From patchwork Mon May 13 13:40:46 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Elias El Yandouzi X-Patchwork-Id: 13663479 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 C4B05C25B5F for ; Mon, 13 May 2024 13:52:10 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.720959.1124102 (Exim 4.92) (envelope-from ) id 1s6W5u-0005Nb-ER; Mon, 13 May 2024 13:51:58 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 720959.1124102; Mon, 13 May 2024 13:51:58 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1s6W5u-0005NU-Ac; Mon, 13 May 2024 13:51:58 +0000 Received: by outflank-mailman (input) for mailman id 720959; Mon, 13 May 2024 13:51:57 +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 1s6Vvx-0002lY-Tx for xen-devel@lists.xenproject.org; Mon, 13 May 2024 13:41:41 +0000 Received: from smtp-fw-80008.amazon.com (smtp-fw-80008.amazon.com [99.78.197.219]) by se1-gles-flk1.inumbo.com (Halon) with ESMTPS id 85cf85a8-112e-11ef-b4bb-af5377834399; Mon, 13 May 2024 15:41:39 +0200 (CEST) Received: from pdx4-co-svc-p1-lb2-vlan3.amazon.com (HELO smtpout.prod.us-east-1.prod.farcaster.email.amazon.dev) ([10.25.36.214]) by smtp-border-fw-80008.pdx80.corp.amazon.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 May 2024 13:41:37 +0000 Received: from EX19MTAUEC002.ant.amazon.com [10.0.44.209:36217] by smtpin.naws.us-east-1.prod.farcaster.email.amazon.dev [10.0.83.223:2525] with esmtp (Farcaster) id df3964f2-8ebf-477e-94f3-b615efdae6ad; Mon, 13 May 2024 13:41:36 +0000 (UTC) Received: from EX19D008UEA001.ant.amazon.com (10.252.134.62) by EX19MTAUEC002.ant.amazon.com (10.252.135.253) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1258.28; Mon, 13 May 2024 13:41:31 +0000 Received: from EX19MTAUWB001.ant.amazon.com (10.250.64.248) by EX19D008UEA001.ant.amazon.com (10.252.134.62) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1258.28; Mon, 13 May 2024 13:41:31 +0000 Received: from dev-dsk-eliasely-1a-fd74790f.eu-west-1.amazon.com (10.253.91.118) by mail-relay.amazon.com (10.250.64.254) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1258.28 via Frontend Transport; Mon, 13 May 2024 13:41:29 +0000 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: 85cf85a8-112e-11ef-b4bb-af5377834399 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1715607699; x=1747143699; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=PLKm6zqnTr1kh3lkUidFqFNcSg3ycGZChl4qwlqzWSo=; b=KJWagw5D9fdR6ecsO306SqBxIvSajVAkKDhbXsR9ECw27XYHzF6Bxvbk lxrzOMMGzQeyXqf5CIX1H/xLN45a8BQX2yG2bLcYb5cQBef12AIfMmWaP nxddpaGDWM087DsHSHpWaf8hiFrThXiNPCthEsdsmLSmB0rVTXqxCLCyo E=; X-IronPort-AV: E=Sophos;i="6.08,158,1712620800"; d="scan'208";a="88768953" X-Farcaster-Flow-ID: df3964f2-8ebf-477e-94f3-b615efdae6ad From: Elias El Yandouzi To: CC: , , , Julien Grall , Andrew Cooper , George Dunlap , Jan Beulich , "Stefano Stabellini" , Bertrand Marquis , Michal Orzel , "Volodymyr Babchuk" , Elias El Yandouzi Subject: [PATCH V3 (resend) 19/19] xen/arm64: Allow the admin to enable/disable the directmap Date: Mon, 13 May 2024 13:40:46 +0000 Message-ID: <20240513134046.82605-20-eliasely@amazon.com> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20240513134046.82605-1-eliasely@amazon.com> References: <20240513134046.82605-1-eliasely@amazon.com> MIME-Version: 1.0 From: Julien Grall Implement the same command line option as x86 to enable/disable the directmap. By default this is kept enabled. Also modify setup_directmap_mappings() to populate the L0 entries related to the directmap area. Signed-off-by: Julien Grall Signed-off-by: Elias El Yandouzi ---- Changes in v2: * Rely on the Kconfig option to enable Secret Hiding on Arm64 * Use generic helper instead of arch_has_directmap() diff --git a/docs/misc/xen-command-line.pandoc b/docs/misc/xen-command-line.pandoc index 743d343ffa..cccd5e4282 100644 --- a/docs/misc/xen-command-line.pandoc +++ b/docs/misc/xen-command-line.pandoc @@ -799,7 +799,7 @@ that enabling this option cannot guarantee anything beyond what underlying hardware guarantees (with, where available and known to Xen, respective tweaks applied). -### directmap (x86) +### directmap (arm64, x86) > `= ` > Default: `true` diff --git a/xen/arch/arm/Kconfig b/xen/arch/arm/Kconfig index 0462960fc7..1cb495e334 100644 --- a/xen/arch/arm/Kconfig +++ b/xen/arch/arm/Kconfig @@ -7,6 +7,7 @@ config ARM_64 depends on !ARM_32 select 64BIT select HAS_FAST_MULTIPLY + select HAS_SECRET_HIDING config ARM def_bool y diff --git a/xen/arch/arm/arm64/mmu/mm.c b/xen/arch/arm/arm64/mmu/mm.c index 826864d25d..81115cce51 100644 --- a/xen/arch/arm/arm64/mmu/mm.c +++ b/xen/arch/arm/arm64/mmu/mm.c @@ -158,16 +158,27 @@ void __init switch_ttbr(uint64_t ttbr) update_identity_mapping(false); } -/* Map the region in the directmap area. */ +/* + * This either populate a valid fdirect map, or allocates empty L1 tables + * and creates the L0 entries for the given region in the direct map + * depending on has_directmap(). + * + * When directmap=no, we still need to populate empty L1 tables in the + * directmap region. The reason is that the root page-table (i.e. L0) + * is per-CPU and secondary CPUs will initialize their root page-table + * based on the pCPU0 one. So L0 entries will be shared if they are + * pre-populated. We also rely on the fact that L1 tables are never + * freed. + */ static void __init setup_directmap_mappings(unsigned long base_mfn, unsigned long nr_mfns) { + unsigned long mfn_gb = base_mfn & ~((FIRST_SIZE >> PAGE_SHIFT) - 1); int rc; /* First call sets the directmap physical and virtual offset. */ if ( mfn_eq(directmap_mfn_start, INVALID_MFN) ) { - unsigned long mfn_gb = base_mfn & ~((FIRST_SIZE >> PAGE_SHIFT) - 1); directmap_mfn_start = _mfn(base_mfn); directmap_base_pdx = mfn_to_pdx(_mfn(base_mfn)); @@ -188,6 +199,24 @@ static void __init setup_directmap_mappings(unsigned long base_mfn, panic("cannot add directmap mapping at %lx below heap start %lx\n", base_mfn, mfn_x(directmap_mfn_start)); + if ( !has_directmap() ) + { + vaddr_t vaddr = (vaddr_t)__mfn_to_virt(base_mfn); + lpae_t *root = this_cpu(xen_pgtable); + unsigned int i, slot; + + slot = first_table_offset(vaddr); + nr_mfns += base_mfn - mfn_gb; + for ( i = 0; i < nr_mfns; i += BIT(XEN_PT_LEVEL_ORDER(0), UL), slot++ ) + { + lpae_t *entry = &root[slot]; + + if ( !lpae_is_valid(*entry) && !create_xen_table(entry) ) + panic("Unable to populate zeroeth slot %u\n", slot); + } + return; + } + rc = map_pages_to_xen((vaddr_t)__mfn_to_virt(base_mfn), _mfn(base_mfn), nr_mfns, PAGE_HYPERVISOR_RW | _PAGE_BLOCK); diff --git a/xen/arch/arm/include/asm/arm64/mm.h b/xen/arch/arm/include/asm/arm64/mm.h index e0bd23a6ed..5888f29159 100644 --- a/xen/arch/arm/include/asm/arm64/mm.h +++ b/xen/arch/arm/include/asm/arm64/mm.h @@ -3,13 +3,10 @@ extern DEFINE_PAGE_TABLE(xen_pgtable); -/* - * On ARM64, all the RAM is currently direct mapped in Xen. - * Hence return always true. - */ +/* On Arm64, the user can chose whether all the RAM is directmap. */ static inline bool arch_mfns_in_directmap(unsigned long mfn, unsigned long nr) { - return true; + return has_directmap(); } void arch_setup_page_tables(void); diff --git a/xen/arch/arm/mm.c b/xen/arch/arm/mm.c index def939172c..0f3ffab6ba 100644 --- a/xen/arch/arm/mm.c +++ b/xen/arch/arm/mm.c @@ -12,6 +12,7 @@ #include #include #include +#include #include diff --git a/xen/arch/arm/setup.c b/xen/arch/arm/setup.c index d15987d6ea..6b06e2f4f5 100644 --- a/xen/arch/arm/setup.c +++ b/xen/arch/arm/setup.c @@ -778,6 +778,7 @@ void asmlinkage __init start_xen(unsigned long boot_phys_offset, cmdline_parse(cmdline); setup_mm(); + printk("Booting with directmap %s\n", has_directmap() ? "on" : "off"); vm_init();