYbqhNVwdvWYnHXF2EGMq3yIxSk5/Deb/bKi1n3UCjjLNzQe Nnv/rzo9vGe8tVIArLjN+ns5B03Y/O00vMYzGHuaWrX7rEVyd9cQR7ljcnk0u6kGJO +NgTpmQuGW1sr9fyhrcN2ME8Q88HRs2nZroddv9GN6nsDifKnRDsXFYKVZ/n/eed3J gaOGn0svYavYA== 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 v1 4/4] x86/fred: Enable FRED right after init_mem_mapping() Date: Wed, 3 Jul 2024 01:54:26 -0700 Message-ID: <20240703085426.274801-5-xin@zytor.com> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240703085426.274801-1-xin@zytor.com> References: <20240703085426.274801-1-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 | 7 ++++++- arch/x86/kernel/smpboot.c | 6 ++++++ arch/x86/kernel/traps.c | 4 ++++ 4 files changed, 17 insertions(+), 6 deletions(-) diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 022ae4ba7997..8d454b6f7def 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..d866136a89ff 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 +1041,11 @@ void __init setup_arch(char **cmdline_p) =20 init_mem_mapping(); =20 - idt_setup_early_pf(); + /* Switch to FRED from early IDT ASAP */ + 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