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 X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 32AE6C352A3 for ; Tue, 11 Feb 2020 13:54:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 13880214DB for ; Tue, 11 Feb 2020 13:54:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729744AbgBKNyM (ORCPT ); Tue, 11 Feb 2020 08:54:12 -0500 Received: from 8bytes.org ([81.169.241.247]:52306 "EHLO theia.8bytes.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729615AbgBKNxa (ORCPT ); Tue, 11 Feb 2020 08:53:30 -0500 Received: by theia.8bytes.org (Postfix, from userid 1000) id E2484EAD; Tue, 11 Feb 2020 14:53:17 +0100 (CET) From: Joerg Roedel To: x86@kernel.org Cc: hpa@zytor.com, Andy Lutomirski , Dave Hansen , Peter Zijlstra , Thomas Hellstrom , Jiri Slaby , Dan Williams , Tom Lendacky , Juergen Gross , Kees Cook , linux-kernel@vger.kernel.org, kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, Joerg Roedel , Joerg Roedel Subject: [PATCH 60/62] x86/sev-es: Support CPU offline/online Date: Tue, 11 Feb 2020 14:52:54 +0100 Message-Id: <20200211135256.24617-61-joro@8bytes.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200211135256.24617-1-joro@8bytes.org> References: <20200211135256.24617-1-joro@8bytes.org> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Joerg Roedel Add a play_dead handler when running under SEV-ES. This is needed because the hypervisor can't deliver an SIPI request to restart the AP. Instead the kernel has to issue a VMGEXIT to halt the VCPU. When the hypervisor would deliver and SIPI is wakes up the VCPU instead. Signed-off-by: Joerg Roedel --- arch/x86/include/uapi/asm/svm.h | 1 + arch/x86/kernel/sev-es.c | 46 +++++++++++++++++++++++++++++++++ 2 files changed, 47 insertions(+) diff --git a/arch/x86/include/uapi/asm/svm.h b/arch/x86/include/uapi/asm/svm.h index a19ce9681ec2..20a05839dd9a 100644 --- a/arch/x86/include/uapi/asm/svm.h +++ b/arch/x86/include/uapi/asm/svm.h @@ -84,6 +84,7 @@ /* SEV-ES software-defined VMGEXIT events */ #define SVM_VMGEXIT_MMIO_READ 0x80000001 #define SVM_VMGEXIT_MMIO_WRITE 0x80000002 +#define SVM_VMGEXIT_AP_HLT_LOOP 0x80000004 #define SVM_VMGEXIT_AP_JUMP_TABLE 0x80000005 #define SVM_VMGEXIT_SET_AP_JUMP_TABLE 0 #define SVM_VMGEXIT_GET_AP_JUMP_TABLE 1 diff --git a/arch/x86/kernel/sev-es.c b/arch/x86/kernel/sev-es.c index d8193d37ed2b..755708f72824 100644 --- a/arch/x86/kernel/sev-es.c +++ b/arch/x86/kernel/sev-es.c @@ -22,6 +22,8 @@ #include #include #include +#include +#include #define DR7_RESET_VALUE 0x400 @@ -252,6 +254,48 @@ static bool __init setup_ghcb(void) return true; } +#ifdef CONFIG_HOTPLUG_CPU +static void sev_es_ap_hlt_loop(void) +{ + struct ghcb *ghcb; + + ghcb = this_cpu_ptr(&ghcb_page); + + while (true) { + ghcb_invalidate(ghcb); + ghcb_set_sw_exit_code(ghcb, SVM_VMGEXIT_AP_HLT_LOOP); + ghcb_set_sw_exit_info_1(ghcb, 0); + ghcb_set_sw_exit_info_2(ghcb, 0); + + write_ghcb_msr(__pa(ghcb)); + VMGEXIT(); + + /* Wakup Signal? */ + if (ghcb_is_valid_sw_exit_info_2(ghcb) && + ghcb->save.sw_exit_info_2 != 0) + break; + } +} + +void sev_es_play_dead(void) +{ + play_dead_common(); + + /* IRQs now disabled */ + + sev_es_ap_hlt_loop(); + + /* + * If we get here, the VCPU was woken up again. Jump to CPU + * startup code to get it back online. + */ + + start_cpu(); +} +#else /* CONFIG_HOTPLUG_CPU */ +#define sev_es_play_dead native_play_dead +#endif /* CONFIG_HOTPLUG_CPU */ + void encrypted_state_init_ghcbs(void) { int cpu; @@ -267,6 +311,8 @@ void encrypted_state_init_ghcbs(void) sizeof(ghcb_page) >> PAGE_SHIFT); memset(ghcb, 0, sizeof(*ghcb)); } + + smp_ops.play_dead = sev_es_play_dead; } static void __init early_forward_exception(struct es_em_ctxt *ctxt) -- 2.17.1