From mboxrd@z Thu Jan 1 00:00:00 1970 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E5911C433F5 for ; Tue, 16 Nov 2021 10:54:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BF4D363213 for ; Tue, 16 Nov 2021 10:54:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234414AbhKPK5p (ORCPT ); Tue, 16 Nov 2021 05:57:45 -0500 Received: from mail.kernel.org ([198.145.29.99]:54340 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234377AbhKPK5p (ORCPT ); Tue, 16 Nov 2021 05:57:45 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 4DFFD61BE3; Tue, 16 Nov 2021 10:54:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1637060088; bh=iF6xBi8UOPUFeQCK8m3e5lJkCdqiTeB/ZS+hHGoueCc=; h=Subject:To:Cc:From:Date:From; b=N91Lpm/6sfbKgKOBzAIRg+wGYuI+XjNH+CGM8jhUlNMDh1Gb2bzUVw/KdxaemftjR 6HkN0IOrbsL45AjG1VErMo9ypVC2wtiKAIi9fpnTJlbI1tIzl9BGRwpgp78FFNDXbS K1WvUOcAu+86OEU0Ct95HpM8tz7a3VMHDyt3orzE= Subject: FAILED: patch "[PATCH] x86/sev: Make the #VC exception stacks part of the default" failed to apply to 5.15-stable tree To: bp@suse.de, brijesh.singh@amd.com, thomas.lendacky@amd.com Cc: From: Date: Tue, 16 Nov 2021 11:54:46 +0100 Message-ID: <1637060086211132@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 541ac97186d9ea88491961a46284de3603c914fd Mon Sep 17 00:00:00 2001 From: Borislav Petkov Date: Fri, 1 Oct 2021 21:41:20 +0200 Subject: [PATCH] x86/sev: Make the #VC exception stacks part of the default stacks storage The size of the exception stacks was increased by the commit in Fixes, resulting in stack sizes greater than a page in size. The #VC exception handling was only mapping the first (bottom) page, resulting in an SEV-ES guest failing to boot. Make the #VC exception stacks part of the default exception stacks storage and allocate them with a CONFIG_AMD_MEM_ENCRYPT=y .config. Map them only when a SEV-ES guest has been detected. Rip out the custom VC stacks mapping and storage code. [ bp: Steal and adapt Tom's commit message. ] Fixes: 7fae4c24a2b8 ("x86: Increase exception stack sizes") Signed-off-by: Borislav Petkov Tested-by: Tom Lendacky Tested-by: Brijesh Singh Link: https://lkml.kernel.org/r/YVt1IMjIs7pIZTRR@zn.tnic diff --git a/arch/x86/include/asm/cpu_entry_area.h b/arch/x86/include/asm/cpu_entry_area.h index 3d52b094850a..dd5ea1bdf04c 100644 --- a/arch/x86/include/asm/cpu_entry_area.h +++ b/arch/x86/include/asm/cpu_entry_area.h @@ -10,6 +10,12 @@ #ifdef CONFIG_X86_64 +#ifdef CONFIG_AMD_MEM_ENCRYPT +#define VC_EXCEPTION_STKSZ EXCEPTION_STKSZ +#else +#define VC_EXCEPTION_STKSZ 0 +#endif + /* Macro to enforce the same ordering and stack sizes */ #define ESTACKS_MEMBERS(guardsize, optional_stack_size) \ char DF_stack_guard[guardsize]; \ @@ -28,7 +34,7 @@ /* The exception stacks' physical storage. No guard pages required */ struct exception_stacks { - ESTACKS_MEMBERS(0, 0) + ESTACKS_MEMBERS(0, VC_EXCEPTION_STKSZ) }; /* The effective cpu entry area mapping with guard pages. */ diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c index 53a6837d354b..4d0d1c2b65e1 100644 --- a/arch/x86/kernel/sev.c +++ b/arch/x86/kernel/sev.c @@ -46,16 +46,6 @@ static struct ghcb __initdata *boot_ghcb; struct sev_es_runtime_data { struct ghcb ghcb_page; - /* Physical storage for the per-CPU IST stack of the #VC handler */ - char ist_stack[EXCEPTION_STKSZ] __aligned(PAGE_SIZE); - - /* - * Physical storage for the per-CPU fall-back stack of the #VC handler. - * The fall-back stack is used when it is not safe to switch back to the - * interrupted stack in the #VC entry code. - */ - char fallback_stack[EXCEPTION_STKSZ] __aligned(PAGE_SIZE); - /* * Reserve one page per CPU as backup storage for the unencrypted GHCB. * It is needed when an NMI happens while the #VC handler uses the real @@ -99,27 +89,6 @@ DEFINE_STATIC_KEY_FALSE(sev_es_enable_key); /* Needed in vc_early_forward_exception */ void do_early_exception(struct pt_regs *regs, int trapnr); -static void __init setup_vc_stacks(int cpu) -{ - struct sev_es_runtime_data *data; - struct cpu_entry_area *cea; - unsigned long vaddr; - phys_addr_t pa; - - data = per_cpu(runtime_data, cpu); - cea = get_cpu_entry_area(cpu); - - /* Map #VC IST stack */ - vaddr = CEA_ESTACK_BOT(&cea->estacks, VC); - pa = __pa(data->ist_stack); - cea_set_pte((void *)vaddr, pa, PAGE_KERNEL); - - /* Map VC fall-back stack */ - vaddr = CEA_ESTACK_BOT(&cea->estacks, VC2); - pa = __pa(data->fallback_stack); - cea_set_pte((void *)vaddr, pa, PAGE_KERNEL); -} - static __always_inline bool on_vc_stack(struct pt_regs *regs) { unsigned long sp = regs->sp; @@ -787,7 +756,6 @@ void __init sev_es_init_vc_handling(void) for_each_possible_cpu(cpu) { alloc_runtime_data(cpu); init_ghcb(cpu); - setup_vc_stacks(cpu); } sev_es_setup_play_dead(); diff --git a/arch/x86/mm/cpu_entry_area.c b/arch/x86/mm/cpu_entry_area.c index f5e1e60c9095..6c2f1b76a0b6 100644 --- a/arch/x86/mm/cpu_entry_area.c +++ b/arch/x86/mm/cpu_entry_area.c @@ -110,6 +110,13 @@ static void __init percpu_setup_exception_stacks(unsigned int cpu) cea_map_stack(NMI); cea_map_stack(DB); cea_map_stack(MCE); + + if (IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT)) { + if (cc_platform_has(CC_ATTR_GUEST_STATE_ENCRYPT)) { + cea_map_stack(VC); + cea_map_stack(VC2); + } + } } #else static inline void percpu_setup_exception_stacks(unsigned int cpu)