From nobody Fri May 3 22:45:55 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) client-ip=192.237.175.120; envelope-from=xen-devel-bounces@lists.xenproject.org; helo=lists.xenproject.org; Authentication-Results: mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; dmarc=pass(p=none dis=none) header.from=kernel.org ARC-Seal: i=1; a=rsa-sha256; t=1614379954; cv=none; d=zohomail.com; s=zohoarc; b=Kvh6tGUVdiFqlmVj2UkSt2wH7OzQVac3/FR8tdB1Lgkf181QFtReoKEHlci/wPXzPdreQcI+GoPNQT4+xO7yHt/fQurogp/0XyQeeYNZXrOq3tpUpGfIDE3TvYThThsiTkxEghwWwtU8LDelk/7Nm5l8ujfP5IxG/pQdMQH9QMo= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1614379954; h=Cc:Date:From:List-Subscribe:List-Post:List-Id:List-Help:List-Unsubscribe:Message-ID:Sender:Subject:To; bh=gkbCRrQKiUYlYG1z9eCHZZ0afYYtiE8WvutfN//Nfss=; b=ED5MsWuojlnQTIFb76g0RLNEvRMfjnvFVsG4uhxYjVt/UarfSihqRmlozS/vOUWgLYShO4GWblVbd1wj7yF3ssNy5s5tYh1S6+U7HIGqQy+xHgqolpxY95OHOYRleDkMIU7eJa3EkCIZFKMw/9kH/kygZPbRvjrl8t8pZDCbnz8= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; dmarc=pass header.from= (p=none dis=none) header.from= Return-Path: Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) by mx.zohomail.com with SMTPS id 1614379954704117.57104454590115; Fri, 26 Feb 2021 14:52:34 -0800 (PST) Received: from list by lists.xenproject.org with outflank-mailman.90615.171602 (Exim 4.92) (envelope-from ) id 1lFlyA-000891-NQ; Fri, 26 Feb 2021 22:52:22 +0000 Received: by outflank-mailman (output) from mailman id 90615.171602; Fri, 26 Feb 2021 22:52:22 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lFlyA-00088u-KS; Fri, 26 Feb 2021 22:52:22 +0000 Received: by outflank-mailman (input) for mailman id 90615; Fri, 26 Feb 2021 22:52:21 +0000 Received: from all-amaz-eas1.inumbo.com ([34.197.232.57] helo=us1-amaz-eas2.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lFly9-00088p-30 for xen-devel@lists.xenproject.org; Fri, 26 Feb 2021 22:52:21 +0000 Received: from mail.kernel.org (unknown [198.145.29.99]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTPS id 39986784-6fb7-4293-82a7-e79b8de519ac; Fri, 26 Feb 2021 22:52:20 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id 6817264EDC; Fri, 26 Feb 2021 22:52:19 +0000 (UTC) X-Outflank-Mailman: Message body and most headers restored to incoming version 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: 39986784-6fb7-4293-82a7-e79b8de519ac DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1614379939; bh=TP3PUri1nqJIGJ0ib6Y6jLpS6FE2eGzTgEFt783zVVs=; h=From:To:Cc:Subject:Date:From; b=noPsku21c4JKET3kCAZnaA7iJuRsJOBLu0bH5RnMQogrUvOwX1IMNXsEizNPf46tg /+EmwMkHJuuKfJL2fC1IoIcDn8+w4KUJSuo2TcUL7BoRGp6EQthXpAGVT4qD0qMJ/b 1bg6NKZ11mroe2IQ3q5AyKmQBKJhtDdKedb5lcj0I1rJxXxTOeBP1ttYeKv9l5lEEw eE9VceFTG92ZZZ8VR6Lem2kW5EimMfnWVfJTnpA7dPoMuWqePNfQqWTzPzSCa5wqhM N9DheWyElw+LBrAs/rTIPGI9jlwij34T1xlMph8YqjzYVWcWKsEJ+Bh1PlpcJwjcJx 5wRpxCubEso2Q== From: Stefano Stabellini To: xen-devel@lists.xenproject.org Cc: sstabellini@kernel.org, Stefano Stabellini , jbeulich@suse.com, andrew.cooper3@citrix.com, julien@xen.org Subject: [PATCH v2] xen: introduce XENFEAT_direct_mapped and XENFEAT_not_direct_mapped Date: Fri, 26 Feb 2021 14:52:17 -0800 Message-Id: <20210226225217.2137-1-sstabellini@kernel.org> X-Mailer: git-send-email 2.17.1 X-ZohoMail-DKIM: pass (identity @kernel.org) Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Introduce two feature flags to tell the domain whether it is direct-mapped or not. It allows the guest kernel to make informed decisions on things such as swiotlb-xen enablement. The introduction of both flags (XENFEAT_direct_mapped and XENFEAT_not_direct_mapped) allows the guest kernel to avoid any guesswork if one of the two is present, or fallback to the current checks if neither of them is present. XENFEAT_direct_mapped is always set for not auto-translated guests. For auto-translated guests, only Dom0 on ARM is direct-mapped. Also, see is_domain_direct_mapped() which refers to auto-translated guests: xen/include/asm-arm/domain.h:is_domain_direct_mapped xen/include/asm-x86/domain.h:is_domain_direct_mapped Signed-off-by: Stefano Stabellini CC: jbeulich@suse.com CC: andrew.cooper3@citrix.com CC: julien@xen.org Reviewed-by: Jan Beulich --- Changes in v2: - code style improvements - better comments - better commit message - not auto_translated domains are direct_mapped --- xen/common/kernel.c | 4 ++++ xen/include/public/features.h | 12 ++++++++++++ 2 files changed, 16 insertions(+) diff --git a/xen/common/kernel.c b/xen/common/kernel.c index 7a345ae45e..431447326c 100644 --- a/xen/common/kernel.c +++ b/xen/common/kernel.c @@ -560,6 +560,10 @@ DO(xen_version)(int cmd, XEN_GUEST_HANDLE_PARAM(void) = arg) (1U << XENFEAT_hvm_callback_vector) | (has_pirq(d) ? (1U << XENFEAT_hvm_pirqs) : 0); #endif + if ( is_domain_direct_mapped(d) || !paging_mode_translate(d) ) + fi.submap |=3D (1U << XENFEAT_direct_mapped); + else + fi.submap |=3D (1U << XENFEAT_not_direct_mapped); break; default: return -EINVAL; diff --git a/xen/include/public/features.h b/xen/include/public/features.h index 1613b2aab8..4aebfd359a 100644 --- a/xen/include/public/features.h +++ b/xen/include/public/features.h @@ -114,6 +114,18 @@ */ #define XENFEAT_linux_rsdp_unrestricted 15 =20 +/* + * A direct-mapped (or 1:1 mapped) domain is a domain for which its + * local pages have gfn =3D=3D mfn. If a domain is direct-mapped, + * XENFEAT_direct_mapped is set; otherwise XENFEAT_not_direct_mapped + * is set. + * + * Not auto_translated domains are always direct-mapped. Also see + * XENFEAT_auto_translated_physmap. + */ +#define XENFEAT_not_direct_mapped 16 +#define XENFEAT_direct_mapped 17 + #define XENFEAT_NR_SUBMAPS 1 =20 #endif /* __XEN_PUBLIC_FEATURES_H__ */ --=20 2.17.1