From nobody Mon Feb 9 15:17:15 2026 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=fail; 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 ARC-Seal: i=1; a=rsa-sha256; t=1586952007; cv=none; d=zohomail.com; s=zohoarc; b=S/5nZzuwahZ07UwPJpXg9oqpwUJdKWVmft+m6XSXYb2ejnVWWoSQQCYANSJxCF/AiDoH72sTT3eLLzA7iYzV0CV78/I9avXxAJF/SsFRaxdfj+en+12JdYzQ6W89f3poNzHKhWR4VtPeukHT72pyH8bkMpYWSRtMWzPEMREUg7M= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1586952007; h=Cc:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Help:List-Unsubscribe:Message-ID:References:Sender:Subject:To; bh=9mcwfS2UNApo7+gpEmAq4QsskjJ6UAD8MG/Ev2F27Uc=; b=Jg8Jrtko1gLnpf3jNg00uJeBAKXwO7rvn1qA6ukkOWUoVy2P+aVUX/sbySHaTbr+HXVHl3JPgVDbQYu8oU6Aav24HsSRoBs/f/cXWn4pgBOS7cPXagXb0uYw8WqssKxN6Zh8gSAEGBKPdypLh7ga71OBGQu7OEGnrJNHrHxiXMs= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=fail; 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 Return-Path: Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) by mx.zohomail.com with SMTPS id 1586952007200963.6059855730624; Wed, 15 Apr 2020 05:00:07 -0700 (PDT) Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1jOghi-0003Ef-Lx; Wed, 15 Apr 2020 11:59:42 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1jOghh-0003EK-5Z for xen-devel@lists.xenproject.org; Wed, 15 Apr 2020 11:59:41 +0000 Received: from mail.xenproject.org (unknown [104.130.215.37]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id 96400832-7f10-11ea-b58d-bc764e2007e4; Wed, 15 Apr 2020 11:59:40 +0000 (UTC) Received: from xenbits.xenproject.org ([104.239.192.120]) by mail.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1jOghg-00027R-9f; Wed, 15 Apr 2020 11:59:40 +0000 Received: from 54-240-197-226.amazon.com ([54.240.197.226] helo=u1bbd043a57dd5a.ant.amazon.com) by xenbits.xenproject.org with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.89) (envelope-from ) id 1jOghf-0008L0-Vd; Wed, 15 Apr 2020 11:59:40 +0000 X-Inumbo-ID: 96400832-7f10-11ea-b58d-bc764e2007e4 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=xen.org; s=20200302mail; h=References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From: Sender:Reply-To:MIME-Version:Content-Type:Content-Transfer-Encoding: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=9mcwfS2UNApo7+gpEmAq4QsskjJ6UAD8MG/Ev2F27Uc=; b=RV3IORgR7mWX/59sDGHfPn9mNz p0JKr88IhtNwd8y4fBK2mP2U45nI4djiIpC63+Rv4jz4VtzY4uP/6GkpPj4MnMDLZyxRUjxDaxLya autw7/H49qggpvOok3nkV0gUVTFOsgn2no1BIuKc9mzV8s8ZhhRhJ1UquB7PbXF4c7KY=; From: Hongyan Xia To: xen-devel@lists.xenproject.org Subject: [PATCH v3 1/4] x86/shim: map and unmap page tables in replace_va_mapping Date: Wed, 15 Apr 2020 12:59:24 +0100 Message-Id: <37ad7487bc6e6f76e2082c0b42b4cf819007f513.1586951696.git.hongyxia@amazon.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: References: In-Reply-To: References: X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: Andrew Cooper , julien@xen.org, Wei Liu , Jan Beulich , =?UTF-8?q?Roger=20Pau=20Monn=C3=A9?= Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" X-ZohoMail-DKIM: fail (Header signature does not verify) Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" From: Wei Liu Also, introduce lYe_from_lXe() macros which do not rely on the direct map when walking page tables. Unfortunately, they cannot be inline functions due to the header dependency on domain_page.h, so keep them as macros just like map_lYt_from_lXe(). Signed-off-by: Wei Liu Signed-off-by: Hongyan Xia --- Changed in v3: - use unmap_domain_page() instead of the macro in several places. - also introduce l1e_from_l2e(). - add _ prefix in macros to avoid aliasing. Changed in v2: - instead of map, map, map, read/write, unmap, unmap, unmap, do map, read PTE, unmap for each level instead. - use lYe_from_lXe() macros and lift them from a later patch to this patch. - const qualify pointers in new macros. --- xen/arch/x86/pv/shim.c | 9 +++++---- xen/include/asm-x86/page.h | 19 +++++++++++++++++++ 2 files changed, 24 insertions(+), 4 deletions(-) diff --git a/xen/arch/x86/pv/shim.c b/xen/arch/x86/pv/shim.c index ed2ece8a8a..31264582cc 100644 --- a/xen/arch/x86/pv/shim.c +++ b/xen/arch/x86/pv/shim.c @@ -168,16 +168,17 @@ const struct platform_bad_page *__init pv_shim_reserv= ed_pages(unsigned int *size static void __init replace_va_mapping(struct domain *d, l4_pgentry_t *l4st= art, unsigned long va, mfn_t mfn) { - l4_pgentry_t *pl4e =3D l4start + l4_table_offset(va); - l3_pgentry_t *pl3e =3D l4e_to_l3e(*pl4e) + l3_table_offset(va); - l2_pgentry_t *pl2e =3D l3e_to_l2e(*pl3e) + l2_table_offset(va); - l1_pgentry_t *pl1e =3D l2e_to_l1e(*pl2e) + l1_table_offset(va); + l4_pgentry_t l4e =3D l4start[l4_table_offset(va)]; + l3_pgentry_t l3e =3D l3e_from_l4e(l4e, l3_table_offset(va)); + l2_pgentry_t l2e =3D l2e_from_l3e(l3e, l2_table_offset(va)); + l1_pgentry_t *pl1e =3D map_l1t_from_l2e(l2e) + l1_table_offset(va); struct page_info *page =3D mfn_to_page(l1e_get_mfn(*pl1e)); =20 put_page_and_type(page); =20 *pl1e =3D l1e_from_mfn(mfn, (!is_pv_32bit_domain(d) ? L1_PROT : COMPAT_L1_PROT)); + unmap_domain_page(pl1e); } =20 static void evtchn_reserve(struct domain *d, unsigned int port) diff --git a/xen/include/asm-x86/page.h b/xen/include/asm-x86/page.h index eb73a0fc23..d50989a357 100644 --- a/xen/include/asm-x86/page.h +++ b/xen/include/asm-x86/page.h @@ -197,6 +197,25 @@ static inline l4_pgentry_t l4e_from_paddr(paddr_t pa, = unsigned int flags) #define map_l2t_from_l3e(x) (l2_pgentry_t *)map_domain_page(l3e_get= _mfn(x)) #define map_l3t_from_l4e(x) (l3_pgentry_t *)map_domain_page(l4e_get= _mfn(x)) =20 +/* Unlike lYe_to_lXe(), lXe_from_lYe() do not rely on the direct map. */ +#define l1e_from_l2e(_l2e, _offset) ({ \ + const l1_pgentry_t *_l1t =3D map_l1t_from_l2e(_l2e); \ + l1_pgentry_t _l1e =3D _l1t[_offset]; \ + unmap_domain_page(_l1t); \ + _l1e; }) + +#define l2e_from_l3e(_l3e, _offset) ({ \ + const l2_pgentry_t *_l2t =3D map_l2t_from_l3e(_l3e); \ + l2_pgentry_t _l2e =3D _l2t[_offset]; \ + unmap_domain_page(_l2t); \ + _l2e; }) + +#define l3e_from_l4e(_l4e, _offset) ({ \ + const l3_pgentry_t *_l3t =3D map_l3t_from_l4e(_l4e); \ + l3_pgentry_t _l3e =3D _l3t[_offset]; \ + unmap_domain_page(_l3t); \ + _l3e; }) + /* Given a virtual address, get an entry offset into a page table. */ #define l1_table_offset(a) \ (((a) >> L1_PAGETABLE_SHIFT) & (L1_PAGETABLE_ENTRIES - 1)) --=20 2.24.1.AMZN