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=-9.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 00DB6C433E2 for ; Tue, 8 Sep 2020 17:46:23 +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 27B8D2098B for ; Tue, 8 Sep 2020 17:46:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=alien8.de header.i=@alien8.de header.b="RM/Zx8iH" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 27B8D2098B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=alien8.de 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 BAADA84E34; Tue, 8 Sep 2020 17:46:21 +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 VyYAGGMjdZZ0; Tue, 8 Sep 2020 17:46:21 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by fraxinus.osuosl.org (Postfix) with ESMTP id 1F80884D9A; Tue, 8 Sep 2020 17:46:21 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id F14B8C0859; Tue, 8 Sep 2020 17:46:20 +0000 (UTC) Received: from fraxinus.osuosl.org (smtp4.osuosl.org [140.211.166.137]) by lists.linuxfoundation.org (Postfix) with ESMTP id CDA32C0051 for ; Tue, 8 Sep 2020 17:46:18 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by fraxinus.osuosl.org (Postfix) with ESMTP id BCBA984D9A for ; Tue, 8 Sep 2020 17:46:18 +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 n0BYmwgndWll for ; Tue, 8 Sep 2020 17:46:18 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from mail.skyhub.de (mail.skyhub.de [5.9.137.197]) by fraxinus.osuosl.org (Postfix) with ESMTPS id 024D48085A for ; Tue, 8 Sep 2020 17:46:18 +0000 (UTC) Received: from zn.tnic (p200300ec2f10bf0070b09dfd4356f225.dip0.t-ipconnect.de [IPv6:2003:ec:2f10:bf00:70b0:9dfd:4356:f225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id 605F51EC0489; Tue, 8 Sep 2020 19:46:16 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1599587176; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:in-reply-to:in-reply-to: references:references; bh=nPj3+c2dIwhanvH9Blvxwpvfl2eV/3k/Q9aSuFLclYg=; b=RM/Zx8iHBvG5Eti/FNmYaWgJjIMOyQ4VltylfyxY4IdCEIFAfWH60weezPSlACosueFynJ DKlNyhaAe9DDi+Up/33riZE7n2E7K1VUYzWs+AuxGZl1Bzei/yP0kIDcV8JJzVPAf4HdRS QJYbhpttRw4vRmtimjYS+Qynt7kt/ms= Date: Tue, 8 Sep 2020 19:46:16 +0200 From: Borislav Petkov To: Joerg Roedel , Ard Biesheuvel Subject: Re: [PATCH v7 71/72] x86/efi: Add GHCB mappings when SEV-ES is active Message-ID: <20200908174616.GJ25236@zn.tnic> References: <20200907131613.12703-1-joro@8bytes.org> <20200907131613.12703-72-joro@8bytes.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200907131613.12703-72-joro@8bytes.org> Cc: Juergen Gross , Tom Lendacky , Dave Hansen , Mike Stunes , Kees Cook , kvm@vger.kernel.org, Peter Zijlstra , Cfir Cohen , x86@kernel.org, linux-kernel@vger.kernel.org, Sean Christopherson , virtualization@lists.linux-foundation.org, Martin Radev , Joerg Roedel , 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" + Ard so that he can ack the efi bits. On Mon, Sep 07, 2020 at 03:16:12PM +0200, Joerg Roedel wrote: > 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 > -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization