From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-dy1-f173.google.com (mail-dy1-f173.google.com [74.125.82.173]) (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 0A0F840587D for ; Fri, 15 May 2026 21:15:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.82.173 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778879749; cv=none; b=Jizehj2pwgDo/DuNZyQXw9z06CLAfv43tB7b0C/XSfobx2rEP/WExHWvj87lAl2N8ife8oejxqeyWBunUZH6BnLgPRaXwHL3vc2lTqWT6Jq1N0KLQ+xvR9Q9HWuSObkyhROeL+2lkJLvgY8KCR4fTmx2rtHPktN/kcNcn5ok/cI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778879749; c=relaxed/simple; bh=lguMqdiHzuRecBR+f+YcsvaeXBnj2IIKNWDOALqRyPk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=INLU1dwh3qdw8ULjRx4nwKPYrA6syoPwNe5iPSxQwXTQNJQ9PLHxhPpJ2RT/PIuDsDwSDjFOknSqwfnWxZnPstFPPyFaSFJJntLMxhf1qOFZRwqPgWeRUn4PB52NRWMXk3GSkGX3U24AELVM9SdU66jXy9jcZ9UHrxLOb+6gOVE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=nFwAoLTA; arc=none smtp.client-ip=74.125.82.173 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="nFwAoLTA" Received: by mail-dy1-f173.google.com with SMTP id 5a478bee46e88-2f0d3e07e30so1355420eec.0 for ; Fri, 15 May 2026 14:15:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1778879747; x=1779484547; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=ermZy1JOQ3bL4uNXgDw9lpn60RTdyK+Y6D8PtSjZ40A=; b=nFwAoLTAbT7PoWVgyyHu35oq2IRVVhfS4E0QjEF1jxxk3+8W3gaGB2vDJEiOOSLh5A X/vBzlFR6FDEZCWJgpNFj4PHD+cV+GdutZ9vrrNjHAhv3S8fX3vZu3fhx12trXfDrucw duR9WF4Nn01rYoO8l0OI7+tDlascPxdTYkKWwGIUOBmWCrolTdhBR56/FWlR4eEIutmw dVgkA6d6aru1RY5UaH4dDyf1Hf2z+6jadRvaF4/pGC61SPzwXBIaCEK+YgLFCvNV5r+3 tzhIRonpBTyVqNyndhGoYYkHToCzkIJclu1Akesu8dT0yrZzp9q6nMGZImUrLsJyeJoS 4P7g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1778879747; x=1779484547; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=ermZy1JOQ3bL4uNXgDw9lpn60RTdyK+Y6D8PtSjZ40A=; b=fHELEwjlXcOe75qZVWIOiAZG+ju3XaIRsrgL9lHaVC1VnbbKiBzhpl5h5GYUMOj1E2 inY4a72c7YU2gjTPdhX/DIX73PuF4f5uim27SoRyNl7SXBxBvWnphW3t1tFjmLcqoH2B ycolKAZWpjOWvYAtFc5Z2ggzjNEtbDye+Q2O7hdQur7kuUpWulMnzrs1BVEFdc9b/vw3 l2l6aIIA14LuQr45QYdZ9fgZGJc5X74eeDOWB7PVa3xPXB8qM2DIwzdKK1bfx5urzCgW MvWEwCbes3hF5vB0kk/kffVa794nJ4DfxjJ3ZNlg9hA0o2jiTVXI8Y3u1JxmAehICDCX DZNw== X-Gm-Message-State: AOJu0YxGVOsV+aDbYiEkBSAG3MnzOB055aKTDxUltP9XSDEcEsxYSuCK Csf3W7CtL6hfTNetmXNUEoUZw5W7WL8nuKgPiLZvYXKbEgPgJip2jlzJhQjTZdz2 X-Gm-Gg: Acq92OFvE121lmR+89S9XkIFCp00wrGMo/u06s4MoJaXbLk8CrPPB7RAY0g3SZe4CCx 8JujG08zw23ljfWoMJa0qGAryIbbEq0/ed4361vjeetqygg/mZHcBsdo+o02S/VRtkRlTLykZoe dPdz9oMhseGNePMiaUeLsjT9h3X1LWPSLsQnyPNRJvcBVhMuYojCLAWo0bNbE0equFIIGq0RFBa svYOHeLZk2lmHEu+EJNz1ql0ronNanMBII7h+IioiOijFY13YqtsPqX1X+zOgtQJvkEs5wc1KUc 8hPbQS6vBfmbJkZngcWrCKBuZErtvBNfQd8/xDFXtMTtOi2tGw+MsaguNOsrRgAy36i+t8Yhusm xbJizm+AFGbvvUQqZ+q7QhqTmASfmrO3/w8oSRms3IQ42ThiN+ccmexdsfc7niYRCw3m4ybxAY1 0ATjr1lQMhV5QdC5Dgf2isLCYNb7+1h7M4hWPUPu0TQA== X-Received: by 2002:a05:7300:d706:b0:2d3:f43c:d684 with SMTP id 5a478bee46e88-30398191408mr2749976eec.2.1778879746758; Fri, 15 May 2026 14:15:46 -0700 (PDT) Received: from mimas.lan ([2603:8000:df01:38f7:a6bb:6dff:fecf:e71a]) by smtp.gmail.com with ESMTPSA id 5a478bee46e88-30293e2e69esm9916134eec.1.2026.05.15.14.15.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 15 May 2026 14:15:46 -0700 (PDT) From: Ross Philipson To: linux-kernel@vger.kernel.org, x86@kernel.org, linux-integrity@vger.kernel.org, linux-doc@vger.kernel.org, linux-crypto@vger.kernel.org, kexec@lists.infradead.org, linux-efi@vger.kernel.org, iommu@lists.linux.dev Cc: ross.philipson@gmail.com, dpsmith@apertussolutions.com, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, hpa@zytor.com, dave.hansen@linux.intel.com, ardb@kernel.org, mjg59@srcf.ucam.org, James.Bottomley@hansenpartnership.com, peterhuewe@gmx.de, jarkko@kernel.org, jgg@ziepe.ca, luto@amacapital.net, nivedita@alum.mit.edu, herbert@gondor.apana.org.au, davem@davemloft.net, corbet@lwn.net, ebiederm@xmission.com, dwmw2@infradead.org, baolu.lu@linux.intel.com, kanth.ghatraju@oracle.com, daniel.kiper@oracle.com, andrew.cooper3@citrix.com, trenchboot-devel@googlegroups.com Subject: [PATCH v16 33/38] x86/slaunch: Secure Launch SMP bringup support Date: Fri, 15 May 2026 14:14:05 -0700 Message-ID: <20260515211410.31440-34-ross.philipson@gmail.com> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260515211410.31440-1-ross.philipson@gmail.com> References: <20260515211410.31440-1-ross.philipson@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit On Intel, the APs are left in a well documented state after TXT performs the secure launch. Specifically, they cannot have #INIT asserted on them so a standard startup via INIT/SIPI/SIPI cannot be performed. Instead the early SL stub code uses MONITOR and MWAIT to park the APs. The realmode/init.c code updates the jump address for the waiting APs with the location of the Secure Launch entry point in the rmpiggy image. The rmpiggy image is a payload contained in the kernel used to start the APs (in 16b or 32b modes). It is loaded at runtime so its location and entry point must be updated in the long jump for the waiting APs by the running kernel. As the APs are woken up by writing the monitor, the APs jump to the Secure Launch entry point in the rmpiggy which mimics what the real mode code would do then jumps to the standard rmpiggy protected mode entry point. Co-developed-by: Daniel P. Smith Signed-off-by: Daniel P. Smith Signed-off-by: Ross Philipson --- arch/x86/include/asm/realmode.h | 3 ++ arch/x86/kernel/slaunch.c | 26 +++++++++++++++ arch/x86/kernel/smpboot.c | 47 ++++++++++++++++++++++++++-- arch/x86/realmode/init.c | 8 +++++ arch/x86/realmode/rm/header.S | 3 ++ arch/x86/realmode/rm/trampoline_64.S | 32 +++++++++++++++++++ 6 files changed, 117 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/realmode.h b/arch/x86/include/asm/realmode.h index e406a1e92c63..e3336c49d26b 100644 --- a/arch/x86/include/asm/realmode.h +++ b/arch/x86/include/asm/realmode.h @@ -38,6 +38,9 @@ struct real_mode_header { #ifdef CONFIG_X86_64 u32 machine_real_restart_seg; #endif +#ifdef CONFIG_SECURE_LAUNCH + u32 sl_trampoline_start32; +#endif }; /* This must match data at realmode/rm/trampoline_{32,64}.S */ diff --git a/arch/x86/kernel/slaunch.c b/arch/x86/kernel/slaunch.c index 0179ff855b62..f6e6f1b7e18c 100644 --- a/arch/x86/kernel/slaunch.c +++ b/arch/x86/kernel/slaunch.c @@ -511,3 +511,29 @@ void __init slaunch_setup(void) if (boot_cpu_has(X86_FEATURE_SMX)) slaunch_setup_txt(); } + +/* + * After a launch, the APs are woken up, enter the DRTM and are left to + * wait for a wakeup call on a MONITOR address. The block where they are + * idle has a long jump to the AP startup code in the mainline kernel. + * This address has to be calculated at runtime and "fixed up" to point + * to the SL startup location in the rmpiggy SMP startup image. This image + * is loaded into separate memory at kernel start time. + */ +void __init slaunch_fixup_ap_wake_vector(void) +{ + struct sl_ap_wake_info *ap_wake_info; + u32 *ap_jmp_ptr; + + if (!slaunch_is_txt_launch()) + return; + + ap_wake_info = slaunch_get_ap_wake_info(); + + ap_jmp_ptr = (u32 *)__va(ap_wake_info->ap_wake_block + + ap_wake_info->ap_jmp_offset); + + *ap_jmp_ptr = real_mode_header->sl_trampoline_start32; + + pr_info("TXT AP startup vector address updated\n"); +} diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index 294a8ea60298..16a0f2718a38 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -61,6 +61,7 @@ #include #include #include +#include #include #include @@ -989,6 +990,45 @@ int common_cpu_up(unsigned int cpu, struct task_struct *idle) return 0; } +#if (IS_ENABLED(CONFIG_SECURE_LAUNCH)) + +/* + * TXT AP startup is quite different than normal. The APs cannot have #INIT + * asserted on them or receive SIPIs. The early Secure Launch code has parked + * the APs using MONITOR/MWAIT in the safe AP wake block area (details in + * sl_stub.S). The SMP boot will wake the APs by writing the MONITOR associated + * with the AP and have them jump to the protected mode code in the rmpiggy where + * the rest of the SMP boot of the AP will proceed normally. + * + * Intel Trusted Execution Technology (TXT) Software Development Guide + * Section 2.3 - MLE Initialization + */ +static void slaunch_wakeup_cpu_from_txt(int cpu, int apicid) +{ + struct sl_ap_stack_and_monitor *stack_monitor; + struct sl_ap_wake_info *ap_wake_info; + + ap_wake_info = slaunch_get_ap_wake_info(); + + stack_monitor = (struct sl_ap_stack_and_monitor *)__va(ap_wake_info->ap_wake_block + + ap_wake_info->ap_stacks_offset); + + for (unsigned int i = SL_MAX_CPUS - 1; i >= 0; i--) { + if (stack_monitor[i].apicid == apicid) { + stack_monitor[i].monitor = 1; + break; + } + } +} + +#else + +static inline void slaunch_wakeup_cpu_from_txt(int cpu, int apicid) +{ +} + +#endif /* IS_ENABLED(CONFIG_SECURE_LAUNCH) */ + /* * NOTE - on most systems this is a PHYSICAL apic ID, but on multiquad * (ie clustered apic addressing mode), this is a LOGICAL apic ID. @@ -998,7 +1038,7 @@ int common_cpu_up(unsigned int cpu, struct task_struct *idle) static int do_boot_cpu(u32 apicid, unsigned int cpu, struct task_struct *idle) { unsigned long start_ip = real_mode_header->trampoline_start; - int ret; + int ret = 0; #ifdef CONFIG_X86_64 /* If 64-bit wakeup method exists, use the 64-bit mode trampoline IP */ @@ -1043,12 +1083,15 @@ static int do_boot_cpu(u32 apicid, unsigned int cpu, struct task_struct *idle) /* * Wake up a CPU in difference cases: + * - Intel TXT DRTM launch uses its own method to wake the APs * - Use a method from the APIC driver if one defined, with wakeup * straight to 64-bit mode preferred over wakeup to RM. * Otherwise, * - Use an INIT boot APIC message */ - if (apic->wakeup_secondary_cpu_64) + if (slaunch_is_txt_launch()) + slaunch_wakeup_cpu_from_txt(cpu, apicid); + else if (apic->wakeup_secondary_cpu_64) ret = apic->wakeup_secondary_cpu_64(apicid, start_ip, cpu); else if (apic->wakeup_secondary_cpu) ret = apic->wakeup_secondary_cpu(apicid, start_ip, cpu); diff --git a/arch/x86/realmode/init.c b/arch/x86/realmode/init.c index 88be32026768..ded4dafc6a0a 100644 --- a/arch/x86/realmode/init.c +++ b/arch/x86/realmode/init.c @@ -4,6 +4,7 @@ #include #include #include +#include #include #include @@ -213,6 +214,13 @@ void __init init_real_mode(void) setup_real_mode(); set_real_mode_permissions(); + + /* + * If Secure Launch is active, it will use the rmpiggy to do the TXT AP + * startup. Secure Launch has its own entry stub in the rmpiggy and this prepares + * it for SMP boot. + */ + slaunch_fixup_ap_wake_vector(); } static int __init do_init_real_mode(void) diff --git a/arch/x86/realmode/rm/header.S b/arch/x86/realmode/rm/header.S index 2eb62be6d256..3b5cbcbbfc90 100644 --- a/arch/x86/realmode/rm/header.S +++ b/arch/x86/realmode/rm/header.S @@ -37,6 +37,9 @@ SYM_DATA_START(real_mode_header) #ifdef CONFIG_X86_64 .long __KERNEL32_CS #endif +#ifdef CONFIG_SECURE_LAUNCH + .long pa_sl_trampoline_start32 +#endif SYM_DATA_END(real_mode_header) /* End signature, used to verify integrity */ diff --git a/arch/x86/realmode/rm/trampoline_64.S b/arch/x86/realmode/rm/trampoline_64.S index 14d9c7daf90f..b0ce6205d7ea 100644 --- a/arch/x86/realmode/rm/trampoline_64.S +++ b/arch/x86/realmode/rm/trampoline_64.S @@ -122,6 +122,38 @@ SYM_CODE_END(sev_es_trampoline_start) .section ".text32","ax" .code32 +#ifdef CONFIG_SECURE_LAUNCH + .balign 4 +SYM_CODE_START(sl_trampoline_start32) + /* + * The early secure launch stub AP wakeup code has taken care of all + * the vagaries of launching out of TXT. This bit just mimics what the + * 16b entry code does and jumps off to the real startup_32. + */ + cli + wbinvd + + /* + * The %ebx provided is not terribly useful since it is the physical + * address of tb_trampoline_start and not the base of the image. + * Use pa_real_mode_base, which is fixed up, to get a run time + * base register to use for offsets to location that do not have + * pa_ symbols. + */ + movl $pa_real_mode_base, %ebx + + LOCK_AND_LOAD_REALMODE_ESP lock_pa=1 + + lgdt tr_gdt(%ebx) + lidt tr_idt(%ebx) + + movw $__KERNEL_DS, %dx # Data segment descriptor + + /* Jump to where the 16b code would have jumped */ + ljmpl $__KERNEL32_CS, $pa_startup_32 +SYM_CODE_END(sl_trampoline_start32) +#endif + .balign 4 SYM_CODE_START(startup_32) movl %edx, %ss -- 2.47.3