From patchwork Tue Oct 3 06:24:57 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Li, Xin3" X-Patchwork-Id: 13406923 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 lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 96E98E7542D for ; Tue, 3 Oct 2023 07:06:54 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.611990.951860 (Exim 4.92) (envelope-from ) id 1qnZUT-0008Ma-Is; Tue, 03 Oct 2023 07:06:45 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 611990.951860; Tue, 03 Oct 2023 07:06:45 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1qnZUT-0008MM-Fj; Tue, 03 Oct 2023 07:06:45 +0000 Received: by outflank-mailman (input) for mailman id 611990; Tue, 03 Oct 2023 07:06:44 +0000 Received: from se1-gles-flk1-in.inumbo.com ([94.247.172.50] helo=se1-gles-flk1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1qnZJH-00047B-9r for xen-devel@lists.xenproject.org; Tue, 03 Oct 2023 06:55:11 +0000 Received: from mgamail.intel.com (mgamail.intel.com [134.134.136.126]) by se1-gles-flk1.inumbo.com (Halon) with ESMTPS id c69c35a2-61b9-11ee-9b0d-b553b5be7939; Tue, 03 Oct 2023 08:55:02 +0200 (CEST) Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by orsmga106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Oct 2023 23:54:53 -0700 Received: from unknown (HELO fred..) ([172.25.112.68]) by fmsmga005.fm.intel.com with ESMTP; 02 Oct 2023 23:54:52 -0700 X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: c69c35a2-61b9-11ee-9b0d-b553b5be7939 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1696316102; x=1727852102; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=gVi2+XfvMsb0EmrgWxnOH1m9wi+KtBF4SipmwmPPA4A=; b=K6Zgt5rNvhLlqI1MNlDI1XD9vPkaZBWkwdQ9nQTpwhPFgb/jPt8gcbGs A2Fh4G0/8d7QtwUuv6rkmT5fNzM4hYS7X6d5/KsyWGR0pTAihxYWDCPWi /T+9i110UFS3yM6XlAgNuvhSXh7Xb9w9atbMtx1F16Hl5HndZcn6LFKHl gPJGrGaejPdTUH9W8t5b3d5Fw53UKkzSY7RyTVVAFrY1fPFWbk1L6MTEl OrnFBPfeUJYuR+31411qAwY+/nr9tPvQbwCriUtuI18nvvxAcvRk+gaPj nUcjfdQNez+wb9ulcqwEqlC70WTlkb9Kv3wRGrp0S2MODyLVSBs5hnDus A==; X-IronPort-AV: E=McAfee;i="6600,9927,10851"; a="367858362" X-IronPort-AV: E=Sophos;i="6.03,196,1694761200"; d="scan'208";a="367858362" X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10851"; a="1081901028" X-IronPort-AV: E=Sophos;i="6.03,196,1694761200"; d="scan'208";a="1081901028" From: Xin Li To: linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-edac@vger.kernel.org, linux-hyperv@vger.kernel.org, kvm@vger.kernel.org, xen-devel@lists.xenproject.org Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com, luto@kernel.org, pbonzini@redhat.com, seanjc@google.com, peterz@infradead.org, jgross@suse.com, ravi.v.shankar@intel.com, mhiramat@kernel.org, andrew.cooper3@citrix.com, jiangshanlai@gmail.com, nik.borisov@suse.com Subject: [PATCH v12 36/37] x86/fred: Add FRED initialization functions Date: Mon, 2 Oct 2023 23:24:57 -0700 Message-Id: <20231003062458.23552-37-xin3.li@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20231003062458.23552-1-xin3.li@intel.com> References: <20231003062458.23552-1-xin3.li@intel.com> MIME-Version: 1.0 From: "H. Peter Anvin (Intel)" Add cpu_init_fred_exceptions() to: - Set FRED entrypoints for events happening in ring 0 and 3. - Specify the stack level for IRQs occurred ring 0. - Specify dedicated event stacks for #DB/NMI/#MCE/#DF. - Enable FRED and invalidtes IDT. - Force 32-bit system calls to use "int $0x80" only. Add fred_complete_exception_setup() to: - Initialize system_vectors as done for IDT systems. - Set unused sysvec_table entries to fred_handle_spurious_interrupt(). Signed-off-by: H. Peter Anvin (Intel) Co-developed-by: Xin Li Tested-by: Shan Kang Signed-off-by: Xin Li --- Changes since v9: * Set unused sysvec table entries to fred_handle_spurious_interrupt() in fred_complete_exception_setup() (Thomas Gleixner). Changes since v5: * Add a comment for FRED stack level settings (Lai Jiangshan). * Define NMI/#DB/#MCE/#DF stack levels using macros. --- arch/x86/entry/entry_fred.c | 21 +++++++++++++ arch/x86/include/asm/fred.h | 5 ++++ arch/x86/kernel/Makefile | 1 + arch/x86/kernel/fred.c | 59 +++++++++++++++++++++++++++++++++++++ 4 files changed, 86 insertions(+) create mode 100644 arch/x86/kernel/fred.c diff --git a/arch/x86/entry/entry_fred.c b/arch/x86/entry/entry_fred.c index 3e33a4ab4624..abe66d65fa2d 100644 --- a/arch/x86/entry/entry_fred.c +++ b/arch/x86/entry/entry_fred.c @@ -140,6 +140,27 @@ void __init fred_install_sysvec(unsigned int sysvec, idtentry_t handler) sysvec_table[sysvec - FIRST_SYSTEM_VECTOR] = handler; } +static noinstr void fred_handle_spurious_interrupt(struct pt_regs *regs) +{ + spurious_interrupt(regs, regs->fred_ss.vector); +} + +void __init fred_complete_exception_setup(void) +{ + unsigned int vector; + + for (vector = 0; vector < FIRST_EXTERNAL_VECTOR; vector++) + set_bit(vector, system_vectors); + + for (vector = 0; vector < NR_SYSTEM_VECTORS; vector++) { + if (sysvec_table[vector]) + set_bit(vector + FIRST_SYSTEM_VECTOR, system_vectors); + else + sysvec_table[vector] = fred_handle_spurious_interrupt; + } + fred_setup_done = true; +} + static noinstr void fred_extint(struct pt_regs *regs) { unsigned int vector = regs->fred_ss.vector; diff --git a/arch/x86/include/asm/fred.h b/arch/x86/include/asm/fred.h index 2fa9f34e5c95..e86c7ba32435 100644 --- a/arch/x86/include/asm/fred.h +++ b/arch/x86/include/asm/fred.h @@ -83,8 +83,13 @@ static __always_inline void fred_entry_from_kvm(unsigned int type, unsigned int asm_fred_entry_from_kvm(ss); } +void cpu_init_fred_exceptions(void); +void fred_complete_exception_setup(void); + #else /* CONFIG_X86_FRED */ static __always_inline unsigned long fred_event_data(struct pt_regs *regs) { return 0; } +static inline void cpu_init_fred_exceptions(void) { } +static inline void fred_complete_exception_setup(void) { } static __always_inline void fred_entry_from_kvm(unsigned int type, unsigned int vector) { } #endif /* CONFIG_X86_FRED */ #endif /* !__ASSEMBLY__ */ diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile index 3269a0e23d3a..8dfdae4111bb 100644 --- a/arch/x86/kernel/Makefile +++ b/arch/x86/kernel/Makefile @@ -47,6 +47,7 @@ obj-y += platform-quirks.o obj-y += process_$(BITS).o signal.o signal_$(BITS).o obj-y += traps.o idt.o irq.o irq_$(BITS).o dumpstack_$(BITS).o obj-y += time.o ioport.o dumpstack.o nmi.o +obj-$(CONFIG_X86_FRED) += fred.o obj-$(CONFIG_MODIFY_LDT_SYSCALL) += ldt.o obj-$(CONFIG_X86_KERNEL_IBT) += ibt_selftest.o obj-y += setup.o x86_init.o i8259.o irqinit.o diff --git a/arch/x86/kernel/fred.c b/arch/x86/kernel/fred.c new file mode 100644 index 000000000000..4bcd8791ad96 --- /dev/null +++ b/arch/x86/kernel/fred.c @@ -0,0 +1,59 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#include + +#include +#include +#include +#include + +/* #DB in the kernel would imply the use of a kernel debugger. */ +#define FRED_DB_STACK_LEVEL 1UL +#define FRED_NMI_STACK_LEVEL 2UL +#define FRED_MC_STACK_LEVEL 2UL +/* + * #DF is the highest level because a #DF means "something went wrong + * *while delivering an exception*." The number of cases for which that + * can happen with FRED is drastically reduced and basically amounts to + * "the stack you pointed me to is broken." Thus, always change stacks + * on #DF, which means it should be at the highest level. + */ +#define FRED_DF_STACK_LEVEL 3UL + +#define FRED_STKLVL(vector, lvl) ((lvl) << (2 * (vector))) + +void cpu_init_fred_exceptions(void) +{ + /* When FRED is enabled by default, remove this log message */ + pr_info("Initialize FRED on CPU%d\n", smp_processor_id()); + + wrmsrl(MSR_IA32_FRED_CONFIG, + /* Reserve for CALL emulation */ + FRED_CONFIG_REDZONE | + FRED_CONFIG_INT_STKLVL(0) | + FRED_CONFIG_ENTRYPOINT(asm_fred_entrypoint_user)); + + /* + * The purpose of separate stacks for NMI, #DB and #MC *in the kernel* + * (remember that user space faults are always taken on stack level 0) + * is to avoid overflowing the kernel stack. + */ + wrmsrl(MSR_IA32_FRED_STKLVLS, + FRED_STKLVL(X86_TRAP_DB, FRED_DB_STACK_LEVEL) | + FRED_STKLVL(X86_TRAP_NMI, FRED_NMI_STACK_LEVEL) | + FRED_STKLVL(X86_TRAP_MC, FRED_MC_STACK_LEVEL) | + FRED_STKLVL(X86_TRAP_DF, FRED_DF_STACK_LEVEL)); + + /* The FRED equivalents to IST stacks... */ + wrmsrl(MSR_IA32_FRED_RSP1, __this_cpu_ist_top_va(DB)); + wrmsrl(MSR_IA32_FRED_RSP2, __this_cpu_ist_top_va(NMI)); + wrmsrl(MSR_IA32_FRED_RSP3, __this_cpu_ist_top_va(DF)); + + /* Enable FRED */ + cr4_set_bits(X86_CR4_FRED); + /* Any further IDT use is a bug */ + idt_invalidate(); + + /* Use int $0x80 for 32-bit system calls in FRED mode */ + setup_clear_cpu_cap(X86_FEATURE_SYSENTER32); + setup_clear_cpu_cap(X86_FEATURE_SYSCALL32); +}