From patchwork Thu Jan 31 20:24:30 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: KarimAllah Ahmed X-Patchwork-Id: 10791479 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id D951713B4 for ; Thu, 31 Jan 2019 20:28:31 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D0833305C4 for ; Thu, 31 Jan 2019 20:28:31 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id C4CED30B0B; Thu, 31 Jan 2019 20:28:31 +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=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,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 59562305C4 for ; Thu, 31 Jan 2019 20:28:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727947AbfAaU1A (ORCPT ); Thu, 31 Jan 2019 15:27:00 -0500 Received: from smtp-fw-33001.amazon.com ([207.171.190.10]:45267 "EHLO smtp-fw-33001.amazon.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726848AbfAaU05 (ORCPT ); Thu, 31 Jan 2019 15:26:57 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.de; i=@amazon.de; q=dns/txt; s=amazon201209; t=1548966416; x=1580502416; h=from:to:cc:subject:date:message-id; bh=AwlZoG+GdDHirdFGtVxNhsjSqiLfpzuSgI13aMAJA1g=; b=p1JC3YVdiHzrZu0ohd2GJmRocKrU28K4RO9b0C4c5GD8kreGuqiNOnxZ h6YAc960bjSq26scCXrDaFJd8xFlQbdDrxVKHy6egjek7/GeOjrHddyQM bU0UarT0SCFYbjNhzleB6rJKcwuVGs7hmrVfwnDNvQwVC0YMQEPmYFUCn I=; X-IronPort-AV: E=Sophos;i="5.56,545,1539648000"; d="scan'208";a="780024355" Received: from sea3-co-svc-lb6-vlan2.sea.amazon.com (HELO email-inbound-relay-1d-2c665b5d.us-east-1.amazon.com) ([10.47.22.34]) by smtp-border-fw-out-33001.sea14.amazon.com with ESMTP/TLS/DHE-RSA-AES256-SHA; 31 Jan 2019 20:26:52 +0000 Received: from u54e1ad5160425a4b64ea.ant.amazon.com (iad7-ws-svc-lb50-vlan3.amazon.com [10.0.93.214]) by email-inbound-relay-1d-2c665b5d.us-east-1.amazon.com (8.14.7/8.14.7) with ESMTP id x0VKQiVc016430 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Thu, 31 Jan 2019 20:26:47 GMT Received: from u54e1ad5160425a4b64ea.ant.amazon.com (localhost [127.0.0.1]) by u54e1ad5160425a4b64ea.ant.amazon.com (8.15.2/8.15.2/Debian-3) with ESMTP id x0VKQhZX028877; Thu, 31 Jan 2019 21:26:43 +0100 Received: (from karahmed@localhost) by u54e1ad5160425a4b64ea.ant.amazon.com (8.15.2/8.15.2/Submit) id x0VKQgS5028874; Thu, 31 Jan 2019 21:26:42 +0100 From: KarimAllah Ahmed To: x86@kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, =?utf-8?b?UmFkaW0gS3LEjW3DocWZ?= , Paolo Bonzini Cc: KarimAllah Ahmed Subject: [PATCH v6 00/14] KVM/X86: Introduce a new guest mapping interface Date: Thu, 31 Jan 2019 21:24:30 +0100 Message-Id: <1548966284-28642-1-git-send-email-karahmed@amazon.de> X-Mailer: git-send-email 2.7.4 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Guest memory can either be directly managed by the kernel (i.e. have a "struct page") or they can simply live outside kernel control (i.e. do not have a "struct page"). KVM mostly support these two modes, except in a few places where the code seems to assume that guest memory must have a "struct page". This patchset introduces a new mapping interface to map guest memory into host kernel memory which also supports PFN-based memory (i.e. memory without 'struct page'). It also converts all offending code to this interface or simply read/write directly from guest memory. Patch 2 is additionally fixing an incorrect page release and marking the page as dirty (i.e. as a side-effect of using the helper function to write). As far as I can see all offending code is now fixed except the APIC-access page which I will handle in a seperate series along with dropping kvm_vcpu_gfn_to_page and kvm_vcpu_gpa_to_page from the internal KVM API. The current implementation of the new API uses memremap to map memory that does not have a "struct page". This proves to be very slow for high frequency mappings. Since this does not affect the normal use-case where a "struct page" is available, the performance of this API will be handled by a seperate patch series. So the simple way to use memory outside kernel control is: 1- Pass 'mem=' in the kernel command-line to limit the amount of memory managed by the kernel. 2- Map this physical memory you want to give to the guest with: mmap("/dev/mem", physical_address_offset, ..) 3- Use the user-space virtual address as the "userspace_addr" field in KVM_SET_USER_MEMORY_REGION ioctl. v5 -> v6: - Added one extra patch to ensure that support for this mem= case is complete for x86. - Added a helper function to check if the mapping is mapped or not. - Added more comments on the struct. - Setting ->page to NULL on unmap and to a poison ptr if unused during map - Checking for map ptr before using it. - Change kvm_vcpu_unmap to also mark page dirty for LM. That requires passing the vCPU pointer again to this function. v4 -> v5: - Introduce a new parameter 'dirty' into kvm_vcpu_unmap - A horrible rebase due to nested.c :) - Dropped a couple of hyperv patches as the code was fixed already as a side-effect of another patch. - Added a new trivial cleanup patch. v3 -> v4: - Rebase - Add a new patch to also fix the newly introduced enlightned VMCS. v2 -> v3: - Rebase - Add a new patch to also fix the newly introduced shadow VMCS. Filippo Sironi (1): X86/KVM: Handle PFNs outside of kernel reach when touching GPTEs KarimAllah Ahmed (13): X86/nVMX: handle_vmon: Read 4 bytes from guest memory X86/nVMX: Update the PML table without mapping and unmapping the page KVM: Introduce a new guest mapping API X86/nVMX: handle_vmptrld: Use kvm_vcpu_map when copying VMCS12 from guest memory KVM/nVMX: Use kvm_vcpu_map when mapping the L1 MSR bitmap KVM/nVMX: Use kvm_vcpu_map when mapping the virtual APIC page KVM/nVMX: Use kvm_vcpu_map when mapping the posted interrupt descriptor table KVM/X86: Use kvm_vcpu_map in emulator_cmpxchg_emulated KVM/nSVM: Use the new mapping API for mapping guest memory KVM/nVMX: Use kvm_vcpu_map for accessing the shadow VMCS KVM/nVMX: Use kvm_vcpu_map for accessing the enlightened VMCS KVM/nVMX: Use page_address_valid in a few more locations kvm, x86: Properly check whether a pfn is an MMIO or not arch/x86/include/asm/e820/api.h | 1 + arch/x86/kernel/e820.c | 18 ++++- arch/x86/kvm/mmu.c | 5 +- arch/x86/kvm/paging_tmpl.h | 38 +++++++--- arch/x86/kvm/svm.c | 97 ++++++++++++------------ arch/x86/kvm/vmx/nested.c | 160 +++++++++++++++------------------------- arch/x86/kvm/vmx/vmx.c | 19 ++--- arch/x86/kvm/vmx/vmx.h | 9 ++- arch/x86/kvm/x86.c | 14 ++-- include/linux/kvm_host.h | 28 +++++++ virt/kvm/kvm_main.c | 64 ++++++++++++++++ 11 files changed, 267 insertions(+), 186 deletions(-)