From patchwork Mon Sep 18 14:40:58 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paul Durrant X-Patchwork-Id: 13389946 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6FC75C46CA1 for ; Mon, 18 Sep 2023 15:49:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229974AbjIRPtz (ORCPT ); Mon, 18 Sep 2023 11:49:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48760 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229883AbjIRPto (ORCPT ); Mon, 18 Sep 2023 11:49:44 -0400 Received: from mail.xenproject.org (mail.xenproject.org [104.130.215.37]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9FC5710D1; Mon, 18 Sep 2023 08:48:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=xen.org; s=20200302mail; h=Content-Transfer-Encoding:MIME-Version:Message-Id:Date: Subject:Cc:To:From; bh=nMePW2zZ3mPcULLvl9sSJ73P4NmXq2jKUmrnGmKZIsQ=; b=PsPSD9 01FfQaMvvuS7NepqPpKn+bffGL5tWMjMUm4vSeKGGzD1MHlW4TUF9jJhPYWU78+QqtaTMuiIMZkxe IjYPzfj93wP5MDViEuJsp5cSyEVVys1JXH9HpDYVhoOTR7k2eN7+net7B4oCKOgWD4dh4K5kCZt9l JhuuUUfQau8=; Received: from xenbits.xenproject.org ([104.239.192.120]) by mail.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1qiFR5-0003Q2-Vc; Mon, 18 Sep 2023 14:41:15 +0000 Received: from ec2-63-33-11-17.eu-west-1.compute.amazonaws.com ([63.33.11.17] helo=REM-PW02S00X.ant.amazon.com) by xenbits.xenproject.org with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1qiFR5-0006IJ-Kk; Mon, 18 Sep 2023 14:41:15 +0000 From: Paul Durrant To: kvm@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Paul Durrant , "H. Peter Anvin" , Borislav Petkov , Dave Hansen , David Woodhouse , Ingo Molnar , Paolo Bonzini , Sean Christopherson , Thomas Gleixner , x86@kernel.org Subject: [PATCH v3 00/13] KVM: xen: update shared_info and vcpu_info handling Date: Mon, 18 Sep 2023 14:40:58 +0000 Message-Id: <20230918144111.641369-1-paul@xen.org> X-Mailer: git-send-email 2.39.2 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: Paul Durrant Currently we treat the shared_info page as guest memory and the VMM informs KVM of its location using a GFN. However it is not guest memory as such; it's an overlay page. So we pointlessly invalidate and re-cache a mapping to the *same page* of memory every time the guest requests that shared_info be mapped into its address space. Let's avoid doing that by modifying the pfncache code to allow activation using a fixed userspace HVA as well as a GPA. Also, if the guest does not hypercall to explicitly set a pointer to a vcpu_info in its own memory, the default vcpu_info embedded in the shared_info page should be used. At the moment the VMM has to set up a pointer to the structure explicitly (again treating it like it's in guest memory, despite being in an overlay page). Let's also avoid the need for that. We already have a cached mapping for the shared_info page so just use that directly by default. Paul Durrant (13): KVM: pfncache: add a map helper function KVM: pfncache: add a mark-dirty helper KVM: pfncache: add a helper to get the gpa KVM: pfncache: base offset check on khva rather than gpa KVM: pfncache: allow a cache to be activated with a fixed (userspace) HVA KVM: xen: allow shared_info to be mapped by fixed HVA KVM: xen: prepare for using 'default' vcpu_info KVM: xen: prevent vcpu_id from changing whilst shared_info is valid KVM: xen: automatically use the vcpu_info embedded in shared_info KVM: selftests / xen: set KVM_XEN_VCPU_ATTR_TYPE_VCPU_ID KVM: selftests / xen: map shared_info using HVA rather than GFN KVM: selftests / xen: don't explicitly set the vcpu_info address KVM: xen: advertize the KVM_XEN_HVM_CONFIG_SHARED_INFO_HVA capability Documentation/virt/kvm/api.rst | 49 ++++-- arch/x86/include/asm/kvm_host.h | 4 + arch/x86/kvm/x86.c | 17 +-- arch/x86/kvm/xen.c | 139 +++++++++++++----- arch/x86/kvm/xen.h | 6 +- include/linux/kvm_host.h | 43 ++++++ include/linux/kvm_types.h | 3 +- include/uapi/linux/kvm.h | 6 +- .../selftests/kvm/x86_64/xen_shinfo_test.c | 75 ++++++++-- virt/kvm/pfncache.c | 129 +++++++++++----- 10 files changed, 360 insertions(+), 111 deletions(-) --- Cc: "H. Peter Anvin" Cc: Borislav Petkov Cc: Dave Hansen Cc: David Woodhouse Cc: Ingo Molnar Cc: Paolo Bonzini Cc: Sean Christopherson Cc: Thomas Gleixner Cc: x86@kernel.org