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=-12.8 required=3.0 tests=BAYES_00, 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 09ACEC2D0E2 for ; Mon, 7 Sep 2020 13:28:00 +0000 (UTC) Received: from fraxinus.osuosl.org (smtp4.osuosl.org [140.211.166.137]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id B98EC215A4 for ; Mon, 7 Sep 2020 13:27:59 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B98EC215A4 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=8bytes.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=virtualization-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by fraxinus.osuosl.org (Postfix) with ESMTP id 3F9C0862C9; Mon, 7 Sep 2020 13:27:59 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from fraxinus.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id Hp5aklbZpy1s; Mon, 7 Sep 2020 13:27:56 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by fraxinus.osuosl.org (Postfix) with ESMTP id 4CCEA860C8; Mon, 7 Sep 2020 13:27:53 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 27476C0895; Mon, 7 Sep 2020 13:27:53 +0000 (UTC) Received: from fraxinus.osuosl.org (smtp4.osuosl.org [140.211.166.137]) by lists.linuxfoundation.org (Postfix) with ESMTP id D6423C0051 for ; Mon, 7 Sep 2020 13:27:49 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by fraxinus.osuosl.org (Postfix) with ESMTP id BE3AD860C4 for ; Mon, 7 Sep 2020 13:27:49 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from fraxinus.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id gPYXDUj92DjZ for ; Mon, 7 Sep 2020 13:27:47 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from theia.8bytes.org (8bytes.org [81.169.241.247]) by fraxinus.osuosl.org (Postfix) with ESMTPS id 957EA85FD7 for ; Mon, 7 Sep 2020 13:27:47 +0000 (UTC) Received: from cap.home.8bytes.org (p549add56.dip0.t-ipconnect.de [84.154.221.86]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (No client certificate requested) by theia.8bytes.org (Postfix) with ESMTPSA id F1CD33AB0; Mon, 7 Sep 2020 15:17:19 +0200 (CEST) From: Joerg Roedel To: x86@kernel.org Subject: [PATCH v7 71/72] x86/efi: Add GHCB mappings when SEV-ES is active Date: Mon, 7 Sep 2020 15:16:12 +0200 Message-Id: <20200907131613.12703-72-joro@8bytes.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200907131613.12703-1-joro@8bytes.org> References: <20200907131613.12703-1-joro@8bytes.org> MIME-Version: 1.0 Cc: Juergen Gross , Tom Lendacky , Joerg Roedel , Mike Stunes , Kees Cook , kvm@vger.kernel.org, Peter Zijlstra , Cfir Cohen , Joerg Roedel , Dave Hansen , linux-kernel@vger.kernel.org, Sean Christopherson , virtualization@lists.linux-foundation.org, Martin Radev , Masami Hiramatsu , Andy Lutomirski , hpa@zytor.com, Erdem Aktas , David Rientjes , Dan Williams , Jiri Slaby X-BeenThere: virtualization@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Linux virtualization List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: virtualization-bounces@lists.linux-foundation.org Sender: "Virtualization" From: Tom Lendacky Calling down to EFI runtime services can result in the firmware performing VMGEXIT calls. The firmware is likely to use the GHCB of the OS (e.g., for setting EFI variables), so each GHCB in the system needs to be identity mapped in the EFI page tables, as unencrypted, to avoid page faults. Signed-off-by: Tom Lendacky [ jroedel@suse.de: Moved GHCB mapping loop to sev-es.c ] Signed-off-by: Joerg Roedel --- arch/x86/boot/compressed/sev-es.c | 1 + arch/x86/include/asm/sev-es.h | 2 ++ arch/x86/kernel/sev-es.c | 30 ++++++++++++++++++++++++++++++ arch/x86/platform/efi/efi_64.c | 10 ++++++++++ 4 files changed, 43 insertions(+) diff --git a/arch/x86/boot/compressed/sev-es.c b/arch/x86/boot/compressed/sev-es.c index 45702b866c33..0a9a248ca33d 100644 --- a/arch/x86/boot/compressed/sev-es.c +++ b/arch/x86/boot/compressed/sev-es.c @@ -12,6 +12,7 @@ */ #include "misc.h" +#include #include #include #include diff --git a/arch/x86/include/asm/sev-es.h b/arch/x86/include/asm/sev-es.h index e919f09ae33c..cf1d957c7091 100644 --- a/arch/x86/include/asm/sev-es.h +++ b/arch/x86/include/asm/sev-es.h @@ -102,11 +102,13 @@ static __always_inline void sev_es_nmi_complete(void) if (static_branch_unlikely(&sev_es_enable_key)) __sev_es_nmi_complete(); } +extern int __init sev_es_efi_map_ghcbs(pgd_t *pgd); #else static inline void sev_es_ist_enter(struct pt_regs *regs) { } static inline void sev_es_ist_exit(void) { } static inline int sev_es_setup_ap_jump_table(struct real_mode_header *rmh) { return 0; } static inline void sev_es_nmi_complete(void) { } +static inline int sev_es_efi_map_ghcbs(pgd_t *pgd) { return 0; } #endif #endif diff --git a/arch/x86/kernel/sev-es.c b/arch/x86/kernel/sev-es.c index 9ab3a4dfecd8..4e2b7e4d9b87 100644 --- a/arch/x86/kernel/sev-es.c +++ b/arch/x86/kernel/sev-es.c @@ -491,6 +491,36 @@ int sev_es_setup_ap_jump_table(struct real_mode_header *rmh) return 0; } +/* + * This is needed by the OVMF UEFI firmware which will use whatever it finds in + * the GHCB MSR as its GHCB to talk to the hypervisor. So make sure the per-cpu + * runtime GHCBs used by the kernel are also mapped in the EFI page-table. + */ +int __init sev_es_efi_map_ghcbs(pgd_t *pgd) +{ + struct sev_es_runtime_data *data; + unsigned long address, pflags; + int cpu; + u64 pfn; + + if (!sev_es_active()) + return 0; + + pflags = _PAGE_NX | _PAGE_RW; + + for_each_possible_cpu(cpu) { + data = per_cpu(runtime_data, cpu); + + address = __pa(&data->ghcb_page); + pfn = address >> PAGE_SHIFT; + + if (kernel_map_pages_in_pgd(pgd, pfn, address, 1, pflags)) + return 1; + } + + return 0; +} + static enum es_result vc_handle_msr(struct ghcb *ghcb, struct es_em_ctxt *ctxt) { struct pt_regs *regs = ctxt->regs; diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c index 6af4da1149ba..8f5759df7776 100644 --- a/arch/x86/platform/efi/efi_64.c +++ b/arch/x86/platform/efi/efi_64.c @@ -47,6 +47,7 @@ #include #include #include +#include /* * We allocate runtime services regions top-down, starting from -4G, i.e. @@ -229,6 +230,15 @@ int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages) return 1; } + /* + * When SEV-ES is active, the GHCB as set by the kernel will be used + * by firmware. Create a 1:1 unencrypted mapping for each GHCB. + */ + if (sev_es_efi_map_ghcbs(pgd)) { + pr_err("Failed to create 1:1 mapping for the GHCBs!\n"); + return 1; + } + /* * When making calls to the firmware everything needs to be 1:1 * mapped and addressable with 32-bit pointers. Map the kernel -- 2.28.0 _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization