From patchwork Mon Apr 3 18:37:50 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marc Zyngier X-Patchwork-Id: 9660081 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 5CA4860352 for ; Mon, 3 Apr 2017 18:39:13 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 52F1A284F3 for ; Mon, 3 Apr 2017 18:39:13 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 47BB3284F8; Mon, 3 Apr 2017 18:39:13 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id C55F8284F3 for ; Mon, 3 Apr 2017 18:39:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754214AbdDCSjK (ORCPT ); Mon, 3 Apr 2017 14:39:10 -0400 Received: from foss.arm.com ([217.140.101.70]:34918 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754163AbdDCSjD (ORCPT ); Mon, 3 Apr 2017 14:39:03 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 35B84199B; Mon, 3 Apr 2017 11:39:03 -0700 (PDT) Received: from approximate.cambridge.arm.com (approximate.cambridge.arm.com [10.1.207.16]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 4F9EA3F3E1; Mon, 3 Apr 2017 11:39:01 -0700 (PDT) From: Marc Zyngier To: linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org, kvmarm@lists.cs.columbia.edu Cc: Russell King , Christoffer Dall , Mark Rutland , Catalin Marinas , James Morse , Ard Biesheuvel , Keerthy Subject: [PATCH v5 17/34] ARM: Expose the VA/IDMAP offset Date: Mon, 3 Apr 2017 19:37:50 +0100 Message-Id: <20170403183807.1620-18-marc.zyngier@arm.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20170403183807.1620-1-marc.zyngier@arm.com> References: <20170403183807.1620-1-marc.zyngier@arm.com> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The KVM code needs to be able to compute the address of symbols in its idmap page (the equivalent of a virt_to_idmap() call). Unfortunately, virt_to_idmap is slightly complicated, depending on the use of arch_phys_to_idmap_offset or not, and none of that is readily available at HYP. Instead, expose a single kimage_voffset variable which contains the offset between a kernel VA and its idmap address, enabling the VA->IDMAP conversion. This allows the KVM code to behave similarily to its arm64 counterpart. Tested-by: Keerthy Acked-by: Russell King Acked-by: Catalin Marinas Signed-off-by: Marc Zyngier --- arch/arm/mm/mmu.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c index 4e016d7f37b3..e98a2b5c4e85 100644 --- a/arch/arm/mm/mmu.c +++ b/arch/arm/mm/mmu.c @@ -87,6 +87,8 @@ struct cachepolicy { #define s2_policy(policy) 0 #endif +unsigned long kimage_voffset __ro_after_init; + static struct cachepolicy cache_policies[] __initdata = { { .policy = "uncached", @@ -1635,4 +1637,7 @@ void __init paging_init(const struct machine_desc *mdesc) empty_zero_page = virt_to_page(zero_page); __flush_dcache_page(NULL, empty_zero_page); + + /* Compute the virt/idmap offset, mostly for the sake of KVM */ + kimage_voffset = (unsigned long)&kimage_voffset - virt_to_idmap(&kimage_voffset); }