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[2620:137:e000::3:1]) by mx.google.com with ESMTPS id i185-20020a639dc2000000b00578c9144919si815333pgd.254.2023.09.19.11.55.53 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 19 Sep 2023 11:55:53 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:1 as permitted sender) client-ip=2620:137:e000::3:1; Authentication-Results: mx.google.com; dkim=pass header.i=@xen.org header.s=20200302mail header.b=2HQaQ7Vw; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:1 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: from out1.vger.email (depot.vger.email [IPv6:2620:137:e000::3:0]) by morse.vger.email (Postfix) with ESMTP id 8FBDC801F993; Tue, 19 Sep 2023 06:42:33 -0700 (PDT) X-Virus-Status: Clean X-Virus-Scanned: clamav-milter 0.103.10 at morse.vger.email Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232481AbjISNmR (ORCPT + 26 others); Tue, 19 Sep 2023 09:42:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48698 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231863AbjISNmJ (ORCPT ); Tue, 19 Sep 2023 09:42:09 -0400 Received: from mail.xenproject.org (mail.xenproject.org [104.130.215.37]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7FC07F4; Tue, 19 Sep 2023 06:42:02 -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=y2odupsqdyYFtVH01DAeQQ9s6gOIdXVgvjaA8jYAyJA=; b=2HQaQ7 VwhLGYJXBUiEDE+j6Q7JaqFyo0KyAbGPnsmYH5mwmJYy/xNoEMlYAHgbsAAePat2ouQMrV6aH9o/s K5FZjS65RjuiELBu3rHJFSoGgYN9TJ5PT4cUvQ+0JoPbUphUlZebTG2QS4s228eWheMikD9061c+t WllJZ6ZKOSM=; Received: from xenbits.xenproject.org ([104.239.192.120]) by mail.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1qiazD-00045Z-OI; Tue, 19 Sep 2023 13:41:55 +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 1qiazD-0005jy-Ce; Tue, 19 Sep 2023 13:41:55 +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 v4 00/13] KVM: xen: update shared_info and vcpu_info handling Date: Tue, 19 Sep 2023 13:41:36 +0000 Message-Id: <20230919134149.6091-1-paul@xen.org> X-Mailer: git-send-email 2.39.2 MIME-Version: 1.0 X-Spam-Status: No, score=-0.9 required=5.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on morse.vger.email Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-Greylist: Sender passed SPF test, not delayed by milter-greylist-4.6.4 (morse.vger.email [0.0.0.0]); Tue, 19 Sep 2023 06:42:33 -0700 (PDT) X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: 1777493348063589407 X-GMAIL-MSGID: 1777493348063589407 From: Paul Durrant Changed in v4: - The offset into the cache returned from get_vcpu_info_cache() was not being factored into kvm_gpc_check() or kvm_gpc_refresh() calls. Fix this. - When transitioning from a default vcpu_info to an explicit one, copy the content across. This was previously the responsibility of the VMM. Changed in v3: - Patch added to make sure Xen vcpu_id is immutable once shared_info is set. - Adjust the xen_shinfo_test selftest accordingly. - Also have the selftest use both mechanisms to set shared_info. - Add text to API documentation discussing copying of vcpu_info. This has been removed in v4. - Adjust the selftest to switch from default to explicit vcpu_info part way through. Changed in v2: - Defer advertizement of KVM_XEN_HVM_CONFIG_SHARED_INFO_HVA to a patch at the end of the series. - Remove the KVM_XEN_HVM_CONFIG_DEFAULT_VCPU_INFO capability. - Add selftests and API documentation. Original text: 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 | 52 ++-- arch/x86/include/asm/kvm_host.h | 4 + arch/x86/kvm/x86.c | 17 +- arch/x86/kvm/xen.c | 244 ++++++++++++++---- 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, 454 insertions(+), 125 deletions(-) Reviewed-by: David Woodhouse --- 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